Glycemic control improves immediately after gastric bypass in patients with type 2 diabetes mellitus (T2DM) (1). The American Diabetes Association defines complete remission of diabetes as a return to normal glucose levels (HbA1c < 6%, fasting glucose <5.6 mmol/L) without glucose-lowering medication for at least 1 year after bariatric surgery (2). Prior studies have indicated that a rapid improvement in glycemic control is known to worsen diabetic retinopathy in cases of intense insulin control (3). However, few studies have examined whether undergoing bariatric surgery would significantly alter the prognosis of diabetes microvascular complications in patients with T2DM.
The Surgical Therapy and Medications Potentially Eradicate Diabetes Efficiently (STAMPEDE) trial observed the effect of bariatric surgery versus intensive medical management on patients with diabetes and examined the ophthalmic outcomes at 2 years (4). This was a prospective, randomized, nonblinded clinical trial that enrolled 150 patients with the primary outcome of examining the efficacy of intensive medical therapy alone versus surgical management with either Roux-en-Y gastric bypass or sleeve gastrectomy for the management of T2DM. As a secondary end point of the trial, patients were assessed with biomicroscopic fundus exam by two ophthalmologists at baseline and at year 2 for the level of retinopathy.
There was a statistically significant difference in mean change in HbA1c values between the medical therapy (−1.1) and surgical (−2.8 in gastric bypass, −2.7 in sleeve gastrectomy) groups (P < 0.001) at 2 years. The study results demonstrated that bariatric surgery (Roux-en-Y gastric bypass or sleeve gastrectomy) did not appear to worsen or improve retinopathy outcomes at 2 years over intensive medical management (P = 0.84), and a majority, 86.5%, of patients within all treatment groups had no change in retinopathy scoring. Additionally, there was no significant change in logMar visual acuity from baseline among the treatment arms (P > 0.05), as the mean baseline and 2-year visual acuity were the same in all three groups (logMar 0, Snellen equivalent 20/20).
The current study is the first of its nature to document intensive medical management and bariatric surgery’s microvascular effect on diabetic retinopathy with a large population of diabetic patients. Currently, there is a lack of ophthalmology screening protocols or a formulated consensus on how to best manage diabetic patients who have undergone bariatric surgery. Results of this study indicate that bariatric surgery and intensive medical therapy patients are not free from the microvascular complications of diabetic retinopathy. Given the increasing volume of diabetic patients being referred for bariatric surgery, there needs to be greater emphasis on figuring out how to best manage these patients on a long-term basis in order to alleviate end organ damage. While this study indicates that there was no significant change in diabetic retinopathy scoring at year 2 from baseline within and between each cohort, the study reinforces the importance of timely ophthalmic exams even with patients who significantly reduce their HbA1c levels for the detection and management of retinopathy.
Article Information
Funding. P.S. reports grants from the National Institutes of Health and the Cleveland Clinic during the study.
Duality of Interest. This study was supported by a grant (EES IIS 19900) from Ethicon Endo-Surgery (Cornelia, GA). S.A.B. is a consultant and speaker for Ethicon Endo-Surgery and a speaker for Covidien. D.L.B. has served on the advisory board for Elsevier Practice Update Cardiology, Medscape Cardiology, and Regado Biosciences; received research grants from Amarin, AstraZeneca, Bristol-Myers Squibb, Eisai, Ethicon, Medtronic, Roche, Sanofi, and the Medicines Company; performed unfunded research for FlowCo, PLx Pharma, and Takeda; has been on the Board of Directors for the Boston VA Research Institute and the Society of Cardiovascular Patient Care; has been a Chair of the American Heart Association Get With The Guidelines Steering Committee; has been on the data monitoring committees of the Duke Clinical Research Institute, Harvard Clinical Research Institute, Mayo Clinic, and Population Health Research Institute; has received honoraria from the American College of Cardiology (Editor, Clinical Trials, CardioSource), Belvoir Publications (Editor in Chief, Harvard Heart Letter), Duke Clinical Research Institute (clinical trial steering committees), Harvard Clinical Research Institute (clinical trial steering committee), HMP Communications (Editor in Chief, Journal of Invasive Cardiology), Population Health Research Institute (clinical trial steering committee), SLACK Publications (Chief Medical Editor, Cardiology Today's Intervention), and WebMD (CME steering committees); and has served as Associate Editor of Clinical Cardiology and as Section Editor, Pharmacology of the Journal of the American College of Cardiology. P.S. reports grants from Ethicon and LifeScan, Inc., during the study; personal fees from Ethicon, personal fees from Lilly; personal fees from Nestle; material support from Novo Nordisk; material support from Stryker; material support from SurgiQuest; material support from Barosense; material support from RemedyMD; personal fees and material support from Physicians Reviews of Surgery, LLC; personal fees and material support from Quadrant Healthcare, LLC; material support from SE Healthcare Quality Consulting; and material support from Springer Publishing Company unrelated to the submitted work. In addition, P.S. has a patent for medical devices for weight loss pending. No other potential conflicts of interest relevant to this article were reported.
Author Contributions. R.P.S., R.B., and P.S. researched data and wrote and reviewed the manuscript. R.G. wrote and reviewed the manuscript. S.R.K. reviewed the manuscript. K.W. researched data. S.A.B., S.E.N., and D.L.B. reviewed the manuscript. R.P.S. is the guarantor of this work and, as such, had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Prior Presentation. Parts of this study were presented in abstract form at the 74th Scientific Sessions of the American Diabetes Association, San Francisco, CA, 13–17 June 2014.
Footnotes
Clinical trial reg. no. NCT00432809, clinicaltrials.gov.
References
- 1.Chuah LL, le Roux CW. Management of patients with type 2 diabetes before and after bariatric surgery: evolution and microvascular complications. Nutr Hosp 2013;28(Suppl. 2):17–22 [DOI] [PubMed] [Google Scholar]
- 2.Buse JB, Caprio S, Cefalu WT, et al. . How do we define cure of diabetes? Diabetes Care 2009;32:2133–2135 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Varadhan L, Humphreys T, Walker AB, Cheruvu CVN, Varughese GI. Bariatric surgery and diabetic retinopathy: a pilot analysis. Obes Surg 2012;22:515–516 [DOI] [PubMed] [Google Scholar]
- 4.Schauer PR, Kashyap SR, Wolski K, et al. . Bariatric surgery versus intensive medical therapy in obese patients with diabetes. N Engl J Med 2012;366:1567–1576 [DOI] [PMC free article] [PubMed] [Google Scholar]