Association of cholesterol, high-density lipoprotein, and glucose index with incident chronic lung diseases: A prospective cohort study

The cholesterol, high-density lipoprotein, and glucose (CHG) index, a novel metabolic indicator with predictive value for metabolic disorders, may influence chronic lung disease (CLD) development through metabolic dysregulation. However, its association with CLD risk remains unclear. This study aimed to investigate the relationship between the CHG index and incident CLDs. Data were obtained from the China Health and Retirement Longitudinal Study, a prospective cohort including adults aged ≥45 years. The CHG index was calculated as follows: CHG = Ln (TC [mg/dL] × fasting blood glucose [mg/dL]/[2 × high-density lipoprotein (mg/dL)]). Incident CLDs were self-reported physician-diagnosed chronic obstructive pulmonary disease, asthma, or chronic bronchitis. Cox proportional hazards models were used to evaluate the association between the CHG index and CLD risk. Restricted cubic spline analyses were applied to examine potential dose-response relationships, and subgroup analyses were conducted to assess heterogeneity across stratified groups. Among 8890 participants free of CLDs at baseline (mean age 59.14 ± 9.44 years; 43.69% female), 1369 individuals (15.40%) developed CLDs during a median follow-up of 8.55 years. In the multivariable Cox model, the highest quartile of the CHG index was associated with an increased risk of CLDs compared with the lowest quartile (hazard ratio = 1.21, 95% confidence interval: 1.08-1.37). Restricted cubic spline analysis demonstrated a significant positive linear association between the CHG index and CLD risk. Subgroup analyses showed consistent results with no significant interactions. A higher CHG index was associated with an increased risk of CLDs in a linear manner, suggesting that it may serve as a potential marker for identifying individuals at higher risk of CLDs.