Polymorphisms of renin-angiotensin system in essential hypertension in Chinese Tibetans.
OBJECTIVE
To evaluate the potential implications of the genetic variability of angiotensin converting enzyme, angiotensinogen and angiotensin II type 1 receptor gene for essential hypertension in Tibetan.


METHODS
A case-control study was conducted in 173 hypertensive individuals and 193 individuals with normal blood pressure. Multiple logistic regression analyses were used to estimate the risks of developing hypertension for different genotypes, and haplotype analyses of the angiotensinogen gene were used to determine the association between two-locus angiotensinogen gene polymorphisms and hypertension.


RESULTS
As to the risk to high blood pressure and high systolic pressure, women with MM genotype were 7.7 (95% CI: 1.3-20.5) and 8.7 (95% CI: 1.8-20.1) times higher than those with TT genotype after adjustment for age and body mass index. Haplotype frequencies for M235T and G-6A were significantly different between hypertensive individuals and controls, which indicated an association of angiotensinogen gene haplotypes with hypertension, and a significant association of 235T/-6A haplotype with hypotensive effect.


CONCLUSIONS
Our results suggest that angiotensinogen gene 235MM is a predictor for hypertension development in Tibetan women but not in men, and may exert its hypertensive effect on linkage disequilibrum with a possible function locus of G-6A.
Sun
Bei
B
National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences/Peking Union Medical College, Beijing 100005, China. sunpumc@yahoo.com.cn
Dronma
Tsering
T
Qin
Wei-Jun
WJ
Cui
Chao-Ying
CY
Tse
Dan
D
Pingtso
Tashi
T
Liu
Ying
Y
Qiu
Chang-Chun
CC
D000328:Adult; D000368:Aged; D000808:Angiotensinogen / Q000235:genetics; D016022:Case-Control Studies; D002681:China; D004247:DNA / Q000032:analysis; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D006973:Hypertension / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D007703:Peptidyl-Dipeptidase A / Q000235:genetics; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D044140:Receptor, Angiotensin, Type 1 / Q000235:genetics; D012084:Renin-Angiotensin System / Q000235:genetics*; D012737:Sex Factors; D018609:Tibet / Q000208:ethnology
D044140:Receptor, Angiotensin, Type 1; D000808:Angiotensinogen; D004247:DNA; D007703:Peptidyl-Dipeptidase A