Exercise-induced change in FGF21 and adiponectin and their association with metabolic syndrome in older women: a randomized controlled trial

Background Metabolic syndrome is common in older adults and increases cardiometabolic risk. The fibroblast growth factor 21 (FGF21)–adiponectin axis regulates metabolic homeostasis, but its exercise responsiveness may differ by metabolic status. This study investigated the effects of exercise on circulating FGF21, adiponectin, and the FGF21/adiponectin ratio in older women with and without metabolic syndrome. Methods Sixty older women (75.2 ± 4.3 years) were classified by metabolic syndrome status and randomly assigned to control or exercise groups. Exercise groups completed a 10-week supervised combined exercise program consisting of body-weight resistance and cross-linked elastic resistance band training (3 sessions/week, 60 min/session), while controls maintained their usual lifestyle. Blood biomarkers, body composition, physical fitness, and metabolic parameters were assessed before and after the intervention and analyzed using two-way repeated-measures ANOVA. Results The FGF21–adiponectin axis was modulated by the intervention. Adiponectin increased in both exercise groups (NMSE: mean change, 1.23; 95% CI, 0.98–1.49; d = 1.04; MSE: mean change, 0.86; 95% CI, 0.31–1.40; d = 0.71). FGF21 increased in the NMSE group (mean change, 16.75; 95% CI, 5.46–28.05; d = 0.40) but decreased in the MSE group (mean change, −15.91; 95% CI, −28.35 to −3.48; d = −0.33). The FGF21/adiponectin ratio decreased in both exercise groups, with a greater reduction in MSE (NMSE: mean change, −2.18; 95% CI, −4.18 to −0.18; d = −0.29; MSE: mean change, −6.48; 95% CI, −9.82 to −3.15; d = −0.86). Secondary outcomes, including body composition, physical fitness, lipid profiles, insulin resistance markers, and inflammatory markers, also improved with small-to-large effect sizes. Conclusion Combined exercise improved metabolic health and modulated the FGF21–adiponectin axis in older women, with differential FGF21 responses by metabolic status. The reduced FGF21/adiponectin ratio may indicate exercise-induced metabolic adaptation. Trial registration KCT 0011558.