Bariatric surgery for patients with type 2 diabetes mellitus requiring insulin: Clinical outcome and cost-effectiveness analyses

Abstract

Background Although bariatric surgery is well established as an effective treatment for patients with obesity and type 2 diabetes mellitus (T2DM), there exists reluctance to increase its availability for patients with severe T2DM. The aims of this study were to examine the impact of bariatric surgery on T2DM resolution in patients with obesity and T2DM requiring insulin (T2DM-Ins) using data from a national database and to develop a health economic model to evaluate the cost-effectiveness of surgery in this cohort when compared to best medical treatment (BMT). Methods and findings Clinical data from the National Bariatric Surgical Registry (NBSR), a comprehensive database of bariatric surgery in the United Kingdom, were extracted to analyse outcomes of patients with obesity and T2DM-Ins who underwent primary bariatric surgery between 2009 and 2017. Outcomes for this group were combined with data sourced from a comprehensive literature review in order to develop a state-transition microsimulation model to evaluate cost-effectiveness of bariatric surgery versus BMT for patients over a 5-year time horizon. The main outcome measure for the clinical study was insulin cessation at 1-year post-surgery: relative risks (RR) summarising predictive factors were determined, unadjusted, and after adjusting for variables including age, initial body mass index (BMI), duration of T2DM, and weight loss. Main outcome measures for the economic evaluation were total costs, total quality-adjusted life years (QALYs), and incremental cost-effectiveness ratio (ICER) at willingness-to-pay threshold of GBP£20,000. A total of 2,484 patients were eligible for inclusion, of which 1,847 had 1-year follow-up data (mean age of 51 years, mean initial BMI 47.2 kg/m2, and 64% female). 67% of patients no longer required insulin at 1-year postoperatively: these rates persisted for 4 years. Roux-en-Y gastric bypass (RYGB) was associated with a higher rate of insulin cessation (71.7%) than sleeve gastrectomy (SG; 64.5%; RR 0.92, confidence interval (CI) 0.86–0.99) and adjustable gastric band (AGB; 33.6%; RR 0.45, CI 0.34–0.60; p < 0.001). When adjusted for percentage total weight loss and demographic variables, insulin cessation following surgery was comparable for RYGB and SG (RR 0.97, CI 0.90–1.04), with AGB having the lowest cessation rates (RR 0.55, CI 0.40–0.74; p < 0.001). Over 5 years, bariatric surgery was cost saving compared to BMT (total cost GBP£22,057 versus GBP£26,286 respectively, incremental difference GBP£4,229). This was due to lower treatment costs as well as reduced diabetes-related complications costs and increased health benefits. Limitations of this study include loss to follow-up of patients within the NBSR dataset and that the time horizon for the economic analysis is limited to 5 years. In addition, the study reflects current medical and surgical treatment regimens for this cohort of patients, which may change. Conclusions In this study, we observed that in patients with obesity and T2DM-Ins, bariatric surgery was associated with high rates of postoperative cessation of insulin therapy, which is, in turn, a major driver of overall reductions in direct healthcare cost. Our findings suggest that a strategy utilising bariatric surgery for patients with obesity and T2DM-Ins is cost saving to the national healthcare provider (National Health Service (NHS)) over a 5-year time horizon.

Cost-effectiveness of metabolic surgery for the treatment of type 2 diabetes and obesity: a systematic review of economic evaluations

“…Thirty original articles from 33 publications fulfilled the inclusion criteria. Of these, 16 reported on the cost-effectiveness of metabolic surgery specifically in a T2D population [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42], including two empirical studybased economic evaluations [34,40]. Seventeen publications reported on the cost-effectiveness of metabolic surgery in a population with obesity in which a subgroup of the population had T2D [43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59].…”

“…Of 14 model-based economic evaluations conducted specifically in a population with T2D, eight considered a mix of metabolic surgery procedures, typically reflective of clinical practice in the reference country (Supplementary Information, Table S4) [27,28,30,31,35,36,38,39]. Six studies considered RYGB or adjustable gastric banding (AGB) only [29,32,33,37,41,42].…”

Sleeve Gastrectomy-Induced AMPK Activation Attenuates Diabetic Cardiomyopathy by Maintaining Mitochondrial Homeostasis via NR4A1 Suppression in Rats

“…Diabetic cardiomyopathy is a pivotal cause of morbidity and mortality in patients with T2DM, and is defined by morphological, functional, and metabolic transformations in the heart as a significant cardiovascular complication in diabetic patients ( Adeghate and Singh, 2014 ; Bugger and Abel, 2014 ). Ample evidence has showed that bariatric surgery had significant metabolic advantages in obesity, T2DM, and following complications ( Ikramuddin et al, 2018 ; McGlone et al, 2020 ). In the present study, we induced DCM rat models by HFD feeding followed with low-dose intraperitoneal injection of STZ.…”

Attenuation of ROS/Chloride Efflux-Mediated NLRP3 Inflammasome Activation Contributes to Alleviation of Diabetic Cardiomyopathy in Rats after Sleeve Gastrectomy

“…Bariatric surgery has remarkable metabolic benefits in obesity, T2DM, and following complications [ 6 , 28 , 29 ]. In the present study, we found that SG surgery alleviated the capability of myocardial contraction and diastole and delayed the progression of DCM.…”