title: Glycaemic control modifies the haptoglobin 2 allele-conferred susceptibility to coronary artery disease in Type 1 diabetes.
abstract: We aimed to assess whether the association of the haptoglobin 2 allele with coronary artery disease is modified by glycaemic control in a prospective cohort study of individuals with childhood-onset Type 1 diabetes.
  
  
  
  Coronary artery disease events (death from coronary artery disease, confirmed myocardial infarction, stenosis ≥50%, revascularization) were assessed between 1986 and 2013 among 480 individuals with Type 1 diabetes (baseline age 28 years; diabetes duration 19 years). Better glycaemic control was defined as an updated mean HbA1cduring follow-up of <8% (64 mmol/mol).
  
  
  
  In crude models, the incidence of coronary artery disease increased with the number of haptoglobin 2 alleles (hazard ratio 1.34, 95% CI 1.05-1.71). This association was more pronounced in those with better than in those with worse glycaemic control (P interaction = 0.05) and remained essentially unaltered after multivariable adjustments (hazard ratio 2.65, 95% CI 1.30-5.41 in those with better glycaemic control and hazard ratio 1.20, 95% CI 0.93-1.56 in those with worse glycaemic control).
  
  
  
  These results suggest that, although better control may reduce the incidence of coronary artery disease in Type 1 diabetes, a residual risk related to the haptoglobin 2 allele remains.
authors.affiliation: Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA, USA. costacout@edc.pitt.edu.
authors.forename: T
authors.initials: T
authors.lastname: Costacou
authors.affiliation: Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: R W
authors.initials: RW
authors.lastname: Evans
authors.affiliation: Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: T J
authors.initials: TJ
authors.lastname: Orchard
mesh_terms: D000328:Adult; D000483:Alleles; D001786:Blood Glucose / Q000378:metabolism*; D003324:Coronary Artery Disease / Q000097:blood / Q000235:genetics*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000150:complications* / Q000235:genetics*; D003925:Diabetic Angiopathies / Q000097:blood / Q000235:genetics*; D005260:Female; D005500:Follow-Up Studies; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006442:Glycated Hemoglobin / Q000378:metabolism; D006242:Haptoglobins / Q000235:genetics*; D006801:Humans; D012307:Risk Factors; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D006242:Haptoglobins; C485359:HP protein, human