Researchers at the University of California, Irvine have shown that higher levels of the hormone asprosin were linked to reduced weight gain over three years among metabolically healthy postmenopausal women without obesity or diabetes. The study, published in The Journal of Nutrition, indicate that the fasting-induced hormone may help identify women who are less likely to experience major weight gain after menopause and may inform approaches to lifestyle or pharmacologic interventions designed to prevent obesity and related cardiometabolic disorders.
“Our findings show that asprosin may help us track and potentially treat weight changes in postmenopausal women,” said Simin Liu, MD, chair and distinguished professor of epidemiology and biostatistics at UC Irvine’s Joe C. Wen School of Population & Public Health. “Understanding the hormonal factors that influence weight after menopause may help us develop more precise strategies for lifestyle management or pharmacologic interventions that prevent obesity and related metabolic disorders while preserving healthy muscle mass.”
Weight gain after menopause is associated with increased risk of cardiometabolic disease, including type 2 diabetes. Prior studies have shown that menopause often coincides with shifts in body composition, including increases in abdominal fat and declines in lean mass. These changes in body composition contribute to insulin resistance and cardiometabolic risk, but the biological reasons for postmenopausal weight changes are not well understood.
For the current study, the researchers focused on asprosin, an adipokine secreted primarily by adipose tissue. The hormone is known to regulate energy balance by stimulating the liver to release glucose and signal the brain to increase appetite. Asprosin was first identified in 2016 and has been a focus of research regarding its broader role in metabolism.
Some of this research has unearthed evidence linking circulating asprosin to metabolic disease, with studies showing that people with obesity, metabolic syndrome, and type 2 diabetes have higher asprosin concentrations. But most of these prior studies were cross-sectional and did not determine whether elevated asprosin levels are a precursor, or a result, of metabolic disease. For this reason, the role of asprosin in predicting future changes in body weight had not been previously established.
To examine whether plasma asprosin levels are directly and prospectively associated with changes in body weight and body composition among postmenopausal women, the researchers conducted a nested case-control analysis using data from the Women’s Health Initiative of postmenopausal women ages 50 to 79.
“In a case-control study of 4,020 postmenopausal women (1,987 newly occurred/incident diabetes cases and 2,033 matched controls) nested within the Women’s Health Initiative (WHI), we prospectively evaluated participants’ baseline plasma levels of asprosin in relation to three-year changes in weight, measures of central obesity, and the risk of major weight gain or loss (≥ 7% of baseline weight),” the researchers wrote.
Blood samples collected between September 1, 1993, and December 31, 1998, were used to measure baseline asprosin levels and the researchers then tracked changes in body weight, central adiposity measures, and body composition over a three-year follow-up period.
The data showed that, overall, baseline asprosin levels were not associated with weight change across the entire cohort. Among women without obesity or diabetes at baseline, those with the highest asprosin levels experienced smaller weight increases over the follow-up period than those with the lowest levels. Participants in the highest quartile gained 1.61 kilograms less weight on average and had lower odds of major weight gain while showing higher odds of major weight loss. The researchers also noted that some of the observed weight loss reflected reductions in lean body mass rather than fat mass.
These data suggest that asprosin may help maintain weight stability when metabolic health is intact, but the relationship may weaken once metabolic dysfunction develops. Further, the findings could support the use asprosin as a biomarker to identify individuals who may benefit from targeted obesity prevention strategies.
While the study evaluated the potential use of asprosin as a prognostic marker it did not search for the causes of the relationship between weight gain and asprosin levels. Regardless, the researchers noted that hormonal markers could help guide precision approaches to obesity prevention in postmenopausal populations.
Future studies will focus on understanding the biological mechanisms underlying the observed associations and evaluating whether modifying asprosin levels could influence metabolic outcomes. Researchers also plan to research how asprosin relates to the development of type 2 diabetes and whether interventions that affect the hormone could be used for treatment and prevention.
