Insulin sensitivity independently influences brachial-ankle pulse-wave velocity in non-diabetic subjects

Aims Measurement of pulse-wave velocity (PWV) is a non-invasive technique for assessing arterial stiffness. Although insulin resistance is associated with intimal-medial thickness of the carotid artery evaluated by B-mode ultrasonography, it is not known whether it is related to PWV. The aim of this study was to determine the relationship between homeostasis model assessment insulin sensitivity index (HOMA-%S) and PWV in non-diabetic subjects. We also examined the effects of oral glucose tolerance test (OGTT) 2-h glucose and plasma high-sensitivity C-reactive protein (CRP) on PWV, as these two parameters are associated with atherosclerosis. Methods A 75-g oral glucose tolerance test was performed in 1934 Japanese subjects who were undergoing health examinations. Of these subjects, we recruited 1541 non-diabetic subjects without chronic or acute inflammation, malignant diseases, autoimmune disorders, elevated serum creatinine levels, and abnormal hepatic function tests. Subjects who had an abnormal ankle/brachial blood pressure index of less than 0.9 were also excluded. Brachial-ankle PWV and plasma high-sensitivity CRP were measured on 1541 subjects who satisfied the admission criteria. Results PWV was 12.55 +/- 1.61 (mean +/- SD) m/s and plasma CRP concentration was 0.4 mg/l (median, range, 0.1-5.8 mg/l) in the study subjects. By multivariate regression analysis, HOMA-%S was found to be an independent negative risk factor for PWV, while systolic blood pressure, age and triglycerides were positively associated with PWV. OGTT 2-h glucose was weakly and independently related to PWV in male subjects. Plasma CRP was not independently associated with PWV. Conclusions Insulin resistance is independently associated with PWV in non-diabetic subjects.