Carbohydrate Intake Strategies Based on CGM Readings

Sensor Glucose (mg/dL)Trend ArrowsCarbohydrate Intake (g)
109–124↓ or ↓↓8 (2 glucose tablets)
90–10816 (4 glucose tablets)
↓↓20 (5 glucose tablets)
<90No arrow16 (4 glucose tablets)
↓ or ↓↓20 (5 glucose tablets)
  • This carbohydrate protocol can be used if CGM-measured glucose is <125 mg/dL and dropping. Because this algorithm was tested in adolescents with type 1 diabetes (15), adults may require more carbohydrate. For safety, people with diabetes should stop exercising if hypoglycemia develops (capillary blood glucose ≤65 mg/dL) and treat with 15–20 g of rapid-acting carbohydrates (28). CGM is not a substitute for capillary glucose monitoring. It should be noted that the CGM trend arrows differ slightly in appearance and display messaging, depending on the type of CGM system used. This table represents the trending arrows for the Medtronic CGM system that was used in this study. The Medtronic system shows a single downward arrow to indicate a rate of decrease in the glucose level of 1–2 mg/dL/minute; two downward arrows indicates that glucose levels are falling by ≥2 mg/dL/minute. The Dexcom CGM system displays a single downward-pointing diagonal arrow to indicate a drop in glucose of 1–2 mg/dL/minute, a single vertical downward-pointing arrow to indicate a drop rate of 2–3 mg/dL/minute, and two downward-pointing vertical arrows to indicate a drop rate >3 mg/dL/minute.