Association of body roundness index, serum α-Klotho and osteoarthritis: A nationwide population-based study of middle-aged and older adults

Background

Previous research has identified associations between the body roundness index (BRI), a novel marker of abdominal obesity, and serum α-Klotho levels with osteoarthritis (OA). However, the interplay between BRI, α-Klotho and OA has been understudied. We aimed to investigate the association between BRI and OA, as well as the potential mediating role of α-Klotho in the bidirectional relationships between BRI and OA among middle-aged and older adults

Methods

This study enrolled 8275 participants from the National Health and Nutrition Examination Survey (NHANES). Weighted logistic regressions and restricted cubic splines were utilized to assess the relationships between BRI, α-Klotho, and OA. Subgroup analyses, interaction effects, and mediation analyses were also conducted

Results

After adjusting for all covariates, higher BRI was associated with lower odds of OA (OR = 1.40, 95 % CI: 1.29 to 1.52, P < 0.001), whereas lower α-Klotho corresponded to higher odds of OA incidence (OR = 0.90, 95 % CI: 0.83 to 0.97, P = 0.009). Moreover, BRI was negatively correlated with serum α-Klotho (β = −0.045, P < 0.001). Notably, α-Klotho partially mediated the relationship between BRI and OA (mediation proportion: 1.46 %, P = 0.004), as well as the relationship between OA and BRI (mediation proportion: 1.56 %, P = 0.001)

Conclusion

The associations between higher BRI and lower α-Klotho levels among individuals with OA was observed. These findings contribute to a better understanding of the bidirectional associations between BRI, α-Klotho levels, and OA among middle-aged and older adults, which may help inform future hypothesis-driven or mechanistic studies