NIH-funded Look AHEAD Study Produced Important Data, Though Not Its Main Focus.
An intervention study funded by the National Institutes of Health (NIH) at the University of Tennessee Health Science Center (UTHSC) has been cut short but still yielded important data. The study, targeted at determining cardiovascular benefits of weight loss in people with Type 2 diabetes, started in 1999 and was scheduled to run through 2014.
The original goal was to find a direct correlation between weight loss and its effects preventing heart attack and strokes in people with long-standing Type 2 diabetes. The NIH discontinued the study early because this correlation could not be shown; however, study participants realized weight loss that resulted in other significant health benefits — lower blood pressure, decreased blood sugar and reductions in cholesterol. Called Look AHEAD (Action for Health in Diabetes), the study included 5,145 people in 16 health centers across the United States. Half of all participants received intensive lifestyle intervention, while the other half followed a general program of diabetes support and education. More than 330 participants enrolled in the study through the UTHSC Department of Preventive Medicine with Karen C. Johnson, MD, MPH, and through the Division of Endocrinology with Abbas Kitabchi, MD, PhD, in Memphis.
“Even though the intervention didn’t reduce cardiovascular events, Look AHEAD showed other important health benefits,” explained Dr. Johnson, who was one of two primary investigators in the study at UTHSC. “People who received the intervention had an improved quality of life. Some people in the study needed less diabetes medication, and decreased sleep apnea, and the weight loss helped almost all of them maintain mobility.”
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 of their body weight after four years, an amount of weight loss that experts recommend to improve health, while the other group, without the intervention, lost 1 percent of their body weight.
“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, 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.
Though officials at NIDDK recommended stopping the intensive lifestyle intervention because they felt there was little chance of finding a difference in cardiovascular events between the groups, investigators were encouraged to continue following all Look AHEAD participants to identify longer-term effects of the intervention. Data is currently being analyzed to fully understand the cardiovascular disease results. Investigators are preparing a report of the findings for a peer-reviewed publication.
In addition to the NIDDK, other NIH support for Look AHEAD comes from the National Heart, Lung, and Blood Institute; the National Institute of Nursing Research; the Office of Research on Women’s Health; and the National Center for Minority Health and Health Disparities. The Indian Health Service and the Centers for Disease Control and Prevention also provided support.
Find more information about the Look AHEAD trial (NCT00017953), including a list of current publications, visit www.lookaheadtrial.org. For a list of centers enrolling patients for diabetes or obesity trials, search for keywords “diabetes” or “obesity” at www.clinicaltrials.gov.