Evaluating anthropometric indices of obesity for early osteoarthritis detection: focus on body fat percentage and relative fat mass.

OBJECTIVE

Osteoarthritis is a prevalent joint disorder with a significant global burden. Identifying individuals at risk for osteoarthritis is essential, and obesity indices may be the key to early detection. This study aimed to explore the relationships between anthropometric indices of obesity and osteoarthritis and to assess their predictive abilities.

METHODS

This cross-sectional study included 54,041 participants aged 20 years or older from NHANES cycles spanning 1999 to 2023. Anthropometric indices of obesity included body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), weight-adjusted waist index (WWI), body roundness index (BRI), body fat percentage (BFP), relative fat mass (RFM), and conicity index (CI). Multivariate logistic regression and receiver operating characteristic curves were conducted to evaluate the associations and predictive capacities of these indices for osteoarthritis.

RESULTS

BMI, WC, WHtR, WWI, BRI, BFP, RFM, and CI were independently positively associated with osteoarthritis risk. RFM (OR = 1.662, 95% CI 1.571 ~ 1.757, P < 0.001) and BFP (OR = 1.555, 95% CI 1.494 ~ 1.617, P < 0.001) showed the strongest associations. The AUCs for the indices ranged from 0.581 to 0.706. BFP had the largest AUC (0.706, 95% CI 0.700 ~ 0.712), with an optimal cut-off of 35.922 (sensitivity, 71.292%; specificity, 59.258%), followed by WWI (AUC = 0.660, 95% CI 0.653 ~ 0.667), CI (AUC = 0.647, 95% CI 0.640 ~ 0.654), and RFM (AUC = 0.639, 95% CI 0.632 ~ 0.646).

CONCLUSION

BFP and RFM emerged as valuable tools for early osteoarthritis identification. Key Points • Anthropometric indices of obesity are positively associated with osteoarthritis and can serve as predictors of its risk. • Relative fat mass (RFM) demonstrates the strongest association with osteoarthritis risk. • Body fat percentage (BFP) exhibits the strongest predictive ability for osteoarthritis. • BFP and RFM are recommended for early osteoarthritis identification.