SCOUT: HbA1c Levels Predict CV and All-Cause Mortality in Overweight and Obese Individuals

Regular readers may recall our previous publication of the Sibutramine Cardiovascular OUTcomes (SCOUT) trial, the largest prospective randomised controlled trial of pharmacological obesity treatment.

In a paper just released in DIABETOLOGIA, we now our analysis of the relationship between HbA1c levels (a measure of diabetes control) and the risk of mortality in participants in this trial.

The analysis is based on 8,252 patients with type 2 diabetes included in SCOUT, 7,479 of who had measurements of HbA1c available at baseline. The median age was 62 years, median BMI was 34.0 and 44% were women. Median HbAic concentration was 7.2% and median diabetes duration was 7 years.

For each 1 percentage point HbA1c increase, the adjusted hazard ratio (HR) for the primary endpoint (nonfatal myocardial infarction, nonfatal stroke, resuscitated cardiac arrest or cardiovascular death) was 1.17; no differential sex effect was observed.

In contrast, the risk of all-cause mortality was found to be greater in women than in men: HR 1.22 vs 1.12 for each 1 percentage point HbA1c increase.

There was no evidence of increased risk associated with HbA1c ≤6.4%.

Glucose-lowering treatment regimens, diabetes duration or a history of cardiovascular disease did not modify the associations.

Thus, the data from this large clinical trial support the notion that in overweight, cardiovascular high-risk patients with type 2 diabetes, increasing HbA1c concentrations are associated with increasing risks of cardiovascular adverse outcomes and all-cause mortality.

Canmore, Alberta

ResearchBlogging.orgAndersson C, van Gaal L, Caterson ID, Weeke P, James WP, Couthino W, Finer N, Sharma AM, Maggioni AP, & Torp-Pedersen C (2012). Relationship between HbA(1c) 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 PMID: 22638548