Interdialytic creatinine change versus predialysis creatinine as indicators of nutritional status in maintenance hemodialysis

• Published in: Nephrology, dialysis, transplantation Vol. 27; no. 2; pp. 771 - 776
• Main Authors: WALTHER, Carl P, WISE CARTER, Caitlin, LOW, Chai L, WILLIAMS, Peter, RIFKIN, Dena E, STEINER, Robert W, IX, Joachim H
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.02.2012
• Subjects: Aged; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Biomarkers - blood; Body Mass Index; Cohort Studies; Creatinine - blood; Emergency and intensive care: renal failure. Dialysis management; Female; Hospitals, Veterans; Humans; Intensive care medicine; Investigative techniques of renal and urinary tract function; Investigative techniques, diagnostic techniques (general aspects); Kidney Failure, Chronic - blood; Kidney Failure, Chronic - therapy; Linear Models; Male; Medical sciences; Middle Aged; Nutritional Requirements; Nutritional Status; Original; Predictive Value of Tests; Prognosis; Proportional Hazards Models; Protein-Energy Malnutrition - diagnosis; Protein-Energy Malnutrition - epidemiology; Protein-Energy Malnutrition - etiology; Renal Dialysis - adverse effects; Renal Dialysis - methods; Risk Assessment; Sensitivity and Specificity; Severity of Illness Index; Time Factors; Kidney disease; Creatinine; Extrarenal dialysis; Urinary system disease; Hemodialysis; Renal failure; Nutritional status; Comparative study
• ISSN: 0931-0509; 1460-2385
• DOI: 10.1093/ndt/gfr389

Protein-energy wasting is common in patients on maintenance hemodialysis and is strongly associated with poor quality of life and mortality. However, clinical assessment of protein-energy wasting remains difficult. Predialysis creatinine levels are associated with mortality risk but may be influenced by both muscle mass and dialysis dose. This might be overcome by examining the rate of rise in creatinine between dialysis sessions. We conducted an observational cohort study among 81 patients on maintenance hemodialysis at our Veterans Affairs unit. Predialysis serum creatinine and change in serum creatinine between midweek dialysis sessions served as the predictor variables of interest and clinically available proxies of nutritional status and time to mortality served as the outcome variables. Linear regression and Cox proportional hazards models evaluated relationships, respectively. The mean age of the study participants was 63 ± 10 years, 77 (95%) were male, mean body mass index was 27 ± 6 kg/m(2) and 69% had diabetes. Median follow-up time was 13 months, during which 12 patients (15%) died. Interdialytic change in serum creatinine showed a strong direct correlation with predialysis serum creatinine (R = 0.96). Higher levels of both markers were associated with younger age, less residual urine volume and higher serum albumin, serum phosphorus and normalized protein catabolic rate (P < 0.05 for all). Both markers were approximately equally strongly associated with mortality. For example, compared to the highest predialysis creatinine tertile, participants in the lowest tertile (<6 mg/dL) had 5.5-fold [95% confidence interval (CI) 1.1, 26.6] higher risk of death. Similarly, participants in the lowest tertile of interdialytic change in creatinine (change <3.7 mg/dL/48 h), had 5.0-fold (95% CI 1.0, 24.4) higher death risk. Predialysis creatinine and interdialytic change in creatinine are both strongly associated with proxies of nutritional status and mortality in hemodialysis patients and are highly correlated. Interdialytic change in creatinine provided little additional information about nutritional status or mortality risk above and beyond predialysis creatinine levels alone.