In the Journal of Clinical Endocrinology and Metabolism, Paola Villa and colleagues report the effect of genistein administration on cardiovascular risk factors, focusing on glucose metabolism and endothelial function, in postmenopausal women . Fifty women (mean age 54 years, mean body mass index 27) were randomized to receive genistein (54 mg/day, n = 30) or placebo (n = 20) tablets for 6 months. Of the women receiving genistein, 14 were considered to be normoinsulinemic and 12 hyperinsulinemic. In addition to basal insulin and glucose levels, glycoinsulinemic metabolism was evaluated in detail by analyzing the response to glucose load, AUC-insulin as an index of hyperinsulinemia, as well as pancreatic insulin secretion (C-peptide levels) and hepatic insulin clearance (fractional hepatic insulin extraction (FHIE) values), by using both the homeostasis model and the euglycemic hyperinsulinemic clamp technique. Vascular function was evaluated by the flow-mediated dilatation (FMD) of the brachial artery in response to hyperemia of the arm and also by nitrate-mediated endothelium-independent dilatation (NMD).
Villa and colleagues found that, in women receiving genistein, basal insulin levels decreased and fasting glucose levels as well as the homeostasis model index of insulin sensitivity (HOMA-IR) improved, compared to the placebo-treated women. Furthermore, genistein administration in the hyperinsulinemic women reduced fasting insulin, fasting C-peptide and AUC-insulin levels while increasing FHIE values. Both FMD and NMD improved after genistein treatment, as compared to placebo; normoinsulinemic women showed both enhanced FMD and NMD, while no significant changes were found in the hyperinsulinemic women.
Department of Obstetrics and Gynecology, Helsinki University Central Hospital, Helsinki, Finland
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