What Is Look AHEAD?
Look AHEAD (Action For Health in Diabetes) is a multicenter randomized clinical trial to examine the effects of a lifestyle intervention designed to achieve and maintain weight loss over the long term through decreased caloric intake and exercise. Look AHEAD is focusing on the disease most affected by overweight and obesity, type 2 diabetes, and on the outcome that causes the greatest morbidity and mortality, cardiovascular disease.
Look AHEAD Background
Overweight (Body Mass Index (BMI) 25.0-29.9) and obesity (BMI greater than or equal to 30.0) now affect more than 50% of adult Americans, reflecting a rapid increase in prevalence. Obesity also is associated with a host of significant comorbid conditions, including diabetes and cardiovascular disease. Many studies have demonstrated that short-term weight loss has beneficial effects on risk factors such as high blood pressure and cholesterol. However, observational studies have raised concerns about negative effects of weight loss and weight cycling. Some of these studies suggest increased, not decreased, mortality; however, most cannot distinguish voluntary from involuntary weight loss.
In 1997, a workshop was convened by the National Institutes of Health (NIH) and the Centers for Disease Control and Prevention (CDC) to address this issue. Workshop participants concluded that only a randomized clinical trial of intentional weight loss could provide needed guidance on the risks and benefits of weight loss to inform rational clinical and public health policy. They suggested that such a study should focus on obese individuals who already had a comorbid medical illness, both because of the clear public health recommendation of weight loss for such individuals and because of their increased risk of adverse health-related outcomes. A trial was considered feasible since several large randomized multi-center trials have demonstrated substantial decreases in weight and increases in activity level for as long as three years. Acting on this recommendation, the NIDDK issued an RFA (DK-98-019) for Clinical Centers and an RFA (DK-98-020) for a Data Coordinating Center for a study then called SHOW (the Study of Health Outcomes of Weight Loss). This study has evolved into the Look AHEAD trial.
Other sponsoring institutes and organizations include the National Heart, Lung, and Blood Institute (NHLBI), National Institute of Nursing Research (NINR), the Office of Research on Women´s Health (ORWH), the National Center for Minority Health and Health Disparities (NCMHD), and the Centers for Disease Control and Prevention (CDC).
Look AHEAD Centers
Fifteen extramural Look AHEAD Clinical Centers and a Data Coordinating Center were funded under the RFA. In addition, a Southwest American Indian Look AHEAD clinical center has also been formed at the NIDDK Phoenix Epidemiology and Clinical Research Branch in Arizona. The trial has been designed collaboratively by the investigators of these 16 Clinical Centers, the Data Coordinating Center, the NIH and the CDC.
Look AHEAD Objectives
The Look AHEAD trial has completed enrollment of 5,145 obese patients with type 2 diabetes. At study entry, participants were randomly assigned to one of two interventions, the Lifestyle Intervention or Diabetes Support and Education. They will be followed for a total period of up to 11.5 years.
The primary aim of Look AHEAD is to study the effects of the two interventions on major cardiovascular events: heart attack, stroke and cardiovascular-related death. Look AHEAD also will investigate the impact of the interventions on other cardiovascular disease-related outcomes, cardiovascular risk factors, and all-cause mortality. Additional outcomes include: diabetes control and complications, fitness, general health, health-related quality of life and psychological outcomes. The cost and cost effectiveness of the Lifestyle Intervention relative to Diabetes Support and Education will be assessed.
A number of Look AHEAD ancillary studies will elucidate additional topics, such as fatty liver disease, sleep apnea and eating disorders in Look AHEAD participants.
Visit the Look AHEAD Web Site
To view the Look AHEAD protocol, please go to the study website at: www.lookaheadtrial.org
LOOK AHEAD COORDINATING CENTERWake Forest University
LOOK AHEAD CLINICAL CENTERS
Johns Hopkins University
Pennington Biomedical Research
Center Baton Rouge, LA
Baylor College of Medicine
University of Texas Health Science Center
San Antonio, TX
University of Colorado Health Sciences Center
University of Minnesota
University of Washington
University of Pittsburgh
University of Tennessee
Massachusetts General Hospital
St. Lukes-Roosevelt Institute for Health Sciences
New York, NY
University of Southern California
Los Angeles, CA
University of Alabama at Birmingham
University of Pennsylvania
The Miriam Hospital
Southwest American Indian Center