1. Home>
2. Specialties>
3. Cardiology>
4. Summary and Comment

Does Glucose Control in Type 2 Diabetes Affect Cardiovascular Risk?

Results from another late-intervention study show no significant effect at about 6 years of follow-up.

Findings from the ACCORD and ADVANCE studies (JW Cardiol Jun 6 2008) called into question the benefit of intensive glucose control for patients with type 2 diabetes. Results are now available from a third study, the open-label Veterans Affairs Diabetes Trial, which also compares an intensive glucose-lowering strategy with standard therapy in these patients.

The investigators enrolled 1791 veterans (mean age, 60.4; mean years since diabetes diagnosis, 11.5) with poorly controlled type 2 diabetes (mean HbA_1c level, 9.4%). Patients with body-mass indexes 27 initially received metformin plus rosiglitazone, and those with BMI <27 initially received glimepiride plus rosiglitazone. Participants randomized to intensive therapy were prescribed maximal doses, and those randomized to standard therapy were prescribed half the maximal doses. Insulin was added for patients who did not achieve HbA_1c levels <6% in the intensive-therapy group and <9% in the standard-therapy group. The primary outcome was time to first occurrence of a cardiovascular event.

The median HbA_1c stabilized by 6 months at 8.4% in the standard-therapy group and at 6.9% in the intensive-therapy group. At a median follow-up of 5.6 years, no significant benefit in the primary outcome was associated with intensive therapy (hazard ratio, 0.88; P=0.14). Ninety-five deaths occurred in the standard-therapy group, and 102 occurred in the intensive-therapy group (HR, 1.07; P=0.62). The two groups did not differ in the incidence of microvascular complications, including retinopathies, neuropathies, and nephropathies.

Comment: Three studies have now failed to show that intensive glucose control in type 2 diabetes reduces the risk for cardiovascular events. Of the three, the present cohort had the highest mean HbA_1c levels at baseline and after standard therapy; the mean HbA_1C level achieved in the intensive-therapy group was the same as that achieved in ADVANCE and slightly higher than that achieved in ACCORD. The authors conclude that control of hypertension, dyslipidemia, and other cardiovascular risk factors, rather than a focus on intensive control of glucose, is the most effective preventive approach in these patients. Critics might wonder if treatment earlier in the course of diabetes or longer follow-up would have altered this study’s findings (JW Cardiol Oct 15 2008).

— Harlan M. Krumholz, MD, SM

Published in Journal Watch Cardiology December 17, 2008

Citation(s):

Duckworth W et al for the VADT Investigators. Glucose control and vascular complications in veterans with type 2 diabetes. N Engl J Med 2008 Dec 17; [e-pub ahead of print]. (http://dx.doi.org/10.1056/NEJMoa0808431)

2011 Top Stories