Recurrent Postprandial Hypoglycaemia in Insulin Autoimmune Syndrome OD01-OD02
Dr. Suresh Kumar Sinha,
B-302, Aditya Birla Residential Colony, Chinchwad, Pune, Maharashtra, India.
Insulin autoimmune hypoglycaemia syndrome (IAS) is not a common entity. It is characterised by auto-antibodies to endogenous insulin in persons without previous exposure to exogenous insulin. IAS is relatively common cause of spontaneous hypoglycaemia in Japan (third most common cause of hypoglycaemia). First case in India was reported in 2013. Since then only four cases of IAS have been reported so far.
The present case is about a middle aged Indian male, who presented with spontaneous, recurrent postprandial hypoglycaemia. He had palpitations, sweating, tremor of hands, feeling of hunger 2-5 hours after meal. He got relief by taking sweets, sugar or orange juice. Estimation of anthropological parameters revealed his BMI to be 28.5 kg/m2. Laboratory findings of serum glucose were 52 mg/dL, serum Insulin >1000 units/mL, Connecting peptide 14.56 ng/mL, Serum Insulin antibody level was >300 units/mL. He was a non-diabetic with HbA1C 5.63%: Rise of serum cortisol was appropriate for hypoglycaemic stress. A diagnosis of IAS was made. He was put on steroid which was tapered in three months. The patient was advised frequent low carbohydrate meals. His symptoms subsided in six moths and after one year all his hormonal parameters returned to normal.
Spontaneous hypoglycaemia with unusually high serum Insulin, high C-Peptide and presence of insulin auto antibodies are strongly suggestive of IAS.