Is there a link between CKD progression and low bicarbonate levels?

June 22, 2020

In adults with chronic kidney disease (CKD), there is an association between low bicarbonate levels and CKD progression. A report examines whether there is a similar relationship in pediatric patients.

In adults who have chronic kidney disease (CKD), there is a link between metabolic acidosis, measured by low serum bicarbonate levels, and CKD progression. A report in the Clinical Journal of American Society of Nephrology looked at whether a similar relationship exists in children with CKD.1

Investigators used data from Chronic Kidney Disease in Children. Their analyses were stratified by glomerular and nonglomerular diagnoses. They also adjusted for phosphate, hypertension, alkali therapy, demographic characteristics, eGFR, proteinuria, and anemia.

In the cohort there were 603 participants nonglomerular disease who contributed 2673 person-years of follow-up and 255 participants with glomerular disease who contributed 808 person-years of follow-up. At the study’s baseline, 39% of the participants with nonglomerular disease had a bicarbonate level of ≤22 meq/L and among that subset, 36% reported alkali therapy treatment. Among participants with glomerular disease, 31% had a bicarbonate level of ≤22 meq/L and in that subset, 18% reported alkali therapy treatment. Following adjusted longitudinal analyses, when compared with children with a bicarbonate level >22 meq/L, the hazard ratios associated with a bicarbonate level of <18 meq/L and 19–22 meq/L were 1.28 (95% confidence interval [CI], 0.84 to 1.94) and 0.91 (95% CI, 0.65 to 1.26), respectively, in children with nonglomerular disease. In children with glomerular disease, the adjusted hazard ratios linked with bicarbonate level ≤18 meq/L and bicarbonate 19–22 meq/L were 2.16 (95% CI, 1.05 to 4.44) and 1.74 (95% CI, 1.07 to 2.85), respectively. When compared with persistently low bicarbonate, the resolution of low bicarbonate was linked with a lower risk of progression of CKD.

The researchers concluded that the association between low bicarbonate and a higher risk of CKD progression was found in children with glomerular disease. As fewer than half of the children with low bicarbonate reported receiving alkali therapy treatment, the researchers said that long-term studies on the treatments efficacy in pediatric patients are still needed.

Reference:

1. Brown DD, Roem J, Ng DK, et al. Low serum bicarbonate and CKD progression in children. Clin J Am Soc Nephrol. 2020:15(6):755-765. doi:10.2215/cjn.07060619