|
||||||||
|
FACULTY SYMPOSIUM Sex Differences Prescribe Changes in Medical CareDoctors are only beginning to learn about the sex differences in health and disease and how those differences translate into medical care, according to speakers at the Faculty Symposium on women's and men's health on June 6.
Explaining the current ambiguities of estrogen-replacement therapy, JoAnn Manson said that today fewer women are candidates for the treatment. (Photo by Graham Ramsay) From one perspective, sex differences boil down to different levels of the same hormones, said symposium cochair Daniel Federman, senior dean for alumni affairs and clinical teaching. Both sexes make androgen using the same cellular pathways. An enzyme called aromatase converts half of a woman's daily androgen production of 300 micrograms to estrogen and only about a quarter of a percent of a man's 7,000 micrograms of daily androgen to estrogen. Also, eleven different promoters in the aromatase gene can turn on the estrogen-converting enzyme in specific tissues, such as the brain, the breast, or the prostate. "A given tissue can create its own estrogen environment when the androgen arrives there from the circulating blood," Federman said. Managing ChangeMenopause marks a transition from women's predictably estrogen-rich environment, but menopause is anything but predictable, said Janet Hall, HMS associate professor of medicine at Massachusetts General Hospital and codirector of research for the HMS Center of Excellence in Women's Health. The mean age of menopause is 51 years, but a woman may experience her final menstrual period as early as 41 or as late as 59. Fluctuating hormone levels make the transition to menopause highly variable among women and require flexibility in managing symptoms, Hall said.Aging-related hormone changes and their effects on different tissues in the body do not stop with menopause, but for most women, long-term hormone-replacement therapy may turn out to be more of a risk than a benefit, said JoAnn Manson, HMS professor of medicine and chief of preventive medicine at Brigham and Women's Hospital. Reduced heart disease risk was supposed to be the big benefit of estrogen-replacement therapy, according to earlier observational studies, but results from the last four years of randomized trials have turned the field on its head. "There's not a single randomized clinical trial yet that demonstrates reduction in the risk of cardiovascular events with hormone therapy," Manson said. "In fact, there may be an early increase in the risk of these events. These findings dramatically change the benefit-to-risk ratio for estrogen-replacement therapy and suggest that fewer women are good candidates." Heart disease remains the leading cause of death in women, said Nanette Wenger, professor of medicine at Emory School of Medicine. Until the last decade or so, most decisions by cardiologists treating women were based on studies done predominantly in middle-aged men. Newer studies are finding clinically significant differences in women, who do not develop clinical evidence of coronary disease until about 10 to 20 years later than men and have more adverse outcomes with myocardial infarction and coronary bypass surgery. Breast cancer is the most commonly diagnosed cancer in women. Black women in Boston have higher death rates than white women. To learn why, symposium cochair JudyAnn Bigby, associate professor of medicine at BWH and director of the HMS Center of Excellence in Women's Health, partnered with the city of Boston and others in the community. The researchers found similar rates of screening mammography, but black women may not get adequate follow-up care for abnormal breast exams and mammograms. The researchers are testing an intervention to educate patients and providers. Screening's Mixed ResultsMeanwhile, the popularity of screening for prostate-specific antigen doubled the number of cases in a decade just by looking for the disease more aggressively, but its effect on mortality rates has been harder to measure, said Michael Barry, HMS associate professor of medicine and chief of general medicine at MGH. In Austria, an evangelical urologist convinced a regional authority to sponsor free screening tests in 1993. Two thirds of the men were tested three years later, and now a follow-up study reports about 20 fewer prostate cancer deaths a year. On the other hand, Seattle area men also were subjected to early detection and aggressive treatment of prostate cancer with no apparent reduction in mortality rates."Why are men the perps?" asked Mark Rosenberg, executive director of the Task Force for Child Survival and Development in Decatur, Georgia, about the disproportionate number of men committing violent acts. "We live in one of the most violent societies in the world," Rosenberg said. No single risk factor explains why men are overwhelmingly the perpetrators of violence, but testosterone levels, individual development, the family and community environment may all contribute. --Carol Cruzan Morton |
