Sodium bicarbonate treatment and clinical outcomes in chronic kidney disease with metabolic acidosis: a meta-analysis

Background: In patients with chronic kidney disease (CKD), impaired kidney acid excretion leads to the onset of metabolic acidosis (MA). However, the evidence is not yet conclusive regarding the effects of sodium bicarbonate in treating CKD with MA. Methods: Databases with PubMed, Embase, and the Cochrane Library were used to search for randomized controlled trials from the inception until November 11, 2023 to identify randomized controlled trials investigating the effect of sodium bicarbonate in participants with CKD and MA. The primary outcome was the change in estimated glomerular filtration rate (eGFR). Secondary outcomes included hospitalization rates, change in systolic blood pressure (SBP), all-cause mortality, and mid-arm muscle circumference (MAMC). A random-effects model was applied for analysis, and subgroup, sensitivity analyses were also performed. Results: Fourteen RCTs comprising 2,037 patients demonstrated that sodium bicarbonate supplementation significantly improved eGFR (standardized mean difference [SMD]: 0.33, 95% CI: 0.03 to 0.63, P = 0.03). The group receiving sodium bicarbonate had a lower hospitalization rate (odds ratio: 0.37, 95% CI: 0.25 to 0.55, P < 0.001). Higher MAMC was observed with sodium bicarbonate treatment compared with those without (SMD:0.23, 95% CI: 0.08 to 0.38, P = 0.003, I 2 < 0.001). However, higher risk of elevated SBP was found with sodium bicarbonate treatment (SMD:0.10, 95% CI: 0.01 to 0.20, P = 0.03). No significant difference in all-cause mortality was noted. Conclusion: In patients with CKD and MA, sodium bicarbonate supplementation may provide potential benefits in preventing the deterioration of kidney function and increasing muscle mass. However, treatment may be associated with higher blood pressure. Due to the risk of bias stemming from the absence of double-blinded designs and inconsistencies in control group definitions across the studies, further research is crucial to verify these findings.