Long-term cardiovascular outcomes improved in U.S. military veterans with type 2 diabetes who received intensive glucose control, although their rate of overall survival was similar to patients who received standard therapy.
Lead researcher Rodney A. Hayward, MD, of the Veterans Affairs Center for Clinical Management Research in Ann Arbor, Mich., and colleagues published their findings online in The New England Journal of Medicine on June 4.
They evaluated the VADT (Veterans Affairs Diabetes Trial), a randomized, controlled study that included 1,791 military veterans with type 2 diabetes who enrolled from Dec. 1, 2000, to May 30, 2003. After a follow-up period of 7.5 years, there was no difference in the time to first major cardiovascular event between the intensive-therapy and standard-therapy groups.
In this analysis, Hayward and colleagues followed the patients for an additional five years, during which they received no further clinical intervention. They evaluated four national data registries and conducted annual, self-administered surveys that asked patients if they had major cardiovascular events such as heart attacks or strokes.
After 9.8 years of follow-up, there were 288 major cardiovascular events in the standard-therapy group and 253 in the intensive-therapy group, which represented a statistically significant difference and a 17 percent relative reduction with intensive therapy.
There were no statistically significant differences with regards to cardiovascular mortality or all-cause mortality.
The researchers said the reduction in cardiovascular events was similar to other large trials, including the UKPDS (United Kingdom Prospective Diabetes Study) and ACCORD (Action to Control Cardiovascular Risk in Diabetes) trials. However, the benefits of intensive glucose control on mortality have varied. They noted there was a significant reduction in mortality in the UKPDS trial and a significant increase in mortality in the ACCORD study.
They also mentioned several potential limitations of the study, including that there may have been differences between the groups besides their glycated hemoglobin levels and that this subgroup analysis may not be generalizable to the full study cohort. However, they said there were no differences between the groups with regards to blood pressure and lipid levels and that they found no evidence of sample-selection bias.