Look AHEAD Trial Finds No Benefit in Intensive Lifestyle Intervention in Reducing CV Events
A new study published June 24 in the New England Journal of Medicine compared an intensive lifestyle intervention for weight loss with conventional diabetes support and education, and showed no significant difference in the rates of cardiovascular events among more than 5,000 overweight or obese patients with type 2 diabetes.
The Look AHEAD (Action for Health in Diabetes) multicenter, randomized clinical trial, was a long-term evaluation of an intensive lifestyle intervention to achieve weight loss and its effect on cardiovascular morbidity and mortality. The trial was stopped early after a median follow-up period of 9.6 years on the basis of a futility analysis.
Results showed that weight loss was greater in the intensive lifestyle intervention group, and the intervention produced greater reductions in glycated hemoglobin and greater initial improvements in fitness and all cardiovascular risk factors, except for low-density lipoprotein cholesterol levels. However, there was no significant difference between the two groups in the primary outcome of a composite of death from cardiovascular causes, nonfatal MI, nonfatal stroke or hospitalization for angina, as the primary outcome occurred in 403 patients in the intensive intervention group and 418 patients in the control group (1.83 and 1.92 events per 100 person-years, respectively; hazard ratio in the interventional group, 0.95; 95 percent confidence interval, 0.83 to 1.09; P=0.51).
The intensive lifestyle intervention was aimed at weight loss of at least seven percent by focusing on reducing caloric intake to 1,200 to 1,800 kcal per day and increasing physical activity to at least 175 minutes of moderate intensity per week. It included both group and individual counseling sessions weekly for the first six months, with decreasing frequency over the course of the trial. Whereas, the diabetes support and education control group received three group sessions per year focused on diet, exercise and social support in years one through four of the trial, and one session per year afterward.
The authors note that although there was no significant difference between the two groups, their findings "showed that overweight or obese adults with type 2 diabetes can lose weight and maintain modest weight loss during a 10-year period." They add that other benefits that were identified during the early years of the trial include "reductions in urinary incontinence, sleep apnea, and depression and improvements in quality of life, physical functioning, and mobility."
An accompanying editorial by Hertzel C. Gerstein, MD, of the Department of Medicine and Population Health Research Institute, McMaster University and Hamilton Health Sciences, Hamilton, ON, Canada, noted that clinicians can use the results to tell patients that changes in physical activity and diet can safely reduce weight and the need for medication, improve the patient's well-being and, in some cases, achieve remission of diabetes. "Even with no clear evidence of cardiovascular benefit, the Look AHEAD investigators have shown that attention to activity and diet can safely reduce the burden of diabetes and have reaffirmed the importance of lifestyle approaches as one of the foundations of modern diabetes care," he adds.
Keywords: Depression, Cholesterol, Stroke, Hemoglobins, Social Support, Weight Loss, Motor Activity, Energy Intake, Risk Factors
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