title: Familial aggregation of gout and relative genetic and environmental contributions: a nationwide population study in Taiwan.
abstract: OBJECTIVE
  To examine familial aggregation of gout and to estimate the heritability and environmental contributions to gout susceptibility in the general population.
  
  
  METHODS
  Using data from the National Health Insurance (NHI) Research Database in Taiwan, we conducted a nationwide cross-sectional study of data collected from 22 643 748 beneficiaries of the NHI in 2004; among them 1 045 059 individuals had physician-diagnosed gout. We estimated relative risks (RR) of gout in individuals with affected first-degree and second-degree relatives and relative contributions of genes (heritability), common environment shared by family members and non-shared environment to gout susceptibility.
  
  
  RESULTS
  RRs for gout were significantly higher in individuals with affected first-degree relatives (men, 1.91 (95% CI 1.90 to 1.93); women, 1.97 (95% CI 1.94 to 1.99)) and also in those with affected second-degree relatives (men, 1.27 (95% CI 1.23 to 1.31); women, 1.40 (95% CI 1.35 to 1.46)). RRs (95% CIs) for individuals with an affected twin, sibling, offspring, parent, grandchild, nephew/niece, uncle/aunt and grandparent were 8.02 (6.95 to 9.26), 2.59 (2.54 to 2.63), 1.96 (1.95 to 1.97), 1.93 (1.91 to 1.94), 1.48 (1.43 to 1.53), 1.40 (1.32 to 1.47), 1.31 (1.24 to 1.39), and 1.26 (1.21 to 1.30), respectively. The relative contributions of heritability, common and non-shared environmental factors to phenotypic variance of gout were 35.1, 28.1 and 36.8% in men and 17.0, 18.5 and 64.5% in women, respectively.
  
  
  CONCLUSIONS
  This population-based study confirms that gout aggregates within families. The risk of gout is higher in people with a family history. Genetic and environmental factors contribute to gout aetiology, and the relative contributions are sexually dimorphic.
authors.affiliation: Department of Rheumatology, Orthopaedics and Dermatology, School of Medicine, University of Nottingham, Nottingham, UK Division of Rheumatology, Allergy and Immunology, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
authors.forename: Chang-Fu
authors.initials: CF
authors.lastname: Kuo
authors.affiliation: Division of Epidemiology and Public Health, School of Medicine, University of Nottingham, Nottingham, UK.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Grainge
authors.affiliation: Department of Public Health, College of Medicine, Chang Gung University, Taoyuan, Taiwan Biostatistics Core Laboratory, Molecular Medicine Research Centre, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Lai-Chu
authors.initials: LC
authors.lastname: See
authors.affiliation: Division of Rheumatology, Allergy and Immunology, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
authors.forename: Kuang-Hui
authors.initials: KH
authors.lastname: Yu
authors.affiliation: Division of Rheumatology, Allergy and Immunology, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
authors.forename: Shue-Fen
authors.initials: SF
authors.lastname: Luo
authors.affiliation: Department of Rheumatology, Orthopaedics and Dermatology, School of Medicine, University of Nottingham, Nottingham, UK.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Valdes
authors.affiliation: Department of Rheumatology, Orthopaedics and Dermatology, School of Medicine, University of Nottingham, Nottingham, UK.
authors.forename: Weiya
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Rheumatology, Orthopaedics and Dermatology, School of Medicine, University of Nottingham, Nottingham, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Doherty
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D004777:Environment; D005260:Female; D020022:Genetic Predisposition to Disease; D006073:Gout / Q000453:epidemiology* / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D017678:Sex Distribution; D012959:Socioeconomic Factors; D013624:Taiwan; D055815:Young Adult
keywords: Arthritis; Epidemiology; Gout