CHG index and carotid atherosclerosis in relatively young adults with obstructive sleep apnea: a cross-sectional...

Obstructive sleep apnea (OSA) predisposes to cardiovascular disease through complex metabolic interactions. The Cholesterol-High-density lipoprotein-Glucose (CHG) index, integrating total cholesterol, HDL-C, and fasting glucose, may serve as a novel metabolic biomarker for subclinical atherosclerosis in OSA. This cross-sectional study aimed to evaluate its association with carotid intima-media thickness (IMT).

A total of 648 patients with OSA (mean age 37 years; range 21-58 years) were analysed. Using Least Absolute Shrinkage and Selection Operator (LASSO) regression, the CHG index, age, and hypertension were identified as key predictors of carotid IMT. Restricted cubic spline models adjusted for these covariates revealed a significant nonlinear association between the CHG index and carotid IMT (P for overall <0.001; P for nonlinearity = 0.001), which was more pronounced than the non-significant association observed for the AHI (P = 0.404). The association was particularly evident in patients with severe OSA (P for overall = 0.019 and 0.025, respectively). Logistic regression showed a synergistic effect: patients with both high CHG and severe OSA had the greatest odds of high carotid IMT (>0.8 mm; adjusted OR = 3.69, 95% CI: 1.26-13.63).

The CHG index is an independent cross-sectional marker of subclinical atherosclerosis in OSA patients, with risk amplified by severe OSA. Due to the cross-sectional design, these findings do not imply that the CHG index can predict individual IMT progression or serve as a direct intervention target. Nevertheless, integrating the CHG index into OSA management could help identify patients at high cardiovascular risk. Future prospective studies are needed to establish temporality.