While reducing blood sugar is critical for managing diabetes, tight glucose control failed to show long-term heart benefits in older adults years after treatment. Findings were recently published in the New England Journal of Medicine and suggest that other steps like losing weight and reducing cholesterol may be more effective for reducing risk for heart disease—America’s leading killer.
Known as the VADT study (Veterans Affairs Diabetes Trial), this trial tested the effects of tight blood sugar control in 1,791 military veterans with type 2 diabetes. The purpose was to see whether lowering blood sugar more aggressively helps reduce risk of heart disease, which is a known complication of diabetes.
The initial results, which were previously published after ten years of follow-up, showed that tight blood sugar control reduced risk for heart events by 17%. However, an extended follow-up of 15 years shows that these benefits fade in the years after treatment has ended.
Through the VADT study, participants were randomly assigned either a standard or aggressive goal for blood sugar control for five years. During the treatment period, half of participants achieved a standard HbA1c level of 8-9%, while the more aggressively treated group reduced hbA1c levels to 7%.
HbA1c refers to glycated hemoglobin and is used to estimate our average blood sugars over a period of time.
After a total of ten years, risk for heart events was significantly lower among those with tight blood sugar control vs. those with standard control. However, the new study found that these benefits went away after an additional five years of follow-up.
In fact, once participants in both groups had similar hbA1c levels following the intervention, those in the tight blood sugar control group had higher cardiovascular risk than those with standard control. Authors note that this may be due to the fact that tight glucose control is often associated with weight gain, which increases risk for heart problems.
The take-home message, according to authors, is that older adults with diabetes should not expect long-term heart benefits from tight blood sugar control. Instead, patients should focus on the tried and true methods for reducing risk for heart disease, such as losing weight and controlling risk factors like high blood pressure and high cholesterol.