Abstract
Objective: To investigate the efficacy of the Diabeloop Generation-1 (DBLG1) closed-loop system to control the hypoglycaemia induced by physical activity (PA) in real-life conditions.Methods: This was a post-hoc analysis of the Diabeloop WP7 multicentre randomized controlled trial. Glycaemic outcomes were compared between days with and without PA in 56 patients with type 1 diabetes (T1D) using DBLG1 for 12 weeks. After the patient announces a PA, DBLG1 reduces insulin delivery and, if necessary, calculates the amount of preventive carbohydrates (CHO).Results: Daily time spent in the interstitial glucose range <70 mg/dL was not significantly different between days with and without PA (2.0 ± 1.5% versus 2.2 ± 1.1%) and this regardless of the intensity or duration of the PA. Preventive CHO intake recommended by the system was significantly higher in days with PA (41.1 ± 35.5 versus 21.8 ± 28.5 g/day; P <0.0001), and insulin delivery was significantly lower (31.5 ± 10.5 versus 34.0 ± 10.5 U/day; P <0.0001). The time spent in hyperglycaemia and the glycaemic variation coefficient increased significantly on days with PA.Conclusions: In real-life conditions, the use of DBLG1 avoids PA-induced hypoglycaemia. Insulin adjustments and preventive CHO recommendation may explain this therapeutic benefit.