title: M235-->T polymorphism of the angiotensinogen gene predicts hypertension in the elderly.
abstract: OBJECTIVE
  To determine whether the M235-->T polymorphism (exon 2) of the angiotensinogen gene is associated with hypertension in elderly patients with isolated systolic hypertension [ISH: systolic blood pressure (SBP) > or = 160 mmHg, diastolic blood pressure (DBP) < 90 mmHg) or systolic-diastolic hypertension (SDH: DBP > or = 90 mmHg, SBP > or = 160 mmHg) compared with normotensive controls (SBP < 160 mmHg, DBP < 90 mmHg).
  
  
  METHODS
  A case-control study in 769 non-institutionalized, elderly (aged > or = 60 years; female:male ratio 0.85) residents of Dubbo, New South Wales.
  
  
  METHODS
  Individuals were classified as having ISH (n = 171), having SDH (n = 218) and being normotensive controls (n = 366) with age and sex matching. MM, TT and MT genotypes were determined by a nested polymerase chain reaction strategy using DNA extracted from serum. The prediction of ISH or SDH by genotype or allele was examined in a multiple-logistic regression model that controlled for various confounders.
  
  
  RESULTS
  SBP (mean +/- SD, mmHg)/DBP (mean +/- SD, mmHg) was 176 +/- 16/79 +/- 8 in the ISH group, 167 +/- 23/97 +/- 7 in the SDH group and 134 +/- 14/74 +/- 9 in the normotensive control group. The frequencies of M and T alleles in the normal population (0.69 and 0.31, respectively) were altered significantly in the ISH group (0.61 and 0.39, respectively; chi 2 = 6.0, P < 0.02) and the SDH group (0.62 and 0.38, respectively; chi 2 = 6.0, P < 0.02). The presence of the TT genotype predicted both ISH (odds ratio 1.9, 95% confidence interval 1.1-3.3) and SDH (1.7, 1.0-3.0) as did that of the T allele (ISH: 1.3, 1.0-1.7; SDH: 1.3, 1.0-1.7).
  
  
  CONCLUSIONS
  The M235-->T polymorphism may be a marker for both forms of hypertension in the elderly. Whether the TT genotype represents a genetic risk factor for the development of hypertension in later life requires confirmation.
authors.affiliation: University Department of Medicine, Princess Alexandra Hospital & University of Queensland, Brisbane, Australia.
authors.forename: A G
authors.initials: AG
authors.lastname: Johnson
authors.forename: L A
authors.initials: LA
authors.lastname: Simons
authors.forename: Y
authors.initials: Y
authors.lastname: Friedlander
authors.forename: J
authors.initials: J
authors.lastname: Simons
authors.forename: D R
authors.initials: DR
authors.lastname: Davis
authors.forename: J
authors.initials: J
authors.lastname: MaCallum
mesh_terms: D000368:Aged; D000808:Angiotensinogen / Q000235:genetics*; D016022:Case-Control Studies; D005260:Female; D005838:Genotype; D006801:Humans; D006973:Hypertension / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D000808:Angiotensinogen