Category: Diabetes/Prediabetes/Hypoglycemia

Monitor: 20


Friday, Apr 26
11:30 AM – 12:00 PM

Objective :

Insulin autoimmune syndrome (IAS) is a potentially life-threatening hypoglycemia disorder characterized by spontaneous hypoglycemia without evidence of exogenous insulin administration, a high serum concentration of total immunoreactive insulin, and a high titer of insulin autoantibodies. 

Methods : n/a

Results :

Case presentation:
 A 69 year old female with history of severe obesity with body mass index (BMI)>50, deep venous thrombosis, elevated antinuclear antibody (ANA) with lupus anticoagulant, and limited mobility who was admitted to our facility after being found unresponsive with capillary blood glucose (BG) of 16 mg/dl. The patient reported recurrent episodes of fasting and post-meal hypoglycemia over the last few months. She underwent a supervised 72 hour fast. Labs were obtained with a concomitant serum BG of 40 mg/dl: insulin level 207 uIU/mL (0-29.1), C-peptide 0.3 ng/mL (0.2-2.7), proinsulin 4.8 pmol/L (<=18.8), beta-hydroxybutyrate 0.2 mmol/l (<0.4), insulin antibody 10.7 U/ml (<0.4). The sulfonylurea screen was negative. Cortisol level at 8 am was 8.3 mcg/dl (3.09-22.4), after ACTH stim test cortisol level was 27 mcg/dl. Abdominal CT did not identify a pancreatic mass. Despite the undetectable c-peptide suggesting exogenous insulin use, the c-peptide was detectable during other hypoglycemic events, and no suspicious behavior was observed. The presentation was more consistent with insulin autoimmune syndrome.  She started Prednisone 60 mg daily with improvement in glucose levels to 150-200 mg/dl. The Prednisone dose was slowly tapered down but she continued to have non-severe hypoglycemic episodes requiring 20 mg daily to manage. She had dietary counseling to encourage small mixed meals every 2-3 hours. Rituximab was not approved by insurance, and there was no appeal process available. The patient declined plasmapheresis, octreotide injections, and diazoxide. Acarbose was prescribed since many of her episodes were postprandial. The patient suffered a fatal pulmonary embolism at a skilled nursing facility, 10 months after the initial presentation. Pancreatic mass was not detected on autopsy.

Discussion : This is a case of severe refractory IAS. The first line treatment for IAS is low carbohydrate meals to prevent postprandial hypoglycemia along with empiric pulse doses of glucocorticoids. Rituximab has been recently introduced as a therapeutic option in patients with life-threatening hypoglycemia refractory to high dose steroids. Plasmapheresis has been also used in several case reports with a good outcome. Although symptoms of IAS are usually mild and transient, very severe cases, like in our patient, have also been described.

Conclusion : n/a


Irina Azaryan

The Ohio State University
Hilliard, Ohio


Dungan Kathleen

Associate Professor
The Ohio State University

Kathleen Dungan, MD, MPH is Associate Professor of Medicine in the Division of Endocrinology, Diabetes & Metabolism at the Ohio State University where she serves as Associate Director of Clinical Services for the Division and Director of Endocrine Clinical Trials. Dr. Dungan earned her medical degree from the Ohio State University, and completed her residency in Internal Medicine and fellowship in Endocrinology at the University of North Carolina. She then completed her Masters in Public Health at The Ohio State University. She has served as primary investigator for NIH and other externally sponsored clinical research in glycemic management of hospitalized patients. She has served as lead investigator, steering committee, or national lead for a number of multi-center clinical trials. She serves as Associate Editor for Endotext and has served on planning committees for the American Diabetes Association Scientific Sessions and the Endocrine Society Clinical Endocrine Update, as well as other editorial board and continuing education planning activities. She has served on advisory panels, clinical trial steering committees, and has published widely on inpatient and outpatient diabetes therapeutics and monitoring.

Irina Azaryan

Irina Azaryan