Effects of insulin detemir and NPH insulin on renal handling of sodium, fluid retention and weight in type 2 diabetic patients

Abstract

Aims/hypothesis In type 2 diabetic patients, insulin detemir (B29Lys(?-tetradecanoyl),desB30 human insulin) induces less weight gain than NPH insulin. Due to the proposed reduction of tubular action by insulin detemir, type 2 diabetic patients should have increased urinary sodium excretion, thereby reducing extracellular volume and body weight when changed from NPH insulin to insulin detemir. Methods In a randomised, open-labelled, two-way crossover study of 24 patients with type 2 diabetes, patients were first treated with NPH insulin or insulin detemir for 8 weeks. Thereafter, they were changed to the other insulin for 8 weeks. In a third 1 week period, they were changed back to the first insulin. Results At the end of 8 weeks, body weight was reduced by 0.8±0.2 kg (mean ± SEM) on insulin detemir compared with NPH insulin (p<0.01). After insulin detemir treatment, we also observed a significant reduction of lean body mass (0.8±0.2 kg, p<0.05) and a non-significant reduction of extracellular volume (0.8±0.5 l/1.73 m 2, p=0.14). The weight loss occurred after as early as 1 week (0.8±0.2 kg, p<0.001), with a simultaneous and transient increase of urinary sodium excretion (p=0.07). Conclusions/interpretation Insulin detemir induces significant and sustained weight loss, which is first observed at 1 week after changing from NPH insulin. The initial weight loss seems to be related to changes in fluid volume and may reflect changed insulin action in the kidneys. © 2011 Springer-Verlag.