Monitoring, Technology, Complications, and Special Populations
Monitoring and technology
Check A1c at least twice yearly when at goal and quarterly when therapy changes or goals are unmet. SMBG frequency depends on regimen: multiple daily injections and insulin pumps need frequent testing, while non-insulin regimens may need little. CGM metrics complement A1c: time in range 70-180 mg/dL >70%, time below range <4% (with <1% below 54 mg/dL), time above range <25%, and glucose management indicator (GMI ≈ 3.31 + 0.02392 × mean glucose in mg/dL). Coefficient of variation <36% indicates stable control. Confirm CGM readings with fingerstick when symptoms do not match, and never use CGM for treatment decisions without confirming within the device's labeled requirements.
Complications screening
Annual dilated retinal exam; urine albumin-to-creatinine ratio and eGFR at least annually; comprehensive foot exam yearly with visual inspection every visit; lipid panel and blood pressure at each visit, targeting <130/80 mmHg. Address smoking, vaccines, and dental care.
Special populations
Pregnancy targets are tighter (A1c <6%, fasting <95, 1-hour <140, 2-hour <120 mg/dL) and many medications must change. Older adults need simplified regimens and relaxed targets to avoid hypoglycemia. Chronic kidney disease requires renal dose adjustment and SGLT2 inhibitor consideration. Hospitalized patients generally use scheduled basal-bolus insulin rather than sliding scale alone.
Traps
Do not use A1c as the sole marker in dialysis, anemia, or after transfusion, and do not confuse GMI with a lab A1c. Do not attribute foot ulcers to neuropathy alone without assessing perfusion and infection.