[Genetic epidemiological study on discordant sib pairs of ischemic stroke in Beijing Fangshan District].

Objective: To investigate the association among serum lipids, blood pressure, -514C/T polymorphism of hepatic lipase gene and subtypes of ischemic stroke in the discordant sib pairs.
Methods: Ischemic stroke cases were enrolled from a hospital-based stroke registry, the proband-initiated contact was used to recruit pedigrees, and participants' information and blood samples were collected through the community-based health care networks in rural areas of China. Statistical analysis was performed by using the Wilcoxon signed rank test to compare quantitative differences between sib pairs and the McNemar test to compare qualitative differences. Generalized estimating equation (GEE) was used to adjust for within-family correlation in analysis of discordant sib pairs. Family based association test (FBAT) was applied to associations between serum lipids, blood pressure and the -514T allele in hepatic lipase gene.
Results: Totally 107 discordant sib pairs from 71 ischemic stroke patients pedigrees were analyzed by univariate and multivariate methods. The blood pressure and serum lipids were associated with ischemic stroke (P<0.05) The lipid level was higher in large-artery atherosclerosis ischemic stroke than in the subtype of small-vessel occlusion, while the blood pressure was higher in the latter. The -514T allele in hepatic lipase gene was associated with low density lipoprotein-cholesterol (LDL-C) and diastolic blood pressure in additive model by FBAT analysis (Z=2.366, P<0.05), and it was also associated with diastolic blood pressure in additive model (Z=-2.277, P<0.05) and recessive model (Z=-2.244,P< 0.05), but not associated with ischemic stroke or its subtypes.
Conclusion: In these discordant sib pairs, the abnormalities of blood pressure and serum lipids may increase risks of ischemic stroke, and different subtypes of ischemic stroke may differ from each other in etiology. The -514T allele in hepatic lipase gene may be associated with LDL-C and diastolic blood pressure.