Small case series suggest bariatric surgery may be an effective treatment for type 2 diabetes mellitus in patients who do not meet body weight criteria for morbid obesity (body mass index [BMI], <35 kg/m2), but large multi-institutional series, which allow better assessment of the safety and efficacy of treatment, have not been reported.
Data from 66,264 research-consented patients with a primary bariatric surgery encounter in the Bariatric Outcomes Longitudinal Database from June 2007 to June 2009 were queried to identify patients with a BMI ≥30 but <35 kg/m2 (1.2%, n = 794) and diabetes requiring any medication (29%).
A total of 235 patients met inclusion criteria. The 2 most common procedures, adjustable gastric banding (n = 109) and gastric bypass (n = 109), were compared. Laparoscopic access was used in 92% of procedures. Gender (76.6% female), race (80.4% White), and age (mean 52.6 ± 10.4 years) did not differ between procedure groups. Gastric bypass provided superior weight loss and diabetes remission but demonstrated more frequent complications (90-day complications: 18% vs. 3%, P < 0.05). No mortalities were reported, and most complications were minor.
The data suggest early effectiveness of surgical treatment of diabetes in patients who do not meet criteria for morbid obesity. Gastric bypass provides more effective treatment for diabetes than adjustable gastric banding within 6 to 12 months.