Study Details Decreases in Death, Cardiovascular Disease from Bariatric Surgery

August 1, 2020

A systematic review and meta-analysis found bariatric surgery in obese patients was linked to decreases of more than 35% in risk of all-cause and cardiovascular mortality.

This article originally appeared on Practical Cardiology's sister site, EndocrinologyNetwork.com.

A national assessment of more than 1.5 million patients from the United Kingdom is quantifying the impact of bariatric surgery on cardiovascular mortality and the incidence of ischemic heart disease.

A comparison between nearly 270,000 patients who underwent bariatric surgery to 1.27 million controls, results of the study indicate bariatric surgery was associated with significant decreases in rates of all-cause mortality and cardiovascular mortality as well as the incidence of diabetes, hypertension, and cardiovascular disease.

“Healthcare providers may use the data on relative risk reduction as part of the discussion with patients considering bariatric surgery,” noted study investigators.

To provide clinicians with a more accurate overview of outcomes following bariatric surgery in obese individuals, a group of investigators from the Imperial College London and Musgrove Park Hospital designed their analysis using data from studies published within Medline, Embase, and Web of Science databases. For inclusion in the study, investigators required articles to be national or regional administrative database cohort studies comparing risk of long-term mortality or incident obesity-related diseases for patients who have undergone bariatric surgery versus appropriate control groups. Additionally, published articles needed to have a minimum follow-up period of 18 months and be published between January 1, 2000 and January 31, 2020.

The primary aim of the analysis was to assess the hazard ratios for all-cause mortality and the pooled odds ratios for incident disease. In total, investigators identified 18 studies with a median follow-up time of 55 months meeting their inclusion criteria.

From the 18 studies, investigators identified information related to 1,539,904 patients for the current study. Of these, 269,818 underwent bariatric surgery and 1,270,086 were included as controls subjects. Of the 269,818 who underwent bariatric surgery, 137,578 underwent gastric bypass, 58,916 underwent a sleeve gastrectomy, 52,973 underwent an adjustable gastric band, and 6397 underwent vertical banded gastroplasty, and 1002 underwent biliopancreatic diversion.

In 11 studies assessing all-cause mortality, investigators noted a significant reduction in relative risk of long-term all-cause mortality in patients who underwent bariatric surgery when compared with controls (POR, 0.62; 95% CI, 0.55-0.69; P <.001). In the 3 studies assessing cardiovascular mortality, those undergoing bariatric surgery had a significantly reduced relative risk of cardiovascular mortality compared to those in the control group (POR, 0.50; 95% CI, 0.35-0.71; P <.001).

Additionally, the analyses indicated bariatric surgery was strongly associated with reduced incidence of type 2 diabetes (POR, 0.39; 95% CI 0.18-0.83, P=.010), hypertension (POR, 0.36; 95% CI, 0.32-0.40, P <.001), dyslipidemia (POR, 0.33; 95% CI 0.14-0.80, P=.010), and ischemic heart disease (POR, 0.46; 95% CI, 0.29-0.73, P=.001). Of note, 6, 5, 2, and 5 studies included in the analyses for each of these diseases, respectively.

Investigators cautioned against over-interpretation of study results without consideration of the possible limitations.

“Our results represent real-world data that may be generalizable to routine clinical practice. As further data accumulate, it may become clearer whether bariatric surgery reduces the incidence of new-onset obstructive sleep apnea or venous thromboembolism,” wrote investigators.

This study, “Association of bariatric surgery with all-cause mortality and incidence of obesity-related disease at a population level: A systematic review and meta-analysis,” was published in PLOS Medicine.