title: Viva la Familia Study: genetic and environmental contributions to childhood obesity and its comorbidities in the Hispanic population.
abstract: BACKGROUND
  Genetic and environmental contributions to childhood obesity are poorly delineated.
  
  
  OBJECTIVE
  The Viva la Familia Study was designed to genetically map childhood obesity and its comorbidities in the Hispanic population. The objectives of this report were to describe the study design and to summarize genetic and environmental contributions to the phenotypic variation in obesity and risk factors for metabolic diseases in Hispanic children.
  
  
  METHODS
  The Viva la Familia cohort consisted of 1030 children from 319 families selected based on an overweight proband between the ages of 4 and 19 y. In-depth phenotyping to characterize the overweight children and their siblings included anthropometric and body-composition traits by dual-energy X-ray absorptiometry and assessments of diet by 24-h recalls, physical activity by accelerometry, and risk factors for metabolic diseases by standard biochemical methods. Univariate quantitative genetic analysis was used to partition phenotypic variance into additive genetic and environmental components by using the computer program SOLAR.
  
  
  RESULTS
  Sex, age, and environmental covariates explained 1-91% of the phenotypic variance. Heritabilities of anthropometric indexes ranged from 0.24 to 0.75. Heritability coefficients for the body-composition traits ranged from 0.18 to 0.35. Diet and physical activity presented heritabilities of 0.32 to 0.69. Risk factors for metabolic diseases were heritable with coefficients ranging from 0.25 to 0.73. Significant genetic correlations between obesity traits and risk factors for metabolic diseases substantiated pleiotropy between traits.
  
  
  CONCLUSIONS
  The Viva la Familia Study provides evidence of a strong genetic contribution to the high prevalence of obesity and its comorbidities in Hispanic children.
authors.affiliation: US Department of Agriculture/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA. nbutte@bcm.edu
authors.forename: Nancy F
authors.initials: NF
authors.lastname: Butte
authors.forename: Guowen
authors.initials: G
authors.lastname: Cai
authors.forename: Shelley A
authors.initials: SA
authors.lastname: Cole
authors.forename: Anthony G
authors.initials: AG
authors.lastname: Comuzzie
mesh_terms: D000293:Adolescent; D000886:Anthropometry; D001774:Blood Chemical Analysis; D001823:Body Composition / Q000235:genetics / Q000502:physiology; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D015897:Comorbidity; D004032:Diet; D004777:Environment; D015444:Exercise / Q000502:physiology; D005260:Female; D014644:Genetic Variation; D005828:Genetics, Population; D005838:Genotype; D006306:Health Surveys; D006630:Hispanic or Latino / Q000235:genetics; D006801:Humans; D008297:Male; D011939:Mental Recall; D009765:Obesity / Q000453:epidemiology / Q000208:ethnology* / Q000235:genetics*; D010641:Phenotype; D013781:Texas / Q000453:epidemiology