title: Aldosterone synthase gene (CYP11B2) C-344T polymorphism, plasma aldosterone, renin activity and blood pressure in a multi-ethnic population.
abstract: BACKGROUND
  The aldosterone synthase gene (CYP1B2) locus is a candidate region involved in the development of hypertension.
  
  
  OBJECTIVE
  To study the relationship between the C-344T CYP1B2 polymorphism, plasma aldosterone, renin activity and blood pressure in a multi-ethnic population.
  
  
  METHODS
  Population-based, cross-sectional study of 1313 middle-aged men and women (456 white, 441 of African origin and 416 South Asian). Anthropometry, blood pressure, biochemistry, questionnaire data and timed urine collections were taken with standardized techniques. All were genotyped for the C-344T CYP11B2 polymorphism.
  
  
  RESULTS
  The frequency of the C allele was significantly lower in people of African origin (0.21) than in white (0.46) and South Asian (0.43) (P < 0.001). After adjustment for age, sex and ethnicity the TT genotype was associated with 14% higher plasma aldosterone levels, 3.7 mmHg higher systolic and 2.1 mmHg higher diastolic blood pressure than CC (P for linear trend < 0.05). No significant interactions with age, sex, ethnicity, body mass index (BMI) and fractional excretion of sodium were found in the associations between genotype and both blood pressure and aldosterone levels. In a sub-sample of participants in which plasma renin activity was measured (n = 457), a significant excess of T alleles was found in those with a raised (>/= 750) aldosterone-to-renin ratio (ARR).
  
  
  CONCLUSIONS
  In this multi-ethnic population, the C-344T CYP1B2 polymorphism is associated with blood pressure, plasma aldosterone levels and ARR. Although significant differences in allele frequencies were found between groups, ethnicity does not explain the results.
authors.affiliation: Department of Community Health Sciences, St George's Hospital Medical School, London, UK.
authors.forename: Antonio
authors.initials: A
authors.lastname: Barbato
authors.forename: Paola
authors.initials: P
authors.lastname: Russo
authors.forename: Alfonso
authors.initials: A
authors.lastname: Siani
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Folkerd
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Miller
authors.forename: Antonella
authors.initials: A
authors.lastname: Venezia
authors.forename: Claudia
authors.initials: C
authors.lastname: Grimaldi
authors.forename: Pasquale
authors.initials: P
authors.lastname: Strazzullo
authors.forename: Francesco P
authors.initials: FP
authors.lastname: Cappuccio
mesh_terms: D000328:Adult; D000450:Aldosterone / Q000097:blood*; D000483:Alleles; D044466:Asian People / Q000235:genetics; D044383:Black People / Q000235:genetics; D001794:Blood Pressure; D003430:Cross-Sectional Studies; D019405:Cytochrome P-450 CYP11B2 / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D044469:Racial Groups / Q000235:genetics*; D012083:Renin / Q000097:blood*; D044465:White People / Q000235:genetics
chemical_list: D000450:Aldosterone; D019405:Cytochrome P-450 CYP11B2; D012083:Renin