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.