The Ambulatory Glucose Profile (AGP) is the standardized 14-day CGM report used by clinicians and people with diabetes to interpret continuous glucose monitoring data. It consolidates Time in Range, GMI, coefficient of variation, and a modal-day visualization onto a single page. The Danne 2017 international consensus defined the format, which is now generated automatically by every major CGM platform.
What the AGP Contains
- Top summary: dates covered, percent of CGM data captured, mean glucose, GMI, glucose management indicator vs A1C, CV, and average daily readings.
- Time-in-range bar: color-coded breakdown — TBR level 2 (red, less than 54), TBR level 1 (red, less than 70), TIR (green, 70 to 180), TAR level 1 (yellow, greater than 180), TAR level 2 (orange, greater than 250).
- Modal day chart: 24-hour graph showing percentile bands across the 14-day window.
- Daily glucose profiles: 14 small daily graphs at the bottom, one per day.
- Annotations: some platforms add automated comments about high or low periods.
Reading the Modal Day
| Line / Band | What It Shows | How to Interpret |
|---|---|---|
| Dark line (50th percentile, median) | Typical glucose at that time of day | Should stay within green band (70 to 180) |
| Inner ribbon (25th to 75th percentile) | Interquartile range | Narrow = stable; wide = variable |
| Outer ribbon (10th to 90th percentile) | Most of the distribution | Should not reach above 250 or below 54 |
| Green band (background) | Target range (70 to 180) | Median ideally within |
Common AGP Patterns
| Pattern | Likely Cause | Action |
|---|---|---|
| Steady spike at breakfast time | Dawn phenomenon plus carb load | Pre-breakfast insulin timing, lower-carb breakfast |
| Spike at dinner only | Largest carb meal | Smaller portion, lower-GI choice, pre-meal walk |
| 3 AM dip (low median) | Excess basal insulin or late alcohol | Reduce basal, change timing |
| Wide ribbon across the day | Inconsistent meals, dosing, or timing | Consistency interventions, AID consideration |
| Median above 180 all day | Insufficient therapy | Intensify medication, review carb intake |
| Frequent dips below 70 after exercise | Exercise-induced hypoglycemia | Carb timing, basal reduction during activity |
| Rising median overnight | Dawn phenomenon | Adjust basal or add basal at bedtime |
See our companion guide on dawn phenomenon vs Somogyi effect for the overnight patterns.
Targets at a Glance
| Metric | Adult Target (T1D/T2D) | Older / High-Risk | Pregnancy (T1D) |
|---|---|---|---|
| TIR (70 to 180) | >70% | >50% | >70% (63 to 140) |
| TBR <70 | <4% | <1% | <4% |
| TBR <54 | <1% | 0% | <1% |
| TAR >180 | <25% | <50% | <25% |
| TAR >250 | <5% | <10% | <5% |
| GMI | <7% | <8% | <6% |
| CV | ≤36% | ≤36% | ≤36% |
How CGM Platforms Generate the AGP
- Dexcom Clarity: web and mobile; updates every time the sensor uploads. Default 14 days.
- FreeStyle LibreView: web-based; uploads from the reader or smartphone app.
- Medtronic CareLink: includes AGP plus pump data.
- Tidepool: open-source platform integrating multiple devices.
- Senseonics Eversense: proprietary platform with similar AGP.
- Glooko: aggregates multiple device data into a unified AGP.
Output format is standardized so that clinicians can read any platform’s AGP without translation.
How to Use AGP in a Clinic Visit
- Print or pull up the AGP before the visit.
- Verify data capture is over 70 percent (greater than 10 of 14 days).
- Look at the summary numbers first — TIR, GMI, CV, TBR.
- Compare TIR and TBR to targets; flag any concern.
- Read the modal day next — where are the median and ribbon shape problems?
- Scan the daily profiles for outlier days (illness, missed dose, exercise).
- Pick one to two patterns to address — not everything at once.
- Plan a follow-up AGP review in 2 to 4 weeks after changes.
AGP Limitations
- Requires CGM with adequate sensor wear (>70 percent of the window).
- 14-day window may not capture longer cycles (menstrual cycles, monthly patterns).
- Outlier days (illness, holidays) can skew the modal day visualization.
- Sensor accuracy errors propagate into all summary metrics.
- Modal day pools all days — context (weekday vs weekend, eating vs exercise days) is lost unless platform offers filtering.
- Some platforms do not report MAGE or detailed nocturnal metrics.
- Not a substitute for symptom history and patient reporting.
What AGP Cannot Tell You
- Cause of any spike or dip — only the pattern.
- Whether a low was symptomatic, unrecognized, or asymptomatic.
- Why variability changes between weeks.
- Whether the patient took insulin as recorded.
- Behavioral or psychosocial drivers of patterns.
Pair the AGP with patient interview to fill in the gaps.
Using AGP at Home
- Review your AGP weekly — most platforms have a mobile app.
- Note one pattern to address; do not try to fix everything at once.
- Compare this week to last week to see if changes worked.
- Take screenshots before clinic visits.
- Ask your clinician to walk through the AGP with you the first few times.
- Watch the trend over months — the direction of change matters more than any single snapshot.
Pregnancy-Specific AGP Use
Pregnant women with type 1, type 2, or gestational diabetes use tighter AGP targets: range 63 to 140 mg/dL (rather than 70 to 180), TIR greater than 70 percent for type 1, and greater than 85 percent for type 2 or gestational. Modal day review weekly is standard; some clinics use 7-day windows for faster feedback during active dose adjustments.
Related Reading
See Time in Range, GMI vs A1C, coefficient of variation, and MAGE. For background, see detection of prediabetes and A1C levels.
The Bottom Line
The Ambulatory Glucose Profile is the standardized one-page report that consolidates 14 days of CGM data — TIR, GMI, CV, TBR, TAR, and a modal-day visualization. It is the lingua franca of modern diabetes care. Read the summary numbers first, then the modal day, then the daily profiles. Identify one or two patterns to address per visit. Aim for TIR greater than 70 percent, CV at or below 36 percent, and a narrow ribbon with the median line in the green target band. The AGP is most powerful when reviewed weekly and used alongside patient interview about what actually happened during those 14 days.
