Management of Type 2 Diabetes After Bariatric Surgery

J.B. is a morbidly obese man with a medical history significant for type 2 diabetes diagnosed at 40 years of age and combined hyperlipidemia with severe hypertriglyceridemia. His diabetes was originally treated with oral agents for ∼ 4 years. Subsequently, his glycemic control worsened, and his hemoglobin A1c (A1C) ranged between 10 and 12%. During this time, he was also diagnosed with hypertension and obstructive sleep apnea. After hospitalization for mild diabetic ketoacidosis at 44 years of age, he was started on insulin therapy. At that time, he weighed 264 lb, and his BMI was 37 kg/m2. During the next 2 years, J.B. required increasing doses of insulin and, because of his significant insulin resistance, was switched to the more concentrated U500 regular insulin formulation. With this therapy, his A1C decreased to < 7%. Previously, he had failed pharmacological and lifestyle changes to lose weight, including low-fat diets, fenfluramine/phentermine, phentermine, and sibutramine. Because of multiple medical issues that could improve with weight loss, he was referred to the bariatric surgery clinic. At that time, his diabetes regimen included U500, 30 units at breakfast and lunch and 70 units at dinner (the equivalent of 150 and 350 units of regular insulin, respectively), and metformin, 1,000 mg twice daily. His weight had increased to 374 lb and his BMI to 52 kg/m2. J.B. had a hand-assisted laparoscopic roux-en-Y gastric bypass. He was discharged home 2 days after surgery on a new diabetes regimen of glargine insulin, 30 units at bedtime, and lispro insulin, 20 units before meals, which was about one-seventh of his total preoperative insulin dose. Despite good glycemic control postoperatively, he developed a wound infection, which responded well to outpatient oral antibiotics. Three weeks after surgery, his average blood glucose was 115 mg/dl, with rare …