Plasma homocysteine levels in ischemic stroke patients with obstructive sleep apnea

OBJECTIVE: To investigate the association of plasma homocysteine and OSA (obstructive sleep apnea) syndrome in ischemic stroke (IS). METHODS: A total of 92 male IS patients were classified by apnea hypopnea index (AHI) into 2 groups: non-OSA group (AHI or = 5). All patients were tested for plasma homocysteine when polysomnography was finished at (14 +/- 2) d after the onset of IS. RESULTS: The mean level of homocysteine was significantly higher in the OSA group than that in the non-OSA group (17 +/- 5 vs 11 +/- 3 micromol/L, P < 0.01). Pearson correlation analysis revealed a positive correlation between the homocysteine level and the severity of AHI (r = 0.482, P < 0.01). Further multiple linear regression analysis showed that AHI and folate were independent predictors of homocysteine level (R2 = 0.553, P < 0.01, beta for AHI = 0.671, beta for folate = -0.256). CONCLUSION: The severity of OSA is significantly associated with an elevated level of homocysteine in IS patients. And this association is independent of other causative factors of an elevated level of homocysteine.