PRESENTATION A 71-year-old Chinese woman with

autoimmune Hashimoto’s hypothy-roidism and mixed connective tissue disease (MCTD) was referred to the Endocrine Unit for frequent epi-sodes of hypoglycemia. The patient was diagnosed with diabetes by her general practitioner several weeks earlier and started on metformin for symptoms of polyuria, polydipsia, and a random blood glucose level of 468 mg/dl. The hyperglycemia was initially thought to be secondary to initiation and subsequent increase in dose of the steroid used for treatment of her MCTD. A week after taking metfor-min, she noted increased episodes of palpitations, dizziness, and diapho-resis, which were relieved with food intake. She subsequently decided for herself to discontinue the metformin. Her fasting capillary blood glucose readings were 44–55 mg/dl. Hypoglycemia occurred despite con-stant and pre-planned food intake. Additionally, these episodes of hypoglycemia became more frequent with discontinuation of her ora