Action For Health in Diabetes (Look AHEAD)
Look AHEAD (Action for Health in Diabetes) is a multi-center, randomized, clinical trial that focuses on lifestyle intervention for participants in order to study its effects on weight loss and long-term maintenance through decreased caloric intake and exercise. Look AHEAD is focusing on the disease most affected by being overweight and obese, Type-2 Diabetes, and on the outcome that causes the greatest morbidity and mortality, Cardiovascular Disease.
Look AHEAD Background
Being overweight (Body Mass Index (BMI) 25.0-29.9) or obese (BMI greater than or equal to 30.0) now affects more than 50% of adult Americans, reflecting a rapid increase in prevalence. Obesity is also 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 the 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 the 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 will also 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.
For more information and to view the Look AHEAD protocol, please visit the study website at www.lookaheadtrial.org
Look AHEAD Coordinating Centers
Wake Forest University
Winston-Salem North Carolina
The aging of the population and the epidemic of obesity have led to a rapid increase in the number of older, obese individuals with diabetes. Little is known about the long-term health effects of lifestyle interventions designed to lower weight and increase physical activity in this population. The Look AHEAD Continuation (Look AHEAD-C) builds on the extraordinary retention and adherence of the Look AHEAD trial, adding assessments of critical outcomes to determine the long-term impact of a nine to 11 year intensive lifestyle intervention (ILI) on the health problems of greatest concern in older, obese individuals with Type-2 Diabetes.
The primary objectives of Look AHEAD-C are to examine the relative impact of random assignment to a nine to 11 year intensive lifestyle intervention to promote and maintain weight loss and increase physical activity on 1) physical function and mobility disability and 2) cognitive function and cognitive impairment. Secondary objectives include additional health-related outcomes of importance to older individuals and to accrue additional power to evaluate secondary and tertiary outcomes of Look AHEAD.
All participants currently participating in the Look AHEAD trial will be invited to enroll in Look AHEAD-C.
The purpose of this study is to continue to follow participants and to help us understand the long–term effects of weight change on overall health. During the main part of the Look AHEAD Clinical Trial, participants were assigned by chance to be in either the Intensive Lifestyle Intervention group or the Diabetes Support and Education group. We are no longer providing these separate programs; however, we want to know whether the many years of participation in these programs has long-term effects on your health.
There are many aspects to overall health. These include heart attacks and strokes, complications of diabetes, and psychological health. We focused on those aspects of health in the early phases of Look AHEAD and will continue to do so in the Look AHEAD Continuation. In addition, we now want to look at some other areas of health. These include participant’s physical function (strength and ability to walk a set distance) and cognitive function (memory and thinking skills).
In the Look AHEAD continuation, we will also continue to follow the changes in participant weight, level of physical activity, use of medications, and a variety of other health problems, including fractures, cancers, and hospitalizations. Continuing to follow participants over time will allow us to determine whether there are long-term benefits or risks of weight loss on each of these different aspects of health.