Association Of Plasma Homocysteine With Cardiovascular And Cerebrovascular Disease

Part I Plasma Homocysteine and Coronary Heart Disease in theAsian Population：A Meta-Analysis of Genetic Association StudiesObjective：To assess whether a genetic variant associated with higher homocy-steine levels are associated with increased coronary heart disease (CHD) risk in theAsian population, as a test of the causal influence of homocysteine on CHD.Methods： We systematically searched EMBASE, MEDLINE, PubMed,HuGENet, Wanfang, CBM, VIP and CNKI databases from inception through toSeptember2012to collect all relevant large studies, which typically had>250casesand>250controls. According to the Cochrane Handbook for systematic reviews,quality assessment and data extraction were conducted by two reviewersindependently. All data were analyzed by using Review Manager5.1.Results：Ten studies were included (total15564CHD cases and20571controls).In the Asian population, individuals with methylenetetrahydrofolate reductase(MTHFR)677TT genotype had about25%higher homocysteine levels than thosewith CC genotype. Individuals with the MTHFR677TT genotype were notassociated with a higher risk of CHD compared with those with the CC genotype(risk ratio [RR],1.09;95%confidence interval [CI],1.00-1.19).Conclusion：In the Asian population, lifelong moderate homocysteine elevationhas little or no effect on CHD, indicating that homocysteine may not be a pathogenicfactor of CHD. Part II Plasma Homocysteine and Ischemic Stroke in the AsianPopulation：A Meta-Analysis of Genetic Association StudiesObjective：To assess whether a genetic variant associated with higher homocy-steine levels are associated with increased ischemic stroke risk in the Asianpopulation, as a test of the causal influence of homocysteine on ischemic stroke.Methods： We systematically searched EMBASE, MEDLINE, PubMed,HuGENet, Wanfang, CBM, VIP and CNKI databases from inception through toSeptember2012to collect all relevant large studies. According to the CochraneHandbook for systematic reviews, quality assessment and data extraction wereconducted by two reviewers independently. All data were analyzed by using STATA12.0.Results：Five studies were included (total2949ischemic stroke cases and4738controls). In the Asian population, individuals with MTHFR677TT genotype hadabout25%higher homocysteine levels than those with CC genotype. Individuals withthe MTHFR677TT genotype had a significantly higher risk of ischemic strokecompared with those with the CC genotype (odds ratio [OR],1.31;95%CI,1.14-1.51).Conclusion： In the Asian population, lifelong moderate elevation ofhomocysteine levels may be causally related to increased risk of ischemic stroke.Further researches and relevant large-scale randomized controlled trials are warrantedto verify it.