Losing weight and engaging in increased physical activity may not lower the risk of heart attacks and strokes in diabetes patients, a landmark US study has claimed.
The 11-year study investigated the long-term effects of weight loss on the risks of cardiovascular disease among patients with Type 2 diabetes.
Conducted at the University of Pittsburgh and at clinical facilities throughout the US, the multicenter clinical trial investigated the effects of an intensive lifestyle intervention programme, intended to achieve and maintain weight loss in overweight or obese people with Type 2 diabetes, on rates of cardiovascular disease.
Begun in 2001, the trial enrolled more than 5,000 people at 16 clinical centres across the US and is the longest intervention study of its type ever undertaken for patients with diabetes.
Among the study's main findings is that weight loss among members of the study's Intensive Lifestyle Intervention group, provided with a programme of weight management and increased physical activity, resulted in no difference in heart attacks and strokes when compared with the study's control group, the Diabetes Support and Education group, which was provided with only general health information and social support.
The effect of the intervention programme on weight loss, however, was significant: Participants in the intervention group lost 8.7 per cent of their initial body weight after one year of the study versus 0.7 per cent among the control group's members.
The intervention group also maintained a greater weight loss, 6 per cent of their initial weight, versus 3.5 per cent for the control group, at the study's conclusion.
"While the findings from the Look AHEAD study did not support that engagement in a weight- loss intervention was effective for reducing the onset of cardiovascular disease incidence or mortality, this does not mean that overweight adults with diabetes should not lose weight and become more physically active," said John Jakicic, principal investigator for the University of Pittsburgh's role in the study.
"Rather, there is an overwhelming amount of evidence from this study to date that has shown that weight loss and physical activity were associated with numerous other health benefits," Jakicic said.
Speculating on the failure of weight loss to reduce the risk of cardiovascular disease, researchers suggested that even greater weight loss may be necessary to reduce cardiovascular risk in diabetes patients who are overweight or obese.
The study was published in the New England Journal of Medicine.