Bariatric surgery was tied to a reduction in the long-term risk of dying, and longer life expectancy, according to researchers in Sweden.
In an additional analysis of the ongoing , people that underwent bariatric surgery had a 23% lower risk of dying during a median 24-year follow-up versus those who received usual obesity care (hazard ratio 0.77, 95% CI 0.68-0.87, P<0.001), reported Lena Carlsson, MD, of Sahlgrenska University Hospital in Gothenburg, and colleagues.
This lower mortality risk was mainly driven by a reduction in death due to cardiovascular disease (CVD), the most common of which were myocardial infarction, heart failure, and sudden death, the authors stated in the .
Specifically, bariatric surgery was linked with a 30% reduced risk of CVD-related death versus usual obesity care (HR 0.70, 95% CI 0.57-0.85), and a drop in cancer-related mortality versus receiving usual obesity care (HR 0.77, 95% CI 0.61-0.96), they reported.
Overall, those who elected for bariatric surgery gained a median 3 years (95% CI 1.8 to 4.2, P<0.001) of life versus those who opted for usual care.
However, bariatric surgery wasn't enough to completely offset mortality risk from obesity, as those who had the procedure still saw about a 5.5-year (95% CI 3.4-7.6, P<0.001) shorter lifespan than the general public.
This finding in particular is helpful for patients to make an informed choice when considering obesity treatment, Carlsson explained to 鶹ý. She also pointed out this is the first study to devise an estimated quantification of just how much bariatric surgery may prolong life expectancy for the average patient.
"But it's important to point out that our results indicate how many life-years are gained on average," Carlsson stated. "Patients are different and the 3-year average increase in life expectancy can therefore not be translated into life-years gained for a specific patient."
Carlsson also explained that some of the remaining excess mortality after obesity surgery -- that median 5.5 years lost -- was largely from diseases that could be prevented. The most common non-CV causes of death in the surgery group included infections, complications from surgery, and other factors aside from disease such as alcoholism, suicide, and trauma.
"We hope this information increases the awareness among doctors about the importance of offering appropriate follow-up after obesity surgery," she explained.
Conducted at 480 primary health centers in Sweden, the SOS study included 2,010 adults in their 40s who underwent bariatric surgery compared with 2,037 matched controlled. All men had to have a BMI of at least 34 while all women had to have a BMI of at least 38.
Those in the surgery group underwent either gastric banding, vertical banded gastroplasty, or gastric bypass surgeries. Those in the matched control group received "conventional," nonsurgical obesity treatment. A study limitation was that it "included surgical techniques that are rarely used today," the authors noted.
During the follow-up period, a total of 457 deaths occurred in the surgery group and 539 deaths in the control group.
Specifically looking at the surgical patients, only five patients (0.2%) died within 90 days of initial bariatric surgery. A total of 59 patients (2.9%) underwent repeat surgery, while 292 (14.5%) experienced at least one complication from surgery, such as a pulmonary event, thromboembolism, hemorrhage, or infection.
These long-term findings build upon many other previous studies, including one recent study that found a 32% reduced risk of all-cause mortality after nearly 5 years of follow-up for patients who underwent bariatric surgery versus nonsurgical obesity care.
Strategies that identify patients who are at an increased risk for substance abuse or self-harm could improve mortality rates even further in bariatric surgery patients, Carlsson's group stated.
Disclosures
The study was supported by the Swedish Research Council, the Swedish state under an agreement between the Swedish government and the county councils, the ALF agreement, the Swedish Diabetes Foundation, the Swedish Heart-Lung Foundation, the Novo Nordisk Foundation, and the National Institute of Diabetes and Digestive and Kidney Diseases.
Authors disclosed relevant relationships with Johnson & Johnson Healthcare Systems, Novo Nordisk Foundation, and AstraZeneca.
Primary Source
New England Journal of Medicine
Carlsson L, et al "Life Expectancy after Bariatric Surgery in the Swedish Obese Subjects Study" N Engl J Med 2020; DOI: 10.1056/NEJMoa2002449,