Automated Insulin Delivery in Older Adults with Type 1 Diabetes.

Background: Older adults with type 1 diabetes are at risk for serious hypoglycemia. Automated insulin delivery can reduce risk but has not been sufficiently evaluated in this population.

Methods: We conducted a multicenter, randomized crossover trial in adults older than or equal to 65 years of age with type 1 diabetes. Participants completed three 12-week periods of using hybrid closed loop, predictive low-glucose suspend, and sensor-augmented pump insulin delivery in a randomized order. The primary outcome was the percentage of time with continuous glucose monitoring glucose values less than 70 mg/dl.

Results: Eighty-two participants between 65 and 86 years of age were randomly assigned: 45% were female; the baseline mean (±SD) glycated hemoglobin level was 7.2±0.9%; and the baseline percentage of time with glucose values less than 70 mg/dl was 2.49±1.78%. In the sensor-augmented pump, hybrid closed-loop, and predictive low-glucose suspend periods, percentages of time with glucose less than 70 mg/dl were 2.57±1.54%, 1.58±0.95%, and 1.67±0.96%, respectively. Compared with the sensor-augmented pump results, the mean difference with the hybrid closed-loop system was -1.05 percentage points (95% confidence interval [CI], -1.48 to -0.73 percentage points; P<0.001) and with the predictive low-glucose suspend system it was -0.93 percentage points (95% CI, -1.27 to -0.66 percentage points; P<0.001). Comparing a hybrid closed-loop system with a sensor-augmented pump, time in the range 70 to 180 mg/dl changed by 8.9 percentage points (95% CI, 7.4 to 10.4 percentage points) and the glycated hemoglobin level changed by 0.2 percentage points (95% CI, -0.3 to -0.1 percentage points). Serious adverse events were uncommon. Severe hypoglycemia occurred in 4% or less of participants; there were two hospitalizations for diabetic ketoacidosis.

Conclusions: In older adults with type 1 diabetes, automated insulin delivery decreased hypoglycemia compared with sensor-augmented pump delivery. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; ClinicalTrials.gov number: NCT04016662.).