Association between the appendicular skeletal muscle mass-to-visceral fat area ratio and bone mineral density and osteoporosis: A cross-sectional study

Abstract

Objective: This cross-sectional study investigated the association between appendicular skeletal muscle mass-to-visceral fat area ratio (SVR), bone mineral density (BMD), and osteoporosis in U.S. adults using NHANES data. Methods: Data from the 2013-2014 and 2017-2018 NHANES cycles were analyzed. Multivariable regression models assessed associations between SVR, BMD, and osteoporosis, adjusting for demographic, lifestyle, metabolic, and comorbidity variables. Generalized Additive Models with smooth curve fitting and likelihood ratio tests evaluated model fit. Subgroup analyses explored effect modifications. Results: The study included 2325 individuals with a mean age of 50.66 +/- 5.55 years. In fully adjusted models, the highest SVR tertile was associated with a 0.05 g/cm(2) higher BMD (beta = 0.05, 95 % CI: 0.03-0.08, P = 0.002) and 57 % lower odds of osteoporosis (OR = 0.43, 95 % CI: 0.24-0.78, P = 0.028) than the lowest tertile. As a continuous variable, SVR remained significantly associated with BMD (beta = 0.03, 95 % CI: 0.02-0.04, P = 0.002) and osteoporosis (OR = 0.67, 95 % CI: 0.50-0.91, P = 0.033). Stronger associations were found in individuals with diabetes (beta = 0.09, 95 % CI: 0.06-0.12, P < 0.01) and BMI >= 30 (beta = 0.07, 95 % CI: 0.05-0.09, P < 0.01). Conclusion: Higher SVR was significantly associated with increased BMD and lower odds of osteoporosis, suggesting its potential as a marker for bone health assessment. However, the cross-sectional design limits causal inference. Further longitudinal and mechanistic studies are warranted to confirm these findings and explore clinical applicability.