Coronary artery disease--is menopause a risk factor?

Cardiovascular disease, especially coronary artery disease (CAD), are leading causes of morbidity and mortality in women over the age of 50, whereas this is rarely the case in younger women. This fact, the overall lower incidence of and the 10-15 year retarded occurrence of CAD in women, has led to the controversially discussed question whether menopause is a risk factor for CAD. There has been universal agreement that surgically induced early menopause with bilateral oophorectomy is a risk factor for CAD, associated with a relative risk of 2, unless estrogen is replaced. Yet pertinent naturally occurring menopause studies showed variable results. This review focuses on the criteria required for an association to be accepted as a risk factor. The occurrence of natural menopause is influenced by preexisting risk factors in different, partly opposing ways. Smoking leads to an earlier occurrence of menopause, obesity, hypertension and diabetes to a later occurrence. These complex interactions complicate statistical analysis. Natural menopause is associated with profound biochemical and metabolic changes, which are established risk factors, e.g., increase in LDL and decrease in HDL cholesterol. These biochemical and metabolic changes are the mechanisms by which menopause can act as a risk factor.

Menopause can be accepted as a risk factor, even if not all requirements, particularly that of reversibility, are fulfilled. The occurrence of menopause indicates the transition from a low to a higher risk for CAD in women.