A hormone produced by fat tissue may help explain why some women gain less weight after menopause, according to new research analyzing data from a large national health study.
In findings published in The Journal of Nutrition, researchers reported that higher levels of the hormone asprosin were linked to smaller weight increases over time among metabolically healthy postmenopausal women.
The study examined more than 4,000 participants in the long-running Women’s Health Initiative, one of the largest studies ever conducted on women’s health in the United States.
Weight gain after menopause is common and can increase the risk of cardiometabolic conditions such as type 2 diabetes. Scientists have long suspected that hormonal changes play an important role, but the biological mechanisms behind long-term weight changes remain unclear.
Asprosin is a hormone released primarily by adipose, or fat, tissue. It helps regulate energy balance by signaling the liver to release glucose and by stimulating appetite through the brain.
Although previous studies have linked asprosin to metabolic disorders, researchers say its role in predicting long-term weight change in humans had not been examined before.
“Our findings show that asprosin may help us track and potentially treat weight changes in postmenopausal women,” said study author Simin Liu of the University of California, Irvine Joe C. Wen School of Population & Public Health.
To explore the connection, researchers analyzed blood samples collected from Women’s Health Initiative participants between 1993 and 1998. They measured baseline asprosin levels and followed changes in body weight and body composition over three years.
Among women who did not have obesity or diabetes at the start of the study, those with the highest asprosin levels gained less weight over time than those with the lowest levels.
Women with higher asprosin concentrations were 43% less likely to experience major weight gain during the follow-up period and 83% more likely to experience major weight loss.
However, researchers noted that some of the weight loss observed in the study was linked to reductions in lean body mass rather than body fat.
The association also appeared to depend on metabolic health. The hormone’s influence was strongest among women without obesity or diabetes, suggesting that metabolic conditions such as insulin resistance may disrupt its effects.
The findings raise the possibility that asprosin could eventually help scientists identify women at higher risk of weight gain after menopause or guide more personalized strategies for managing weight and metabolic health.
But the study does not show that asprosin directly causes changes in body weight. It also does not demonstrate that altering hormone levels would prevent weight gain.
Researchers say further studies are needed to better understand how the hormone interacts with metabolism and whether it could play a role in future obesity prevention or treatment strategies.
The team also plans to explore whether asprosin influences the development of type 2 diabetes and other cardiometabolic conditions.
For now, the findings offer new insight into the complex hormonal changes that influence metabolism and body composition after menopause.
The study analyzed data from the Women’s Health Initiative, a long-running U.S. health study of women ages 50 to 79. The research was supported by the National Institute of Diabetes and Digestive and Kidney Diseases and the National Heart, Lung, and Blood Institute and was published in the peer-reviewed Journal of Nutrition.