Hyperhomocysteinemia and Risk of Cognitive Decline: A Meta-Analysis of Prospective Cohort Studies

Objective: To evaluate the association between hyperhomocysteinemia (HHcy) and risk of cognitive decline. Methods: Electronic databases such as PubMed and EMBASE were searched for prospective cohort studies that involved the relationship between HHcy and risk of cognitive decline. Adjusted risk ratios (RRs) and corresponding 95% confidence intervals (95% CIs) were calculated by Review Manager 5.2.7. Subgroup analyses were conducted on stratification of some important variables. Results: Fourteen publications were included in the analysis. The pooled RR was 1.53 (95% CI, 1.231.91; p = 0.0002) for patients with HHcy compared to subjects without HHcy. Subgroup analyses indicated that the pooled RRs were 1.51(95% CI, 1.10-2.05; p = 0.01) for more than five-year follow-up studies and 1.56 (95% CI, 1.13-2.14; p = 0.007) for less than five-year follow-up studies. The pooled RRs were 1.66 (95% CI, 1.21-2.26; p = 0.001) for studies excluding the confounder of B vitamins and 1.34 (95% CI, 1.08-1.66; p = 0.008) for non-excluded studies. In terms of region, the pooled RR was 1.60 (95% CI, 1.21-2.13; p = 0.001) for European and American countries, while the pooled RR was 1.27 (95% CI, 1.02-1.59; p = 0.03) for other regions. Conclusion: As one of the independent risk factors, HHcy was associated with an increased risk of cognitive decline. (C) 2014 S. Karger AG, Basel