Study finds lifestyle intervention did not reduce cardiovascular events in obese
But Study Found Numerous Other Health Benefits of Modest Weight Loss
BATON ROUGE, LA-Pennington Biomedical Research Center took part in a study that found a long-term intensive lifestyle intervention program, focused on weight loss, can improve physical quality of life, reduce microvascular complications, lower the risk of depression and lower medical costs by reducing the need for hospitalizations, outpatient care and medications for obese people with type 2 diabetes, according to research presented at the American Diabetes Association's 73rd Scientific Sessions®.
Results from the Look AHEAD (Action for Health in Diabetes) clinical trial revealed the intensive lifestyle intervention did not reduce the risk for heart attacks or strokes more than a comparison group provided with diabetes support and education.
Look AHEAD is a two-armed randomized trial conducted in 16 centers across the United States, including Pennington Biomedical, with more than 5,000 overweight or obese adults aged 45-76 years diagnosed with type 2 diabetes. Of the 5,000 participants nationwide, 320 were from the Baton Rouge area.
Funded by the National Institutes of Health (NIH), the study assigned participants to one of two interventions: lifestyle (involving physical activity and weight loss), or diabetes support and education (involving three counseling sessions per year on nutrition, physical activity, and social support).
Participants were followed for up to 11.5 years, with a median follow-up of 9.6 years at the time the intervention ended. "The primary goal was to determine whether the intensive intervention would reduce the risk of cardiovascular mortality and morbidity," said Rena Wing, Ph.D., chair of the Look AHEAD trial and professor of Psychiatry and Human Behavior at Brown Medical School.
George Bray, M.D., Boyd Professor and principal investigator of the Look AHEAD trial at Pennington Biomedical added, "Look AHEAD produced many benefits for the participants that would help them live better with their diabetes, and even though it didn't reduce mortality the other gains from weight loss and exercise are worth hanging on to."
Though participants in the intensive lifestyle intervention group initially lost 8.6% of body weight and maintained a loss of 6% of body weight at the end of intervention, which was better than researchers expected, the intensive lifestyle group did not reduce their risk of cardiovascular morbidity or mortality or the level of LDL-cholesterol (the so-called "bad" cholesterol) compared to the group that received diabetes support and education. The support and education group lost 0.7% initially and 3.5% at the end of intervention.
Wing said there were numerous possible explanations for the unexpected results, including the greater use of medications to lower LDL cholesterol in the comparison condition, which may have minimized any difference between the groups. The study cannot rule out the possibility that greater weight losses might impact cardiovascular risk.
However, the intensive lifestyle intervention group did experience other benefits when compared to those in the comparison group, including reducing the risk of kidney disease, self-reported retinopathy, and depressive symptoms. "The incidence of high risk kidney disease was reduced by 30% in the intensive lifestyle group. This is an important benefit, since diabetes is the leading cause of kidney failure which progresses to costly dialysis treatment with an artificial kidney machine," said Frank Greenway, M.D., professor and co-investigator of the Look AHEAD trial at Pennington Biomedical.
Other benefits included an improved physical quality of life and reduced annual hospital rates and costs. Lifestyle intervention also produced greater reductions in A1C and greater initial improvements in fitness and all CVD risk factors except LDL cholesterol.
"This study shows that overweight and obese adults with type 2 diabetes can lose weight and keep it off, with many important health benefits," said Griffin P. Rodgers, M.D., director of the National Institute of Diabetes and Digestive and Kidney Diseases, part of the National Institutes of Health, which funded the study. "It reinforces the recommendation that overweight and obese people with type 2 diabetes should increase their physical activity levels and lose weight to improve their health."
About the Pennington Biomedical Research Center
The Pennington Biomedical Research Center is at the forefront of medical discovery as it relates to understanding the causes of obesity, diabetes, cardiovascular disease, cancer and dementia. It is a campus of the Louisiana State University System and conducts basic, clinical and population research. The research enterprise at Pennington Biomedical includes approximately 80 faculty and more than 30 post-doctoral fellows who comprise a network of 50 laboratories supported by lab technicians, nurses, dieticians, and support personnel, and 17 highly specialized core service facilities. Pennington Biomedical's more than 500 employees perform research activities in state-of-the-art facilities on the 234-acre campus located in Baton Rouge, Louisiana. For more information, see www.pbrc.edu.