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

Abstract 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.