Type 2 diabetes mellitus and microvascular complications 1 year after Roux-en-Y gastric bypass: a case–control study

AIMS/HYPOTHESIS: We aimed to examine the effects of bariatric surgery on microvascular complications in patients with type 2 diabetes using objective measures. METHODS: Prospective case–control study of 70 obese surgical patients with type 2 diabetes undergoing gastric bypass surgery matched for age, sex and duration of diabetes to 25 medical patients treated using international guidelines. Microvascular complications were assessed before and 12–18 months after intervention using urine albumin creatinine ratio (ACR) measurements, two-field digital retinal images and peripheral nerve conduction studies (in the surgical group only). RESULTS: Urine ACR decreased significantly in the surgical group but increased in the medical group. There were no significant differences between the surgical and medical groups in the changes in retinopathy. There were no changes in the nerve conduction variables in the surgical group. CONCLUSIONS/INTERPRETATION: In the short term, bariatric surgery may be superior to medical care in the treatment of diabetic nephropathy, but not retinopathy or neuropathy.