NIH study halted: Weight loss failed to improve CVD outcomes

The NIH has announced the early termination of the Look AHEAD study, which tested whether weight loss achieved through lifestyle intervention could reduce the rate of heart disease, stroke and cardiovascular-related deaths in overweight and obese people with type 2 diabetes.

According to a press release, the intensive diet and exercise program did not reduce CV events such as myocardial infarction and stroke in people with long-term type 2 diabetes.

The Look AHEAD (Action for Health in Diabetes) study included 5,145 participants; half were randomly assigned to an intensive lifestyle intervention and the other half to a general diabetes support and education program. The study was conducted at 16 centers around the US.

Study participants were aged 45 to 76 years when enrolled, 60% were women and more than 37% were from racial and ethnic minority groups.

“Although the intervention did not reduce cardiovascular events, Look AHEAD has shown other important health benefits of the lifestyle intervention, including decreasing sleep apnea, reducing the need for diabetes medications, helping to maintain physical mobility, and improving quality of life,” according to the press release.

“Look AHEAD found that people who are obese and have type 2 diabetes can lose weight and maintain their weight loss with a lifestyle intervention,” Rena Wing, PhD, chair of the Look AHEAD study and professor of psychiatry and human behavior at Brown University, said in the press release. “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.”

Wing and colleagues are currently preparing for the results for a peer-reviewed publication, and the CVD data are being analyzed for further clarification.

Participants in the intervention group lost an average of more than 8% of their initial body weight after 1 year of intervention. An average weight loss of nearly 5% was maintained at 4 years. Those in the diabetes support and education group lost about 1% of their initial weight after 1 and 4 years.

The intervention arm was stopped in September, based on a recommendation from the study’s data and safety monitoring board, who found that the intensive lifestyle did no harm but did not decrease occurrence of CV events — the primary study goal. At the time, participants had been in the intervention for up to 11 years, according to the press release.

The monitoring board encouraged the study to continue following Look AHEAD participants for long-term effects of intervention.

“The intervention group did not have fewer cardiovascular events than the group receiving general diabetes support and education, but one positive factor we saw was that both groups had a low number of cardiovascular events compared to previous studies of people with diabetes,” 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 (NIDDK), the study's primary sponsor, said in the release.

Researchers are currently examining data to measure effects of the lifestyle intervention on subgroups, including racial and ethnic groups and people with a history of CVD.