title: Contemporary Risk Estimates of Three HbA1c Variables for Myocardial Infarction in 101,799 Patients Following Diagnosis of Type 2 Diabetes.
abstract: OBJECTIVE
  This study evaluated the risk of myocardial infarction (MI) by impaired glycemic control in a contemporary large cohort of patients with type 2 diabetes followed from diagnosis.
  
  
  METHODS
  Patients with type 2 diabetes diagnosed between 1995 and 2011 were retrieved from the Clinical Practice Research Datalink in the U.K., and followed from diagnosis until event of MI or end of study in 2013. Two subcohorts were defined: an early cohort with those diagnosed from 1997 to 2004 and a recent cohort with those diagnosed from 2004 to 2011. Association between each of three HbA1c metrics and MI was estimated using adjusted proportional hazards models.
  
  
  RESULTS
  In the overall cohort (n = 101,799), the risk increase for MI per 1% (10 mmol/mol) increase in HbA(1c) was higher for updated latest and updated mean HbA(1c) of 1.11 (95% CI 1.09-1.13) and 1.15 (1.13-1.18) than for baseline HbA(1c) of 1.05 (1.03-1.06). In the early subcohort, the corresponding risk estimates were greater than those in the recent subcohort. When categorized, the updated latest variable showed an increased risk for HbA(1c) <6% (42 mmol/mol), relative category 6-7%, in the recent but not in the early subcohort, with hazard ratios of 1.23 (1.08-1.40) and 1.01 (0.84-1.22), respectively.
  
  
  CONCLUSIONS
  The two time-updated HbA(1c) variables show a stronger relation with MI than baseline HbA(1c). The risk association between HbA(1c) and MI has decreased over time. In recently diagnosed patients with type 2 diabetes, an increased risk of MI exists at a current HbA(1c) of <6.0% (42 mmol/mol).
authors.affiliation: R&D AstraZeneca, Mölndal, Sweden Mathematical Sciences, Chalmers University of Technology, Gothenburg, Sweden marita.olsson@astrazeneca.com.
authors.forename: Marita
authors.initials: M
authors.lastname: Olsson
authors.affiliation: R&D AstraZeneca, Mölndal, Sweden.
authors.forename: Volker
authors.initials: V
authors.lastname: Schnecke
authors.affiliation: R&D AstraZeneca, Mölndal, Sweden.
authors.forename: Claudia
authors.initials: C
authors.lastname: Cabrera
authors.affiliation: R&D AstraZeneca, Mölndal, Sweden Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Stanko
authors.initials: S
authors.lastname: Skrtic
authors.affiliation: Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden Department of Medicine, NU-Hospital Organization, Uddevalla Hospital, Uddevalla, Sweden.
authors.forename: Marcus
authors.initials: M
authors.lastname: Lind
mesh_terms: D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000209:etiology*; D003925:Diabetic Angiopathies / Q000097:blood / Q000209:etiology*; D004812:Epidemiologic Methods; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000209:etiology*
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin