7176 Unusual Case Of Extreme Insulin Resistance In A Pregnant Patient With Type 1 Diabetes Mellitus

Abstract Disclosure: J. Khoury: None. A. Ibrahim: None. L. Esper: None. N. El Asmar: None. R. Jain: None. Introduction: During pregnancy, it is crucial to maintain tight glycemic control to prevent maternal and fetal complications. We report a unique case of extreme insulin resistance during pregnancy in a woman with type 1 diabetes mellitus (T1DM) with insulin requirements reaching up to 1000 units/day necessitating an unorthodox insulin algorithm. Clinical Case: A 25-year-old female patient diagnosed with hypothyroidism and type 1 DM at age of 15 was referred to our Endocrinology clinic at 22 weeks of gestation. Pre-pregnancy, her home regimen consisted of insulin degludec 70 units daily in addition to mealtime lispro using an insulin to carbohydrate ratio (IC) of 1:15 and correction factor (CF) of 1:20 for a target of 140 mg/dl. Her pre-conception BMI was 28.3. She was using a continuous glucose monitor (Dexcom G7) for blood glucose tracking and her HbA1C was 6.8% in the third trimester. Her insulin requirements progressively increased and her regimen at week 31 was degludec 100 units three times daily, Humulin R U500 210 units/day in divided doses, and Humalog IC of 1:1, and CF of 1:5 with a target of 100 mg/dl, reaching up to 1100 units/day. At 32 weeks of gestation, she was hospitalized for management of severe pre-eclampsia. She had gained 20 kg since conception. During her stay, she was treated with two doses of 12 mg of betamethasone. Her blood glucose readings were elevated and reached 239 mg/dl. The decision was to start I.V. insulin infusion, in addition to subcutaneous Humulin R U500 and Humalog insulin. The patient was administering her own mealtime and correction Humalog insulin. Her insulin requirements abrubtly decreased to around 500 units a day within 2 days after admission. Her insulin drip was then turned off. There were no signs of placental insufficiency. At 33w2d, insulin requirements increased again to 955 units/day two days prior to delivery. The patient then underwent a c-section at 34w1d in the setting of breech presentation and pre-eclampsia, with successful outcome while utilizing an I.V. insulin infusion peri-operatively. The infant’s weight was 2020g. The patient was discharged on degludec 40 units daily and Humalog with IC 1:15 premeal and CF of 1:20 with a target of 150mg/dl. Conclusion: Such a case has not been described in the literature before. Insulin requirements in patients with T1DM increase by 70% on average, however in this case they increased by around 150% even prior to the use of steroids. The change in insulin requirements is a combined effect of placental hormones and obesity. Continuous glucose monitoring was invaluable in managing her case along with an unorthodox insulin regimen. Pregnant patients with T1DM are complex, and thus a multidisciplinary approach between the endocrinologist, obstetrician, and patient is crucial to mitigate complications that would otherwise adversely affect the infant and mother. Presentation: 6/2/2024