Hello, His and Her Healthcare
Medicine now recognizes that women are different
Pain provides a good example of how hormones and genes work together. Women suffer pain more often than men by a margin of as much as 10 to 1, says Jeffrey Mogil, who runs the pain genetics lab in the department of psychology at McGill University in Montreal. Perceived intensity also varies; pressure and electrical stimulation seem to hurt women more than men, while extreme heat or cold affects the sexes similarly. Hormones certainly bear some responsibility: The drop in estrogen before a woman's period may account for a temporary increase in sensitivity to pain (one reason that time is a good one to avoid an eyebrow wax). But what is also now understood, says Mogil, is that different genes are responsible for processing pain in men and women.
"The brain is simply wired up differently to process pain from the get-go," he says. (To capture those differences in basic research, Mogil is on a crusade to persuade scientists to use female mice as well as males in their labs.) Someday, that may mean sex-specific painkillers. For now, research is focused on how existing drugs work differently in men and women. One class of painkillers called kappa opioid agonists, sometimes prescribed for post-surgical or cancer pain, is already known to help women more effectively than men.
Indeed, researchers are investigating how all sorts of drugs affect the sexes differently. How are they absorbed at different rates in the gut? How do proteins that transport and activate the drugs act differently in men and women? Women tend to require higher doses of Valium than men, because they more quickly metabolize it. But they are slower to metabolize certain antibiotics. Gail Anderson, a pharmacologist at the University of Washington in Seattle, has surveyed 163 drug applications featuring a sex analysis that were reviewed by the FDA in a five-year period. Eleven showed a difference of more than 40 percent in their action in men and women.
One study led by Susan Kornstein, executive director of the Institute for Women's Health at Virginia Commonwealth University, found that premenopausal women responded better than men to Zoloft, one of the class of antidepressants called selective serotonin reuptake inhibitors (SSRIs), while men responded better to imipramine, one of the tricyclic antidepressants. Postmenopausal women responded to both. (Other studies of these differences have been inconclusive.) Another recent study showed aspirin cuts the risk of heart problems in both men and women but in different ways: In men, it cuts the odds of a heart attack, and in women, the risk of stroke.
Cancer, too, behaves differently in men and women. While colorectal cancer is more common in men, for example, women tend to develop polyps higher in the colon, where they are less likely to be detected by one kind of test, a flexible sigmoidoscopy. A study last year recommended that women choose the more comprehensive colonoscopy instead. Women tend to get lung cancer at an earlier age and are more likely to develop the kind that isn't associated with smoking--but they also have better survival rates. "Right now we don't have anything where you'd treat a man differently from a woman in any type of cancer,"says Kathy Albain, an oncologist at Loyola University in Chicago. But she and other researchers are working on it.