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PFAS (per- and polyfluoroalkyl substances) are class of over 12,000 synthetic chemicals containing strong carbon-fluorine bonds. Called “forever chemicals” because – extremely resistant to environmental breakdown; persist in environment and body for years to decades; bioaccumulate up food chain; widely distributed in environment globally (detected in remote Arctic). Major types – PFOA (perfluorooctanoic acid; phased out US 2015 but legacy contamination); PFOS (perfluorooctane sulfonate; phased out US 2002); GenX (newer replacement; environmental concerns); over 100 in commerce. Uses – non-stick cookware (Teflon); water-resistant clothing (Gore-Tex, rain jackets, hiking gear); food packaging (grease-resistant; pizza boxes, microwave popcorn bags, fast food wrappers); firefighting foam (AFFF used at airports, military bases – major contamination source); stain-resistant carpets, furniture, fabrics (Scotchgard formerly); personal care products (some cosmetics, dental floss); industrial – semiconductors, manufacturing; some pesticides. Exposure – drinking water (most concerning – widespread contamination); food packaging; cookware; consumer products; dust; some food (fish from contaminated water). Most Americans have detectable PFAS in blood (NHANES data). Emerging evidence linking PFAS to diabetes with multiple proposed mechanisms – epidemiological (several large studies suggest 30-50% increased T2D risk in highest vs lowest PFAS exposure quartiles); PFAS measured in blood; cumulative body burden; mechanisms proposed – endocrine disruption (PFAS bind to PPAR receptors); insulin resistance; beta cell dysfunction; thyroid hormone disruption (affects metabolism); lipid metabolism effects; oxidative stress; inflammation; gut microbiome alterations; animal studies confirm metabolic effects; specific compounds (PFOA, PFOS, PFNA, GenX all implicated); long-term exposure with cumulative bioaccumulation matters. Effects beyond diabetes – high cholesterol; thyroid disease; immune effects (reduced vaccine response); reproductive issues; pregnancy outcomes (low birth weight, preeclampsia); kidney and testicular cancer (PFOA); developmental effects in children; possible neurological effects. EPA recently set drinking water limits (2024) – PFOA and PFOS at 4 ppt (parts per trillion); PFHxS, PFNA, GenX at 10 ppt; mixture limit. Most cities exceed; treatment requirements being implemented. Multiple practical strategies for exposure reduction – drinking water (test water specifically for PFAS; use NSF 53 + 401 + P473 certified filter for PFAS removal; reverse osmosis works); cookware (stainless steel; cast iron – best alternatives; seasoned ceramic; uncoated copper; avoid non-stick); food packaging (avoid microwave popcorn bags; greaseproof food packaging; fast food wrappers); clothing (choose untreated fabrics; minimize water-resistant gear when not needed); carpets and furniture (avoid stain-resistant treatments); personal care (check for PTFE, fluoro-, perfluoro- in ingredients); fish consumption (if from PFAS-contaminated waters, follow local advisories); reduce fast food; eat fresh whole foods.

PFAS Sources

PFAS Health Effects

EPA 2024 Drinking Water Limits

Exposure Reduction Strategies

• Test water for PFAS (newer required by EPA but home test available).
• NSF 53 + 401 + P473 certified water filter (specific for PFAS).
• Reverse osmosis system removes PFAS effectively.
• Activated carbon (some) – varies; check certification.
• Stainless steel cookware.
• Cast iron cookware (no PFAS).
• Seasoned ceramic cookware.
• Avoid non-stick (Teflon, even PFOA-free still PFAS).
• Avoid scratched non-stick (more leaching).
• Don’t overheat non-stick (releases fumes).
• Avoid microwave popcorn bags.
• Bring containers for takeout.
• Choose plain paper packaging over treated.
• Reduce fast food consumption.
• Untreated natural fabric clothing.
• Minimize water-resistant gear when not needed.
• Avoid stain-resistant treatments on furniture/carpet.
• Check personal care for fluoro-, perfluoro-, PTFE.
• PFAS-free dental floss available.
• Eat fresh whole foods.
• Wash hands before eating.
• Wet-mop and dust (reduce dust exposure).

Cookware Alternatives

• Stainless steel (best general purpose; no PFAS).
• Cast iron (excellent; some iron leaching beneficial).
• Carbon steel (similar to cast iron; lighter).
• Seasoned ceramic (some brands genuine PFAS-free).
• Glass (oven use).
• Enameled cast iron (Le Creuset, others).
• Avoid non-stick (Teflon, etc.).
• “PFOA-free” still PFAS.
• “Ceramic-coated” – check ingredients.
• Replace older non-stick cookware.

Regulatory Actions

• EPA PFAS Strategic Roadmap (2021).
• EPA 2024 – finalized drinking water standards.
• Designated as hazardous substances (Superfund).
• State regulations (Michigan, New Jersey, others stricter).
• Manufacturer phase-out of long-chain PFAS.
• 3M $10.3 billion settlement (2023).
• DuPont $1.18 billion settlement.
• Military base cleanups (AFFF contamination).
• Consumer products voluntary phase-out.
• Environmental Working Group (EWG) consumer guides.

The Bottom Line

PFAS (per- and polyfluoroalkyl substances) are class of over 12,000 synthetic chemicals containing strong carbon-fluorine bonds. Called “forever chemicals” because extremely resistant to environmental breakdown; persist in environment and body for years to decades; bioaccumulate; widely distributed globally. Major types – PFOA (perfluorooctanoic acid; phased out US 2015 but legacy contamination); PFOS (perfluorooctane sulfonate; phased out US 2002); GenX (newer replacement); over 100 in commerce. Uses – non-stick cookware (Teflon); water-resistant clothing (Gore-Tex); food packaging (grease-resistant; pizza boxes, microwave popcorn bags, fast food wrappers); firefighting foam (AFFF used at airports, military bases – major contamination source); stain-resistant carpets, furniture, fabrics; personal care products (some cosmetics, dental floss); industrial. Exposure – drinking water (most concerning – widespread contamination); food packaging; cookware; consumer products; dust; fish from contaminated water. Most Americans have detectable PFAS in blood. Emerging evidence linking to diabetes – epidemiological studies suggest 30-50% increased T2D risk in highest vs lowest PFAS exposure; mechanisms proposed include endocrine disruption (PPAR receptor binding), insulin resistance, beta cell dysfunction, thyroid hormone disruption, lipid metabolism effects, oxidative stress, inflammation, gut microbiome alterations. Effects beyond diabetes – high cholesterol; thyroid disease; immune effects (reduced vaccine response); reproductive issues; pregnancy outcomes; kidney and testicular cancer; developmental effects in children. EPA 2024 drinking water limits – PFOA and PFOS at 4 ppt; PFHxS, PFNA, GenX at 10 ppt; mixture limit; treatment requirements 3-5 years to comply. Multiple practical strategies for exposure reduction – drinking water (NSF 53 + 401 + P473 certified filter for PFAS; reverse osmosis effective); cookware (stainless steel, cast iron – best alternatives; avoid non-stick, even “PFOA-free”); food packaging (avoid microwave popcorn bags – one of highest PFAS; bring containers for takeout; reduce fast food); clothing (untreated fabrics; minimize water-resistant gear); carpets and furniture (avoid stain-resistant treatments); personal care (check for PTFE, fluoro-, perfluoro-); PFAS-free dental floss; fish consumption follow local advisories; eat fresh whole foods. Regulatory actions – EPA PFAS Strategic Roadmap; 2024 finalized drinking water standards; designated hazardous substances (Superfund); state regulations; manufacturer phase-outs; major litigation settlements (3M $10.3 billion; DuPont $1.18 billion); ongoing military base cleanups. For adults with type 2 diabetes – PFAS contribution to risk is one of many environmental factors; exposure reduction reasonable through cookware swap, water filtration, food packaging awareness, consumer product choices; not magic bullet but cumulative protection; broader environmental health awareness is part of comprehensive diabetes management. See our broader prediabetes risk factors guide for context.

Several heavy metals with established or emerging links to diabetes – lead (causes insulin resistance and beta cell damage in animal studies; epidemiological studies suggest increased T2D risk; sources – lead water pipes in older homes, lead paint pre-1978, contaminated soil, some imported food, hunting ammunition, batteries); mercury (linked to T2D in some studies; affects insulin signaling and pancreatic function; sources – large predatory fish, older dental amalgam, broken thermometers, some imported skin lightening products); cadmium (one of strongest established links to T2D; mechanisms include oxidative stress, beta cell toxicity, kidney damage; sources – tobacco smoke active and passive, industrial exposure, some fertilizers, shellfish, organ meats); arsenic (inorganic arsenic linked to T2D; mechanisms include insulin signaling disruption; sources – contaminated drinking water, rice and rice products, some seafood); other (nickel, manganese, aluminum, uranium). EPA, FDA, CDC regulate but environmental exposures continue. Multiple mechanisms link heavy metals to diabetes – oxidative stress (heavy metals generate reactive oxygen species; damage cells throughout body including pancreatic beta cells); beta cell damage (direct toxicity to insulin-producing cells; reduced insulin production); insulin resistance (interference with insulin signaling in target tissues); inflammation (chronic systemic); mitochondrial dysfunction; kidney damage (reduces kidney function; affects metabolism); liver effects (hepatic insulin resistance); endocrine disruption; microbiome alterations; bone effects (lead, cadmium store in bones; released during metabolism). Cumulative exposure matters – heavy metals can accumulate in body over years; some metals (lead, cadmium) stored in bones for decades; release during pregnancy, lactation, osteoporosis. Toxic at lower levels than previously thought – “no safe level” for lead established. Source-specific reduction strategies. Lead reduction – test water if pre-1986 home; filter if positive (NSF 53 certified); run cold water 30+ seconds; never drink hot tap water; test/remove lead paint in older homes; wash hands after handling old painted surfaces; don’t use imported pottery for food; test soil if gardening; don’t use lead hunting ammunition. Mercury reduction – choose lower-mercury fish (FDA “Best Choices” – salmon, sardines, anchovies, tilapia, shrimp); limit high-mercury fish (shark, swordfish, king mackerel, tilefish, bigeye tuna); pregnancy and children especially careful; limit albacore tuna more than light tuna. Cadmium reduction – don’t smoke; avoid secondhand smoke; limit organ meats; cautious about fertilizers. Arsenic reduction – test well water; limit rice consumption (especially brown rice; basmati and jasmine lower); rinse rice; cook rice 1:6 ratio and drain; limit rice products in children.

Heavy Metals and Diabetes

Lead Exposure Reduction

• Test water if pre-1986 home (lead pipes/solder).
• NSF 53 certified water filter if lead detected.
• Run cold water 30+ seconds after sitting in pipes.
• Never drink hot tap water (more lead leaching).
• Test/remove lead paint in pre-1978 homes.
• Use HEPA vacuum if paint dust possible.
• Wash hands after handling old painted surfaces.
• Don’t use imported pottery for food.
• Test soil if gardening (especially urban).
• Use lead-free hunting ammunition or don’t eat game.
• Lead-free brass plumbing fittings.

Mercury Exposure Reduction

• Choose lower-mercury fish (salmon, sardines, anchovies, tilapia, shrimp).
• Limit high-mercury fish (shark, swordfish, king mackerel, tilefish, bigeye tuna).
• Light tuna better than albacore (less mercury).
• Pregnancy and children – follow FDA-EPA fish advice strictly.
• Avoid imported skin lightening products.
• Don’t break old thermometers.
• Properly dispose of fluorescent bulbs.
• Older dental amalgam – generally not concerning for removal.
• 2-3 servings per week of low-mercury fish good for diabetes.

Cadmium Exposure Reduction

• Don’t smoke – tobacco is major source.
• Avoid secondhand smoke.
• Limit organ meats (liver, kidney).
• Be cautious about fertilizers in vegetable gardens.
• Wash vegetables thoroughly.
• Limit shellfish (especially scallops which concentrate cadmium).
• Adequate iron intake (low iron increases cadmium absorption).
• Calcium and zinc adequate intake reduces cadmium absorption.
• Industrial workers – protective equipment essential.

Arsenic Exposure Reduction

• Test well water (private wells).
• Public water systems regulated; less concern.
• Limit rice consumption (especially brown rice).
• Basmati and jasmine rice lower arsenic than other types.
• Rinse rice thoroughly before cooking.
• Cook rice 1:6 ratio (rice:water) and drain (like pasta).
• Vary grain consumption (don’t rely on rice as only grain).
• Limit rice products in children – infant rice cereal, rice milk, rice crackers.
• Apple juice has some arsenic – limit for children.
• Brown rice syrup in some products – watch labels.

Testing Considerations

• Routine screening NOT recommended for adults.
• Indications – symptoms, occupational exposure, older home, well water, pregnancy, high-risk children.
• Blood lead level (BLL) – over 3.5 mcg/dL recommended action threshold.
• Urine cadmium, arsenic – 24-hour collection accurate.
• Hair testing NOT recommended.
• Provoked testing controversial; not standard.
• Discuss with healthcare provider if concerns.
• Insurance coverage variable.
• Most exposure reduction can be done without testing.

General Heavy Metal Reduction

• Filtered water (NSF 53 certified).
• Varied diet (don’t rely on single foods).
• Fresh whole foods.
• Don’t smoke.
• Test water if any concerns.
• Healthy soil for gardening.
• Avoid lead paint dust in older homes.
• Choose lower-arsenic grains/rice varieties.
• Choose lower-mercury fish.
• Adequate iron, calcium, zinc reduce metal absorption.
• Antioxidants in diet (vitamin C, vitamin E, selenium).
• Some natural detoxification through liver/kidney function.

The Bottom Line

Several heavy metals have established or emerging links to diabetes – lead (causes insulin resistance and beta cell damage; sources include lead water pipes in older homes, lead paint pre-1978, contaminated soil, imported food, hunting ammunition); mercury (linked to T2D in some studies; affects insulin signaling and pancreatic function; sources – large predatory fish, older dental amalgam, broken thermometers, imported skin lightening products); cadmium (one of strongest established links to T2D; mechanisms include oxidative stress, beta cell toxicity; sources – tobacco smoke, industrial exposure, some fertilizers, shellfish, organ meats); arsenic (inorganic arsenic linked to T2D; sources – contaminated drinking water, rice and rice products, some seafood); other (nickel, manganese, aluminum). Multiple mechanisms – oxidative stress, beta cell damage, insulin resistance, inflammation, mitochondrial dysfunction, kidney damage, liver effects, endocrine disruption. Cumulative exposure matters – some metals stored in bones for decades. “No safe level” for lead established. Source-specific reduction strategies. Lead reduction – test water if pre-1986 home; NSF 53 certified water filter if positive; run cold water 30+ seconds; never drink hot tap water; test/remove lead paint in older homes; don’t use imported pottery for food; test soil if gardening; don’t use lead hunting ammunition. Mercury reduction – choose lower-mercury fish (salmon, sardines, anchovies, tilapia, shrimp); limit high-mercury fish (shark, swordfish, king mackerel, tilefish, bigeye tuna); pregnancy and children especially careful; light tuna better than albacore. Cadmium reduction – don’t smoke (tobacco is major source); avoid secondhand smoke; limit organ meats; cautious about fertilizers in vegetable gardens; adequate iron, calcium, zinc intake. Arsenic reduction – test well water; limit rice consumption (especially brown rice; basmati and jasmine lower); rinse rice thoroughly; cook rice 1:6 ratio and drain; vary grain consumption; limit rice products in children. Testing – routine screening not recommended for adults; indications include symptoms, occupational exposure, older home, well water, pregnancy, high-risk children. Blood lead level over 3.5 mcg/dL action threshold; urine cadmium and arsenic – 24-hour collection accurate; hair testing not recommended; provoked testing controversial. Most exposure reduction can be done without testing. General strategies – filtered water; varied diet; fresh whole foods; don’t smoke; test water if concerns; healthy soil for gardening; avoid lead paint dust in older homes; choose lower-arsenic grains; choose lower-mercury fish; adequate iron, calcium, zinc reduce metal absorption; antioxidants in diet support natural detoxification. For adults with type 2 diabetes – heavy metals are environmental risk factors; reasonable to reduce exposure through source-specific strategies; smoking cessation particularly important (cadmium); fish selection thoughtful; water testing if older home; rice consumption moderation; broader environmental health awareness is part of comprehensive diabetes management. See our broader prediabetes risk factors guide for context.

BPA (bisphenol A) is industrial chemical used since 1960s in production of – polycarbonate plastics (hard, clear plastic; water bottles, food storage containers, plates, eyewear, electronics); epoxy resins (line metal food and beverage cans; dental sealants; coatings); thermal paper (receipts – gas station, store, ATM; some labels); some PVC plastics; various consumer products. Endocrine disruptor – structurally similar to estrogen; can bind to estrogen receptors (acts like weak estrogen); also affects other hormone systems including insulin and thyroid. Exposure routes – primarily dietary (canned food, plastic-stored food); thermal receipt handling; dust inhalation; small amounts from various sources. Most people have detectable BPA in urine (NHANES data). FDA position – banned BPA from baby bottles and infant formula packaging (2012-2013); considers other exposures at current levels safe. Many in scientific community disagree – call for stricter limits due to endocrine effects at low doses. BPA-free products often use BPS (bisphenol S) or BPF (bisphenol F) – similar structure, similar concerns; not necessarily safer. Multiple lines of evidence linking BPA to diabetes – epidemiological (higher urinary BPA levels associated with type 2 diabetes; meta-analyses show 21-45% increased T2D risk in highest vs lowest BPA exposure quartiles); animal studies (BPA exposure causes insulin resistance, impaired glucose tolerance, beta cell dysfunction); in vitro studies (BPA disrupts insulin signaling in adipocytes and muscle cells); mechanism studies (affects insulin-producing pancreatic beta cells; promotes inflammation; alters adipose tissue function; affects gut microbiome); pregnancy exposure (linked to childhood metabolic problems and increased adult diabetes risk); some intervention studies (reducing BPA-containing food storage shows modest insulin/glucose improvements). Other endocrine disrupting chemicals (EDCs) also concerning – phthalates (in plastics, personal care products), PFAS (forever chemicals), pesticides, dioxins. “Cocktail effect” – multiple low-dose exposures combine. Type 2 diabetes risk linked to broader EDC exposure. Multiple practical strategies for exposure reduction – food storage (use glass containers instead of plastic; avoid plastic for hot foods); avoid heating plastic (never microwave in plastic; transfer to glass before microwaving); don’t put plastic in dishwasher; reduce canned foods (most cans lined with BPA-containing epoxy); avoid receipts (thermal paper coated with BPA); drink filtered tap water in glass vs bottled water; replace old polycarbonate water bottles and food containers; don’t reuse single-use plastic bottles; BPA-free baby products; eat fresh whole foods.

BPA Sources

BPA Health Effects

Exposure Reduction Strategies

• Glass containers for food storage and beverages.
• Never microwave food in plastic.
• Hand-wash plastics (no dishwasher).
• Reduce canned foods – choose fresh, frozen, glass jars.
• BPA-free cans when must buy canned (still check labels).
• Decline thermal receipts when possible.
• Wash hands after handling receipts.
• Don’t put receipts in wallet or pocket near food.
• Filtered tap water in glass; avoid plastic water bottles.
• Stainless steel water bottle for travel.
• Replace scratched plastic containers.
• Avoid #7 plastic; choose #1, #2, #4, #5.
• Don’t reuse single-use plastic bottles.
• BPA-free baby items (now law).
• Eat more fresh whole foods.
• Stainless steel or cast iron cookware (not non-stick PFAS).
• Fragrance-free personal care.
• Wet-mop and dust (reduces dust exposure).

Other Endocrine Disruptors

• Phthalates – in plastics, personal care, vinyl.
• PFAS – non-stick cookware, water-resistant fabrics, food packaging.
• Pesticides – some endocrine-active.
• Heavy metals – lead, mercury, cadmium, arsenic.
• Dioxins and PCBs – persistent organic pollutants.
• Parabens – in personal care products.
• Brominated flame retardants – furniture, electronics.
• Triclosan – antibacterial products.
• Bisphenol S (BPS) – in BPA-free products; similar concerns.
• Bisphenol F (BPF) – similar to BPS.

Comprehensive Approach for Diabetes

• Choose fresh whole foods.
• Glass storage containers.
• Avoid heating plastic.
• Reduce canned foods.
• Fragrance-free personal care.
• Filtered water in glass.
• Organic produce when affordable (Dirty Dozen priority).
• Reduce overall chemical exposures.
• Address indoor air quality.
• Wash produce thoroughly.
• Stainless steel/cast iron cookware.
• Be aware during pregnancy/childcare.
• Advocate for stronger regulations.

The Bottom Line

BPA (bisphenol A) is industrial chemical used since 1960s in production of polycarbonate plastics (water bottles, food storage containers); epoxy resins (line metal food and beverage cans); thermal paper (receipts); some PVC plastics; various consumer products. Endocrine disruptor – structurally similar to estrogen; can bind to estrogen receptors; also affects other hormone systems including insulin and thyroid. Exposure routes – primarily dietary (canned food, plastic-stored food); thermal receipt handling; dust inhalation. Most people have detectable BPA in urine. FDA banned BPA from baby bottles and infant formula packaging (2012-2013); considers other exposures at current levels safe. Many in scientific community disagree. BPA-free products often use BPS (bisphenol S) or BPF (bisphenol F) – similar concerns; not necessarily safer. Multiple lines of evidence linking BPA to diabetes – epidemiological (meta-analyses show 21-45% increased T2D risk); animal studies (BPA exposure causes insulin resistance, impaired glucose tolerance, beta cell dysfunction); in vitro (disrupts insulin signaling); mechanism studies (affects pancreatic beta cells; promotes inflammation; alters adipose tissue; affects gut microbiome); pregnancy exposure (linked to childhood metabolic problems and adult diabetes risk); intervention studies (reducing BPA-containing food storage shows modest improvements). Other endocrine disrupting chemicals (EDCs) also concerning – phthalates, PFAS, pesticides, dioxins. “Cocktail effect” – multiple low-dose exposures combine. Multiple practical strategies for exposure reduction – food storage (glass containers instead of plastic; avoid plastic for hot foods); avoid heating plastic (never microwave in plastic; transfer to glass before microwaving); don’t put plastic in dishwasher; reduce canned foods (most cans lined with BPA-containing epoxy; choose fresh, frozen, BPA-free canned or glass jars); avoid receipts (thermal paper coated with BPA – decline when possible; wash hands; don’t put in pocket near food); drink filtered tap water in glass vs bottled water; replace old polycarbonate water bottles and food containers; don’t reuse single-use plastic bottles; BPA-free baby items; choose products labeled “BPA-free” but be aware may contain BPS; wash plastic containers gently; replace if scratched; eat fresh whole foods. Other endocrine disruptors to reduce – phthalates, PFAS (forever chemicals – non-stick cookware, water-resistant fabrics), pesticides (organic when possible especially Dirty Dozen), heavy metals, parabens, brominated flame retardants. Comprehensive approach – choose fresh whole foods; minimize packaged/processed; glass storage; avoid heating plastic; choose fragrance-free; filtered water; organic when affordable; reduce overall chemical exposures; advocate for stronger regulations. Pregnancy, infancy, childhood particularly sensitive periods for EDC exposure with long-term metabolic implications. For adults with type 2 diabetes – BPA exposure linked to diabetes risk and metabolic outcomes; reasonable to reduce exposure with glass storage, fresh foods, avoiding heating plastic, declining thermal receipts; broader EDC reduction also worthwhile; not magic bullet but cumulative protection. See our broader prediabetes risk factors guide for context.

Air pollution has emerged as significant risk factor for type 2 diabetes. Major pollutants studied – PM2.5 (fine particulate matter under 2.5 micrometers; can penetrate deep into lungs and bloodstream; most extensive evidence); PM10 (particulate matter under 10 micrometers); NO2 (nitrogen dioxide – traffic-related pollutant); ozone (O3 – secondary pollutant); sulfur dioxide. Mechanisms linking pollution to diabetes – systemic inflammation (particles trigger inflammatory cascade); oxidative stress; insulin resistance (direct effect on insulin signaling); beta cell dysfunction; autonomic nervous system effects; endothelial dysfunction (cardiovascular); sympathetic activation; gut microbiome changes. Studies show – 10-20% increased T2D incidence in highest pollution areas vs lowest; relationship dose-dependent; even WHO-compliant pollution levels associated with diabetes risk. Beyond diabetes development – air pollution worsens cardiovascular disease (already main cause of death in diabetes), kidney disease progression, retinopathy progression, cognitive decline. Urban dwellers, low-income communities particularly at risk. Geographic risk – urban areas typically higher pollution; cities near major highways, industrial areas, ports; some U.S. cities (Los Angeles, Phoenix, Riverside, Bakersfield, Fresno, Atlanta) higher pollution. Population factors – low-income communities and communities of color disproportionately exposed (environmental justice issue); near major roadways; near industrial facilities; near ports/airports; downwind from industrial areas. Indoor pollution sources – cooking (gas stoves; wood/coal); heating (wood, coal); smoking (own or secondhand); cleaning products; off-gassing furniture and carpet (VOCs); poor ventilation; fragranced products. Climate change considerations – wildfires increasing PM2.5 exposure dramatically; heat waves concentrate pollution. Air quality monitoring – AirNow.gov shows real-time data; AQI (Air Quality Index) scale 0-500 (0-50 good, 51-100 moderate, 101-150 unhealthy for sensitive, 151-200 unhealthy for all, 201-300 very unhealthy, 301+ hazardous). Adults with diabetes particularly vulnerable group; consider in “sensitive” category for AQI. Multiple strategies for exposure reduction – air quality monitoring (AirNow.gov daily); indoor air filtration (HEPA filters; portable air purifiers; whole-house HEPA if possible); HVAC system (good filter MERV 13+; regular replacement); open windows when air quality good (close when poor); avoid outdoor exercise during high pollution; avoid high-traffic times for outdoor activities; masks for high pollution days (N95 or P100 respirators most effective); indoor sources (induction or electric stove vs gas; avoid wood-burning fireplace; low-VOC products); smoking cessation; live in lower-pollution area if possible; vehicle (keep windows closed in heavy traffic; use recirculate AC mode); wildfire response (evacuate or stay indoors with filtration).

Air Pollution and Diabetes

AQI (Air Quality Index) Categories

Mechanisms Linking Pollution to Diabetes

• Systemic inflammation – particles trigger inflammatory cascade.
• Oxidative stress – reactive oxygen species damage.
• Insulin resistance – direct insulin signaling effects.
• Beta cell dysfunction.
• Autonomic nervous system effects.
• Endothelial dysfunction (cardiovascular implications).
• Sympathetic nervous system activation.
• Gut microbiome changes.
• Adipose tissue inflammation.
• Liver inflammation (NAFLD/MASLD).

Exposure Reduction Strategies

• Monitor air quality daily (AirNow.gov, apps).
• HEPA air purifiers in home (especially bedroom).
• HVAC with MERV 13+ filters.
• Open windows when air quality good; close when poor.
• Avoid outdoor exercise during high pollution (AQI 101+).
• Exercise early morning (often cleaner air).
• Indoor exercise alternative on high-pollution days.
• N95 or P100 respirator for unavoidable exposure.
• Avoid high-traffic times (rush hour).
• Distance from major roadways (200+ meters reduces exposure).
• Vehicle – windows closed in traffic; recirculate AC.
• Don’t smoke; eliminate secondhand smoke.
• Induction or electric stove (vs gas).
• Avoid wood-burning fireplaces indoors.
• Low-VOC paint and household products.
• Regular HVAC maintenance.
• Stay informed about wildfires; evacuate or shelter.

Indoor Pollution Sources

• Gas stoves and ovens (NO2, PM2.5).
• Wood-burning fireplaces.
• Tobacco smoke.
• Candles (especially scented).
• Cleaning products (VOCs).
• Off-gassing furniture (formaldehyde).
• Carpet off-gassing.
• Fragranced products (air fresheners, perfumes).
• Pesticides.
• Building materials (lead in older homes).
• Mold and mildew.
• Pet dander (allergy-related but airborne).

Diabetes-Specific Considerations

• Sensitive population for AQI considerations.
• Cardiovascular risk amplified by pollution.
• Kidney disease progression accelerated.
• Retinopathy progression possibly affected.
• Cognitive decline accelerated.
• Wildfire smoke causes blood sugar elevation.
• Mortality risk increased.
• Air filtration at home is reasonable investment.
• Avoid exercise during high pollution.
• Mask use during wildfires/high pollution events.
• Advocacy for cleaner air policies.

Policy and Public Health Response

• Cleaner air standards (EPA, state).
• Transportation policy – electric vehicles, public transit.
• Industrial emissions reduction.
• Building codes (ventilation, low-VOC).
• Wildfire prevention and management.
• Community air monitoring.
• Environmental justice (disproportionate community impacts).
• Climate change mitigation (reduces wildfires).
• Coal phase-out (PM2.5 source).

The Bottom Line

Air pollution has emerged as significant risk factor for type 2 diabetes. Major pollutants studied – PM2.5 (fine particulate matter under 2.5 micrometers; can penetrate deep into lungs and bloodstream; most extensive evidence); PM10; NO2 (traffic-related pollutant); ozone (O3); sulfur dioxide. Mechanisms linking pollution to diabetes – systemic inflammation; oxidative stress; insulin resistance; beta cell dysfunction; autonomic nervous system effects; endothelial dysfunction; sympathetic activation; gut microbiome changes; adipose tissue inflammation; liver inflammation. Studies show – 10-20% increased T2D incidence in highest pollution areas vs lowest; relationship dose-dependent; even WHO-compliant pollution levels associated with diabetes risk. Beyond diabetes development – air pollution worsens cardiovascular disease (already main cause of death in diabetes), kidney disease progression, retinopathy progression, cognitive decline. Highest risk populations – urban dwellers, low-income communities, communities of color (environmental justice issue), people near major roadways, industrial facilities, ports. Indoor pollution sources include gas stoves, wood-burning, smoking, cleaning products, VOCs, fragranced products, poor ventilation. Climate change – wildfires increasing PM2.5 exposure dramatically. AirNow.gov shows real-time AQI; adults with diabetes considered sensitive group. Multiple strategies for exposure reduction – air quality monitoring (check AirNow.gov daily); indoor air filtration (HEPA purifiers in bedroom and main living area; HVAC with MERV 13+ filters); avoid outdoor exercise during high pollution; avoid high-traffic times for outdoor activities; masks (N95 or P100) for high pollution days; eliminate indoor sources (gas stove if possible, no smoking, low-VOC products); live in lower-pollution area if possible; vehicle precautions (windows closed in traffic, recirculate AC mode); wildfire response (evacuate or shelter with filtration). Latest research – 14% of new T2D cases globally attributable to PM2.5; no safe level; cardiovascular outcomes worsened; mortality 4-15% increased by PM2.5 in diabetes; kidney disease progression accelerated; cognitive decline worsened; air purifier interventions show improved cardiometabolic markers; wildfire smoke causes blood sugar increases. For adults with type 2 diabetes – air pollution is established risk factor; awareness and exposure reduction important; air filtration at home reasonable investment; activity timing based on AQI; wildfire response critical; advocate for cleaner air policies; environmental factors are part of comprehensive diabetes management. See our broader prediabetes risk factors guide for context.

Sundowning (sundown syndrome) is pattern of late-afternoon or evening worsening of behavioral and cognitive symptoms in people with dementia (especially Alzheimer’s). Typical symptoms – agitation, irritability, anxiety, confusion, disorientation, suspiciousness, hallucinations or delusions, pacing or wandering, restlessness, mood changes, hostility, aggressive behavior, demanding attention, calling out, sleeplessness. Time pattern – usually starts mid-to-late afternoon (around 3-5 PM), peaks in evening (around 7-9 PM), may continue into night; resolves by morning typically. Prevalence – affects 20-45% of dementia patients; more common in moderate to severe dementia. Causes (multifactorial) – circadian rhythm disruption (damage to suprachiasmatic nucleus from dementia); fatigue from day’s mental effort; fading light (sundown literally); schedule changes; hunger or thirst; constipation; pain; need to use bathroom; medications (some peak in evening); hospital or unfamiliar environment; caffeine, alcohol; daytime napping disrupting sleep; blood sugar fluctuations (diabetes-specific). Different from acute confusion (delirium – sudden, fluctuating, often medical cause). Multiple diabetes-related contributors to sundowning – blood sugar swings (hyperglycemia after dinner; hypoglycemia in evening or overnight; either causes confusion); late-day glucose patterns; evening medications (insulin or sulfonylureas peak effect timing; could cause evening hypoglycemia); nocturnal hypoglycemia (can manifest as nighttime restlessness, vivid dreams, agitation; may be mistaken for sundowning); dehydration (common in diabetes; worsens confusion); frequent urination; hunger; coexisting sleep apnea (common in both conditions); polypharmacy; constipation. For diabetes patients with dementia – watch for blood sugar contribution; CGM can help identify patterns; adjust evening medication timing; ensure regular meals; address hydration. May reduce sundowning severity with better diabetes control. Multifaceted approach focusing on environment and routine – establish daily routine; light therapy (bright light morning and afternoon); avoid afternoon naps; active days; evening environment with bright lighting; calming evening activities; reduce stimulation (limit TV); comfortable temperature; avoid caffeine after noon; limit alcohol; adequate hydration; address pain, bathroom needs, hunger before they trigger agitation; consistent caregiver; reorient gently; medication adjustments; address depression; treat sleep apnea; manage blood sugar; family education and support; respite care for caregivers.

Sundowning Symptoms

Diabetes Contributors to Sundowning

Sundowning vs Delirium

Management Strategies

• Establish daily routine (consistent meals, activities, bedtime).
• Light therapy (bright light morning and afternoon; outdoor sun).
• Avoid afternoon naps.
• Active days (physical and mental engagement).
• Maintain bright lighting in evening (avoid dimming).
• Calming evening activities (music, reading).
• Reduce stimulation (limit dramatic TV).
• Comfortable temperature.
• Avoid caffeine after noon.
• Limit alcohol.
• Adequate hydration during day.
• Address pain, bathroom needs, hunger early.
• Consistent caregivers.
• Reorient gently (calendar, clock visible).
• Address depression.
• Treat sleep apnea.
• Manage blood sugar.
• Family education and respite care.

Diabetes-Specific Management

• CGM for evening/overnight glucose patterns.
• Avoid evening hypoglycemia – reduce evening insulin/sulfonylurea if pattern.
• Avoid hyperglycemia after dinner – timing and dose.
• Smaller frequent evening meals if helpful.
• Address dehydration.
• Adjust diabetes medication timing.
• Less tight A1C goal (7.5-8.5% in advanced dementia) to avoid hypoglycemia.
• Continue medications if person is taking but watch carefully.
• Coordinate with endocrinology and primary care.
• Address constipation (metformin, opioids, aging).
• Hearing aids – hearing loss worsens confusion.
• Treat any infection promptly.

When to Suspect Delirium (Not Just Sundowning)

• Sudden onset (not regular pattern).
• Significantly worse than usual.
• Confused throughout day (not just evening).
• Fever or systemic signs.
• New neurological signs.
• Significant functional decline.
• Falls.
• Hallucinations new or worse.
• UTI symptoms (frequency, urgency, foul-smelling urine).
• Need medical evaluation – urinalysis, blood tests, exam.

The Bottom Line

Sundowning (sundown syndrome) is pattern of late-afternoon or evening worsening of behavioral and cognitive symptoms in people with dementia (especially Alzheimer’s). Typical symptoms – agitation, irritability, anxiety, confusion, disorientation, suspiciousness, hallucinations or delusions, pacing or wandering, restlessness, mood changes, hostility, aggressive behavior, demanding attention, calling out, sleeplessness. Time pattern – usually starts mid-to-late afternoon (around 3-5 PM), peaks in evening (around 7-9 PM), may continue into night; resolves by morning typically. Prevalence – affects 20-45% of dementia patients; more common in moderate to severe dementia. Causes (multifactorial) – circadian rhythm disruption; fatigue; fading light; schedule changes; hunger or thirst; constipation; pain; need to use bathroom; medications; hospital or unfamiliar environment; caffeine, alcohol; daytime napping; blood sugar fluctuations (diabetes-specific). Different from acute confusion (delirium – sudden, fluctuating, often medical cause). Multiple diabetes-related contributors – blood sugar swings (hyperglycemia after dinner; hypoglycemia in evening or overnight); late-day glucose patterns; evening medications (insulin or sulfonylureas peak effect timing); nocturnal hypoglycemia (can manifest as nighttime restlessness; may be mistaken for sundowning); dehydration; frequent urination; hunger; coexisting sleep apnea; polypharmacy; constipation. For diabetes patients with dementia – watch for blood sugar contribution; CGM can help identify patterns; adjust evening medication timing; ensure regular meals; address hydration. Multifaceted approach focusing on environment and routine – establish daily routine; light therapy (bright light morning and afternoon, outdoor sunlight if possible); avoid afternoon naps; active days; evening environment with bright lighting; calming evening activities; reduce stimulation; comfortable temperature; avoid caffeine after noon; limit alcohol; adequate hydration; address pain, bathroom needs, hunger before triggers; consistent caregiver; reorient gently (calendar, clock visible); medication adjustments; address depression; treat sleep apnea; manage blood sugar; family education and support; respite care for caregivers. Diabetes-specific – CGM for evening/overnight glucose patterns; avoid evening hypoglycemia; adjust diabetes medication timing; less tight A1C goal (7.5-8.5% in advanced dementia) to avoid hypoglycemia; address dehydration. Important to distinguish from delirium – sudden onset, worse than usual, signs of medical cause warrant evaluation for UTI, hypoglycemia, infection, medication changes. For adults with type 2 diabetes and dementia – sundowning is common and challenging; diabetes considerations important (blood sugar contribution); routine and environment most important interventions; CGM helps identify glucose contributions; less tight glycemic targets to avoid hypoglycemia; differentiate from delirium when sudden or worse. See our broader diabetes complications guide for context.

Brain fog is not a medical diagnosis; describes constellation of symptoms – difficulty concentrating, slow thinking, mental fatigue, memory issues, word-finding difficulty, foggy feeling, reduced mental clarity. Common complaint in adults with diabetes. Distinguishes from formal cognitive impairment by – subjective complaint (not necessarily objective); often reversible (vs progressive MCI/dementia); related to specific triggers (vs constant in dementia); occurs with normal cognitive testing usually. Causes in diabetes – hyperglycemia (blood sugar over 180-200 mg/dL impairs cognitive function within hours); hypoglycemia (blood sugar under 70 mg/dL causes immediate cognitive impairment; recurrent severe hypoglycemia cumulative damage); glucose variability (frequent swings between high and low; CGM data shows correlations); diabetic ketoacidosis (DKA – dramatic cognitive impairment); hyperosmolar state; medications (some diabetes meds may cause cognitive side effects; multiple medications combined); sleep disturbance (common in diabetes; sleep apnea; nocturnal hypoglycemia); dehydration (common in diabetes); depression and anxiety (both cause cognitive complaints); chronic stress. Both blood sugar extremes impair cognition. Hyperglycemia (high blood sugar) – blood sugar above 180-200 mg/dL impairs cognitive function; effects on attention, working memory, processing speed; can cause confusion at very high levels (over 400); chronic hyperglycemia damages brain over time via AGEs and vascular changes; recovery within hours of normalizing glucose. Hypoglycemia (low blood sugar) – blood sugar below 70 mg/dL causes immediate cognitive symptoms – confusion, difficulty concentrating, slurred speech, irritability, dizziness; cumulative damage with repeated severe episodes; brain depends on continuous glucose supply. Glucose variability (the swings) – high glucose variability associated with worse cognitive function; may matter more than average glucose. Hypoglycemia unawareness – autonomic neuropathy or recurrent lows blunt warning symptoms; dangerous; CGM essential. CGM data shows cognitive symptoms often correlate with glucose levels; some patients identify specific patterns (fog after meals due to spikes; afternoon fog from low blood sugar). Glycemic targets balance – too tight control causes more hypoglycemia; too loose causes hyperglycemia; individualized targets important. Multiple contributors beyond blood sugar – sleep disturbance (obstructive sleep apnea very common in T2D – 70% prevalence; insufficient sleep; nocturnal hypoglycemia; restless legs); dehydration; depression (2x more common in diabetes); anxiety; medication effects; vitamin B12 deficiency (common with metformin use – 10-30%); vitamin D deficiency; thyroid disease; chronic kidney disease; anemia; chronic pain (neuropathy, OA); burnout from diabetes self-management.

Brain Fog Causes in Diabetes

Brain Fog vs Other Cognitive Issues

Brain Fog Symptoms

• Difficulty concentrating.
• Slow thinking.
• Mental fatigue.
• Word-finding difficulty.
• Forgetfulness (short-term).
• Reduced mental clarity.
• Difficulty multitasking.
• Foggy feeling.
• Difficulty making decisions.
• Confusion (mild).
• Daytime drowsiness.
• Often pattern-related (time of day, meals).
• Doesn’t progress over time (vs dementia).

Addressing Underlying Causes

• CGM for glucose pattern identification.
• Smooth glucose variability (time in range 70-180 over 70%).
• Treat sleep apnea (CPAP).
• Optimize sleep (7-8 hours).
• Address depression actively.
• Exercise regularly.
• Hydration (8+ glasses water daily).
• Medication review.
• Test B12, vitamin D, thyroid.
• Check kidney function.
• Treat chronic pain.
• Reduce stress (mindfulness).
• Mediterranean diet pattern.
• Limit alcohol.
• Cognitive engagement.
• Social support.
• Address hearing/vision.

When to See Provider

• Persistent symptoms despite addressing causes.
• Sudden cognitive changes.
• Concerning progression.
• Symptoms with neurological signs.
• Mood symptoms.
• Significant functional impact.
• Worsening despite good blood sugar control.
• Concerns about MCI or dementia.
• Falls, balance issues.
• Memory problems concerning to family.

The Bottom Line

Brain fog is not a medical diagnosis; describes constellation of symptoms – difficulty concentrating, slow thinking, mental fatigue, memory issues, word-finding difficulty, foggy feeling, reduced mental clarity. Common complaint in adults with diabetes. Distinguishes from formal cognitive impairment by – subjective complaint (not necessarily objective); often reversible (vs progressive MCI/dementia); related to specific triggers (vs constant in dementia); occurs with normal cognitive testing usually. Causes in diabetes – hyperglycemia (blood sugar over 180-200 mg/dL impairs cognitive function within hours); hypoglycemia (blood sugar under 70 mg/dL causes immediate cognitive impairment; recurrent severe hypoglycemia cumulative damage); glucose variability (frequent swings; CGM data shows correlations); diabetic ketoacidosis; hyperosmolar state; medications; sleep disturbance (sleep apnea, nocturnal hypoglycemia); dehydration; depression and anxiety; chronic stress. Both blood sugar extremes impair cognition – hyperglycemia (effects on attention, working memory, processing speed; chronic hyperglycemia damages brain over time via AGEs and vascular changes); hypoglycemia (immediate confusion, difficulty concentrating, slurred speech; cumulative damage with repeated severe episodes). Glucose variability (the swings) – associated with worse cognitive function; may matter more than average glucose. CGM essential for identifying patterns. Multiple contributors beyond blood sugar – sleep disturbance (obstructive sleep apnea 70% prevalence in T2D); dehydration (common in diabetes); depression (2x more common); anxiety; medication effects; vitamin B12 deficiency (common with metformin – 10-30%); vitamin D deficiency; thyroid disease; chronic kidney disease; anemia; chronic pain; burnout from diabetes self-management. Most are addressable. Strategies to reduce brain fog – get and use CGM (identify glucose patterns affecting cognition; smooth variability; time-in-range 70-180 mg/dL more than 70%); sleep optimization (7-8 hours; address sleep apnea; treat restless legs); hydration; address depression actively; exercise regularly; medication review; test B12, vitamin D, thyroid; check kidney function; CBC; treat chronic pain; reduce stress; nutrient-dense diet (Mediterranean pattern); limit alcohol; cognitive engagement; address hearing/vision; diabetes education reinforcement; social support. When to see provider – persistent symptoms despite addressing causes; sudden cognitive changes; concerning progression; symptoms with neurological signs; mood symptoms; significant functional impact; concerns about MCI or dementia. For adults with type 2 diabetes – brain fog is common and addressable; CGM helps identify glycemic patterns affecting cognition; multifaceted approach addressing blood sugar variability, sleep, depression, vitamins, medications, hydration; distinguish from MCI/dementia (brain fog typically reversible). See our broader diabetes complications guide for context.

Vascular dementia (VaD) is second most common cause of dementia (after Alzheimer’s disease); accounts for 10-20% of dementia cases alone; mixed Alzheimer-vascular dementia common (50%+ of dementia in diabetes). Caused by cerebrovascular disease – strokes (large or small), silent strokes (occur without symptoms but cause damage), small vessel disease (chronic damage to small brain arteries), reduced overall brain perfusion. Diabetes connection – 2-4x higher VaD risk than general population; major risk factor due to extensive vascular disease. Symptoms – cognitive decline; symptoms often relate to area of brain affected; classic pattern is “stepped” decline (sudden worsening with each stroke or TIA, plateau in between) vs gradual Alzheimer’s pattern; executive function issues prominent; gait disturbance common (frontal lobe involvement); urinary symptoms; mood changes; less prominent memory loss initially (vs Alzheimer’s). Risk factors – hypertension, diabetes, hyperlipidemia, smoking, atrial fibrillation, prior stroke, heart disease, advanced age. Diagnosis – similar to other dementias plus evidence of cerebrovascular disease on imaging (MRI shows strokes, small vessel changes). Diabetes causes vascular damage throughout body. Specific mechanisms – large vessel disease (atherosclerosis in carotid and intracranial arteries; increased ischemic stroke risk; hemorrhagic stroke risk); small vessel disease (white matter changes on MRI; lacunar strokes; microbleeds; characteristic of “diabetic cerebrovascular disease”); silent strokes (very common in diabetes; 2-4x more frequent than general population; each contributes to cumulative damage); cerebral atrophy from chronic ischemia; blood-brain barrier dysfunction; reduced cerebral blood flow regulation; endothelial dysfunction; AGEs in cerebral vessels; pro-inflammatory state. Long-duration diabetes (10+ years) particularly increases VaD risk. Mixed dementia (Alzheimer-vascular) very common – both processes occur simultaneously, making strict diagnostic categories less meaningful. Cognitive testing plus brain imaging for diagnosis – clinical assessment, brain imaging (MRI shows strokes, white matter changes, silent strokes), vascular risk factor assessment, cardiac assessment (EKG, possibly echocardiogram for atrial fibrillation), vascular assessment (carotid ultrasound). Treatment focuses on cardiovascular risk factor management – BP control (less than 130/80 if tolerated), cholesterol management (statins), antiplatelet therapy (aspirin), blood sugar control. No FDA-approved disease-modifying medications specifically for VaD. Cholinesterase inhibitors sometimes used. Address modifiable factors – sleep apnea, atrial fibrillation (anticoagulation), depression. Lifestyle interventions – exercise, Mediterranean diet, cognitive engagement, social engagement. Aggressive cardiovascular risk management for prevention.

Vascular Dementia in Diabetes

Alzheimer’s vs Vascular Dementia Patterns

Vascular Brain Damage in Diabetes

• Strokes (ischemic – blockage; hemorrhagic – bleeding).
• Silent strokes (no symptoms but visible on MRI).
• Transient ischemic attacks (TIAs).
• Small vessel disease (white matter changes, lacunar strokes).
• Cerebral microbleeds.
• Cerebral atrophy.
• Blood-brain barrier dysfunction.
• Reduced cerebral blood flow.
• Endothelial dysfunction.
• Atherosclerosis in cerebral arteries.

Vascular Dementia Symptoms

• Cognitive decline (variable based on affected region).
• Executive function impairment prominent.
• Slowness of thinking.
• Difficulty planning, organizing, problem-solving.
• Memory issues (less prominent early than AD).
• Gait disturbance (shuffling, unsteady).
• Urinary incontinence (frontal lobe).
• Mood changes (depression common).
• Personality changes.
• Language difficulties.
• Visuospatial issues.
• Stepped decline pattern (sudden worsening with strokes).
• Focal neurological signs (from strokes).

Cardiovascular Risk Factor Management

• Blood pressure – less than 130/80 if tolerated (less than 140/90 minimum).
• Blood sugar – A1C 7-8% older adults; avoid hypoglycemia.
• Cholesterol – statins for most adults with diabetes 40+; LDL less than 70 high risk.
• Antiplatelet therapy – aspirin 81 mg if CVD history.
• Don’t smoke – quitting helps at any age.
• Atrial fibrillation – identify and anticoagulate (major stroke prevention).
• Exercise 150+ min/week moderate aerobic.
• Strength training 2x weekly.
• Mediterranean diet.
• MIND diet for cognitive specifically.
• Limit alcohol (1 drink/day max).
• Sleep apnea treatment (CPAP).
• Healthy weight.
• Address depression.
• Hearing aids if needed.
• SGLT2 inhibitors and GLP-1 agonists with CV benefits.

Lifestyle Approach

• Mediterranean diet pattern (strong evidence).
• MIND diet for brain specifically.
• Regular exercise (most evidence-based prevention).
• Mental engagement.
• Social engagement.
• Adequate sleep.
• Limit ultra-processed foods.
• Avoid air pollution exposure.
• Hearing health.
• Vision care.
• Oral health.
• Limit alcohol.
• Stay hydrated.
• Manage all CV risk factors aggressively.

The Bottom Line

Vascular dementia (VaD) is second most common cause of dementia (after Alzheimer’s disease); accounts for 10-20% of dementia cases alone; mixed Alzheimer-vascular dementia common (50%+ of dementia in diabetes). Caused by cerebrovascular disease – strokes (large or small), silent strokes (occur without symptoms but cause damage), small vessel disease (chronic damage to small brain arteries), reduced overall brain perfusion. Diabetes connection – 2-4x higher VaD risk than general population; major risk factor due to extensive vascular disease. Symptoms – cognitive decline; symptoms often relate to area of brain affected; classic “stepped” decline pattern (sudden worsening with each stroke or TIA, plateau in between) vs gradual Alzheimer’s pattern; executive function issues prominent; gait disturbance common (frontal lobe involvement); urinary symptoms; mood changes; less prominent memory loss initially. Risk factors – hypertension, diabetes, hyperlipidemia, smoking, atrial fibrillation, prior stroke, heart disease, advanced age. Diabetes contributes through multiple vascular mechanisms – large vessel disease (atherosclerosis in carotid and intracranial arteries); small vessel disease (white matter changes, lacunar strokes, microbleeds); silent strokes (very common; 2-4x more frequent); cerebral atrophy; blood-brain barrier dysfunction; reduced cerebral blood flow regulation; endothelial dysfunction; AGEs in cerebral vessels; pro-inflammatory state. Long-duration diabetes (10+ years) particularly increases VaD risk. Mixed dementia (Alzheimer-vascular) very common. Diagnosis – clinical assessment, cognitive testing, brain imaging (MRI shows strokes, white matter changes), vascular risk factor assessment, cardiac assessment (atrial fibrillation), vascular assessment (carotid ultrasound). Treatment – cardiovascular risk factor management is mainstay (BP control, cholesterol management, antiplatelet therapy, blood sugar control). No FDA-approved disease-modifying medications specifically for VaD. Cholinesterase inhibitors sometimes used. Address modifiable factors – sleep apnea, atrial fibrillation, depression. Lifestyle interventions – exercise, Mediterranean diet, cognitive engagement, social engagement. Aggressive cardiovascular risk management for prevention – blood pressure control (less than 130/80 target if tolerated); blood sugar control (A1C 7-8% in older adults; avoid hypoglycemia); cholesterol management (statins for most adults with diabetes 40+; LDL target less than 70 mg/dL high risk); antiplatelet therapy (aspirin 81 mg for most adults with diabetes and CV disease); don’t smoke; exercise 150+ min/week moderate aerobic + strength training; Mediterranean diet; MIND diet; limit alcohol; sleep apnea treatment (CPAP); atrial fibrillation identification and anticoagulation (major stroke prevention); healthy weight; treat depression; hearing aids; cognitive and social engagement; consider GLP-1 agonists with proven cardiovascular benefit. For adults with type 2 diabetes – vascular dementia is 2-4x more common; silent strokes occur 2-4x more often (cumulative brain damage); aggressive cardiovascular risk management is most important prevention; what’s good for heart is good for brain; comprehensive multidomain intervention can substantially reduce risk. See our broader diabetes complications guide for context.

Alzheimer’s disease (AD) is most common cause of dementia (60-80% of cases); progressive neurodegenerative disease characterized by memory loss, cognitive decline, behavior changes, eventual loss of function and death. Diabetes-Alzheimer’s connection – adults with type 2 diabetes have 2x higher AD risk; some research suggests stronger link in younger-onset diabetes. “Type 3 diabetes” hypothesis – controversial but increasingly supported concept that AD is form of insulin resistance specifically in the brain; brain has many insulin receptors; impaired insulin signaling affects neuronal function, memory formation, amyloid clearance. Shared mechanisms – insulin resistance in brain (affects neuronal energy metabolism); hyperinsulinemia (high systemic insulin reduces brain insulin sensitivity); hyperglycemia (direct damage to brain proteins; advanced glycation end products); vascular damage (both micro and macrovascular contribute to mixed Alzheimer’s-vascular dementia); chronic inflammation; oxidative stress; mitochondrial dysfunction; glucotoxicity; reduced amyloid clearance from brain. Brain is target organ for diabetes complications just like eyes, kidneys, nerves. Progressive multi-stage condition. Pre-clinical (silent) stage – brain changes occur 10-20+ years before symptoms. Mild cognitive impairment (MCI) due to AD – early symptoms; subtle memory and thinking changes; about 50% progress to dementia within 5 years. Mild AD dementia – memory problems noticeable; word-finding issues; complex tasks difficult; mood changes. Moderate AD dementia – more pronounced cognitive impairment; daily activities need assistance; behavior changes (agitation, anxiety, depression); sundowning common. Severe AD dementia – severe cognitive and physical decline; total dependence for care; immobility; incontinence; eventual death. Course – average 4-8 years from diagnosis to death; can range 3-20 years. Mixed dementia common – 50%+ of “Alzheimer’s” cases also have vascular components (especially in diabetes). Multi-faceted diagnosis; emerging treatments. Diagnosis includes clinical assessment, lab workup, brain imaging, biomarkers (CSF amyloid and tau, PET scans, blood biomarkers p-tau 217), sometimes genetic testing. Treatment – traditional symptomatic (cholinesterase inhibitors, memantine). Newer disease-modifying treatments – lecanemab (Leqembi, FDA-approved 2023) and donanemab (Kisunla, FDA-approved 2024) – anti-amyloid monoclonal antibodies; modestly slow progression in early AD; significant ARIA side effects; expensive. Diabetes-specific research – GLP-1 agonists (semaglutide especially) being investigated for cognitive benefits; intranasal insulin trials; metformin some cognitive benefit research.

Alzheimer’s in Diabetes

Alzheimer’s Stages

Newer Alzheimer’s Treatments

• Lecanemab (Leqembi) – FDA-approved 2023; anti-amyloid mAb.
• Donanemab (Kisunla) – FDA-approved 2024; anti-amyloid mAb.
• Indication – early AD with confirmed amyloid pathology.
• Mechanism – removes amyloid plaques from brain.
• Benefit – modestly slows cognitive decline.
• Side effects – ARIA (amyloid-related imaging abnormalities) – brain swelling/bleeding; mild to severe; rare deaths.
• Need MRI monitoring during treatment.
• IV infusion every 2 weeks for lecanemab; every 4 weeks for donanemab.
• Expensive ($26,500+ annually).
• Modest benefit for some patients; not a cure.
• Earlier intervention better outcomes.

Diabetes-Specific Research for Alzheimer’s

• GLP-1 agonists (semaglutide, liraglutide) – some cognitive research.
• Semaglutide for AD prevention – large trials underway.
• Intranasal insulin trials – directly to brain.
• Metformin – some observational data showing cognitive benefits.
• SGLT2 inhibitors – emerging research.
• Brain insulin resistance directly addressed.
• Type 3 diabetes hypothesis driving research.
• Tight glycemic control with hypoglycemia avoidance.
• Pioglitazone – mixed evidence; not currently recommended for AD.

Modifiable Risk Factors

• Hearing loss (significant modifiable factor; hearing aids help).
• Hypertension.
• Smoking.
• Obesity.
• Physical inactivity.
• Diabetes (poor control).
• Excessive alcohol.
• Depression.
• Social isolation.
• Low education.
• Air pollution.
• Traumatic brain injury.
• Sleep apnea (untreated).
• Cholesterol (high LDL).
• Vision loss (uncorrected).

Prevention Strategy for Diabetes Patients

• Blood sugar control – A1C 7-8% in older adults; avoid hypoglycemia.
• Blood pressure control (less than 130/80).
• Cholesterol management (statins safe and likely beneficial).
• Don’t smoke.
• 150+ min/week aerobic exercise.
• Strength training 2x weekly.
• Mediterranean or MIND diet.
• Limit ultra-processed foods.
• Adequate sleep (7-8 hours); treat sleep apnea.
• Mental engagement (reading, learning, puzzles).
• Social engagement (avoid isolation).
• Treat depression.
• Hearing aids if needed.
• Vision correction.
• Limit alcohol.
• Avoid head injuries.
• GLP-1 agonist discussion with provider.
• Maintain healthy weight.

The Bottom Line

Alzheimer’s disease (AD) is most common cause of dementia (60-80% of cases); progressive neurodegenerative disease characterized by memory loss, cognitive decline, behavior changes, eventual loss of function and death. Diabetes-Alzheimer’s connection – adults with type 2 diabetes have 2x higher AD risk. “Type 3 diabetes” hypothesis – controversial but increasingly supported concept that AD is form of insulin resistance specifically in the brain; brain has many insulin receptors; impaired insulin signaling affects neuronal function, memory formation, amyloid clearance. Shared mechanisms – insulin resistance in brain; hyperinsulinemia; hyperglycemia (direct damage to brain proteins; AGEs); vascular damage; chronic inflammation; oxidative stress; mitochondrial dysfunction; reduced amyloid clearance. Brain is target organ for diabetes complications. Progressive multi-stage condition – pre-clinical (silent) stage, MCI due to AD, mild AD dementia, moderate AD dementia, severe AD dementia. Course – average 4-8 years from diagnosis to death. Mixed dementia common – 50%+ of “Alzheimer’s” cases also have vascular components (especially in diabetes). Multi-faceted diagnosis – clinical assessment, lab workup, brain imaging, biomarkers (CSF amyloid and tau, PET scans, blood biomarkers p-tau 217), sometimes genetic testing. Treatment – traditional symptomatic (cholinesterase inhibitors – donepezil, rivastigmine, galantamine; memantine). Newer disease-modifying treatments – lecanemab (Leqembi, FDA-approved 2023) and donanemab (Kisunla, FDA-approved 2024) – anti-amyloid monoclonal antibodies; modestly slow progression in early AD; significant ARIA side effects (brain swelling/bleeding); expensive. Diabetes-specific research – GLP-1 agonists being investigated for cognitive benefits; intranasal insulin trials; metformin some cognitive benefit research. Lifestyle interventions matter for prevention – blood sugar control with caution (A1C 7-8% in older adults; avoid hypoglycemia which damages brain); blood pressure control; cholesterol management; don’t smoke; regular aerobic exercise (150+ min/week); strength training; Mediterranean diet; MIND diet; limit ultra-processed foods; adequate sleep (treat sleep apnea); mental engagement; social engagement; treat depression; address hearing loss (significant modifiable factor); maintain vision; limit alcohol; avoid head injuries; discuss GLP-1 agonists with provider; maintain healthy weight. NIH FINGER trial showed multidomain intervention can slow cognitive decline. For adults with type 2 diabetes – Alzheimer’s is 2x more common comorbidity; brain is target organ for diabetes complications; “type 3 diabetes” concept reflects shared mechanisms; comprehensive risk factor management including blood sugar, blood pressure, lipids, sleep, depression, hearing, exercise, diet, cognitive engagement; new disease-modifying treatments available for early AD; brain health is the new frontier of diabetes management. See our broader diabetes complications guide for context.

Mild cognitive impairment (MCI) is condition where cognitive abilities decline more than expected for age and education but not severely enough to interfere significantly with daily life. Distinguishes from normal aging (occasional forgetfulness; word retrieval issues; slower processing) and dementia (interferes with daily function, multiple cognitive domains). Two subtypes – amnestic MCI (memory primarily affected; higher risk of progression to Alzheimer’s) and non-amnestic MCI (other cognitive domains primarily affected – executive function, attention, visuospatial, language). Prevalence – increases with age; 10-20% of adults 65+; 20-40% of adults 80+. Progression to dementia – about 10-15% per year of MCI patients develop dementia; not all progress; some stabilize; some return to normal. Causes – Alzheimer’s disease (most common progression cause); vascular disease (strokes, small vessel disease); Lewy body disease; frontotemporal disorders; reversible causes (depression, sleep apnea, medications, thyroid disease, B12 deficiency, normal pressure hydrocephalus). About 2x higher prevalence in diabetes than general population. Studies suggest adults with type 2 diabetes have 50-100% increased MCI risk compared to those without diabetes. Mechanisms – microvascular damage to brain (similar to retinopathy, nephropathy); macrovascular disease (strokes, including silent strokes); hyperglycemia direct effects on brain (advanced glycation end products in brain proteins); insulin resistance in brain (brain has insulin receptors; impaired insulin signaling affects neurons); chronic inflammation; hypoglycemia episodes (especially recurrent severe) can cause cumulative brain damage; sleep disturbance; depression; medications; comorbid hypertension, atherosclerosis, dyslipidemia. Long-duration diabetes (10+ years) and poor glycemic control associated with greater MCI/dementia risk. Type 3 diabetes – term coined by some researchers for Alzheimer’s relationship with insulin resistance in brain. Clinical assessment with cognitive testing – subjective cognitive complaint (patient or family notes change); objective cognitive impairment (testing shows below-expected performance); preserved daily function (can still manage daily activities); not dementia. Cognitive testing – Mini-Mental State Exam (MMSE; max 30, MCI typically 24-27), Montreal Cognitive Assessment (MoCA; max 30, MCI typically 18-25; more sensitive than MMSE), Mini-Cog. Workup – history, exam, blood tests (CBC, CMP, TSH, B12, folate); brain MRI; depression screening; sleep history; medication review. Lifestyle interventions important – blood sugar control (A1C 7-8% in older adults), blood pressure control, cholesterol management, don’t smoke, exercise (150+ min/week moderate), Mediterranean diet, MIND diet, cognitive engagement, social engagement, sleep optimization, treat depression, avoid medications with cognitive side effects, maintain hearing and vision, limit alcohol, avoid head injuries, adequate B12.

MCI vs Normal Aging vs Dementia

Diabetes MCI Risk Factors

Cognitive Tests

• Mini-Mental State Exam (MMSE) – 30-point; MCI typically 24-27.
• Montreal Cognitive Assessment (MoCA) – 30-point; MCI 18-25; more sensitive.
• Mini-Cog – 3-word recall + clock drawing.
• Detailed neuropsychological testing – comprehensive.
• Self-administered apps available but consult provider.
• Routine screening recommended for adults over 65 by some guidelines.

Reversible MCI Causes

• Medication side effects (anticholinergics, sedatives, opioids).
• Depression (pseudodementia).
• Sleep apnea.
• Thyroid disease (hypothyroid).
• B12 deficiency.
• Folate deficiency.
• Normal pressure hydrocephalus.
• Alcohol use disorder.
• Severe stress.
• Subdural hematoma.
• Hearing/vision loss (causes apparent cognitive decline).
• Vitamin D deficiency.
• Chronic infections (HIV, syphilis).

Lifestyle Interventions for MCI in Diabetes

• Blood sugar control (avoid both highs and lows).
• A1C target 7-8% in older adults (avoid hypoglycemia).
• CGM helpful for monitoring.
• Blood pressure control (less than 140/90 most; less than 130/80 if tolerated).
• Don’t smoke.
• Aerobic exercise 150+ min/week.
• Resistance training 2x weekly.
• Mediterranean or MIND diet.
• Cognitive engagement (puzzles, reading, learning).
• Social engagement.
• Sleep optimization (7-8 hours; treat apnea).
• Treat depression actively.
• Address hearing loss (hearing aids).
• Address vision loss.
• Oral health.
• Limit alcohol.
• Avoid head injuries.
• B12 supplementation if low (especially metformin users).
• Address medication burden.

The Bottom Line

Mild cognitive impairment (MCI) is condition where cognitive abilities decline more than expected for age and education but not severely enough to interfere significantly with daily life. Distinguishes from normal aging and dementia. Two subtypes – amnestic MCI (memory primarily affected; higher risk of progression to Alzheimer’s) and non-amnestic MCI (other cognitive domains). Prevalence – 10-20% of adults 65+; 20-40% of adults 80+. Progression to dementia – about 10-15% per year of MCI patients develop dementia; not all progress; some stabilize; some return to normal. Causes – Alzheimer’s disease (most common progression cause); vascular disease (strokes, small vessel disease); Lewy body disease; frontotemporal disorders; reversible causes (depression, sleep apnea, medications, thyroid disease, B12 deficiency). About 2x higher prevalence in diabetes than general population. Mechanisms – microvascular damage; macrovascular disease (strokes); hyperglycemia direct effects (AGEs in brain proteins); insulin resistance in brain; chronic inflammation; hypoglycemia episodes (cumulative brain damage); sleep disturbance; depression; medications; comorbid hypertension, atherosclerosis, dyslipidemia. Long-duration diabetes (10+ years) and poor glycemic control associated with greater MCI/dementia risk. Type 3 diabetes term sometimes used for Alzheimer’s relationship with insulin resistance in brain. Clinical assessment – subjective cognitive complaint; objective cognitive impairment; preserved daily function; not dementia. Cognitive testing options – MMSE, MoCA (more sensitive), Mini-Cog, detailed neuropsychological testing. Workup – history, exam, blood tests (CBC, CMP, TSH, B12, folate), brain MRI, depression screening, sleep history, medication review. Lifestyle interventions important – blood sugar control (A1C 7-8% in older adults; avoid hypoglycemia which damages brain); blood pressure control; cholesterol management; don’t smoke; exercise 150+ min/week moderate intensity; Mediterranean diet; MIND diet (Mediterranean-DASH Intervention for Neurodegenerative Delay – emphasizes leafy greens, berries, nuts, olive oil, fish, whole grains); cognitive engagement (puzzles, reading, learning new skills); social engagement; sleep optimization (treat sleep apnea); treat depression; avoid medications with cognitive side effects (anticholinergics, benzodiazepines, opioids); maintain hearing (hearing aids help); maintain vision; oral health; limit alcohol; avoid head injuries; adequate B12 (deficiency common with metformin); consider GLP-1 agonists (some emerging research on cognitive benefits). For adults with type 2 diabetes – MCI is 2x more common; brain is target organ for diabetes complications; comprehensive approach addressing diabetes, cardiovascular risk factors, sleep, depression, hearing, exercise, diet, cognitive engagement can slow progression; some cases reversible if underlying cause addressed; baseline cognitive assessment reasonable for older adults with diabetes; communicate with healthcare team about changes. See our broader diabetes complications guide for context.

Polymyalgia rheumatica (PMR) is inflammatory rheumatologic condition characterized by stiffness and pain in shoulders, neck, hips, and proximal extremities; almost exclusively affects adults over 50 (average age 70); about 2x more common in women than men; more common in people of Northern European descent. Pathophysiology – inflammatory condition affecting bursae, tendons, and synovium around shoulders and hips; not joint destruction like RA. Symptoms – sudden onset of bilateral shoulder/hip stiffness and pain; pain worse in morning (lasting 30+ minutes); difficulty raising arms; difficulty rising from chair; fatigue, low-grade fever, weight loss possible; sleep disturbance; depression. Distinguishing from osteoarthritis – PMR is bilateral and symmetric; PMR has elevated inflammatory markers; PMR responds dramatically to steroids; OA is mechanical and joint-specific. Distinguishing from RA – RA usually starts younger; RA has small joint involvement (hands, feet); RA has positive rheumatoid factor often; RA progresses to joint damage. Associated condition – giant cell arteritis (GCA, temporal arteritis) occurs in 15-30% of PMR patients; vasculitis of medium arteries; can cause vision loss; monitor carefully. Clinical diagnosis with supportive tests – 2012 EULAR/ACR criteria require patient age 50+ with bilateral shoulder pain plus 2+ of: morning stiffness over 45 minutes; hip pain or limited range of motion; absence of rheumatoid factor or anti-CCP antibodies; absence of other joint pain. Laboratory findings – markedly elevated ESR (40+ mm/hr, often 100+); markedly elevated hsCRP; mild anemia possible; mild liver enzyme elevation; normal CK (distinguishes from inflammatory myopathies). Rapid clinical improvement (within days to a week) to low-dose prednisone (15-20 mg) is virtually diagnostic. Imaging – ultrasound or MRI may show bursitis/tenosynovitis. Standard treatment is steroids with significant diabetes impact. Prednisone or methylprednisolone 12.5-25 mg daily starting dose (typically 15 mg); rapid clinical improvement expected within 1 week; gradual taper over 12-18 months; total treatment 12-24+ months typical; relapses common during taper. CRITICAL diabetes considerations – prednisone significantly raises blood glucose; effects appear within hours; peak 4-8 hours after morning dose; “steroid diabetes” common; need aggressive diabetes management adjustment. Strategies – increase diabetes medication dose (typically increase insulin 30-50% or more during high-dose steroid period); add basal insulin to oral regimen if not already on insulin; add prandial insulin coverage at lunch (when steroid peak hits); SGLT2 inhibitors good choice; GLP-1 agonists helpful; CGM essential for monitoring. As steroid dose tapers – diabetes medication tapers accordingly; watch for hypoglycemia.

PMR Characteristics

Distinguishing PMR from Other Conditions

Steroid Diabetes Management

• Prednisone causes 30-50%+ blood sugar increase.
• Effects appear within hours of dose.
• Peak 4-8 hours after morning dose.
• Often worst in afternoon hours.
• Increase diabetes meds proactively.
• Add basal insulin if not on it.
• Add lunchtime prandial insulin coverage.
• SGLT2 inhibitors very helpful.
• GLP-1 agonists helpful.
• CGM essential.
• Frequent communication with endocrinology.
• Monitor A1C every 3 months during treatment.
• Watch for hypoglycemia as steroid tapers.
• Consider DKA risk with SGLT2 inhibitors plus illness.

Giant Cell Arteritis Warning Signs

• New temporal headache.
• Scalp tenderness.
• Jaw claudication (pain with chewing).
• Vision changes – URGENT.
• Vision loss – can be permanent.
• Fatigue, fever, weight loss.
• Arm claudication (if subclavian involved).
• Any vision change in PMR patient – immediate evaluation.
• Higher steroid doses required.
• Major diabetes management challenge.

PMR Treatment Course

• Initial prednisone 15 mg daily typical.
• Rapid improvement within 1 week.
• Slow taper over 12-18 months.
• Maintenance 5 mg daily often for extended period.
• Relapses common during taper – increase dose temporarily.
• Methotrexate as steroid-sparing for some.
• Tocilizumab for refractory cases (also GCA approved).
• Calcium and vitamin D for bone protection during steroids.
• Bisphosphonate if steroid use 3+ months and at risk.
• Monitor for steroid side effects (diabetes, BP, infections).

The Bottom Line

Polymyalgia rheumatica (PMR) is inflammatory rheumatologic condition characterized by stiffness and pain in shoulders, neck, hips, and proximal extremities; almost exclusively affects adults over 50 (average age 70); about 2x more common in women than men; more common in people of Northern European descent. Pathophysiology – inflammatory condition affecting bursae, tendons, and synovium around shoulders and hips; not joint destruction like RA. Symptoms – sudden onset of bilateral shoulder/hip stiffness and pain; pain worse in morning (lasting 30+ minutes); difficulty raising arms; difficulty rising from chair; fatigue, low-grade fever, weight loss possible. Distinguishing from osteoarthritis – PMR bilateral and symmetric; PMR has elevated inflammatory markers; PMR responds dramatically to steroids. Distinguishing from RA – RA usually starts younger; RA has small joint involvement; RA has positive rheumatoid factor often. Associated condition – giant cell arteritis (GCA, temporal arteritis) occurs in 15-30% of PMR patients; vasculitis of medium arteries; can cause vision loss. Clinical diagnosis with supportive tests – 2012 EULAR/ACR criteria; ESR (40+ mm/hr often 100+) and hsCRP markedly elevated; rapid clinical improvement to low-dose prednisone is virtually diagnostic. Standard treatment is steroids – prednisone 12.5-25 mg daily starting dose; rapid clinical improvement expected within 1 week; gradual taper over 12-18 months; total treatment 12-24+ months typical; relapses common during taper. CRITICAL diabetes considerations – prednisone significantly raises blood glucose; effects appear within hours; peak 4-8 hours after morning dose; “steroid diabetes” common. Strategies – increase diabetes medication dose (insulin 30-50% increase); add basal insulin if not on it; add prandial insulin coverage at lunch; SGLT2 inhibitors good choice; GLP-1 agonists helpful; CGM essential; tight communication with endocrinology. As steroid dose tapers – diabetes medication tapers; watch for hypoglycemia. Non-steroid treatments – methotrexate (steroid-sparing); tocilizumab (IL-6 inhibitor) for refractory cases. GCA important associated condition – 15-30% of PMR patients develop GCA; risk continues during PMR treatment. Symptoms – new headache, scalp tenderness, jaw claudication, vision changes (URGENT – can cause permanent vision loss). Treatment – higher steroid dose (40-60 mg prednisone); tocilizumab approved for GCA. Diabetes impact of GCA treatment – high-dose steroids cause major hyperglycemia; emergency situation if vision changes. Education – PMR patients should know GCA symptoms; immediate medical attention if vision changes. For adults with type 2 diabetes – PMR diagnosis triggers significant diabetes management challenge due to steroid treatment; aggressive insulin/medication increase typically needed; CGM essential; SGLT2 inhibitors and GLP-1 agonists particularly helpful; coordinate endocrinology, rheumatology, primary care; monitor for GCA symptoms (especially vision changes); manage bone health and other steroid side effects. See our broader diabetes complications guide for context.