My contribution to this year’s EASD was an oral presentation entitled “Roux-en-Y gastric bypass and diabetic retinopathy – long term effects”.
It is well-known that Roux-en-Y gastric bypass has the ability to remit type 2 diabetes mellitus in some type 2 diabetes patients, if not permanently then temporarily. We set out to investigate whether or not the surgical induced diabetes remission in addition might have an effect on diabetic retinopathy, a common microvascular complication.
In a clinical cross-sectional study, we included 96 Roux-en-Y gastric bypass operated obese type 2 diabetes patients and 48 non-operated obese type 2 diabetes patients matched on age, gender, and currant body mass index. We evaluated fundus photos alongside blood pressure, height, weight, urine- and blood samples, and inquiries of smoking, medication use, and diabetes duration by questionnaire. We separated the operated patients into groups of remission or non-remission of type 2 diabetes based on hemoglobin A1c measurements. Time since Roux-en-Y gastric bypass was more than six years.
We found that obese Roux-en-Y gastric bypass operated type 2 diabetes patients in remission displayed 65 % less diabetic retinopathy than matched controls. And those in non-remission displayed 25 % less diabetic retinopathy than matched controls (adjusted for diabetes duration, gender and smoking status).
A previous routine fundus photo was available in nearly half of our participants, which made us capable of exploring change in diabetic retinopathy over time. Over the course of six years obese Roux-en-Y gastric bypass operated type 2 diabetes patients both in remission and non-remission had a 60 % higher chance of unchanged or better diabetic retinopathy than matched controls (adjusted for diabetes duration and severity of first grading).
Overall, the long-term effect of Roux-en-Y gastric bypass on diabetic retinopathy in obese type 2 diabetes patients seems beneficial. We presume that the effect is caused by the optimized blood glucose regulation following surgery and not the surgery per se.