Metabolic Syndrome Is a Significant Predictor of Postoperative Morbidity and Mortality Following Bariatric Surgery.

INTRODUCTION/PURPOSE: Metabolic syndrome is commonly demonstrated in patients with morbid obesity undergoing bariatric surgery. The purpose of this study was to determine the effect of metabolic syndrome on morbidity and mortality following bariatric surgery.

MATERIALS AND METHODS: The National Surgical Quality Improvement Program (NSQIP) dataset was queried for patients who underwent bariatric surgical procedures between 2012 and 2014. Patient demographics, comorbid conditions, bariatric procedure type, and postoperative complications were analyzed. Metabolic syndrome was defined as having a body mass index > 30 kg/m2 in the presence of the comorbid conditions of hypertension and diabetes. Regression analysis was used to determine the relationship between metabolic syndrome and postoperative morbidity and mortality.

RESULTS: During the study interval, 59,404 patients underwent bariatric surgery (Roux-en-Y gastric bypass = 28,263, sleeve gastrectomy = 30,239, revision = 422, and biliopancreatic diversion = 480). The mean body mass index was 45.9 kg/m2 , and the mean age was 45 years. Of the cohort, 30,104 (50.6%) patients had a diagnosis of hypertension, 16,558 (27.8%) had diabetes mellitus, and 12,803 (21.5%) met the criteria for metabolic syndrome. Patients with metabolic syndrome were more likely to have Roux-en-Y gastric bypass procedure, a history of congestive heart failure, severe COPD, renal failure, and diminished functional status (p < 0.0001). Morbidity was greater for patients with metabolic syndrome (7.5% vs. 5%; p < 0.0001), and patients in this subset also had a 3.2-fold increased risk of mortality (p < 0.0001).

DISCUSSION: Metabolic syndrome is prevalent in patients who undergo bariatric surgery. We have demonstrated that patients with the constellation of comorbid conditions defining metabolic syndrome are at an increased risk of morbidity and mortality following bariatric surgery. Patients and surgeons should be informed of the potential increased risk in this patient population.