Unaltered insulin sensitivity during calcium channel blockade with amlodipine

Summary The sensitivity of peripheral tissues to insulin is of pathophysiological, therapeutic and possibly also of prognostic relevance. Calcium channel blockers are widely used in the treatment of cardiovascular disorders that are commonly associated with decreased insulin sensitivity (S_I). To evaluate the effects of calcium channel blokkade on S_I, glucose homoeostasis and lipid profiles, studies were made of S_I (determined by the Minimal Model Method of Bergman), basal glucose and insulin levels, serum total triglyceride (Tg) and lipoprotein cholesterol (C) fractions and certain other variables in 38 healthy young men (24 y) during placebo and after 3 weeks of calcium channel blockade with amlodipine 5 mg once daily. Measurements were made after 3 days on a standard diet (2200 kcal · day^–1, 45% carbohydrates, 40% fat and 15% proteins) and after an overnight fast. Compared to placebo, amlodipine decreased supine systolic blood pressure (P<0.01). Heart rate, body weight and 24 h urinary sodium excretion were unaltered, and so were fasting plasma glucose (placebo vs amlodipine: 4.86 vs 4.83 mmol·1^–1, respectively) and insulin levels (7.7 vs 7.9 U·ml^–1), S_I (10.5 vs 9.6·10^–4 × min^–1 pro U·ml^–1), serum total Tg, C and lipoprotein C fractions.The findings demonstrate unchanged insulin sensitivity and secretion, as well as lipoprotein regulation, during maintenance administration of 5 mg amlodipine daily to healthy young men.This work was supported in part by the Swiss National Science Foundation