5th April 2024

A 49-year-old librarian with familial hypertriglyceridemia has annual monitoring blood tests performed, which show a serum sodium of 122 mmol/L, haemoglobin of 125 g/L with a normal haematocrit.

A 49-year-old librarian with familial hypertriglyceridemia has annual monitoring blood tests performed, which show a serum sodium of 122 mmol/L, haemoglobin of 125 g/L with a normal haematocrit. She reports no symptoms of polydipsia and does not drink alcohol. Clinical examination reveals crops of xanthoma to extensor surfaces of both arms but is otherwise normal. Her GCS is 15 and serum osmolality is 290 mOsm/Kg (reference range 280 – 295 mOsm/kg). What is the likely cause of her hyponatremia?

Select the SINGLE most appropriate option from the list below. Select ONE option only.