Non-linear relationship between body roundness index and albuminuria among children and adolescents aged 8–19 years: A cross-sectional study

Introduction: Obesity has been found to be correlated with numerous health issues, including an elevated risk of albuminuria in adults. However, this correlation is still controversial among children and adolescents, as several recent large-scale cross-sectional studies have observed a negative correlation between obesity and albuminuria. Our study aimed to investigate the link between the body roundness index (BRI) and albuminuria among children and adolescents, in order to further understand the correlation between obesity and albuminuria in this demographic. Methods: We employed information from the National Health and Nutrition Examination Survey (NHANES) 1999–2010 for cross-sectional analysis. Weighted logistic regression was employed to explore the linear relationship between BRI and albuminuria, with subgroup analyses performed for more detailed insights. Weighted linear regression analysis was employed to explore the relationship between BRI and the urine albumin-creatinine ratio (UACR). Additionally, we applied smooth curve fitting to investigate their non-linear relationship and conducted threshold effect analysis to identify any turning point. Results: In this study of 15,487 participants aged 8–19 years, multivariate logistic regression analysis revealed a significant negative correlation between BRI and albuminuria (OR = 0.616, 95%CI: 0.526–0.722). The relationship between BRI and UACR, as shown by multivariate linear regression analysis, was significantly inversely correlated (β: -5.424, 95%CI: -7.416 to -3.433). Furthermore, smooth curve fitting and threshold effect analysis showed a non-linear relationship between BRI and albuminuria, with a BRI inflection point identified at 2.906. Conclusions: These findings of our study suggest a significant nonlinear negative association between BRI and the presence of albuminuria among children and teenagers, and maintaining an appropriate BRI may decrease the occurrence of albuminuria in this population.