title: Environmental factors, familial aggregation and heritability of total cholesterol, low density lipoprotein-cholesterol and high density lipoprotein-cholesterol in a Brazilian population assisted by the Family Doctor Program.
abstract: OBJECTIVE
  To estimate familial aggregation and the heritability of total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C) and high density lipoprotein-cholesterol (HDL-C) in families assisted by the Family Doctor Program in a Brazilian city, and to evaluate associations between some environmental factors and familial aggregation of these lipids.
  
  
  METHODS
  Cross-sectional familial study.
  
  
  METHODS
  The association of lipids with sociodemographic factors, lifestyle factors and comorbidities (e.g. physical activity, alcohol consumption, smoking, hypertension, impaired glucose tolerance, body mass index) was estimated using linear models and generalized estimating equations. Correlation of TC, LDL-C and HDL-C between pairs of relatives was estimated with the familial correlation procedure, and heritability was estimated with the ASSOC procedure.
  
  
  RESULTS
  All associations were statistically significant. There was familial aggregation of TC (parent/offspring, r=0.33; sibling/sibling, r=0.37), LDL-C (parent/offspring, r=0.29; sibling/sibling, r=0.37) and HDL-C (parent/offspring, r=0.25; sibling/sibling, r=0.48), but less than 3%, 6% and 14%, respectively, which was explained by lifestyle factors. Correlation between pairs with genetic sharing (parent/offspring and sibling/sibling) was higher than that observed between father and mother. Heritability estimates ranged between 0.32 (HDL-C) and 0.50 (TC). Similar results were found for the two approaches used to estimate the contribution of genetic and environmental factors in the correlation of TC, LDL-C and HDL-C between the family pairs.
  
  
  CONCLUSIONS
  The results showed that there is familial aggregation of TC, LDL-C and HDL-C, and point to the predominance of genetic factors because little influence of environmental variables was found.
authors.affiliation: Department of Epidemiology and Biostatistics, Universidade Federal Fluminense, Niterói, Rio de Janeiro, RJ, Brazil.
authors.forename: S V
authors.initials: SV
authors.lastname: de Miranda Chagas
authors.forename: S
authors.initials: S
authors.lastname: Kanaan
authors.forename: H
authors.initials: H
authors.lastname: Chung Kang
authors.forename: M
authors.initials: M
authors.lastname: Cagy
authors.forename: R E
authors.initials: RE
authors.lastname: de Abreu
authors.forename: L A
authors.initials: LA
authors.lastname: da Silva
authors.forename: R C
authors.initials: RC
authors.lastname: Garcia
authors.forename: M L
authors.initials: ML
authors.lastname: Garcia Rosa
mesh_terms: D000328:Adult; D001938:Brazil; D002784:Cholesterol / Q000097:blood / Q000235:genetics*; D008076:Cholesterol, HDL / Q000097:blood / Q000235:genetics*; D008078:Cholesterol, LDL / Q000097:blood / Q000235:genetics*; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D006304:Health Status; D006801:Humans; D040582:Inheritance Patterns; D008019:Life Style; D008297:Male; D012307:Risk Factors; D012959:Socioeconomic Factors
chemical_list: D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D002784:Cholesterol