Overview

• In Diabetes Technology & Therapeutics, Mass General Brigham researchers report strong alignment between CGM metrics and HbA1c only in adults with type 2 diabetes.
• In prediabetes, associations weakened, and in normoglycemia most CGM measures showed no relationship to HbA1c, with only mean glucose and the J‑index showing weak links.
• The study tracked adults aged 40 and older who wore Dexcom G6 sensors every five minutes for up to 10 days while baseline HbA1c and eight CGM metrics were analyzed.
• Findings held after adjustment for body mass index, supporting guidance that CGM readouts should not replace HbA1c for longer‑term glycemic assessment outside diabetes.
• Authors advise using CGMs as short‑term behavioral biofeedback for people without diabetes and call for longer studies and clinician education as OTC use expands.