Exploring Gender Differences in the Association Between TyG Index and COPD: A Cross-Sectional Study from NHANES 1999-2018

Association of triglyceride glucose and obesity indices with chronic obstructive pulmonary disease in US adults: data from 2013 to 2018 NHANES

BACKGROUND

The impact of insulin resistance (IR) on chronic obstructive pulmonary disease (COPD) has caught increasing attention, and the triglyceride-glucose (TyG) index and related indices are deemed reliable indicators for evaluating IR. Nevertheless, the potential associations of TyG and obesity-related indexes with COPD are currently understudied. Hence, this paper was to inspect the links of TyG and obesity-related indices with COPD.

METHODS

This was a cross-sectional study based on data from the NHANES 2013-2018. Weighted logistic regression (WLR), restricted cubic sample (RCS), and receiver operating characteristic (ROC) curves were leveraged to examine the links of the TyG index and obesity indices with COPD. The stability of the correlations was also assessed via subgroup analyses.

RESULTS

Data from 6383 participants were finally included, including 583 patients with COPD. WLR discovered positive associations of TyG, TyG-body mass index (TyG-BMI), TyG-waist circumference (TyG-WC), and TyG-waist height ratio (TyG-WHtR) with COPD regardless of covariate adjustment (p-value < 0.05, p for trend test < 0.05). After adjusting for all confounders, RCS analysis signaled notable linear links of TyG and obesity-related indices with COPD (p-value < 0.05, p for nonlinear > 0.05). TyG-WHtR showed the highest association with COPD among the indices tested, albeit with limited discriminative ability (AUC = 0.643, 95% CI: 0.619 ~ 0.665). Subgroup analyses further validated the stability and reliability of the results.

CONCLUSION

TyG and its combination with obesity-related indicators are associated with COPD. Among these, TyG-WHtR showed the strongest association with COPD, although causal relationships cannot be inferred and its discriminative ability remained modest. Further prospective studies are warranted to validate these findings.

CLINICAL TRIAL NUMBER

Not applicable.

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.