Bariatric surgery for severe obesity in two adolescents with type 1 diabetes

Bariatric surgery has been effective in treating type 2 diabetes mellitus (T2DM); it has not been used frequently in obese patients with type 1 diabetes mellitus (T1DM). This is the first case series reporting on the effect of bariatric surgery on diabetes control in adolescents with T1DM. Patient A is a 19-year-old obese man with T1DM who underwent vertical sleeve gastrectomy. At 12 months after surgery he demonstrated 28% reduction in BMI. His daily total insulin requirement had decreased; however, hemoglobin A1c remained primarily unchanged at 8.8%. Patient B is a 13-year-old obese girl with an initial clinical diagnosis of T2DM controlled on only metformin. She underwent Roux-en-Y gastric bypass; at 1 month after surgery she presented in diabetic ketoacidosis and was found to have positive islet cell antibodies, which were also present before surgery. Her diagnosis was revised to T1DM, and she was started on insulin. By 28 months after surgery her BMI had decreased by 42%. Since initiation of insulin, her daily total insulin requirement had decreased, but hemoglobin A1c had significantly worsened from 6.3% to 10%. We found that despite significant weight loss, improvements in cardiovascular risk factors (dyslipidemia and obstructive sleep apnea), and quality of life in our patients, bariatric surgery does not necessarily lead to improved glycemic control of T1DM. Patients with T1DM have ongoing dependency on exogenous insulin, and optimal glycemic control still depends on patient compliance with diabetes care.