title: Blood pressure and genetic and biological markers in a pediatric population.
abstract: BACKGROUND
  It is universally accepted that atherosclerosis originates in childhood and that high LDL and low HDL serum cholesterol, hypertension and obesity are some of the main risk factors. In the past few years, increasing importance has been attributed to the deleterious effect of reactive oxygen species (ROS) on lipids, on the endothelial lining of arteries, and on the occurrence of cardiovascular disease. The relationship between blood pressure, active renin (AR) and the genetic polymorphism of haptoglobin in a population of adolescents was studied using pro-oxidant status markers, and also using some enzyme systems involved in the antioxidant defense mechanism of the body.
  
  
  METHODS
  51 healthy children, 9 to 12 years of age, were evaluated. The following examinations were performed: nutritional status (weight, height, skinfolds and body mass index) and blood pressure; note was made of any family history of cardiovascular disease. The biological parameters assessed by internationally recommended methods included haptoglobin phenotyping and determination of active renin (AR), the Na+/Li+ countertransport system (Na+/Li+ CTR), antioxidant enzyme systems, metahemoglobin reductase (MetHbRed) and transmembrane reductase (TMR) and indicators of oxidative status, namely activity of plasma epinephrine oxidase (EO) and erythrocytic acid phosphatase (LMW-PTP).
  
  
  RESULTS
  The study of the behavior of AR, Na+/Li+ CTR, EO and erythrocyte enzymes (MetHbRed, TMR and LMW-PTP) according to haptoglobin genetic phenotypes, only showed a significant difference for renin, with lower values for allele 1 carriers (homo- and heterozygous) (p < 0.05). There were no significant differences in blood pressure as regards the haptoglobin genetic phenotypes. The analysis of the behavior of the same biochemical parameters considering a family history of cardiovascular disease (CVD) showed higher values of TMR and lower values of EO in individuals with negative family history. Linear multiple regression showed some biological (Na+/Li+ CTR and MetHbRed) and genetic parameters (haptoglobin and family history of cardiovascular disease) to be stronger determinants of systolic blood pressure.
  
  
  CONCLUSIONS
  It would appear that there is a tendency for some intermediate biochemical phenotypes to express early on in childhood in individuals with a family history of CVD, which would point to an evident genetic disposition towards this type of pathology.
authors.affiliation: Departamento de Pediatria, Hospital de S. João-Faculdade de Medicina do Porto Centro de Saúde de R. Pena.
authors.forename: António
authors.initials: A
authors.lastname: Guerra
authors.forename: Carla
authors.initials: C
authors.lastname: Rego
authors.forename: Diana
authors.initials: D
authors.lastname: Silva
authors.forename: Paulino
authors.initials: P
authors.lastname: Rodrigues
authors.forename: Zelinda
authors.initials: Z
authors.lastname: Silva
authors.forename: Luísa
authors.initials: L
authors.lastname: Breitenfeld
authors.forename: Armando Teixeira
authors.initials: AT
authors.lastname: Pinto
authors.forename: Manuel
authors.initials: M
authors.lastname: Bicho
mesh_terms: D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000235:genetics; D008297:Male; D011446:Prospective Studies
chemical_list: D015415:Biomarkers