THE CORRELATION OF SERUM BICARBONATE AND METABOLIC ACIDOSIS TO ALBUMIN IN HEMODIALYSIS PATIENTS

Abstract

Metabolic acidosis, indicated by low serum bicarbonate levels (CO2), is common in patients with end stage renal disease (ESRD). The specific aim of this project is to statistically correlate laboratory and descriptive human data with the association of serum CO2, metabolic acidosis, and nutritional assessment indices in hemodialysis patients. In a retrospective observational design, 144 hemodialysis patient charts were reviewed. One year of data was collected. To control for differences within individuals, within-subject correlations and analysis of covariance (ANCOVA) was used to analyze variables. Pearson and Spearman correlations were used to analyze correlations across the sample. Serum CO2 significantly correlated with albumin as an individual variable collected in the same month within-subjects (r = 0.079, p = 0.005), however not from the prior month (r = 0.042, p = 0.140). When including additional nutrition and inflammation related biomarkers (creatinine, hemoglobin, nPCR) with albumin and CO2 in an ANCOVA mixed model, within-subject correlation strengthened and was significant (r = 0.093, p = 0.004) for the prior month's CO2 impact on albumin. Albumin and the same month's CO2 changed to not significant (r = 0.026, p = 0.412) in the mixed model. Despite small correlations with some variables, this study provides insight into why albumin does not always correlate with CO2 in hemodialysis patients. Results portray the benefit of correcting metabolic acidosis and the limitation of albumin as the main nutrition indicator and outcome goal in ESRD. Future research should focus on validating better nutritional outcome measures for patients with ESRD.