Plasma homocysteine concentrations and risk of intracerebral hemorrhage: a systematic review and meta-analysis

Intracerebral hemorrhage (ICH) has the highest mortality rate in all strokes. However, controversy still exists concerning the association between plasma homocysteine (Hcy) and ICH. A systematic review and meta-analysis was conducted using Pubmed, Embase, and Web of Science up to April 18, 2017. Standard mean difference (SMD) for mean differences of plasma Hcy levels with 95% confidence intervals (CI) was calculated. Seven studies including 667 ICH patients and 1821 ischemic stroke patients were identified for meta-analysis. Our results showed that Hcy levels in ICH patients were significantly higher than those in healthy controls (SMD = 0.59, 95% CI = 0.51-0.68, P < 0.001); no statistic differences were found in the comparisons of Hcy levels between ICH and ischemic stroke (SMD = -0.03, 95% CI = -0.13-0.06, P > 0.05); further subgroup analysis of ethnicity (Asians: SMD = 0.57, 95% CI = 0.48-0.66, P < 0.001; Caucasians: SMD = 0.77, 95% CI = 0.51-1.02, P < 0.001) and sample size (small samples: SMD = 0.55, 95% CI = 0.30-0.80, P < 0.001; large samples size: SMD = 0.60, 95% CI = 0.51-0.69, P < 0.001) in relation to Hcy levels between ICH and healthy controls did not change these results. In conclusion, Hcy level may be an aggravating factor in atherosclerosis, which is positively associated with high risk of ICH. Race-specific differences between Asians and Caucasians have no impact on the risk of ICH.