An intensive lifestyle intervention that results in weight loss does not reduce the risk of cardiovascular events in overweight/obese patients with long-standing type 2 diabetes. Although the intensive diet and exercise intervention failed to reduce cardiovascular risk, it did have other important health benefits, said researchers from the Look AHEAD (Action for Health in Diabetes) study, which was supported by the National Institutes of Health (NIH).
In September 2012, the NIH stopped the intervention arm, acting on the recommendation of the study's data and safety monitoring board (DSMB) . At the time, participants had been in the intervention for up to 11 years. The DSMB concluded that it was extremely unlikely that a difference in the rate of cardiovascular events would emerge between the intervention and control groups with longer follow-up.
Look AHEAD is the first study to assess the long-term effects of intensive lifestyle intervention on the rate of major cardiovascular disease events and death in adults with type 2 diabetes. Some 5,145 patients managed at 16 centers across the United States were randomized to intensive lifestyle intervention or a program of diabetes support and education. Participants were 45 to 76 years old when enrolled. Sixty percent were women and >37% were from racial and ethnic minority groups.
“Although the study found weight loss had many positive health benefits for people with type 2 diabetes, the weight loss did not reduce the number of cardiovascular events,” said Rena Wing, PhD, chair of Look AHEAD and professor of psychiatry and human behavior at Brown University, Providence, RI, in an NIH press release.
Patients in the lifestyle intervention group had improvements in their sleep apnea, reductions in their need for diabetes medications, maintained their physical mobility, and improved their quality of life relative to the controls, she noted.
Those in the intervention group lost an average of >8% of their initial body weight after 1 year of intervention. They maintained an average weight loss of nearly 5% at 4 year. Participants in the support and education group lost about 1% of their initial weight after 1 and 4 years.
Although the intervention group did not have fewer cardiovascular events than the group receiving general diabetes support and education, both groups had a low number of cardiovascular events compared with previous studies of people with diabetes, said Mary Evans, PhD, director of Special Projects in Nutrition, Obesity, and Digestive Diseases within the NIH’s National Institute of Diabetes and Digestive and Kidney Diseases.
According to the NIH, researchers are now analyzing data to measure effects of the lifestyle intervention on subgroups, including racial and ethnic groups and people with a history of cardiovascular disease.