Association of Leptin in Sarcopenia and Bone Density in Elderly Women: An Observational Analysis

Background: Sarcopenia and osteoporosis are common age-related conditions that markedly increase fracture risk and morbidity in the elderly. Leptin, an adipokine secreted by adipose tissue, has been implicated in musculoskeletal health, but its clinical relevance in aging populations remains uncertain. This study aimed to evaluate the associations between serum leptin levels, skeletal muscle mass, muscle strength, bone mineral density (BMD), and fracture risk in elderly women. Methods: This observational analysis included 79 community-dwelling women aged 65 years and older. Participants underwent assessments of body composition, serum leptin concentration, grip strength, and femoral neck BMD. Sarcopenia and obesity were classified based on established criteria. Correlation analyses and binomial logistic regression were performed to examine the relationships among leptin levels, musculoskeletal parameters, and fracture occurrence. Results: Leptin concentrations were significantly associated with fat-related parameters, including BMI, fat index, and total body fat percentage, but showed no significant correlation with skeletal muscle mass (ASM), grip strength, or BMD. Obese participants demonstrated higher leptin levels and fat parameters compared with non-obese participants, but no significant differences were observed in grip strength or BMD. Binomial logistic regression analysis identified femoral neck BMD and grip strength as significant independent predictors of fracture risk, whereas leptin and ASM were not identified as such. Conclusions: In elderly women, serum leptin levels primarily reflect adiposity rather than musculoskeletal health. Leptin is not an independent predictor of spinal fracture risk. These findings highlight the critical importance of maintaining bone density and muscle strength for fracture prevention in aging populations.