Nonlinear Association Between Body Roundness Index and Axial Spinal Pain in Middle-Aged and Older Chinese Adults: A...

Axial spinal pain is a major cause of disability in middle-aged and older adults. The body roundness index (BRI) reflects central fat distribution, but its association with axial spinal pain is unclear.

We analyzed cross-sectional data from 10,689 adults aged ≥ 50 years from a national cohort in China. The association between BRI and axial spinal pain was examined using multivariable logistic regression, restricted cubic splines, subgroup analyses, and an evaluation of combined BRI and body mass index (BMI) categories.

Higher BRI was associated with increased odds of axial spinal pain (adjusted OR = 1.05 per unit; 95% CI 1.01-1.08), with the highest quartile showing 22% greater odds than the lowest (OR = 1.22; 95% CI 1.06-1.40). The association was nonlinear (threshold near BRI = 3.0) and modified by drinking status (p interaction = 0.007). The greatest odds were observed in individuals with both high BMI and high BRI (OR = 1.16; 95% CI 1.04-1.30).

In this cross-sectional study, elevated BRI was independently and nonlinearly associated with axial spinal pain, with stronger associations in drinkers and high-BMI individuals. BRI shows promise for community health profiling, though longitudinal studies are needed to establish causality.