Serum glycated albumin‐to‐albumin ratio and mortality risk in cardiovascular–kidney–metabolic syndrome: Evidence from NHANES over 15 years

AIMS: To evaluate the prognostic value of serum albumin (ALB), glycated albumin (GA), and the GA-to-ALB ratio (%GA) for survival outcomes in individuals with cardiovascular-kidney-metabolic (CKM) syndrome. MATERIALS AND METHODS: This study included 4524 adult participants with CKM syndrome stages 0-3 from the National Health and Nutrition Examination Survey (1999-2004), with linked mortality information available through 2019. Multivariable Cox regression models and subgroup analyses were used to evaluate hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality. Restricted cubic spline (RCS) models were used to assess nonlinear associations. Time-dependent ROC curves and random survival forest (RSF) models determined the predictive accuracy of serum ALB, GA, and %GA for survival outcomes. RESULTS: During the median follow-up of 17.6 years, 1032 deaths occurred, including 281 from cardiovascular-cerebrovascular disease (CCD). Higher %GA was associated with increased risk of all-cause (HR = 1.59; 95% CI: 1.17-2.15) and CCD mortality (HR = 1.94; 95% CI: 1.07-3.53), while higher ALB levels were consistently associated with lower all-cause mortality risk. Absolute GA was not independently associated with either outcome after multivariable adjustment. ROC curve analysis and RSF models revealed that %GA was the most robust marker among the three for long-term mortality risk, with consistent results across 5-, 10-, and 15-year follow-up periods. CONCLUSIONS: This study indicated that higher %GA levels were associated with increased all-cause and CCD mortality risk, supporting the potential predictive value of %GA for the early identification and stratification of mortality risk in CKM stages 0-3.