Abstract
Perception of weight loss requirements before bariatric surgery varies among patients, physicians, and health insurance payers. Current clinical guidelines do not require preoperative weight loss because of a lack of scientific support regarding its benefits. To examine the association of preoperative body mass index (BMI) and weight loss with 30-day mortality after bariatric surgery. This cohort study used data from 480 075 patients who underwent bariatric surgery from 2015 to 2017 in the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program, which covers more than 90% of all bariatric surgery programs in the United States and Canada. Clinical and demographic data were collected at all participating institutions using a standardized protocol. Data analysis was performed from December 2018 to November 2019. Preoperative BMI and weight loss. 30-day mortality after bariatric surgery. Of the 480 075 patients (mean [SD] age 45.1 [12.0] years; 383 265 [79.8%] women), 511 deaths (0.1%) occurred within 30 days of bariatric surgery. Compared with patients with a preoperative BMI of 35.0 to 39.9, the multivariable-adjusted odds ratios for 30-day mortality for patients with preoperative BMI of 40.0 to 44.9, 45.0 to 49.9, 50.0 to 54.9, and 55.0 and greater were 1.37 (95% CI, 1.02-1.83), 2.19 (95% CI, 1.64-2.92), 2.61 (95% CI, 1.90-3.58), and 5.03 (95% CI, 3.78-6.68), respectively (P for trend < .001). Moreover, compared with no preoperative weight loss, the multivariable-adjusted odds ratios for 30-day mortality for patients with weight loss of more than 0% to less than 5.0%, 5.0% to 9.9%, and 10.0% and greater were 0.76 (95% CI, 0.60-0.96), 0.69 (95% CI, 0.53-0.90), and 0.58 (95% CI, 0.41-0.82), respectively (P for trend = .003). In this study, even moderate weight loss (ie, >0% to <5%) before bariatric surgery was associated with a lower risk of 30-day mortality. These findings may help inform future updates of clinical guidelines regarding bariatric surgery.
Highlights
Obesity is a rising epidemic in the US and worldwide
Compared with patients with a preoperative body mass index (BMI) of 35.0 to 39.9, the multivariable-adjusted odds ratios for 30-day mortality for patients with preoperative BMI of 40.0 to 44.9, 45.0 to 49.9, 50.0 to 54.9, and 55.0 and greater were 1.37, 2.19, 2.61, and 5.03, respectively (P for trend < .001)
In this study, even moderate weight loss before bariatric surgery was associated with a lower risk of 30-day mortality
Summary
Obesity is a rising epidemic in the US and worldwide. Obesity is associated with increased all-cause mortality, and more than 300 000 deaths annually in the US are attributed to obesity.[1,2] In addition to the health consequences of obesity, the direct medical costs related to adult obesity in the US has been estimated at more than $315 billion yearly.[3] Bariatric surgery has been shown to be the most effective and durable treatment for clinically morbid obesity (ie, body mass index [BMI; calculated as weight in kilograms divided by height in meters squared] Ն35.0 with comorbidities), which is difficult to reverse through traditional approaches such as lifestyle intervention.[4] There has been long-standing uncertainty and debate regarding the value of preoperative weight loss as a requirement for bariatric surgery. Current clinical guidelines by the American Society for Metabolic and Bariatric Surgery do not recommend preoperative weight loss because of a lack of scientific support regarding its benefits.[5] Clearly, there is an urgent and critical need to clarify the potential influence of preoperative weight loss on postoperative outcomes after bariatric surgery
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