title: Diabetes in the Old Order Amish: characterization and heritability analysis of the Amish Family Diabetes Study.
abstract: OBJECTIVE
  The Old Order Amish (OOA) are a genetically well-defined closed Caucasian founder population. The Amish Family Diabetes Study was initiated to identify susceptibility genes for type 2 diabetes. This article describes the genetic epidemiology of type 2 diabetes and related traits in this unique population.
  
  
  METHODS
  The study cohort comprised Amish probands with diabetes who were diagnosed between 35 and 65 years of age and their extended adult family members. We recruited 953 adults who represented 45 multigenerational families. Phenotypic characterization included anthropometry, blood pressure, diabetes status, lipid profile, and leptin levels.
  
  
  RESULTS
  The mean age of study participants was 46 years, and the mean BMI was 26.9 kg/m2. Subjects with type 2 diabetes were older, more obese, and had higher insulin levels. The prevalence of diabetes in the OOA was approximately half that of the Caucasian individuals who participated in the Third National Health and Nutrition Examination Survey (95% CI 0.23-0.84). The prevalence of diabetes in the siblings of the diabetic probands was 26.5% compared with a prevalence of 7.0% in spouses (lambdaS = 3.28, 95% CI 1.58-6.80). The heritability of diabetes-related quantitative traits was substantial (13-70% for obesity-related traits, 10-42% for glucose levels, and 11-24% for insulin levels during the oral glucose tolerance test; P = 0.01 to <0.0001).
  
  
  CONCLUSIONS
  Type 2 diabetes in the Amish has similar phenotypic features to that of the overall Caucasian population, although the prevalence in the Amish community is lower than that of the Caucasian population. There is significant familial clustering of type 2 diabetes and related traits. This unique family collection will be an excellent resource for investigating the genetic underpinnings of type 2 diabetes.
authors.affiliation: Southwest Foundation for Biomedical Research, San Antonio, Texas, USA.
authors.forename: W C
authors.initials: WC
authors.lastname: Hsueh
authors.forename: B D
authors.initials: BD
authors.lastname: Mitchell
authors.forename: R
authors.initials: R
authors.lastname: Aburomia
authors.forename: T
authors.initials: T
authors.lastname: Pollin
authors.forename: H
authors.initials: H
authors.lastname: Sakul
authors.forename: M
authors.initials: M
authors.lastname: Gelder Ehm
authors.forename: B K
authors.initials: BK
authors.lastname: Michelsen
authors.forename: M J
authors.initials: MJ
authors.lastname: Wagner
authors.forename: P L
authors.initials: PL
authors.lastname: St Jean
authors.forename: W C
authors.initials: WC
authors.lastname: Knowler
authors.forename: D K
authors.initials: DK
authors.lastname: Burns
authors.forename: C J
authors.initials: CJ
authors.lastname: Bell
authors.forename: A R
authors.initials: AR
authors.lastname: Shuldiner
mesh_terms: D000328:Adult; D000368:Aged; D000886:Anthropometry; D001323:Autoantibodies / Q000097:blood; D001794:Blood Pressure; D001824:Body Constitution; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D005968:Glutamate Decarboxylase / Q000276:immunology; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D020738:Leptin / Q000032:analysis; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D010414:Pennsylvania; D010641:Phenotype; D012067:Religion
chemical_list: D001323:Autoantibodies; D005968:Glutamate Decarboxylase; D006442:Glycated Hemoglobin; D020738:Leptin; D008055:Lipids