Abstract
Background
Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. The weight-adjusted waist index (WWI) is a recently developed index for measuring adiposity, but the relationship between the WWI and COPD has not been well studied. This study aimed to investigate the potential correlation between these two health variables.
Methods: This cross-sectional study used data from the National Health and Nutrition Examination Survey (NHANES) 2013–2018. The WWI was calculated as waist circumference divided by the square root of weight. Multiple linear regression was performed to estimate the association between the WWI and COPD incidence, and subgroup analysis was performed to identify sensitive cohorts. Smoothing curve fitting and threshold effect analysis were conducted to assess possible nonlinear relationships.
Results: A total of 15,278 participants were included. Participants in the higher WWI tertile tended to have a greater incidence of COPD. Compared to body mass index and waist circumference, the correlation between the WWI and COPD incidence has better discrimination and accuracy. In the final adjusted model, a positive association between the WWI and COPD incidence was observed (OR = 1.70, 95% CI: 1.48–1.95). Participants in the highest WWI quartile had a 290% greater risk of COPD than did those in the lowest WWI tertile (OR = 3.90, 95% CI: 2.60–5.86). A nonlinear correlation was found between the WWI and COPD incidence, with an inflection point of 12.54. Subgroup analysis revealed that the relationship was significant in all subgroups.
Conclusion: Compared with BMI and WC, WWI was related to an increased likelihood of COPD and had a stronger relationship with COPD incidence. Our findings indicated that the WWI could be a cost-effective and simple way to detect COPD.