Insulin resistance independently influences arterial stiffness in normoglycemic normotensive postmenopausal women

Objective: Cardiovascular disease risk increases after menopause, which may be related to insulin resistance, and arterial stiffness is a significant predictor of atherosclerosis. We investigated the relationships among insulin resistance, adiponectin, and arterial stiffness in normoglycemic normotensive postmenopausal women. Methods: From 9,555 participants who had routine health checkups, 455 normoglycemic normotensive postmenopausal women were enrolled. Serum concentrations of glucose, total cholesterol, triglyceride (TG), and high-density lipoprotein cholesterol (HDL-C) and adiponectin were measured. Insulin resistance was estimated by the insulin resistance index of homeostasis model assessment (HOMA-IR). Pulse wave velocity (PWV) was evaluated to assess arterial stiffness. Results: The women were stratified into three groups according to their HOMA-IR values, and comparisons were made among the three groups. There were significant differences in metabolic parameters between the groups. The mean age, body mass index, waist circumference, fasting plasma glucose, TG, systolic blood pressure (SBP), diastolic blood pressure (DBP), aortic PWV, and peripheral PWV increased sequentially with the degree of insulin resistance. Meanwhile, HDL-C and adiponectin levels decreased with the worsening of insulin resistance. Age, body mass index, fasting plasma glucose, TG, insulin, SBP, HOMA-IR, aortic PWV, and peripheral PWV were significantly higher in women with central obesity, and HDL-C and adiponectin were significantly lower in women with central obesity. Aortic PWV and peripheral PWV were significantly correlated with age, waist circumference, total cholesterol, SBP, DBP, insulin, and HOMA-IR, but adiponectin was not associated with PWV. The results of multiple regression analysis indicated that SBP, DBP, and insulin resistance were independently correlated with PWV. Conclusions: Insulin resistance was independently associated with PWV in normoglycemic normotensive postmenopausal women.