Continuous Glucose Monitoring Holds Potential

▸ For an upward trend, delay eating or at least reduce carbs. This is especially true if the glucose is rising faster than 1 mg/dL per minute. And remember Pearl #2: For a correction dose with an upward trend before a meal, more insulin is needed.

▸ For a downward trend, fingerstick glucose measurements are critical. That's because of the lag time with the interstitial fluid that the RT-CGM is sampling. Relying solely on the RT-CGM reading is especially dangerous with significant insulin on board. If the glucose is dropping rapidly, you want to take less insulin or decrease the time between the insulin and the food. Consider a snack at the low end of the target range if the downward trend is at 1–2 mg/dL per minute, and at the high end of the target range if the trend is at or above 2 mg/dL per minute.

“With RT-CGM, we're starting to talk about the velocity of glucose changes. Velocity is a concept we've never talked about before,” Dr. Hirsch noted.

▸ We have much yet to learn from this new technology. “What is the potential for use in the hospital? In pregnant patients? Insulin-requiring patients with type 2 diabetes? We're just at the beginning, but one thing is certain right now: If the technology allows some of our patients to live happier lives without hypoglycemia, there's something to be said for that, even if the reimbursers don't agree.”

Dr. Hirsch said he has received grants and research support from Medtronic, but has no financial relationship with DexCom.