Endocrine Abstracts

Introduction: Hypoglycaemia is an endocrine and medical emergency. It is usually due to the excessive dose of insulin or oral anti-diabetic agents. Although rare, hypoglycaemia can be a tumour–induced. Some of the other causes include renal and liver failure, hormonal deficiency, antibodies to insulin, infection, starvation, spontaneous hypoglycaemia and reactive hypoglycaemia.

Case report: A 70-year-old man presented with 6 months’ history of recurrent collapses; progressively worse over the last 3 months. He required frequent hospital admissions with ‘funny turns’ and seizures. He denied palpitations or chest pain. He was hypoglycemic during every admission with glucose levels <2 mmol/L, requiring treatment with i.m glucagon and iv dextrose. The blood test results showed glucose 3.1 mmol/L (< 2 mmol/L previous admissions), C-peptide <94 pmol/L, low insulin level (1 pmol/L), GH 0.38 mcg/L, ketones (beta-hydroxybutyrate) <0.05 mmo/L, IGF-1 29.2 nmol/L (1.5–35), and IGF-2 134.5 nmol/L. IGF2:IGF-1 4.5 (<10); not hypoglycaemic at that time(glucose 5.5 mmol/L. SST (cortisol 255,719). Urine sulphonylurea screen was negative. CXR- chronic right-sided pleural effusion and lung mass. His background includes right-sided pleural effusion, IHD, heart failure, hypertension and right-sided lung tumour diagnosed in 2010. His medications include aspirin, atorvastatin, candesartan, furosemide, omeprazole, paracetamol and eplerenone. He was treated with steroids and given growth hormone. He underwent radiotherapy for the right lung mass and subsequently, his hypoglycaemia resolved.

Discussion: Tumour-induced hypoglycaemia is a rare paraneoplastic process. This can be divided into an insulin-secreting tumour, due to a tumour related infiltration of the liver or adrenal glands, and tumours producing substances interfering with glucose metabolism such as IGF-1 and tumours that produce partially processed precursors of IGF-2 (“big IGF-2”).

Conclusion: Tumour-induced hypoglycaemia should be considered in the differential diagnosis in patients with active malignancy or past medical history of malignancy presenting with hypoglycaemia.