Exogenous insulin antibody syndrome in a patient with diabetes secondary to total pancreatectomy

A Case of Exogenous Insulin Autoimmune Syndrome: A Case Report

Insulin autoimmune syndrome (IAS) is a rare cause of endogenous hyperinsulinemic hypoglycemia triggered by insulin autoantibodies. Through extensive research on IAS in recent years, it has been revealed that the use of exogenous insulin by diabetic patients can result in clinical manifestations similar to those of IAS. This phenomenon is known as exogenous IAS (EIAS). This article describes a case of a patient with EIAS who presented with atypical clinical manifestations. The patient, a middle-aged female with a 17-year history of type 2 diabetes, had been using Insulin Aspart 30 Injection for almost 10 years. She developed severe hyperinsulinemia, low C-peptide levels, positive insulin antibodies, poor postprandial glycemic control, and occasional autonomic nervous system symptoms such as hunger, palpitations, fatigue, and excessive sweating. Despite these symptoms, hypoglycemia was not detected. Switching the type of insulin for two weeks resulted in a significant reduction in insulin dosage, leading to stabilization of fasting and two-hour postprandial blood glucose levels within the target range. This article aims to alert medical professionals about diabetic patients who have hyperinsulinemia, insulin antibodies, and difficulty controlling blood sugar due to EIAS. It is crucial to prevent missed diagnoses, misdiagnoses, and potentially unnecessary surgical interventions through increased awareness.

S100A9 exerts insulin-independent antidiabetic and anti-inflammatory effects

Type 1 diabetes mellitus (T1DM) is characterized by insulin deficiency leading to hyperglycemia and several metabolic defects. Insulin therapy remains the cornerstone of T1DM management, yet it increases the risk of life-threatening hypoglycemia and the development of major comorbidities. Here, we report an insulin signaling-independent pathway able to improve glycemic control in T1DM rodents. Co-treatment with recombinant S100 calcium-binding protein A9 (S100A9) enabled increased adherence to glycemic targets with half as much insulin and without causing hypoglycemia. Mechanistically, we demonstrate that the hyperglycemia-suppressing action of S100A9 is due to a Toll-like receptor 4-dependent increase in glucose uptake in specific skeletal muscles (i.e., soleus and diaphragm). In addition, we found that T1DM mice have abnormal systemic inflammation, which is resolved by S100A9 therapy alone (or in combination with low insulin), hence uncovering a potent anti-inflammatory action of S100A9 in T1DM. In summary, our findings reveal the S100A9-TLR4 skeletal muscle axis as a promising therapeutic target for improving T1DM treatment.