麻豆传媒

Bariatric surgery staved off 5-year mortality, a large Canadian study found.

In a comparison of 13,679 bariatric surgery patients with the same number of matched nonsurgical patients, those who underwent surgery had a 32% reduced risk of all-cause mortality after nearly 5 years of follow-up (HR 0.68, 95% CI 0.57-0.81), reported Aristithes Doumouras, MD, MPH, of McMaster University in Toronto, and colleagues.

As shown in their study online in , this equated to an overall mortality rate of 1.4% among those who opted for bariatric surgery compared with 2.5% in the nonsurgical group.

A reduction in all-cause mortality wasn't the only benefit seen after bariatric surgery, the researchers noted. Compared with patients who didn't undergo bariatric surgery, those who did also saw a 47% reduced risk for cardiovascular mortality (HR 0.53, 95% CI 0.34-0.84), as well as a 46% reduced risk for cancer-related mortality (HR 0.54, 95% CI 0.36-0.80).

Interestingly, certain patients saw greater mortality reduction with bariatric surgery.

First, the protective mortality benefits were greater in men compared with women (absolute risk reduction 2.3% for men, 95% CI 1.2%-3.3%). Additionally, those with a body mass index (BMI) of 40-50 reaped the largest reduction in mortality (38%) of all the BMI subgroups. While those who had a BMI of 50+ also saw a significant drop in mortality risk, those with a BMI of 40 or less didn't see any difference in risk of death.

The mortality benefits of bariatric surgery were even more pronounced in older patients, with an absolute mortality risk reduction of 3.3% (95% CI 2.3%-4.3%) for patients age 55 and older. This equated to a 47% reduced death risk for older bariatric surgery patients (HR 0.53, 95% CI 0.41-0.69). On the other hand, those younger than 45 didn't see any significant risk difference in mortality.

Doumouras told 麻豆传媒 that although the findings didn't come as much of a surprise to the researchers, they were surprised to see exactly which subgroups reaped the biggest protective benefits from bariatric surgery -- i.e., patients over age 55 and men.

"For the former, there have been some thoughts that perioperative risk may be too high or that much of the 'damage' had already been done and the surgery would not be able to reverse or mitigate this," he explained. "I think this study demonstrated those to likely be inaccurate perceptions, and the surgery should definitely be offered to older patients. Furthermore, males had a large absolute observed benefit, which I think underscores the mortality risk in men with obesity and how beneficial to their health surgical weight loss can be."

Doumouras added that the results also underscore that both older patients and men should be encouraged to opt for bariatric surgery based on these "excess short-term potential benefits."

The population-based matched cohort study -- which Doumouras noted is the "first and largest study of its kind in Canadian history" -- included Ontario residents who underwent a primary bariatric surgery from 2010 to 2016.

He also noted that since private healthcare insurance wasn't a confounder among this cohort, the research can be considered a "true population-based study."

Exclusion criteria included being age 70 or older, having a BMI of 35 or lower, and having a 2-year history of cancer, among other comorbidities. Participants were matched based on age, sex, BMI, diabetes status, and duration of disease.

Among the surgical cohort, the vast majority opted for gastric bypass, accounting for about 87% of all surgeries. The remaining 13% of the cohort underwent sleeve gastrectomy. Prior to surgery, the average BMI was 47, and over 81% were women. There were nine deaths among the bariatric surgery group, resulting in a 30-day mortality rate of 0.07%.

When the bariatric surgery patients were split according to surgery type, those who opted for sleeve gastrectomy didn't see the significant mortality benefit that gastric bypass patients did.

Writing in an , Annals deputy editor Christina Wee, MD, MPH, of Beth Israel Deaconess Medical Center in Boston, said the results should be considered hypothesis-generating due to the small number of patients who underwent sleeve gastrectomy and, more importantly, had contraindications to Roux-en-Y gastric bypass (RYGB) surgery.

She said that along with the 3-year findings of the Gastric Bypass to Treat Obese Patients With Steady Hypertension (GATEWAY) study, also published today in the same journal, the results "taken together ... lend greater support for RYGB as a treatment option for obesity, particularly for middle-aged and older adults."

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