Folic Acid Therapy and Cardiovascular Disease in ESRD or Advanced Chronic Kidney Disease: A Meta-Analysis

Background and objectives The efficacy of folic acid therapy to lower homocysteine (Hcy) levels in an effort to reduce cardiovascular disease (CVD) risk in patients with ESRD or advanced chronic kidney disease (ACKD; creatinine clearance, <30 ml/min) remains inconclusive. We conducted a meta-analysis of relevant randomized trials to further examine this issue. Design, setting, participants, & measurements This meta-analysis included 3886 patients with ESRD/ACKD from seven qualified randomized trials using folic acid therapy and with CVD reported as one of the end points. Results When pooling the seven trials, folic acid therapy reduced the risk of CVD by 15% (RR, 0.85; 95% CI, 0.76 to 0.96; P = 0.009). A greater beneficial effect was observed among those trials with a treatment duration >24 months (RR, 0.84; 95% Cl, 0.72 to 0.98; P = 0.02), a decrease in Hcy level >20% (RR, 0.83; 95% CI, 0.73 to 0.95; P = 0.007), and no or partial folic acid fortification (RR, 0.80; 95% CI, 0.65 to 0.99; P = 0.04). The beneficial effect also was seen when Hcy levels decreased >20%, even in the presence of folic acid fortification (RR, 0.85; 95% CI, 0.73 to 0.99; P = 0.04). In the corresponding comparison groups, the estimated RRs were attenuated and insignificant. Conclusions Folic acid therapy can reduce CVD risk in patients with ESRD/ACKD by 15%. A greater beneficial effect was observed among those trials with no or partial folic acid fortification or a decrease in Hcy level >20% regardless of folic acid fortification. Clin J Am Soc Nephrol 6: 482-488, 2011. doi: 10.2215/CJN.05310610