Weight loss needed to reduce CV risk in severely obese underestimated
MedWire News: Results of a Swedish study suggest that greater long-term weight loss than previously thought is needed to achieve significant effects on cardiovascular (CV) risk factors in the severely obese.
"Weight changes in the order of 10-45 kg (9%-38%) were required to achieve significant risk factor changes," report the researchers in the International Journal of Obesity.
Many short-term studies have previously stated that a 5% weight loss in the obese is enough to induce significant improvements in CV risk factors.
David Sjöström (Sahlgrenska University Hospital, Göteborg) and team examined data on 959 surgically treated and 842 conventionally treated obese individuals (body mass index ≥34 kg/m2), aged 37-60 years from the Swedish Obese Subjects (SOS) study.
Patients were divided into 11 groups based on their average weight change over the 10-year study period, and the necessary weight change for significant alterations in CV risk factors was determined. In addition, the team assessed the effect of 10 years of aging and secular trends on CV risk factors, in the absence of weight change.
The researchers found that the weight loss required to achieve significant changes in risk factors ranged from 10 to 44 kg, and that a 5-kg change in weight was not associated with any significant changes in risk factors.
Ten years of aging with no change in weight was associated with significant increases in systolic blood pressure, pulse pressure, high-density lipoprotein cholesterol, and glucose, and significant decreases in diastolic blood pressure, total cholesterol, triglycerides, and insulin.
The researchers say that because weight-loss data from prospective clinical trials with follow-up periods longer than a few years are very scarce, their study may help people to understand the long-term effects of weight-loss.
"Currently, bariatric surgery is the only treatment resulting in large enough weight losses that are sustained over time," say Sjöström and team.
They stress that there is urgent need for broader therapeutic approaches to the treatment of obesity.
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By Nikki Withers