The Weight-Adjusted Waist Index as a Screening Indicator for Obesity-Related Bone Loss in American Men Aged 18-59: Evidence From the National Health and Nutrition Examination Survey

This study explores the relationship between the weight-adjusted waist index (WWI) and bone mineral density (BMD) in American men aged 18-59 years old and evaluates whether WWI can serve as a simple screening indicator for obesity-related bone loss. A total of 5,726 men from four cycles of the National Health and Nutrition Examination Survey (2011-2018) were included. WWI was calculated as waist circumference divided by the square root of body weight. Multivariate linear regression, segmented linear regression, subgroup analysis, and receiver operating characteristic (ROC) curve analysis were used to evaluate the association and predictive efficacy. Results showed that for every 1 cm/√kg increase in WWI, total BMD decreased by 0.02 g/cm 2 . A turning point of 10.525 cm/√kg was identified for lumbar BMD; below this point, each 1 cm/√kg increase was associated with a 0.09 g/cm 2 decrease, whereas above this point, the decrease was 0.025 g/cm 2 . Compared with body mass index (BMI) and waist circumference (WC), WWI demonstrated the highest area under the curve (AUC; 65.1%) for predicting low total BMD. WWI was independently associated with lower BMD and can be used as a simple screening indicator for obesity-related bone loss in young and middle-aged American men.