A Case-Control Study On Environmental And Genetic Factors Of Essential Hypertension In The Yi Nationality Group Living In Liangshan Of China

Background and ObjectivesEssential hypertension (EH) was a disease with polygenic complex trait. According to thenational investigation in 2002, the prevalence rate of hypertension was 18.8% in peopleabove 18 years old in china, that meant there were over 160 million hypertensives in ourcountry. It was an important public health issue for the hypertension control andprevention in China. The Yi people, living in Liangshan, Sichuang Province, stillmaintain primitive life style and they are a genetic homogeneous population. Theprevalence rate of hypertension of the Yi people was at the towest level in China. Fromthe former research on this special population, the results had showed that theenvironmental risk factors had important influence on EH in the Yi people, we weregoing to try to study the environmental risk factors of EH and the relationship betweenthe genotype of insulin receptor gene exon 17 and EH in the Yi migrations and the Yifarmers.Materials and MethodsIt was a case-control study with taget sampling and flequency matching of sex and age.There were 8 counties in Liangshan selected to enroll Yi people above 35 years old. Inthe end, we collected 113 Yi hypertensives as cases and 156 Yi normotensives as control.All the subjects were interviewed with questionnaire and their blood pressure weremeasured, also their blood specimens were collected for biochemical and geneticmeasurement, including fasting glucose, insulin, lipid and the genotype of INSR gene.ResultsFor the Yi migrations, Univariate analysis showed that average income, the level ofeducation, some foods, IR, IFG, TG and LDL-C were associated with EH significantly;multivariate analysis showed that IR, LDL-C, average income, buckwheat were thepossible risk factors of EH, while oat was the protective factors. For the Yi farmers,Univariate analysis showed that only LDL-C was associated with EH significantly andthere were no risk factors with multivariate analysis. No association between thegenotype of INSR gene exon 17 and EH was found in the Yi migrations and the Yifarmers.ConclusionsEnvironmental factors such as some foods, average income. IR and LDL-C hadimportant influence on EH in the Yi migrations, while it was not the same in the Yifarmers. In conclusion the environmental risk factors of EH were likely different betweenthe Yi farmers and the Yi migrations. There was no effect of INSR gene C/Tpolymorphism was observed in the Yi migrations and the Yi farmers.