Significance of Serum Cholinesterase as a Prognostic Marker in Patients with Non-dialysis-dependent Chronic Kidney Disease.

Objective Malnutrition is a common problem among patients with chronic kidney disease (CKD). It is unknown whether serum cholinesterase, an indicator of the nutritional status, has a significant value as a prognostic marker in patients with non-dialysis-dependent CKD, including those in the early phase. Methods A total of 4,505 middle-aged and older people with stage 1-4 CKD who were free from cardiovascular events (mean age: 67.2 years) were followed up for an average of 10.3±2.4 years. We investigated the association of serum cholinesterase levels with all-cause mortality using multivariable regression analyses and restricted cubic spline analyses. Results A total of 840 (18.6%) participants died. The multivariable-adjusted hazard ratios (HRs) for all-cause mortality were significantly increased in patients with serum cholinesterase in the first and second quartiles compared to patients in the highest quartile in the entire cohort [HR=1.61, 95% confidence interval (CI), 1.28-2.03; HR=1.37, 95% CI, 1.09-1.71, respectively]. A reverse-J relationship between the serum cholinesterase levels and all-cause mortality was found in the entire cohort as well as in patients grouped according to stage 1-2 CKD and stage 3-4 CKD (all p for nonlinearity: <0.030). The inclusion of the serum cholinesterase level improved the accuracy of reclassification in a conventional prediction model for 10-year all-cause mortality (continuous net reclassification improvement=0.167, p<0.001; integrated discrimination improvement=0.005, p<0.001). Conclusion In middle-aged and older people with stage 1-4 CKD, the serum cholinesterase level had significant value in predicting all-cause mortality and added prognostic information to conventional risk assessments.