Association of menopause with risk of carotid artery atherosclerosis

Observational studies suggest that the risk of cardiovascular disease increases during menopause; however, the menopause-related risk of subclinical atherosclerosis is unclear. The aim of the current study is to evaluate menopause and the risk of subclinical carotid atherosclerosis through a retrospective analysis of data from a population-based prospective cohort study.

The study sample comprised 879 women in the Beijing community enrolled in the Chinese Multi-provincial Cohort Study at baseline study in 1992 and followed up to at least one carotid ultrasound examination at three on-site follow-up surveys. Age at menopause was categorized as <40 years (premature menopause), 40-44 years (early menopause), 45-49 years (relatively early menopause), 50-51 years (reference), and >51 years (relatively late menopause). Menopause staging at baseline was categorized as: reproductive, menopausal transition/perimenopause, early postmenopause, and late postmenopause. Menopause as a time-varying covariate was calculated using waiting time to menopause and menopause status at the last follow-up (2012).

The main outcome measures included carotid plaque and intima-media thickening. Gray's test was performed to assess the equality of cumulative incidence functions between age groups at menopause and between menopause stages. Multivariate Cox regression models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) associated with menopause.

Of the 879 women included (mean [SD] age at baseline, 48.6 [8.1] years), 573 (65.2%) developed carotid plaques and 430 (48.9%) developed intima-media thickening during follow-up. Menopause was significantly associated with risk of developing carotid plaques (HR 1.93, 95% CI 1.05-3.54; P = 0.03) after adjustment for age at baseline, age at menopause, use of oral estrogen due to menopause, and traditional cardiovascular risk factors at baseline. No significant association was found between age at menopause and risk of carotid atherosclerosis.

Menopausal women, irrespective of age at menopause, had an increased risk of carotid plaque.