Is menopause an independent cardiovascular risk factor? Evidence from population-based studies

Abstract

The question on whether menopause is an independent cardiovascular risk factor is still under debate. The results of four studies conducted by our staff in North East Italy, including > 11,000 subjects from the general population and covering a range of ages from 18 to 95 years, have been employed. We found apparently higher blood pressure (BP) values in naturally menopausal than in fertile women, but this difference disappeared after age-correction, or after identifying fertile and menopausal age-matched women. Significantly higher levels of serum lipids were also observed in menopausal than in fertile women but, in this case too, any difference disappeared after age-correction/matching. In a 16-year longitudinal analysis we found that BP increase and incidence of hypertension were the same in the women who remained fertile, in those becoming naturally menopausal and in those already menopausal at baseline; going through the menopause period, therefore, has no effect on BP. A mild and transitory BP increase was only observed during the climacterium. The BP increase during a follow-up and the incidence of new cases of hypertension were also similar in the women who remained fertile and in those who underwent bilateral ovariectomy, indicating no direct effect on BP for surgical menopause. In contrast, vectorial analysis demonstrated an excess increment of serum lipids among the women who underwent oophorectomy. In our populations, menopause had no predictive role and was rejected from the multivariate equations of risk, cardiovascular risk being completely explained by age and BP (both higher in menopausal then in fertile women).