"Most women start having symptoms in their late 40s. They can include occasional hot flushes, sleep disturbances, irritability, mood changes, changes in menstrual cycles. These things are, by and large, subtle and non-specific and I think that's why they haven't been taken seriously. But now we are able to quantify changes with blood level tests and bone tests so precisely that we know there are some pretty substantial changes."
Take, for instance, the hot flash, or hot flush -- a phenomenon estimated to occur in as many as three quarters of all women going through menopause. When the body's level of estrogen drops, the brain can react in a way that makes a woman's body temperature feel as if it's skyrocketing. The blood vessels beneath the skin of a woman's face and upper body dilate for a period lasting from a few seconds to an hour. Perspiration brings the skin temperature back to normal.
Estrogen therapy can reduce these symptoms. Sometimes physicians recommend a low-dose birth control pill to help relieve other perimenopausal symptoms such as heavy bleeding.
One of the main issues about the entire menopause process, however, is whether its symptoms should be treated as a "medical problem" or a natural event.
Women at work
"On the one hand, just like puberty, menopause and perimenopause are a normal process of aging," Dr. Bush says. "They just happen. On the other hand, these stages carry severe symptoms for many women. And women in the workplace are much less willing to tolerate symptoms which disrupt their work.
"I hear women say 'I can't be in a business meeting, break out in a hot flash and start sweating. It's not good for business.' "
Hormone replacement therapy usually alleviates such menopausal symptoms as hot flashes, urinary incontinence and vaginal dryness. Many physicians believe it also helps protect against developing the heart disease and osteoporosis which become a hazard for many post-menopausal women.
Estrogen replacement therapy raises the "good" HDL-cholesterol while lowering the "bad" LDL-cholesterol, according to Dr. Roger Blumenthal, assistant professor of cardiology at the Johns Hopkins University School of Medicine and associate director of the Estrogen Consultation Service. A recent study at Hopkins also suggests that estrogen may help improve blood flow to the heart muscle.
"Hormone therapy can be very helpful [in managing menopause] if we have objective evidence that a woman's estrogen is low," Dr. Blumenthal says. "We can tell if a woman in her 40s actually has a physiological state that's more consistent with the average woman in her 50s."
The first large study
But no one yet knows the long-term benefits and risks of hormone replacement therapy. The nation's first large study, the Postmenopausal Estrogen/Progestin Intervention (PEPI) study, is currently testing the results of five different hormone combinations on volunteers at various centers, including Hopkins. The results of the study, which is funded by the National Institutes of Health, are expected next year.
Dr. Bush has also applied to NIH for a grant to study perimenopause. This research, which Hopkins would conduct with the University of Maryland, would track 400 women for five years as they move from the perimenopausal to menopausal state.
Another government-funded study has just begun at the National Institute on Aging's Gerontology Research Center in Baltimore. The Perimenopausal Initiative will study 100 African-American women and 100 white women as they pass through mid-life transition.
One goal of both studies is to collect information about the physiological changes in women from various racial backgrounds; most current knowledge applies to white women of Northwest European ancestry.
"Menopause is the only universal thing that happens with aging except death," says Jordan Tobin, the study director and chief of the NIA's applied physiology section. "We can talk about kidney changes or strength changes or muscle changes, but they don't happen equally to everyone. Menopause happens to every woman. It's a very important transition for people interested in normal aging."
Dr. Bush also hopes to test the truths of such conventional wisdoms as:
* Women become greater health care consumers around the time of perimenopause. If so, why?
* Women gain 10 to 15 pounds during the ages of 45 to 55. If so, why?
Dr. Bush says one theory behind the weight gain holds that when ovaries produce less estrogen, then fat, which also produces estrogen, becomes nature's way to compensate for the ovaries' loss.
"One of the things we're learning is that all of the cells in the body have estrogen receptors," she says. "If you think of how profound a physiological event puberty is, then it's just as profound when you withdraw that estrogen. The tissues are used to it. Even though it is withdrawn slowly, we can expect the effects to be dramatic in some women."
Hormones and mood
Another area for research are the mood swings which can accompany hormonal changes.