Closed-Loop Insulin Delivery Effects on Glycemia During Sleep and Sleep Quality in Older Adults with Type 1 Diabetes: Results from the ORACL Trial.

Sleep-related effects of closed-loop therapy among older adults with type 1 diabetes have not been well established. In the OldeR Adult Closed-Loop (ORACL) randomized, crossover trial of first-generation closed-loop therapy (MiniMed 670G), participants wore actigraphy and completed sleep diaries for 14-day periods at stage end. During objectively measured sleep (actigraphy) with closed-loop versus sensor-augmented pump therapy, glucose time-in-range 70-180 mg/dL (3.9-10.0 mmol/L) was greater (90.3% vs. 78.7%, respectively; difference 8.2 percentage points [95% confidence interval {CI} 1.5 to 13.0];  = 0.008), and there were fewer sensor hypoglycemia episodes (18 vs. 43, respectively; incident rate ratio 0.40 [95% CI 0.20 to 0.55];  = 0.007). Sleep quality recorded daily was worse with closed-loop therapy ( = 0.006); Pittsburgh Sleep Quality Index did not differ. There were 30% more system alarms during monitored sleep with closed-loop therapy ( < 0.001). First-generation closed-loop therapy has important glycemic benefits during sleep for older adults, with deterioration in some sleep quality measures. Sleep quality warrants prioritization and investigation during advancement of closed-loop technology.