title: Haptoglobin phenotype and prevalent coronary heart disease in the Framingham offspring cohort.
abstract: BACKGROUND
  The haptoglobin (Hp) locus is polymorphic with two major alleles denoted 1 and 2. Several recent prospective longitudinal studies have demonstrated conflicting results regarding whether there is an increase or decrease in the relative risk of coronary heart disease (CHD) conferred on individuals homozygous for the haptoglobin 1 allele (Hp 1-1).
  
  
  METHODS
  We sought to examine the relationship between Hp type and prevalent coronary heart disease in a cross-sectional study from a large community-based cohort, the Framingham Heart Offspring Study (n = 3273).
  
  
  RESULTS
  Overall we found no relation between Hp type and CHD prevalence. In secondary analyses we found a different pattern of Hp type and CHD prevalence by diabetes status. In nondiabetics, compared with Hp 1-1, Hp 2-1 (OR 1.71, 95% CI 1.03, 2.83) was associated with excess prevalence of CHD. In contrast in diabetic individuals we observed the opposite pattern; Hp 2-1 (OR 0.49, 95% CI 0.24, 0.99) and Hp 2-2 (OR 0.46, 95% CI 0.22, 0.96) were associated with diminished prevalence of CHD.
  
  
  CONCLUSIONS
  These data are consistent with an interaction between Hp type and diabetes in the prevalence of CHD. These findings will need to be confirmed in other cohorts and in longitudinal studies.
authors.affiliation: Technion Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel. alevy@tx.technion.ac.il
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Levy
authors.forename: Martin G
authors.initials: MG
authors.lastname: Larson
authors.forename: Diane
authors.initials: D
authors.lastname: Corey
authors.forename: Rachel
authors.initials: R
authors.lastname: Lotan
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Vita
authors.forename: Emelia J
authors.initials: EJ
authors.lastname: Benjamin
mesh_terms: D015331:Cohort Studies; D003327:Coronary Disease / Q000453:epidemiology* / Q000235:genetics; D003430:Cross-Sectional Studies; D048909:Diabetes Complications; D005260:Female; D006242:Haptoglobins / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D015995:Prevalence
chemical_list: D006242:Haptoglobins