Long-term Impact of Laparoscopic Sleeve Gastrectomy on Drug Costs of Japanese Patients with Obesity and Type 2 Diabetes Mellitus

Purpose Laparoscopic sleeve gastrectomy (LSG) is the most common type of bariatric surgery in Japan, and it is the only such procedure covered by national health insurance. The long-term cost of bariatric surgery in Japan has not yet been analyzed. We aimed to evaluate the long-term impact of LSG on the drug treatment costs of patients with type 2 diabetes mellitus (T2DM). Materials and Methods We retrospectively analyzed data from 230 patients who had undergone LSG at our institution for their obesity and T2DM between 2007 and 2018. The clinicopathological data included age, sex, body mass index (BMI), as well as preoperative and postoperative medications for T2DM, hypertension, and dyslipidemia. We then calculated the drug treatment costs for T2DM, hypertension, and dyslipidemia before and after LSG; and we evaluated the remission rates of these obesity-related diseases. Results The median preoperative body weight and BMI of the 230 patients who underwent LSG were 115 kg and 40.6 kg/m(2), respectively. Preoperative drug treatment costs per month per patient for T2DM, hypertension, and dyslipidemia were (sic)3795 ((sic)0-40285), (sic)3269 ((sic)0-14577), and (sic)1428 ((sic)0-19464). Post-operation, the median drug treatment costs for all these diseases became nil. The remission rates of T2DM, hypertension, and dyslipidemia 5 years after LSG were 82.8%, 50%, and 43.8%, respectively. In Japan, the cost of an LSG operation corresponds to 4.75 years of median drug costs to treat T2DM and hypertension. Conclusion In the long term, LSG in Japan is effective both physically and cost-wise for patients with obesity and T2DM.