The Look AHEAD trial has been stopped early due to lack of cardiovascular benefit, according to a statement released Oct. 19 from the National Institute of Health (NIH), the funders of the trial.
"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, MD, chair of the Look AHEAD study and professor of psychiatry and human behavior at Brown University in the statement.
The trial aimed to compare the long-term health impacts and effects of an intensive lifestyle intervention (ILI) and diabetes support and education on the incidence of the major cardiovascular events in 5,145 overweight or obese individuals with type 2 diabetes mellitus.
The trial's one year results were published in 2007 and found ILI resulted in clinically significant weight loss and improved diabetes control and cardiovascular risk factors in individuals with type 2 diabetes, whereas the four year results were published in 2010 and showed that ILI continued to produce sustained weight loss and improvements in fitness, glycemic control and cardiovascular risk factors. Additional results were slated to be released in the coming years.
The statement notes that "few, if any, studies of this size and duration have had comparable success in achieving and maintaining weight loss. Participants in the intervention group lost an average of more than 8 percent of their initial body weight after one year of intervention. They maintained an average weight loss of nearly 5 percent at four years, an amount of weight loss that experts recommend to improve health. Participants in the diabetes support and education group lost about 1 percent of their initial weight after one and four years."
"In September 2012, the NIH stopped the intervention arm, acting on the recommendation of the study's data and safety monitoring board. The independent advisory board, charged with monitoring the study data and safety of participants, found that the intensive lifestyle did no harm but did not decrease occurrence of cardiovascular events, the primary study goal. At the time, participants had been in the intervention for up to 11 years."
"Because there was little chance of finding a difference in cardiovascular events between the groups with further intervention, the board recommended stopping the intensive lifestyle intervention, but encouraged the study to continue following all Look AHEAD participants to identify longer-term effects of the 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,' said Mary Evans, MD, 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."
According to the statement, "data are currently being analyzed to fully understand the cardiovascular disease results. Investigators are preparing a report of the findings for a peer-reviewed publication."