A Case-control Study On The Genetic Epidemiology Of Stroke

Objectives:To study the environmental and genetic factors of stroke and to define the family of the ischemic stroke and the hemorrhagic stroke and to propose a new kind of strategy about the primary and the second-level prevention of stroke.Methods:According to the diagnostic criteria of stroke which was determined in the fourth national conference on cerebrovascular disease, we choose 260 pairs in the case-control study barring the cases suffered from cerebral embolism. All of the objects were investigated in uniform questionnaires about suspected risk factors and pedigree analysis which included population feature, individual behavior feature, history of past illness, family medical history, blood sugar, blood fat, fibrinogen, ECG, index of carotid artery ultrosound, etc. The hetitability of cerebral stroke was estimated by the case-control study method and the family line investigation method. All of the data were processed with non-conditional logistic regression with SPSS 12.0.Results:Individual logistic analysis showed that 10 factors were related to ischemic cerebral stroke (P<0.05), including history of hypertension and diabetes, smoking, years of alchohol intake, family stroke history, blood-fasting sugar, LDL-C, TC, TG and HDL-C, in which HDL was a protective factor; and that 10 factors were related to hemorrhagic stroke (P<0.05), including history of hypertension and diabetes, smoking, history of drink, years of alchohol intake, family stroke history, high salt and fat diet, TG and blood-fasting sugar. Multiple regression analysis showed that history of hypertension and diabetes, family stroke history, LDL-C, TC, TG, HDL-C were independent risk factors of ischemic cerebral stroke; and that history of hypertension and diabetes, family stroke history were independent risk factors of hemorrhagic stroke. The results showed that the prevalence rates of the first-degree, the second-degree relatives of the cases of cerebral infarction and the controls'were 6.69%,4.28%,1.77%, and 3.37%; and in the cases of hemorrhagic stroke, the prevalence rates were 5.21%,1.75%,1.61% and 1.46%. They were significantly higher than that in controls(P=0.000). The stroke prevalence rates of the spouses of the cases of stroke were no significantly higher than of controls (P>0.005). The segregation ratio of the first-degree of the cases of cerebral infarction was 0.1390, and Sx=0.0142, 95%CI:0.1248～0.1532; and the segregation ratio of the first-degree of the cases of hemorrhagic stroke was 0.0983, and Sx=0.0128,95%CI:0.0732～0.1234. The results showed that the heritability of the first-degree and the second-degree relatives of cerebral infarction were 44.94%,18.81%; and of hemorrhagic stroke were 41.46%,11.32%. The genetic mode of stroke was estimated by Penrose's method. In the group of stroke, the results of s/q were 3.32 and 4.27, which were close to the result of 1/(?)(6.82 and7.67).Conclusion:There were important influences of common risk factors of environment to stroke. Both cerebral infarction and intralcerebral hemorrhage showed familial aggregation, and one of the important causes of it was heredity factor. The multigenetic inheritable mode was found in stroke. The study of the familial aggregation of stroke was favor of the primary and secondary prevention of cerebral infarction and hemorrhage, and it promoted the individual treatment and prevention of stroke to develop more.