Risk of complications after bariatric surgery among individuals with and without type 2 diabetes mellitus

Background: Type 2 diabetes mellitus is highly prevalent in obese individuals. Bariatric surgery, promoted for reducing the medical problems of morbid obesity, has been increasingly recognized for its particular efficacy in treating diabetes. However, before bariatric surgery can be recommended for the treatment of diabetes, its safety in the diabetic population must be known. We assessed the odds of complications after bariatric surgery in patients with and without diabetes. Methods: This was a retrospective cohort study. Using an administrative database from 7 Blue Cross/Blue Shield plans, we identified 22,288 subjects who had undergone bariatric surgery from 2002 to 2008. From this cohort, we selected 6754 pairs of surgical patients (1 with and 1 without diabetes) matched by age, gender, health plan, and year of surgery. With conditional logistic regression analysis, we determined the relative odds of postoperative complications for ≤12 months after surgery in the 2 groups. Results: The mean age of the surgical patients was 46 years, and 79% were women. Postoperative complications were rare and comparable in those with and without diabetes. The most common complications were nausea, vomiting, and abdominal pain (8.8%), the need for a gastric revision procedure (5.0%), and upper endoscopy (2.3%). Select cardiac, infectious, and renal complications occurred more frequently in the diabetic group. The incidence of cardiac complications was greater in the 2-3-month and 4-6-month postoperative periods (odds ratio [OR] 1.7, P <.001), the incidence of infectious complications was greater in the 0-1-month (OR 1.3, P <.02) and 4-6-month (OR 1.8, P <.001) periods, and the incidence of renal complications was greater in the 2-3-month postoperative period (OR 4.6, P =.01). Conclusions: Our findings support the safety of bariatric surgery in obese individuals with diabetes, although management strategies to avert postoperative cardiac, infectious, and renal complications in this population might be warranted.