Bariatric Surgery and Psychological Health: A Randomised Controlled Trial in Patients with Obesity and Type 2 Diabetes

Abstract

Background: The increasing prevalence of obesity and type 2 diabetes presents a significant public health challenge, both globally and in Aotearoa New Zealand. Bariatric surgery is increasingly recognised as an effective strategy to facilitate weight loss and diabetes remission. However, while the physiological impact of bariatric surgery is well documented, the psychological impact is less clear. Aim: This study was conducted to (a) investigate the impact of Roux-en-Y Gastric Bypass with Silastic Ring (SR-RYGB) and Sleeve Gastrectomy (SG) on psychological health; (b) to determine if pre-surgical depressive symptoms influenced weight loss or diabetes remission; and (c) to investigate the impact of bariatric surgery on psychological health outcomes in Māori and Pacific peoples compared to New Zealand Europeans. Method: The current study was a single-centre, double-blind randomised trial comparing the efficacy of SR-RYGB and SG surgery. A total of 114 participants undergoing bariatric surgery at North Shore Hospital were recruited and randomised to receive either SR-RYGB or SG. Depression, anxiety and quality of life were assessed using the Hospital Anxiety and Depression Scale (HADS) and Short Form-36 Item Health Survey at baseline (pre-surgery), 12 months, 24 months, 36 months and 48 months. A total of 84 participants with complete 4-year primary data (HADS) were included in the analysis. Results: SR-RYGB and SG resulted in comparable improvements to psychological health, with the majority of improvement occurring in the first 12 months. Depression, anxiety and physical quality of life scores remained significantly improved at 48 months, however, despite an initial improvement in mental quality of life, this was not sustained at 48 months. Pre-surgical depressive symptoms did not influence post-surgical weight loss or diabetes remission however, there was some evidence to indicate it was significantly associated with weight regain between 36 and 48 months. Māori and Pacific peoples demonstrated comparable improvements to psychological health from baseline to 48 months compared to New Zealand Europeans. Conclusion: The findings of the current study contribute to the growing body of literature establishing psychological benefits of bariatric surgery, as well as providing insight into the role of psychological health in long term weight maintenance. Importantly, these findings may inform the provision of psychological support for bariatric surgery patients in New Zealand.