Long-Term Outcomes in Patients with Morbid Obesity and Type 1 Diabetes Undergoing Bariatric Surgery

Background This study aims to describe the long-term outcomes of bariatric surgery in a cohort of patients with type 1 diabetes (T1DM). Methods Thirty-two patients with T1DM and initial BMI of 41.3 ± 4.8 kg/m 2 were studied, 18.7 % undergoing duodenal switch (DS), 34.4 % gastric bypass, and 46.9 % sleeve gastrectomy and followed-up after surgery for 4.6 ± 2.6 years. Changes in BMI, HbA 1c , insulin requirements, evolution of comorbidities, and microvascular complications were registered annually after surgery. Results Percentage of total weight loss (%TWL) 12 months after surgery was 30.4 ± 9.2 % and at 5 years, it decreased to 28.1 ± 11.5 % ( p = 0.02). HbA 1c was reduced during the first year from 8.5 ± 1.3 to 7.9 ± 1.4 %, p = 0.016. In the long-term, HbA 1c returned to baseline values. There was a sustained reduction of 51 % in total daily insulin dose, and the decrease in the number of patients with hypertension, dyslipidemia, and obstructive sleep apnea was 42.8, 25, and 66 %, respectively. Retinopathy remained mainly unaffected, and 25 % of patients with microalbuminuria regressed to normoalbuminuria. Conclusions Bariatric surgery in patients with T1DM mainly provides benefits of weight reduction, on insulin requirements, obesity comorbidities, and some benefits in diabetes complications, but might have only minimal effect on the glycemic control in the long term. This trial was registered at www.controlledtrials.com as ISRCTN49980913.