Interview with: Carlos KH Wong, PhD, MPhil, BSc Department of Family Medicine and Primary Care LKS Faculty of Medicine The University of Hong Kong

Type 2 Diabetes: Effects of Bariatric Surgery on Kidney, Heart Disease and Severe Hypoglycemia Interview with: Interview with: Carlos KH Wong, PhD, MPhil, BSc Department of Family Medicine and Primary Care LKS Faculty of Medicine The University of Hong Kong

Dr. Wong

Carlos KH Wong, PhD, MPhil, BSc
Department of Family Medicine and Primary Care
LKS Faculty of Medicine
The University of Hong Kong What is the background for this study?

Response: The background is that bariatric surgery has been widely indicated for the management of obesity and related comorbidities. However, there are uncertainties pertaining to the risks of post-bariatric severe hypoglycaemia (SH), cardiovascular diseases (CVDs), end-stage kidney diseases (ESKDs) and all-cause mortality in obese patients with Type 2 diabetes mellitus (T2DM), especially among Asian populations. What are the main findings? 

Response: Our main findings are

1) Among patients with obesity and T2DM, bariatric surgery significantly lowered the risks of CVD (HR = 0.464, P = 0.015);

2) No patients in the surgery group died during the observation period; and

3) Although there were no significant differences in risks of SH [HR = 0.469, 95% confidence interval (CI): 0.204–1.081], Stage 4/5 CKD (HR =0.896, 95% CI: 0.519–1.545) and ESKD (HR = 0.666, 95% CI: 0.264–1.683) between two groups, surgical patients had significantly higher eGFR within 12 months and had significantly lower urine albumin creatinine ratio until 48 months. What should readers take away from your report? 

Response: This propensity score-matched population-based cohort study determined the benefits of bariatric surgery towards lowering risks of CVD and all-cause mortality events among Chinese patients who have obesity and T2DM. Although the risks of severe hypoglycaemia, stage 4/5 chronic renal diseases and ESKD were not significantly different between the surgery group and the control group, the incidence rates of these diseases were lower for surgical patients. Therefore, bariatric surgery has protective effects on CVD, SH, renal functions and mortality. Bariatric surgery could be an optimal option for patients with obesity and T2DM, if costs are not their major concern. What recommendations do you have for future research as a result of this work? 

Response: Future studies with similar research objectives can be further refined by extending follow-up time and increasing sample size. It will be interesting to know the incidence risks of renal diseases, severe hypoglycaemia, CVD and mortality in the long run and how long the effect of bariatric surgery can last. Lifestyle risk factors, such as exercise and diet, and time-varying facts, such as use of medications and clinical parameters, can be taken into consideration when conducting statistical analyses. If it is possible, a randomized control trial design is preferred, as it can eliminate the selection bias that can easily be introduced by observational study designs. Is there anything else you would like to add?

Response: We would like to add the results competing the incidences of SH, CVD, ESKD and all-cause mortality among laparoscopic sleeve gastrectomy, Roux-en-Y gastric bypass and laparoscopic adjustable gastric banding. However, since most of the surgical patients in our study (244 out of 303) underwent laparoscopic sleeve gastrectomy while few patients underwent other bariatric surgical procedures, the results of comparison among these three surgical operations might be biased. Comparing the post-bariatric incidences of diseases among different surgery types can help us understand the efficacy of each surgery and help bariatric surgeons to decide the most suitable surgical type for eligible patients.

Authors have nothing to disclose. 


Carlos K H Wong, Tingting Wu, Simon K H Wong, Betty T T Law, Eleanor Grieve, Enders K W Ng, Olivia Wu, Cindy L K Lam, Effects of bariatric surgery on kidney diseases, cardiovascular diseases, mortality and severe hypoglycaemia among patients with Type 2 diabetes mellitus, Nephrology Dialysis Transplantation, , gfaa075, 


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Last Updated on July 3, 2020 by Marie Benz MD FAAD