Association of the CHG Index with the onset, progression, and prognosis of cardiovascular-kidney-metabolic syndrome: findings from two large prospective cohorts

BACKGROUND: Cardiovascular-kidney-metabolic (CKM) syndrome represents a composite disease state driven by glucose and lipid metabolic dysregulation. The Cholesterol, High-density lipoprotein, and Glucose (CHG) index reflects the composite burden of these metabolic factors. However, its impact on the onset, stage-wise progression, and prognosis of CKM syndrome remains unclear. METHODS: This study utilized data from two large-scale prospective cohorts. In the UK Biobank (UKB) cohort, Fine-Gray proportional subdistribution hazards models were employed to investigate associations between CHG levels and the risk of incident cardiovascular disease (CVD), chronic kidney disease (CKD), and type 2 diabetes mellitus (T2DM), as well as the risk of progression from CKM Stage 0-1 to 2-3 and Stage 1-3 to 4. In the Beijing Anzhen Hospital cohort, Cox regression models assessed the impact of CHG on major adverse cardiovascular and cerebrovascular events (MACCE) in patients with CKM Stage 4 (established coronary artery disease). A causal forest algorithm was used to identify high-value subpopulations, and restricted cubic splines (RCS) characterized dose-response relationships. Sensitivity analyses were conducted to verify result robustness. RESULTS: The study included 370,916 participants free of CKM diseases from UKB (median follow-up: 16.5 years) and 8,494 patients with CKM Stage 4 from Beijing Anzhen Hospital (median follow-up: 645 days). In the general population, each 1-SD increase in the CHG index was significantly associated with an increased risk of incident T2DM (HR: 1.47; 95% CI: 1.40-1.53), CVD (HR: 1.07; 1.06-1.09), and CKD (HR: 1.07; 1.04-1.10). Furthermore, elevated CHG significantly accelerated CKM progression from Stage 0-1 to 2-3 (HR: 1.16; 1.11-1.23) and from Stage 1-3 to 4 (HR: 1.06; 1.05-1.08) per 1-SD increase. In patients with established CAD (Stage 4), a 1-SD increase in CHG was associated with a higher risk of MACCE (HR: 1.12; 1.05-1.19). Machine learning analysis revealed that this prognostic impact was particularly pronounced in patients with low systemic inflammation and elevated HbA1c. CONCLUSIONS: The CHG index demonstrates significant predictive value for the onset of component diseases, stage-wise progression, and adverse prognosis across the entire CKM syndrome continuum.