New research presented at the American Diabetes Associations 73rd Scientific Sessions suggests that a long-term intensive lifestyle intervention promoting weight loss in obese people with type 2 diabetes did not reduce the incidence of cardiovascular events such as myocardial infarction and stroke, when compared to a control group who received diabetes education and support.
However, results from the LOOK AHEAD (Action For Health in Diabetes) clinical trial revealed multiple other benefits for obese people with type 2 diabetes, including a reduced risk of microvascular complications and depression, an improved physical quality of life, and decreased medical costs, which were achieved by lowering the need for hospitalisation, outpatient care and medications.
The study, published in the New England Journal of Medicine, randomised over 5000 obese people with type 2 diabetes to receive either a weight-loss-centred intensive lifestyle intervention involving physical activity or diabetes support and education, which consisted of social support in addition to three counselling sessions per year for advice on nutrition and physical activity. Participants, enrolled from 16 centres across the US, were followed up for a median time of 9.6 years to examine the incidence of cardiovascular events.
After 1 year, participants in the control group displayed a weight loss of 0.7% compared to 8.6% in the intervention group, which was substantially more than researchers had expected. At the end of the trial, mean weight loss in the intervention group was 6% compared to 3.5% in the control group. Despite this, the intensive lifestyle intervention was not associated with a decrease in overall risk of cardiovascular mortality, morbidity, or low-density lipoprotein (LDL) cholesterol levels compared to the control group.
These findings could be explained by a greater use of medication to lower LDL cholesterol in the control group, which may have nullified the difference between the groups. The study cannot exclude the effect of weight loss on cardiovascular disease.
Professor Rena Wing, Chair of Look AHEAD and Professor of Psychiatry and Human Behaviour at the Alpert Medical School, Brown University, said: “Look AHEAD showed that participants with diabetes can lose weight and maintain it. This weight loss has many beneficial effects on glycaemic control and cardiovascular disease (CVD) risk factors; however, it did not affect the risk of CVD.”
“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 Dr Griffin P Rodgers, 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.”
