Impact of Metabolic Acidosis Correction with Sodium Bicarbonate on Preservation of Renal Function Among Predialysis Chronic Kidney Disease Patients

Abstract

Background: Chronic kidney disease (CKD) is frequently complicated by metabolic acidosis, which contributes to declining renal function, skeletal muscle protein degradation, and poor nutritional status. Objectives: This study evaluated whether correction of metabolic acidosis with oral sodium bicarbonate could influence changes in estimated glomerular filtration rate (eGFR), serum albumin concentration, and muscle mass in predialysis patients with CKD. Methods: A prospective, randomized, open-label, parallel-group study was conducted at a tertiary care center. Ninety predialysis patients with CKD and serum bicarbonate levels of 10 - 20 mEq/L were randomized equally into two groups. Group 1 received oral sodium bicarbonate plus standard CKD care according to the KDIGO 2024 recommendations, whereas Group 2 received standard treatment alone. The sodium bicarbonate dose was titrated to maintain serum bicarbonate levels between 19 and 25 mEq/L. Estimated glomerular filtration rate, serum bicarbonate, serum albumin, and mid-arm muscle circumference (MAMC) were assessed at baseline and after 9 months. The primary treatment effect was assessed as the between-group difference in the change from baseline to 9 months. Results: At 9 months, patients receiving sodium bicarbonate showed a significant increase in serum bicarbonate and statistically significant preservation of renal function compared with the controls. The mean between-group difference in eGFR change was 2.98 mL/min/1.73 m2 (95% CI, 2.66 to 3.30; P < 0.001). Between-group differences in changes in serum bicarbonate, serum albumin, and MAMC were also statistically significant. Conclusions: Correction of metabolic acidosis with sodium bicarbonate was associated with short-term preservation of renal function and improvements in serum albumin levels and muscle mass among predialysis patients with CKD.