DOI: 10.2337/dc05-2146 © 2006 by the American Diabetes Association
Metformin Improves Endothelial Vascular Reactivity in First-Degree Relatives of Type 2 Diabetic Patients With Metabolic Syndrome and Normal Glucose ToleranceDepartment of Physiological Sciences, Laboratório de Pesquisas em Microcirculação, State University of Rio de Janeiro, Rio de Janeiro, Brazil Address correspondence and reprint requests to L.G. Kraemer de Aguiar, Av. Sete de Setembro, 332 apto 601, CEP 24230-253, Niterói, RJ, Brazil. E-mail: gkraemer{at}ig.com.br OBJECTIVEEndothelial dysfunction is an early marker of atherosclerosis seen in type 2 diabetic subjects. Metformin is commonly used in the treatment of type 2 diabetes and has known vasculoprotective effects beyond its hypoglycemic ones. We aimed to investigate the vascular effects of metformin in first-degree relatives with metabolic syndrome of type 2 diabetic patients. RESEARCH DESIGN AND METHODSThe study included 31 subjects (age 38.3 ± 7.6 years and BMI 36.3 ± 5.2 kg/m2), who were first-degree relatives of type 2 diabetic patients and who had metabolic syndrome and normal glucose tolerance. The subjects were randomly assigned 1:1 in a double-blind fashion to receive placebo (n = 15) or metformin (n = 16). Endothelial function was assessed by venous occlusion plethysmography, measuring forearm blood flow (FBF) and vascular resistance responses to three intra-arterial infusions of endothelium-dependent (acetylcholine 7.5, 15, and 30 µg/min) and independent (sodium nitroprusside 2, 4, and 8 µg/min) vasodilators. Weight, BMI, systolic and diastolic blood pressure, waist, and laboratory parameters (lipid profile and fasting plasma glucose [FPG]) were assessed at baseline and after treatment. RESULTSThe metformin and placebo groups did not differ in anthropometric, clinical, laboratory, and vascular measurements at baseline. The metformin group had decreased weight, BMI, systolic blood pressure, and FPG and improved lipid profile. Endothelium-dependent FBF responses were also improved, without any effect on endothelium-independent responses. There was no correlation between the improvement on FBF responses and the observed changes on anthropometric, clinical, and laboratory parameters. CONCLUSIONSWe concluded that metformin improved vascular endothelial reactivity in first-degree relatives with metabolic syndrome of type 2 diabetic patients, independently of its known antihyperglycemic effects.
Abbreviations: ACh, acetylcholine FBF, forearm blood flow FFA, free fatty acid FPG, fasting plasma glucose SNP, sodium nitroprusside
This article has been cited by other articles:
|
|
|
|||||||||||||||||||||||||||||||||||||||||||||||||||