A University of Washington study, published in JAMA, followed 2,500 middle-aged obese patients who had undergone bariatric surgery and compared them to 7,400 control patients to understand the impact weight-loss surgery had on long-term survival.
Within the surgery group, 74% had had a gastric bypass procedure, 15% a sleeve gastrectomy, 10% adjustable gastric banding and 1% had other procedures.
Participants were mostly sampled from US veteran centres, meaning patients were predominantly older men in their fifties, a group often underrepresented in previous trials which have focused on younger female patients, the researchers said.
At the end of the 14-year study period, they that found participants who had undergone surgery were less likely to die from all causes at five years and 10 years after having the procedure compared to control patients.
Lower mortality rate
After five years, patients in the surgery group had a 6.4% mortality rate compared to 10.4% in the control group. After 10 years, the mortality rate for surgery patients was 13.8% compared to 23.9%.
Across a five- to 14-year period, the patients who had undergone surgery were 53% less likely to die from all causes.
Having a lower BMI is associated with a longer life span, but the results show that intentional, surgical weight loss can also help drive down mortality and improve long-term survival rates, the researchers said.
Lead author Dr David Arterburn said: ‘We have tracked a large group of patients for a long enough time that we can clearly see a strong link between bariatric surgery and long-term survival.’
Beneficial for older patients
The findings show that bariatric surgery has clear benefits even in older patients, who are more likely to have acquired obesity-related complications and co-morbidities, he added.
‘Our results may have broader implications for encouraging weight loss in general,' he said. 'Not much evidence has linked intentional weight loss (from surgery, medication, or diet and exercise) with longer survival. But our results, combined with other studies of bariatric surgery, may help to make that case.’
In further study, the team hope to explore how weight-loss surgery can affect the course of diseases associated with obesity, such as diabetes, and whether health care costs could ultimately be reduced in the long run as a result of surgery.