title: Association of a common variant of the leptin gene with blood pressure in an obese Brazilian population.
abstract: BACKGROUND
  This study assessed in obese Brazilians subjects whether a common variant of leptin gene, -2548G>A, is associated with blood pressure changes.
  
  
  METHODS
  A total of 140 subjects, 99 women; mean age of 45.2 +/- 12.4 years; body mass index (BMI) = 38.5 +/- 8.0 kg/m2 were included. Blood pressure was recorded using Dinamap 1846 (Critikon, Tampa, FL). Molecular analysis was made by use of PCR and restriction fragment-length polymorphism analysis. Plasma insulin and leptin concentrations were determined by radioimmunoassay.
  
  
  RESULTS
  AA homozygotes, in comparison with the G-allele carriers, showed significant lower levels of systolic, diastolic, and mean arterial pressure (120 +/- 10 vs. 132 +/- 17 mm Hg, P = 0.01; 75 +/- 6 vs. 84 +/- 12 mm Hg, P = 0.009; 92 +/- 7 vs. 100 +/- 12 mm Hg, P = 0.007, respectively). The differences in blood pressure remained significant after adjusting for the influence of gender, age, obesity, and body fat distribution as well as for leptin, insulin, and homeostasis model assessment of insulin resistance. A stepwise regression analysis confirmed that the LEP AA genotype independently predicted blood pressure changes. On the other hand, in GG homozygotes, insulinemia showed a significant association with blood pressure values. This suggests that common LEP genotype carriers exhibiting high insulin levels, reflecting an insulin-resistant state, were particularly prone to higher blood pressure levels.
  
  
  CONCLUSIONS
  Our results showing that higher blood pressure levels were found with the most prevalent -2548G>A genotype, whereas patients with the AA genotype seemed to be protected from hypertension, indicate that the -2548G>A polymorphism of LEP appears to be an important mediator of obesity hypertension.
authors.affiliation: Hypertension Clinic, Laboratory of Clinical and Experimental Pathophysiology (CLINEX), School of Medicine, Rio de Janeiro State University, Rio de Janeiro, Brazil.
authors.forename: Virginia A
authors.initials: VA
authors.lastname: Genelhu
authors.forename: Bruno M J
authors.initials: BM
authors.lastname: Celoria
authors.forename: Marcia M G
authors.initials: MM
authors.lastname: Pimentel
authors.forename: Stênio F P
authors.initials: SF
authors.lastname: Duarte
authors.forename: Pedro H
authors.initials: PH
authors.lastname: Cabello
authors.forename: Emílio A
authors.initials: EA
authors.lastname: Francischetti
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000235:genetics; D005260:Female; D006801:Humans; D006973:Hypertension / Q000235:genetics*; D020738:Leptin / Q000235:genetics*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000235:genetics* / Q000503:physiopathology
chemical_list: D020738:Leptin