Association between body roundness index and age-related macular degeneration: A cross-sectional analysis of NHANES...

The specific relationship between body roundness index (BRI) and age-related macular degeneration (AMD) in US adults aged 40 years and older remains insufficiently understood. This study aimed to elucidate the association between BRI and AMD. Data were sourced from the National Health and Nutrition Examination Survey conducted in the United States from 2005 to 2008. The BRI was calculated using anthropometric measurements, specifically height and waist circumference (WC). AMD was diagnosed based on distinct ocular characteristics observed in fundus photographs, evaluated through a recognized grading classification system. Weighted logistic regression analyses were conducted to examine the association between BRI and AMD. Spline smoothing and threshold effects were utilized to identify potential linear or nonlinear correlations. Subgroup analyses were performed to investigate possible factors influencing this relationship. Additionally, receiver operating characteristic (ROC) curve analysis was employed to evaluate predictive capability of BRI for AMD. This study included a total of 5033 participants. The findings indicated a significant positive association between BRI and the risk of AMD in both unadjusted and adjusted logistic regression models (odds ratio [OR]: 1.18, 95% confidence interval [CI]: 1.07-1.31; OR: 1.37, 95% CI: 1.14-1.66). When BRI was divided into quartiles, the highest quartile demonstrated a stronger association with AMD risk compared to the lowest quartile (OR: 1.70, 95% CI: 1.16-2.49) in the unadjusted categorical model. Subgroup analyses and interaction tests confirmed the consistency of the BRI-AMD relationship across various populations. Spline smoothing and threshold effect analyses indicated an approximately positive linear relationship between BRI and AMD incidence in the general population. Furthermore, ROC analysis showed that BRI was slightly more effective in predicting AMD compared to body mass index (BMI) and WC. Since the area under the curve values for BRI, BMI, and WC were 0.549, 0.533, and 0.504, they all showed limited discriminatory performance for AMD prediction. Moreover, the ROC analysis of multi-model comparisons revealed that a combination of WC, BMI, and BRI provided a little better predictive capability for AMD prevalence than any single predictive model. There is a positive association between BRI and AMD among US adults aged 40 years and older. BRI serves as a modest predictor of obesity for forecasting AMD risk. Strategies for managing obesity related to BRI are essential for the prevention and treatment of AMD to some extent.