Weight-Adjusted Waist Index as a Novel Predictor of Chronic Obstructive Pulmonary Disease: Evidence from NHANES 2013-2018

Background: Chronic obstructive pulmonary disease (COPD) is a major global health burden. The weight-adjusted waist index (WWI), a novel adiposity metric, may improve COPD risk prediction, but its association remains underexplored. Methods: Using the National Health and Nutrition Examination Survey (NHANES) 2013-2018 data (n=15,278), we assessed the WWI-COPD relationship via multivariable logistic regression, ROC analysis, and subgroup evaluations. Results: Higher WWI tertiles correlated with elevated COPD incidence. After full adjustment, each WWI unit increase linked to 70% higher COPD risk (OR=1.70, 95% CI: 1.48-1.95). Participants in the highest quartile of WWI faced a 290% increased risk compared to the lowest quartile (OR=3.90, 95% CI: 2.60-5.86). WWI (AUC=0.707) outperformed BMI (AUC=0.525) and waist circumference (AUC=0.609) in COPD prediction. A nonlinear threshold effect emerged at WWI=12.54. Subgroup analyses confirmed robustness across demographics. Conclusion: WWI is a simple, cost-effective tool for early COPD detection, outperforming BMI and waist circumference, especially in resource-limited settings, enabling timely intervention and reducing disease burden.