Association between albumin-corrected anion gap status with all-cause and cardiovascular mortality in individuals with chronic kidney disease: A national retrospective cohort study

The mortality rate associated with chronic kidney disease (CKD) has been steadily increasing, with disturbances in acid-base balance being a significant factor exacerbating the risk of mortality. Our objective was to evaluate whether the albumin-corrected anion gap (ACAG) status, which reflects acid-base balance, could be used as a mortality risk biomarker for the CKD population in the United States. We conducted a cross-sectional study utilizing the National Health and Nutrition Examination Survey data, collected from 1999 to 2018. Kaplan-Meier curves, weighted Cox regression, restricted cubic spline and subgroup analyses were employed to examine the relation of ACAG with all-cause and cardiovascular mortality in CKD participants. The analysis included a total of 6776 participants. We found a positive relation of ACAG to the mortality risk among CKD participants (all-cause mortality: HR = 1.10, 95% CI = 1.08-1.13, P < .01; cardiovascular mortality: HR = 1.09, 95% CI = 1.04-1.14, P < .01). Subgroup analyses revealed significant interactions between smoking and drinking with regard to the relation between ACAG and mortality in CKD patients. Our research indicates that higher levels of ACAG are related to unfavorable outcomes in CKD. Future research should further explore the role of ACAG and acid-base balance in mortality among CKD patients, as well as investigate potential intervention strategies.