Losing weight and increasing physical activity reduces decline in mobility in obese adults with type 2 diabetes

Weight loss and increased physical fitness nearly halved the decline in mobility in overweight or obese adults with type 2 diabetes, according to four-year results of the Look AHEAD (Action for Health in Diabetes) trial funded by the National Institutes of Health (NIH). The results are published in the March 29, 2012, issue of the New England Journal of Medicine.

"The largest and longest-running study of its kind, this research confirms how important losing weight and increasing physical activity are in the treatment of mobility-related problems among people with type 2 diabetes as they age," said lead author Jack Rejeski, Ph.D, Thurman D. Kitchin Professor of Health and Exercise Science at Wake Forest University. "The weight loss and physical activity goals promoted in the study are well within the reach of most Americans. Future research is needed to determine if this sort of intervention can be translated into public health interventions, particularly in light of possible effects on health care costs."

Look AHEAD is a multi-center, randomized clinical trial designed to determine the long-term effects of intentional weight loss on the risk of cardiovascular disease in overweight and obese individuals with type 2 diabetes. Beginning in 2001, a total of 5,145 Look AHEAD participants were randomly assigned to either an intensive lifestyle intervention (ILI) group or a usual care, or Diabetes Support and Education (DSE) group. The ILI treatment involved group and individual meetings to achieve and maintain weight loss through decreased caloric intake and increased physical activity. The DSE group attended three meetings each year that provided general education on diet, activity, and social support.

"Being able to perform routine activities is an important contributor to quality of life," said Griffin P. Rodgers, M.D., director of the NIH's National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), which oversaw the study.

To assess mobility, Look AHEAD participants rated their ability to carry out activities with or without limitations. Included were vigorous activities such as running and lifting heavy objects and moderate ones such as pushing a vacuum cleaner or playing golf. Participants also separately rated their ability to climb a flight of stairs; bend, kneel or stoop; walk more than a mile; and walk one block. Both groups were weighed annually and completed a treadmill fitness test at baseline, after year one, and at the end of four years.

After four years of the study, Look AHEAD participants in the intensive lifestyle group experienced a 48 percent reduction in mobility-related disability compared with the diabetes support and education group.

"This is the first long-term study to demonstrate that by participating in an intensive lifestyle intervention, overweight or obese adults with type 2 diabetes can reduce decline in mobility as they age," Rejeski said.

Overweight and obesity affects more than two-thirds of U.S. adults age 20 and older. More than one-third of adults are obese. Many factors contribute to the problem, including genetics and lifestyle habits. Excess weight can lead to type 2 diabetes, heart disease, high blood pressure, stroke, and certain cancers. Nearly 26 million Americans have diabetes, and more than 7 million of them do not know it.

"With nearly two-thirds of participants reporting mild, moderate, or severe restrictions in mobility when Look AHEAD began, it is critical to address to this problem," said Mary Evans, Ph.D., project scientist for Look AHEAD. "This study of mobility highlights the value of finding ways to help adults with type 2 diabetes keep moving as they age. We know that when adults lose mobility, it becomes difficult for them to live on their own, and they are likely to develop more serious health problems, increasing their health care costs."