Hot flashes can be debilitating for more than 50 percent of menopausal women, said Dr. Taraneh Shirazian, an assistant professor of obstetrics, gynecology and reproductive science at the Icahn School of Medicine at Mount Sinai Hospital in New York City. About one-third of menopausal women experience more than 10 hot flashes a day, and she added that hot flashes are more common in obese women.
Another expert, Dr. Jill Rabin, co-chief of ambulatory care and women's health programs at North Shore-LIJ Health System in New Hyde Park, N.Y., said estrogen can also be produced in fat tissue.
Rabin said she has found that obese and overweight women have, in general, more severe and more frequent hot flash symptoms.
"They have a harder time with the menopausal transition," she said. "It may be the extra fat that makes heat dissipation more difficult."
Connecting the results of this study and others similar to it, experts have proposed two different explanations. The first is that fat could be acting as an insulator. Excess adiposity could make heat dissipation harder for your body. The second is that overweight and obese women may suffer from recurrent diet-binge or yo-yo diet cycles. This back-and-forth can impact your body's estrogen levels, making it harder for your hypothalamus to regulate your internal temperature.
These findings were supported by other similar studies, but, surprisingly not reinforced by others. The long lasting clarification has been received from the recent study, performed at UC Davis, which suggested that greater weight increases the likelihood of night sweats and hot flashes during early stages of the menopause transition but reduces those symptoms throughout menopause and beyond.
Thus, the study clarified mixed results from previous research indicating that higher weight was both a prevention and potential cause of hot flashes and night sweats, also known as vasomotor symptoms, which affect up to 80 percent of menopausal women and are a major reason for doctors' office visits.
"The relationship between weight and these symptoms differs depending on the timing," said lead author Ellen Gold, a UC Davis professor of public health sciences and women's health researcher.
"It's possible that the greater heat insulation provided by excess weight predisposes women to these symptoms early in the menopause transition, when the ovaries are still producing estrogen and women are still menstruating," Gold said. "Higher estrogen production that occurs with higher body fat plays a more influential role and becomes protective later -- after the final menstrual period and when estrogen production by the ovaries is greatly reduced."
In conducting the study, Gold and her colleagues used data from the Study of Women's Health Across the Nation, or SWAN, a longitudinal, multicenter study of more than 3,000 women aged 42 to 52 years from five racial/ethnic groups.
During annual visits over the course of 10 years, participants were measured for body mass index (BMI) and responded to questions about their experiences with frequently occurring menopausal symptoms. Those undergoing treatments that could trigger or reduce vasomotor symptoms were excluded.
The longitudinal results showed that being obese, or having a BMI greater than 30, was significantly related to increased occurrence of vasomotor symptoms in the premenopausal or early perimenopausal stage, when women were still menstruating but periods may have started to become somewhat irregular. Being obese, however, was negatively associated with these symptoms during later stages of menopause, when periods were 3 to 11 months apart or had ceased. Changes in weight during either stage did not alter the outcomes.
The results suggest that maintaining a healthy weight just prior to and at the onset of the menopause transition could be helpful for reducing hot flashes and night sweats, but some excess weight late in the transition or after the final menstrual period may be protective.
While the study benefited from a large, diverse study sample, Gold said that much still needs to be learned about these frequent menopause symptoms.
"We really need additional research on the underlying biologic mechanisms by which weight and women's circulating hormone levels interact to help us develop safe and effective preventive strategies for hot flashes and night sweats," Gold said.
The outline of the study results may be quote comforting to many women –rushing to drop your weight drastically may cause you by intensification of the unwanted hot flashes and night sweats symptoms of your menopausal life stage.
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