Carvedilol Does not Alter the Insulin Sensitivity in Patients with Congestive Heart Failure

BACKGROUND: Congestive heart failure (CHF) has previously been shown to be associated with insulin resistance and hyperinsulinemia. A beneficial effect of the non-selective beta-blocker carvedilol has been demonstrated in patients with CHF. However, whether the drug affects the insulin sensitivity (S(i)) is unknown. AIMS: To investigate whether treatment with carvedilol alters the S(i) in patients with CHF during a prospective, double-blinded, placebo-controlled study. METHODS AND RESULTS: The patients were randomized to receive either carvedilol (n=29) or matched placebo (n=17). Insulin and glucose responses were measured during a 0.3 g/kg intravenous glucose tolerance test, and S(i) was calculated according to Bergman's Minimal Model. Baseline S(i) values correlated significantly with body mass index (r=-0.42, P=0.002), plasma urate (r=-0.42, P=0.002), plasma HDL-cholesterol (r=0.39, P=0.003), maximal oxygen uptake (r=0.35, P=0.009), plasma triglycerides (r=-0.34, P=0.01) and weight (r=-0.29, P=0.03). During the study the insulin sensitivity was unchanged in the carvedilol group compared with placebo (2.63+/-1.45 to 2.38+/-1.64 vs. 2.81+/-2.36 to 2.48+/-1.84x10(-4) min(-1)/mUl(-1), P=0.83). CONCLUSION: Additional treatment with carvedilol is neutral with regard to influence the insulin sensitivity in patients with mild to moderate CHF.