ABSTRACT
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. CONCLUSION: 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.
Subject(s)
Hypertension/genetics , Polymorphism, Genetic , Renin-Angiotensin System/genetics , Adult , Aged , Angiotensinogen/genetics , Case-Control Studies , China , DNA/analysis , Female , Genetic Predisposition to Disease , Genotype , Haplotypes , Humans , Male , Middle Aged , Peptidyl-Dipeptidase A/genetics , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Receptor, Angiotensin, Type 1/genetics , Sex Factors , Tibet/ethnologyABSTRACT
OBJECTIVE: To investigate the plasma insulin levels and insulin sensitivity in the offspring of parents with family hypertensive history in Tibetan population. METHODS: Tibetan hypertensive pedigrees and normotensive pedigrees based on a door-to-door cross section study performed from 1997 to 1998 in stable communities in the ruban district of Lhasa city were set up, 47 offsprings from hypertensive pedigrees (group I) and 21 offsprings from normotensive pedigrees (group II) were enrolled into this study. Plasma insulin levels using by radioimmunoassay and insulin sensitivity with the formulae insulin sensitivity = 1/(fasting plasma glucose x fasting plasma insulin) were compared between two groups. RESULTS: There were no statistically significant differences in fasting blood glucose levels between group I and group II. But fasting plasma insulin level was 10.20 +/- 6.95 m IU/L in group I and 6.56 +/- 2.81 m IU/L in group II, respectively, and there were statistically significant differences between these two groups. The insulin sensitivity index in group I was significantly lower than that in group II (0.036 +/- 0.024 and 0.046 +/- 0.022, respectively). CONCLUSION: Offspring of Tibetan hypertensive pedigrees were observed to be hyperinsulinemia and reduced insulin sensitivity. These metabolic abnormalities may be associated with hypertension and dyslipidemia in adulthood.
