Relationship between HbA1c levels and risk of cardiovascular adverse outcomes and all-cause mortality in overweight and obese cardiovascular high-risk women and men with type 2 diabetes

Diabetologia - Clinical and Experimental Diabetes and Metabolism, 05/31/2012

Andersson C et al. – In overweight, cardiovascular high–risk patients with type 2 diabetes, increasing HbA1c concentrations were associated with increasing risks of cardiovascular adverse outcomes and all–cause mortality.

Methods

  • HRs for meeting the primary endpoint (nonfatal myocardial infarction, nonfatal stroke, resuscitated cardiac arrest or cardiovascular death) and all–cause mortality were analysed using Cox regression models.

Results

  • Of 8,252 patients with type 2 diabetes included in SCOUT, 7,479 had measurements of HbA1c available at baseline (i.e. study randomisation).
  • Median age was 62 years (range 51–86 years), median BMI was 34.0 kg/m2 (24.8–65.1 kg/m2) and 44% were women.
  • The median HbA1c concentration was 7.2% (3.8–15.9%) (55 mmol/l [18–150 mmol/l]) and median diabetes duration was 7 years (0–57 years).
  • For each 1 percentage point HbA1c increase, the adjusted HR for the primary endpoint was 1.17 (95% CI 1.11, 1.23); no differential sex effect was observed (p = 0.12 for interaction).
  • In contrast, the risk of all–cause mortality was found to be greater in women than in men: HR 1.22 (1.10, 1.34) vs 1.12 (1.04, 1.20) for each 1 percentage point HbA1c increase (p = 0.02 for interaction).
  • There was no evidence of increased risk associated with HbA1c ≤6.4% (≤46 mmol/l).
  • Glucose–lowering treatment regimens, diabetes duration or a history of cardiovascular disease did not modify the associations.

Print Article Summary