Essential Hypertension In Chinese Research Articles

Lack of association between the G protein beta3 subunit gene and essential hypertension in Chinese: a case-control and a family-based study.

A C825T polymorphism of the gene encoding the G protein beta3 subunit (GNB3) is associated with enhanced G protein activity and increased intracellular signal transduction. The 825T allele has been implicated in the development of hypertension in some ethnic groups, especially in whites. Studies in Asians and blacks are more controversial, and little information is available on this polymorphism in the susceptibility to hypertension in the Chinese population. Furthermore, the inconsistency between studies may be due to genetic heterogeneity of the population selected and/or the lack of statistical power. We investigated the relationship of this polymorphism with hypertension in two independent northern Chinese populations using both a case-control and a family-based study design. The GNB3 C825T polymorphism was determined by polymerase chain reaction and restriction enzyme digestion. In the case-control study which included 585 hypertensive case subjects and 580 normotensive control subjects there was no significant association between the polymorphism and hypertension status or blood pressure levels. The lack of association was confirmed by the results obtained in 181 hypertensive families using both transmission disequilibrium test and sib transmission disequilibrium test. No preferential transmission was observed for the GNB3 825T allele to the affected subjects. Furthermore, there was no significant association between the polymorphism and body mass index in the case-control study. Therefore our work does not provide evidence in favor of GNB3 C825T being a candidate gene for conferring genetic susceptibility to hypertension or obesity in northern Chinese population.

Angiotensinogen gene and hypertension in Chinese.

The renin-angiotensin system plays a major role in regulating blood pressure and maintaining electrolyte and volume homeostasis. Previously, the angiotensinogen gene, which encodes the key substrate for renin within this system, has been reported linked to and associated with essential hypertension in White Europeans, African-Caribbeans, and Japanese. Therefore, we investigated whether the angiotensinogen gene might be similarly implicated in the pathogenesis of essential hypertension in Chinese by carrying out linkage analysis in 310 hypertensive sibling pairs. Genotypes for two diallelic DNA polymorphisms observed at amino acid residues 174 (T174M) and 235 (M235T) within the coding sequence and for two highly informative dinucleotide (GT)-repeat sequences (one in the 3' flanking region, and one at a distance of 6.1 cM from the gene) were determined. Affected sibpair analysis conducted according to three different algorithms (S.A.G.E./SIBPAL, MAPMAKER/ SIBS, and APM methods) revealed no evidence for linkage of the angiotensinogen gene to hypertension. Our data indicate that molecular variants of this gene do not appear to contribute materially to the pathogenesis of primary hypertension among Chinese (a notion supported by concomitant, direct estimates of power), and that the disease relevance of this gene may vary therefore depending on ethnicity.

Erythrocyte sodium-lithium countertransport in Chinese: its relationship to family history of hypertension.

Rates of sodium (Na+)-stimulated lithium (Li+) efflux (Na(+)-Li+ countertransport) and ouabain-sensitive Na+ efflux (Na+ pump) were determined in erythrocytes of Chinese normotensive and hypertensive subjects. Near-maximal rate of Na(+)-Li+ countertransport was found to be significantly higher in hypertensive than normotensive subjects. No significant difference was observed for the rate of Na+ pump between them. A second series of study involved normotensive subjects without and with hypertensive parent(s) (group A and B, respectively) and hypertensive subjects (group C). We found that the rate of Na(+)-Li+ countertransport in group A was significantly lower than that of group B and C, while no difference existed between group B and C. No significant difference was observed for the rate of Na+ pump among the three groups. Our results suggested that Na(+)-Li+ countertransport activity could be a genetic marker for essential hypertension in Chinese, similar to that as proposed in Caucasians.