New findings from the University of California – Los Angeles Health Sciences finds the menopause transition phase, also known as perimenopause, is a period when women lose lean body mass and more than double their fat mass.
Perimenopause is the time in a woman’s life when hormonal changes lead to irregular menstruation, hot flashes and other symptoms leading up to menopause when menstruation stops altogether.
Once women transitioned fully to menopause, the researchers found that women’s lean and fat mass remained stable.
How was the Study Conducted?
Participants of the study were from the Study of Women’s Health Across the Nation (SWAN) cohort.
There were 1246 participants, including 356 Black, 153 Chinese, 178 Japanese, and 559 White women.
The researchers examined 18 years of data from the women’s health study, assessing women’s body composition using a model that gave them a picture of that composition from the time before and after their final menstrual period, accounting for race, ethnicity and hormone therapy.
The researchers also observed racial/ethnic variation in menopause transition-associated changes in body composition and weight.
They found that increases in fat mass and decreases in lean mass were similar in Black and White women, however, findings in Chinese and Japanese groups were distinctive.
“On average, we found that Japanese participants, like White participants, lost lean mass during the menopause transition, but unlike White participants, their fat mass and weight did not change during the menopause transition,” the authors state.
“This is in contrast to a cross-sectional survey of Japanese women aged 20–70 years that found postmenopause was associated not only with lower lean mass but also with greater body fat.”
In the study, during the postmenopausal interval, Chinese study participants lost fat mass and body weight and gained lean mass proportion, which is in opposition to a prior single-site, cross-sectional study analysis that reported lower lean mass and higher percent body fat in late peri- or postmenopausal Chinese participants.
The authors indicate their findings in the Asian subgroups differ from those of earlier, cross-sectional approaches likely due to the current study’s design.
The study provides enough detailed data to enable researchers to disentangle the effects of chronological aging and reproductive aging.
It also demonstrates that a simple measurement of body weight does not illustrate what is happening “under the skin.”
Other research has found that, as women grow older, body mass index becomes a less reliable predictor of conditions such as diabetes or cardiovascular disease.
These menopause-related shifts in fat and lean mass may be one of the reasons for the decline in the ability to predict the capacity of body mass index in older women.
The article was published in the journal JCI Insight.
The National Institutes of Health; Department of Health and Human Services, through the National Institute on Aging; the National Institute of Nursing Research; and the National Institutes of Health Office of Research on Women’s Health supported this study.
University of California – Los Angeles Health Sciences
- Study links perimenopause to accelerated fat mass gains, lean mass losses. (2019, March 21). EurekAlert! Retrieved: https://www.eurekalert.org/pub_releases/2019-03/uoc–slp032019.php