Diabetes Technology and Glycemic Monitoring
What the exam expects
Know how to interpret A1C, self-monitoring of blood glucose, continuous glucose monitoring metrics, and when each is appropriate. Understand time in range, time below range, glucose management indicator, and coefficient of variation. Know the difference between real-time and intermittently scanned CGM and the value of alarms and trend arrows.
Concepts to master
- A1C limitations and discordance with CGM or fingerstick data.
- CGM metrics: time in range, time below range, time above range, variability.
- Insulin pump therapy, automated insulin delivery, and infusion set troubleshooting.
- Blood glucose meter accuracy, coding, and control solution use.
- Data download review and shared decision-making using reports.
- Cybersecurity, alarm fatigue, and appropriate expectations.
Traps
Questions may ask for the best next step when A1C and CGM disagree; the answer is usually to investigate the discrepancy (anemia, hemoglobinopathy, sensor accuracy) rather than change therapy blindly. Another trap is confusing time in range targets across populations, or assuming CGM replaces all fingersticks in every situation.
Rule of thumb
Use A1C for population-level average and CGM for pattern-level decisions; when they conflict, trust the more granular data after confirming accuracy.
Worked example
A patient reports A1C 8.2% but CGM shows 75% time in range with frequent overnight lows. The discrepancy suggests hypoglycemia driving rebound hyperglycemia; review overnight basal and consider alarm settings rather than simply increasing insulin.