There were no significant differences in DCI group with non-DCI in gender, age, smoking history, drinking history, diabetes, hypertension, cerebral infarction, coronary heart disease, aneurysm location, lymphocyte, monocyte, procalcitonin, hematocrit, red blood cell distribution width, average blood platelet volume, platelet count, large platelet volume, total cholesterol, triglyceride, high density lipoprotein, low density lipoprotein, apolipoprotein A1, apolipoprotein B100, fibrinogen and albumin levels (P > 0.05). The gene discussed is APOA1; the disease is diabetes mellitus.