Lower Within-Subject Variability of Insulin Detemir in Comparison to NPH Insulin and Insulin Glargine in People With Type 1 Diabetes

Abstract

The aim of this randomized double-blind study was to compare the within-subject variability of the glucose-lowering effect of a novel insulin analog, insulin detemir, with that of insulin glargine and NPH insulin in people with type 1 diabetes. Fifty-four subjects (32 males and 22 females, age 38 ± 10 years [mean ± SD], BMI 24 ± 2 kg/m², HbA_1c 7.5 ± 1.2%, diabetes duration 18 ± 9 years) participated in this parallel group comparison. Each subject received four single subcutaneous doses of 0.4 units/kg of either insulin detemir (n = 18), insulin glargine (n = 16), or human NPH insulin (n = 17) under euglycemic glucose clamp conditions (target blood glucose concentration 5.5 mmol/l) on four identical study days. The pharmacodynamic (glucose infusion rates [GIRs]) and pharmacokinetic (serum concentrations of insulin detemir, human insulin, and insulin glargine) properties of the basal insulin preparations were recorded for 24 h postdosing. Insulin detemir was associated with significantly less within-subject variability than both NPH insulin and insulin glargine, as assessed by the coefficient of variation (CV) for the pharmacodynamic end points studied [GIR-AUC_{(0–12 h)} 27% (detemir) vs. 59% (NPH) vs. 46% (glargine); GIR-AUC_{(0–24 h)} 27 vs. 68 vs. 48%; GIR_max 23 vs. 46 vs. 36%; P < 0.001 for all comparisons]. Insulin detemir also provided less within-subject variability in the pharmacokinetic end points: maximal concentration (C_max) 18 vs. 24 vs. 34%; INS-AUC_(0–∞) 14 vs. 28 vs. 33%. The results suggest that insulin detemir has a significantly more predictable glucose-lowering effect than both NPH insulin and insulin glargine.