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.
OBJECTIVE
The optimal HbA(1c) concentration for prevention of macrovascular complications and deaths in obese cardiovascular high-risk patients with type 2 diabetes remains to be established and was therefore studied in this post hoc analysis of the Sibutramine Cardiovascular OUTcomes (SCOUT) trial, which enrolled overweight and obese patients with type 2 diabetes and/or cardiovascular disease.


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 HbA(1c) available at baseline (i.e. study randomisation). Median age was 62 years (range 51-86 years), median BMI was 34.0 kg/m(2) (24.8-65.1 kg/m(2)) and 44% were women. The median HbA(1c) 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 HbA(1c) 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 HbA(1c) increase (p = 0.02 for interaction). There was no evidence of increased risk associated with HbA(1c) ≤ 6.4% (≤ 46 mmol/l). Glucose-lowering treatment regimens, diabetes duration or a history of cardiovascular disease did not modify the associations.


CONCLUSIONS
In overweight, cardiovascular high-risk patients with type 2 diabetes, increasing HbA(1c) concentrations were associated with increasing risks of cardiovascular adverse outcomes and all-cause mortality.
Department of Cardiology, Gentofte University Hospital of Copenhagen, Niels Andersens vej 65, 2900 Hellerup, Denmark. ca@heart.dk
C
C
Andersson
L
L
van Gaal
I D
ID
Caterson
P
P
Weeke
W P T
WP
James
W
W
Coutinho
W
W
Couthino
N
N
Finer
A M
AM
Sharma
A P
AP
Maggioni
C
C
Torp-Pedersen
D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000097:blood* / Q000401:mortality / Q000503:physiopathology; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000401:mortality / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood* / Q000401:mortality / Q000503:physiopathology; D011237:Predictive Value of Tests; D012307:Risk Factors
D015415:Biomarkers; D001786:Blood Glucose; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human