Obese patients who undergo weight-loss surgery have a lower death rate than those who receive other forms of treatment, according to a new study.
Meanwhile, a second study suggests obese adults with type 2 diabetes are better able to control their condition after undergoing gastric bypass surgery but found improvements lessened over time.
While much is known about the short-term outcomes of bariatric surgery, the two studies published in the Journal of the American Medical Association, provide insight into the longer-term impact.
The first looked at data on more than 8,300 obese patients in Israel who underwent three different forms of weight-loss surgery – laparoscopic banding, a Roux-en-Y gastric bypass or laparoscopic sleeve gastrectomy.
This was compared with information on more than 25,000 obese patients who received standard non-surgical care from primary care clinicians, such as advice on diet and lifestyle changes, noted study authors in JAMA.
The researchers found the death rate from any cause was lower among those who had the bariatric surgery compared with those who experienced standard care. The death rate was 1.3% among surgical patients, compared to 2.3% when followed-up after roughly four years.
The second study, led by the University of Minnesota and conducted four locations in the US and Taiwan, followed 120 obese adults with type 2 diabetes.
Half underwent Roux-en-Y gastric bypass surgery plus lifestyle and medical interventions, while the others received lifestyle and medical management only. Both groups were followed up over five years.
Researchers found those who had undergone surgery were doing “significantly better” overall at meeting targets for blood glucose, cholesterol and blood pressure. However, they also found the improvement seemed to diminish over the five-year follow-up period.
“Because the effect size diminished over five years, further follow-up is needed to understand the durability of the improvement,” said the study paper in JAMA .
Participants in the study had diabetes for an average of nine years when they signed up, it noted.
The effect of different treatments on those who had diabetes for a shorter time could be different, added the researchers.