Comparative safety and efficacy of insulin degludec with insulin glargine in type 2 and type 1 diabetes: a meta-analysis of randomized controlled trials

To determine the safety and efficacy of insulin degludec versus glargine in patients with type 1 (T1D) and type 2 (T2D) diabetes mellitus.

Databases were searched until July 5, 2017. We included randomized controlled trials comparing degludec with glargine in diabetic patients, each with a minimum of 16 weeks of follow-up.

Eighteen trials with 16,791 patients were included. Degludec was associated with a statistically significant reduction in risk for all confirmed hypoglycemia at the maintenance treatment period [estimated rate ratio (ERR) 0.81; 95% confidence interval (CI) 0.72‒0.92; P = 0.001], nocturnal confirmed hypoglycemia at the entire (ERR 0.71; 95% CI 0.63‒0.80; P < 0.001) and maintenance treatment period (ERR 0.65; 95% CI 0.59‒0.71; P < 0.001), all irrespective of the pooled diabetic populations and follow-up durations. The differences in the rate of hypoglycemia were more pronounced in nocturnal period and maintenance period and in T2D than T1D patients. Degludec reduced the incidence of severe hypoglycemia in T2D [ERR 0.65; (0.52; 0.89); P = 0.005] but not T1D patients. HbA1c concentration was slightly higher in degludec over glargine but was not clinically relevant [estimated treatment difference (ETD) 0.03; 95% CI − 0.00 to 0.06%; P = 0.06]. Fasting plasma glucose level was lower in degludec-treated patients (ETD − 0.28 mmol/L; 95% CI − 0.44 to − 0.11 mmol/L; P = 0.001). Several subgroup analyses showed largely consistent findings. The rates of adverse events including total mortality and cardiovascular events were not significantly different between two treatment strategies.

Insulin degludec appears to have better safety in reducing hypoglycemic events with similar efficacy compared with insulin glargine.