title: Heritability of physical activity traits in Brazilian families: the Baependi Heart Study.
abstract: BACKGROUND
  It is commonly recognized that physical activity has familial aggregation; however, the genetic influences on physical activity phenotypes are not well characterized. This study aimed to (1) estimate the heritability of physical activity traits in Brazilian families; and (2) investigate whether genetic and environmental variance components contribute differently to the expression of these phenotypes in males and females.
  
  
  METHODS
  The sample that constitutes the Baependi Heart Study is comprised of 1,693 individuals in 95 Brazilian families. The phenotypes were self-reported in a questionnaire based on the WHO-MONICA instrument. Variance component approaches, implemented in the SOLAR (Sequential Oligogenic Linkage Analysis Routines) computer package, were applied to estimate the heritability and to evaluate the heterogeneity of variance components by gender on the studied phenotypes.
  
  
  RESULTS
  The heritability estimates were intermediate (35%) for weekly physical activity among non-sedentary subjects (weekly PA_NS), and low (9-14%) for sedentarism, weekly physical activity (weekly PA), and level of daily physical activity (daily PA). Significant evidence for heterogeneity in variance components by gender was observed for the sedentarism and weekly PA phenotypes. No significant gender differences in genetic or environmental variance components were observed for the weekly PA_NS trait. The daily PA phenotype was predominantly influenced by environmental factors, with larger effects in males than in females.
  
  
  CONCLUSIONS
  Heritability estimates for physical activity phenotypes in this sample of the Brazilian population were significant in both males and females, and varied from low to intermediate magnitude. Significant evidence for heterogeneity in variance components by gender was observed. These data add to the knowledge of the physical activity traits in the Brazilian study population, and are concordant with the notion of significant biological determination in active behavior.
authors: Laboratory of Genetics and Molecular Cardiology, Heart Institute, Medical School of University of São Paulo, Av, Dr, Enéas de Carvalho Aguiar, 44, São Paulo, SP, 05403-000, Brazil.
authors: Andréa R V R
authors: AR
authors: Horimoto
authors: Suely R
authors: SR
authors: Giolo
authors: Camila M
authors: CM
authors: Oliveira
authors: Rafael O
authors: RO
authors: Alvim
authors: Júlia P
authors: JP
authors: Soler
authors: Mariza
authors: M
authors: de Andrade
authors: José E
authors: JE
authors: Krieger
authors: Alexandre C
authors: AC
authors: Pereira
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D001938:Brazil / Q000453:epidemiology; D002318:Cardiovascular Diseases / Q000209:etiology / Q000235:genetics; D003710:Demography; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000235:genetics*; D010641:Phenotype; D019655:Quantitative Trait, Heritable; D012307:Risk Factors; D057185:Sedentary Behavior; D012737:Sex Factors; D011795:Surveys and Questionnaires