Folic acid therapy and cardiovascular disease in ESRD or advanced chronic kidney disease: a meta-analysis

Abstract

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% CI, 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.

Figure 1.

Study selection.

Figure 2.

Forest plot of RR and 95% CI of primary cardiovascular outcome for folic acid treatment versus control in individual trial and pooled data.