Folic acid treatment protective against CKD progression in certain patients

Fortification or supplementation with folic acid may confer benefits for reducing the likelihood of chronic kidney disease (CKD) progression among patients with mild-to-moderate disease and elevated vitamin B12 levels, a recent study has found.

Researchers performed a posthoc analysis using data from the kidney disease substudy of the China Stroke Primary Prevention Trial (CSPPT), including 1,374 hypertensive adults with mild-to-moderate CKD. All participants had low folate intake and had undergone vitamin B12 measurements at baseline.

The participants were assigned to a double-blinded daily treatment of enalapril 10 mg alone or in combination with folic acid 0.8 mg. The primary endpoint was progression of CKD, defined as a reduction in estimated glomerular filtration rate (eGFR) ≥30 percent and to a level of <60 mL/min/1.73 m² if baseline eGFR was ≥60 mL/min/1.73 m²; or a decrease in eGFR ≥50 percent if baseline value was <60 mL/min/1.73 m²; or kidney failure.

Mean eGFR at baseline in the cohort was 86.1 mL/min/1.73 m², and the median treatment duration was 4.4 years. Compared with enalapril monotherapy, treatment with the enalapril–folic acid combo yielded an 83-percent reduction in the odds of CKD progression among participants with higher baseline B12 levels (≥248 pmol/L; odds ratio [OR], 0.17, 95 percent confidence interval [CI], 0.07–0.40).

The beneficial effect on the risk of progression was not observed among participants with lower baseline B12 levels (<248 pmol/L; metabolic B12 deficiency; OR, 1.21, 95 percent CI, 0.51–2.85). Baseline vitamin B12 levels had a significant interaction with folic acid treatment (p=0.001).

There were several limitations to the study, including those inherent in a posthoc analysis and the low event rate.