Association between body roundness index and perceived stress in Chinese adults: A cross-sectional study

The objective of this research was to explore the association between perceived stress (PS) levels and the body roundness index (BRI) among adults and older adults in China. Using cross-sectional data extracted from the 2015 China Health and Nutrition Survey, this study analyzed information from 8315 Chinese adults. The 14-item Perceived Stress Scale was used to measure PS, and participants were categorized into high- and low-stress groups based on the median score. Logistic regression analyses were used to assess the relationship. Restricted cubic spline analyses were further performed to explore the potential dose-response relationship and assess the linearity of the association between BRI and perceived stress. Receiver operating characteristic curves were constructed to examine the effectiveness of BRI as an indicator at the individual level. Participants in the highest quartile of BRI had higher odds of elevated PS compared with those in the lowest quartile (fully adjusted odds ratio = 1.35; 95% confidence interval: 1.12-1.62; P = .001). Subgroup analyses indicated that the association between BRI and PS was largely consistent across demographic and lifestyle characteristics. No significant interactions were observed, except for smoking status (P for interaction = .033), with stronger associations identified among smokers. Sensitivity analyses using a generalized linear model yielded consistent results. Restricted cubic spline modeling identified a linear relationship (P = .677), with an apparent rise in PS risk when BRI values exceeded 3.82. Receiver operating characteristic analysis showed limited predictive ability, with area under the curve values ranging from 0.52 to 0.55. This study indicated that elevated BRI was significantly associated with PS among Chinese adults. However, the limited discriminative performance of BRI indicates that this association should not be interpreted as evidence of effective screening capability. Further longitudinal studies are warranted to validate these findings and elucidate the mechanisms underlying this association.