Background: The mechanisms by which menopause may influence the systemic subclinical atherosclerosis are unexplained. The aim of this cross-sectional study was to evaluate the associations between early menopause, established cardiovascular (c-v) risk factors, metabolic parameters (insulin secretion and sensitivity, plasma adiponectin), and carotid intima-media thickness (IMT) in healthy women.
Methods: In 74 menopausal women (mean age = 51 +/- 3 years, mean duration of menopause = 2.9 +/- 1.2 years) and in 74 nonmenopausal women comparable for age and body mass index (BMI), common carotid artery (CCA) luminal diameter, and IMT in different carotid segments were measured in digitized ultrasound images. Insulin sensitivity and secretion were assessed using the euglycemic hyperinsulinemic clamp technique and oral glucose tolerance test (OGTT). Insulin secretion was reconstructed by mathematical modeling.
Results: CCA diameter (5.55 +/- 0.46 vs. 5.21+/- 0.51 mm, P < 0.001), CCA IMT (608 +/- 78 vs. 576 +/- 74 microm, P < 0.01) and systolic blood pressure (BP) (117 +/- 12 vs. 113 +/- 11 mm Hg, P < 0.05) were higher in menopausal women, whereas CCA IMT/diameter ratio and IMT in other carotid segments did not differ between the groups. By multivariate models, independent predictors of CCA diameter were menopause and body weight (cumulative R2 = 0.37) and independent correlates of CCA IMT were luminal diameter, systolic BP and low-density lipoprotein (LDL) cholesterol (cumulative R2 = 0.48). Fasting insulin, insulin secretion, and sensitivity and plasma adiponectin were similar in the two groups and were not related to carotid IMT.
Conclusions: Early menopause is associated with CCA remodeling, characterized by a proportional increase in luminal diameter and wall thickness, independent of atherosclerotic risk factors and metabolic variables.