Estrogen, Nitric Oxide, and Primate Atherosclerosis

Coronary heart disease (CHD) is the leading cause of death among postmenopausal women in Western societies. It is generally accepted that CHD risk is reduced by about 50% in postmenopausal women who take conjugated equine estrogens (CEE) daily (Bush 1990; Stampfer and Colditz 1991). Observational studies of postmenopausal women undergoing angiography for chest pain have shown that coronary artery occlusions are fewer among estrogen users than nonusers (Sullivan 1993; Gruchow et al. 1988; Hong et al. 1992). These data suggest that estrogen may reduce CHD risk by affecting atherogenesis. Recent studies have explored the mechanism(s) by which estrogen reduces CHD risk and inhibits atherogenesis. One of the main areas of attention is the potential role of nitric oxide (NO) as an important mediator of estrogen’s effects on coronary artery disease.