New Puzzles Over Estrogen and Heart Disease

Recently 2 researchers confirmed the findings of Gerald Phillips Columbia University College of Physicians and Surgeons and St. Lukes Roosevelt Hospital Center in New York that men who have heart disease have abnormally high concentrations of estrogen in their blood. Investigators at the Framingham Heart Study in Massachusetts and the National Heart Lung and Blood Institute subsequently collaborated with Phillips and found that men with heart disease have higher levels of the estrogen derivative estradiol in their blood. Myron Luria and associates at St. Lukes Hospital and Case Western Reserve School of Medicine in Cleveland recently decided to see if Phillips findings held up in men who had not yet had heart attacks but who had chronic angina pectoris due to partially blocked coronary arteries and in older men aged 37-58 who had just had heart attacks. These investigators reported that the men with angina and the men with heart attacks had significantly more estradiol in their blood than the controls. The stress hormone norepinephrine can increase the amount of estradiol in the blood by speeding up the conversion of testosterone to estradiol so the question that arises is whether the high estradiol levels in heart disease patients are an artifact of the stress they are under. Edward Klaiber and Donald Broverman of the Worcester Foundation for Experimental Biology in Shrewsbury Massachusetts working with James Dalen and associates at the University of Massachusetts Medical School measured serum estradiol in men who had heart attacks in men with unstable angina who were thus at high risk of having heart attacks in men hospitalized in intensive care who did not have heart disease and in a control group of healthy men. The heart disease patients had higher estradiol levels than the men without heart disease including the men in intensive care who presumably were under stress. A question that arises is what about women. Women generally are protected from heart disease before they reach menopause and many researchers believe that it is estrogen that protects them. Womens estrogen levels can reach 3-4 times those of men at some points of their menstrual cycles. Women who have their ovaries removed are at an increased risk of heart disease unless they take estrogen yet high doses of estrogen seem to increase the risk of heart attacks in men. Questions that need to be answered are how does estrogen increase the risk of heart attacks in men if it does increase the risk and what is the source of this excess estrogen.