Bariatric surgery versus medical therapy in Korean obese patients: Prospective multicenter nonrandomized controlled trial (KOBESS trial)

Purpose: The aim of this study was to show that bariatric surgery (BS) is more effective than medical therapy (MT) in Asian obese patients. Methods: In this prospective, multicenter, nonrandomized, controlled trial, obese patients with body mass index of ≥35 kg/m² or 30.0-34.9 kg/m² with obesity-related comorbidities were assigned to undergo BS, such as laparoscopic sleeve gastrectomy and Roux-en-Y gastric bypass, or MT. Patients who underwent BS were evaluated 4, 12, 24, and 48 weeks after surgery, whereas patients who received MT were monitored at a hospital every 6 weeks for 1 year. At each visit, weight, waist and hip circumference, and blood pressure were measured, and patients underwent physical examination and laboratory testing. Health-related quality of life (HQOL) was investigated using Euro QOL-5 Dimension, Impact of Weight on Quality of Life questionnaire-Lite and Obesity-related Problems scale. Results: The study included 264 patients from 13 institutions; of these, 64 underwent BS and 200 received MT. Of the patients who underwent BS, 6.3% experienced early complications. Relative weight changes from baseline to 48 weeks were significantly greater in the BS than in the MT group (26.9% vs. 2.1%, P < 0.001), as were the rates of remission of diabetes (47.8% vs. 16.7%, P = 0.014), hypertension (60.0% vs. 26.1%, P < 0.001), and dyslipidemia (63.2% vs. 22.0%, P < 0.001). HQOL was better in the BS than in the MT group at 48 weeks. Conclusion: BS was safe and effective in Korean obese patients, with greater weight reduction, remission of comorbidities, and quality of life improvement than MT.