Relationships between plasma homocysteine level and both recurrence and mortality in patients with acute ischemic stroke

Objective To investigate whether homocysteine (Hcy) level in the acute phase of stroke influences the recurrence of stroke and mortality of the patients. Methods A total of 3799 patients with first-onset ischemic stroke, admitted to our hospital from September 2005 to March 2011, were recruited; their demographic information, comorbidities, and clinical data were collected; Hcy level was measured within 24 h of primary admission. According to the Hcy level, patients were divided into normal Hcy group (Hcy<15 μmol/L, n=2267), and hyperhomocysteinemia (HHcy) group (Hcy≥15 μmol/L, n=1532). Patients were followed up for three years, univariate analysis and Cox proportional hazards regression analysis were used to analyze the relations of Hcy level with recurrence and mortality. Results During the three years of follow-up, 702 patients suffered recurrent stroke, and 303 died. The HHcy group had significantly higher recurrence stroke rate (21.8% vs. 16.2% ) and mortality (11.2% vs. 5.8%) than the normal Hcy group (P<0.05). After being adjusted for age, gender, diabetes, hyperlipidemia, drinking, smoking, hyperuricemia, low density lipoprotein level, apolipoprotein B/apolipoprotein AI ratio and fasting blood glucose level, patients in the HHcy group had significantly increased risk of recurrent stroke (hazard ratio[HR]=1.101, 95%CI: 1.037-1.257, P=0.002) and mortality (HR=1.701, 95%CI: 1.040-2.283, P=0.000) than patients in the normal Hcy group. Further subgroup analysis showed that this correlation was only significant in the large artery atherosclerosis stroke subtype: the recurrent stroke risk (adjusted HR=1.071, 95% CI: 1.037-1.106, P=0.003) and mortality risk(HR=1.86, 95%CI: 1.12-2.97, P=0.001) in the HHcy group were significantly higher than those in normal Hcy group; however, in small-vessel occlusion subtype, the risk of recurrence stroke (HR=0.731, 95%CI: 0.043-1.205, P=0.058) and mortality risk(HR=0.77, 95% CI: 0.29-2.34, P=0.061) in the HHcy group were not significant as compared with those in the normal Hcy group. Conclusions Hcy level is a risk factor for stroke recurrence and mortality in patients with acute ischemic stroke. Key words: Homocysteine; Acute ischemic stroke; Recurrent stroke; Mortality; Prognosis