Association Between Triglyceride-Glucose Index and Airflow Limitation Severity in Older Adult Nondiabetic Inpatients With Normoxemic COPD

Background:The triglyceride-glucose (TyG) index is a reliable insulin resistance biomarker linked with impaired lung function.Existing studies enrolled patients with diabetes or hypoxemia, confounding the relationship between TyG and chronic obstructive pulmonary disease (COPD) airflow limitation.This study explored the independent association between the TyG index and airflow limitation severity in older adult nondiabetic, normoxemic inpatients with COPD. Material/Methods:This single-center retrospective cross-sectional study included 116 COPD inpatients aged  55 years and 87 age-and sex-matched healthy controls.Airflow limitation severity was graded based on 2023 GOLD criteria.Ordinal logistic regression analyzed TyG-severity association.Confounders were screened via the change-inestimate rule, the Brant test verified proportional odds assumptions, and sensitivity analyses assessed data consistency. Results:After adjusting for age, BMI, smoking status, and COPD Assessment Test score, elevated TyG was independently associated with more severe airflow limitation (OR = 3.16, 95% CI: 1.04-9.62,P = 0.042).Consistent significant results were observed for continuous TyG values (OR = 2.74, P = 0.045) and TyG tertile trend analysis (P for trend = 0.043).The crude intergroup TyG difference was eliminated after smoking adjustment.Sensitivity analyses were directionally consistent, although statistical significance was not uniform across all specifications.This biomarker shows potential for auxiliary severity evaluation for this specific inpatient subgroup, pending further prospective validation. Conclusions:Elevated TyG index independently correlates with aggravated airflow limitation in nondiabetic, normoxemic older adult COPD inpatients.As a readily accessible laboratory index, TyG provides hypothesis-generating correlational evidence for stratifying airflow limitation severity; prospective predictive studies with clinical cutoff validation are mandatory before any routine screening use can be recommended.