Background: Bariatric surgery has been shown to improve glycemic control in patients with type 2 diabetes. However, less is known whether it can also reduce diabetic renal, neurological, and ophthalmic complications.

Methods: This prospective multicenter cohort study compared renal, ophthalmic, and neurological complications between 49 patients with obesity/overweight receiving bariatric surgery and 338 patients receiving standard medical treatment after follow-up for 2 years. Patients received neurological examinations including toe tuning fork vibration test, ankle tendon reflex test, 10-g monofilament test, and ophthalmic examinations including visual acuity measurement and fundus examinations. Multiple regressions, propensity score weighting, and matching were employed to adjust for baseline differences.

Results: After 2 years of follow-up, patients with type 2 diabetes receiving bariatric surgery had greater reduction in BMI, HbA1c, and urine albumin-creatinine ratio, greater improvement in estimated glomerular filtration rate, and greater increase in tuning fork test score of right and left toes compared with the medical group. However, there is no improvement in 10 g-monofilament test, visual acuity, diabetic non-proliferative retinopathy, and proliferative retinopathy. Similar results were obtained using multiple regression adjustment, propensity-score weighting, or comparing age-, sex-, and BMI-matched subjects.

Conclusions: After 2-year follow-up, patients with obesity/overweight and type 2 diabetes receiving bariatric surgery have increased glomerular filtration rate, reduced albuminuria, and improved tuning folk vibration sensation.