Continuous Glucose Monitoring-Recorded Hypoglycemia with Insulin Degludec or Insulin Glargine U100 in People with Type 1 Diabetes Prone to Nocturnal Severe Hypoglycemia.

Nocturnal hypoglycemia is mainly a consequence of inappropriate basal insulin therapy in type 1 diabetes (T1D) and may compromise optimal glycemic control. Insulin degludec is associated with a lower risk of nocturnal hypoglycemia in T1D. As nocturnal hypoglycemia is often asymptomatic, we applied continuous glucose monitoring (CGM) to detect a more precise occurrence of nocturnal hypoglycemia in the HypoDeg trial, comparing insulin degludec with insulin glargine U100 in people with T1D and previous nocturnal severe hypoglycemia. In the HypoDeg trial, 149 people with T1D were included in an open-label randomized cross-over trial. Sixty-seven participants accepted optional participation in the predefined substudy of 4 × 6 days of blinded CGM requiring completion of at least one CGM period in each treatment arm. CGM data were reviewed for hypoglycemic events. Treatment with insulin degludec resulted in a relative rate reduction (RRR) of 36% (95% confidence interval [CI]: 10%-54%;  < 0.05) in nocturnal CGM-recorded hypoglycemia (≤3.9 mmol/L), corresponding to an absolute rate reduction (ARR) of 0.85 events per person-week. In nocturnal CGM-recorded hypoglycemia (≤3.0 mmol/L), we found an RRR of 53% (95% CI: 36%-65%;  < 0.001), corresponding to an ARR of 0.75 events per person-week. At the lower detection limit of the CGM (≤2.2 mmol/L), treatment with insulin degludec resulted in a significant RRR of 58% (95% CI: 23%-77%;  = 0.005). The reductions were primarily due to significant RRRs in asymptomatic hypoglycemia. In people with T1D, prone to nocturnal severe hypoglycemia, insulin degludec compared with insulin glargine U100 significantly reduces nocturnal CGM-recorded hypoglycemia. www.clinicaltrials.gov (#NCT02192450).