OBJECTIVETo assess the association of extracellular superoxide dismutase (EC-SOD) gene methylation with cerebral infarction.

METHODSEighty-three patients with cerebral infarction and 94 healthy controls were enrolled. Based on cerebral MR findings, the size of infarction, extent of intracranial atherosclerosis, the National Institutes of Health Stroke Scale (NIHSS) score, and Barthel index were calculated. Methylation-specific PCR was used to analyze the methylation status of the EC-SOD gene in peripheral blood samples and its correlation with cerebral infarction.

RESULTSThe rate of EC-SOD gene promoter region methylation of the cerebral infarction group was lower than that of the control group (30.1% vs. 53.2%, P < 0.05). Patients with larger area of cerebral infarction (>4 cm in diameter) showed a lower methylation rate than those with a smaller cerebral infarction (0 vs. 39.1%, P < 0.05). Based on their cerebral MRA, 57 patients were divided into none, mild, moderate, and severe cerebral arteriosclerosis groups. The rate of EC-SOD gene methylation of the four groups showed a downward trend (at 45.5%, 42.9%, 23.8%, and 14.3%, respectively), though no statistical significance was found (P > 0.05). For the cerebral infarction group, those with higher rate of methylation had lower NIHSS scores (P < 0.05) but insignificantly higher Barthel index (P > 0.05).

CONCLUSIONThe EC-SOD methylation frequency of case group was lower than the control group. The methylation status is associated with the size of cerebral infarction, degree of cerebral arteriosclerosis and severity of neurological impairment.