Abstract
Introduction:
Obesity in patients with type 1 diabetes (T1D) may worsen their prognosis. Bariatric surgery in these patients can be associated with complications such as diabetic ketoacidosis and severe hypoglycemic episodes. Closed-loop insulin delivery could be a solution to avoid them.
Case Report:
A 45-year-old woman with T1D and obesity (body mass index of 38.4 kg/m2) was included in our preoperative course of bariatric surgery. Three months before surgery, a closed-loop insulin delivery was instituted due to one prior severe hypoglycemia. Patient did not have immediate or late postoperative hypoglycemia despite consuming a weak amount of carbohydrate. Three months after surgery glycemic control was on target with 86% of time in range 70–180 mg/dL and no time below 70 mg/dL.
Conclusion:
This case report shows that the use of a closed-loop insulin delivery made it possible to perform bariatric surgery in complete safety for our patient.
Introduction
The prevalence of obesity is increasing in patients with type 1 diabetes (T1D) reaching 2.8%–37% across lifetime. 1,2 Obesity makes more difficult the care of these patients and conveys specific complications that may worsen their prognosis, particularly cardiovascular complications. 1,3 Bariatric surgery in patients with T1D leads to weight loss, reduction in the daily dose of insulin, and may improve cardiovascular risk factors. 3 As expected, this has modest impact on glycemic control. 4 –6 However, increased risks of diabetic ketoacidosis and severe hypoglycemic episodes require close postoperative follow-up of these patients. 7,8 Here, we report for the first time the benefits of the use of closed-loop insulin delivery before, during, and after bariatric surgery in a patient with T1D.
Case Report
A 45-year-old woman with T1D was referred for bariatric surgery because of an obesity (body mass index [BMI] 38.4 kg/m2) associated with dyslipidemia and high blood pressure. Diagnosis of diabetes was made when the patient was 12 years old; she had a normal BMI at the time. The patient also has a history of Graves' disease treated with radioactive iodine. The patient was treated with continuous subcutaneous insulin with an external pump for 12 years. Seven months before surgery, a MEDTRONIC 780G pump was instituted with the latest compatible glucose sensor, Guardian 4th Generation. The system was then in open loop. Continuous glucose monitoring is known to be the gold standard to assess glycemic control. Recent guidelines recommend a time in range between 70 and 180 mg/dL >70% of the time, a time below 70 mg/dL <4% and a time below 54 mg/dL <1%. 9 For our patient, before initiation of closed-loop therapy, the time in range 70–180 mg/dL was 73%, time between 54 and 70 mg/dL was 2% and time below 54 mg/dL was 0%. The coefficient of variation was 28.5%, HbA1C was 6.5%, and total insulin dose was 35.5 UI/day (0.37 UI/kg·day) (Fig. 1Aa). Three months before bariatric surgery, the insulin pump was put into closed-loop mode due to one severe hypoglycemia. Due to the bariatric surgery course, we chose the MEDTRONIC 780G insulin pump as there is total daily dose tracking and because it does not take into account underlying basal rates. Two months later, total insulin dose was 37.7 UI/day (0.39 UI/kg·day), time in range 70–180 mg/dL had increased to 89%, time 54–70 mg/dL was 2%, time below 54 mg/dL was 0%, and the coefficient of variation had decreased to 26.9% ( Fig. 1Ab). At this time, mean daily carbohydrate intake was 228 g. A Roux-en-Y gastric bypass (RYGB) was performed by an expert surgeon after validation in multidisciplinary meeting. Forty minutes before surgery, smartguard was left on a “physical activity temporary rate” with a subcutaneous glucose target of 150 mg/dL and was maintained for 48 h. The patient had no postoperative hypoglycemia despite consuming ∼20 g carbohydrate/day for 10 days after surgery. Four days after surgery, continuous glucose monitoring was very stable (Fig. 1B). During the 15 postoperative days, the patient did not report any carbohydrate intake. Fifteen days after surgery, the patient started announcing her meals again. Carbohydrate intake was 30 g/day, insulin dose was 13.7 UI/day (0.15 UI/kg·day), time in range 70–180 mg/dL was 86%, time below 70 mg/dL was 0%, and coefficient of variation was 22.1%. Three months after surgery, the patient had lost 15 kg and her BMI was 32.5 kg/m2. She was consuming 93 g carbohydrate per day, and insulin dose was 13.1 UI/day (0.16 UI/kg·day). Time in range 70–180 mg/dL was stable at 86%, and coefficient of variation at 24.4%. Time below 70 mg/dL was 0%, compared to 2% before bariatric surgery (Fig. 1Ac).
Continuous glucose monitoring in the patient before closed-loop insulin delivery, before, during, and after bariatric surgery.
Discussion
Bariatric surgery in obese patients with T1D aims to lose weight to avoid or reduce metabolic and mechanical complications of obesity and not to improve glycemic control. 10,11 For these patients, it can be complicated with diabetic ketoacidosis (15%–23%), severe hypoglycemia (15%–31%), and glucose fluctuations during the per- and postoperative period. 5,11 –13 Due to this, the evaluation of the risk: benefit of bariatric surgery in these patients must be considered. These patients also need close diabetological follow-up around surgery 14 and communication between the diabetologist, the surgeon, and the anesthesiologist. The complications do not seem to be related to the surgical technique. Studies did not find more hypoglycemia post-RYGB than postsleeve gastrectomy in patients with T1D. 15 In our case, time in hypoglycemia was lower after bariatric surgery than before. Moreover, bad glycemic control in diabetes mellitus is known to be associated with postoperative complications such as infection and wound healing disorders. 16 As closed-loop insulin delivery improves glycemic control, it is a good way to reduce postoperative complications. Nevertheless, another article reports two cases of euglycemic ketoacidosis in T1D on a closed-loop insulin delivery after bariatric surgery: one with control IQ and one with MEDTRONIC 780G pump. 17 In conclusion, this report shows that the use of a closed-loop insulin delivery makes it possible to perform bariatric surgery in safety for well-selected obese patients with T1D.
Footnotes
Authors' Contributions
A.-C.P., E.C., C.G., and J.-P.L.B.: Conceptualization, methodology, data curation, writing—original draft preparation. P.J., J.B., A.-L.P., and V.M.: Writing—reviewing. All authors approved the final version of the manuscript.
Consent Statement
Informed consent has been obtained from the patient for publication of the case report.
Author Disclosure Statement
No competing financial interests exist.
Funding Information
No funding was received for this article.