Endocrine Abstracts

A 49-year-old female was admitted to with diabetic ketoacidosis (DKA) and newly diagnosed diabetes. Her only significant medical problem was malignant hypertension with poorly controlled blood pressure (BP) on four antihypertensive agents. She reported no exogenous glucocorticoid or liquorice ingestion. She also complained of a 6-month history of lethargy, weight gain, and a two-month history of easy bruising, lower-limb weakness, increasing polyuria and polydipsia. There was no history of a headache, palpitations, flushing or diaphoresis. She had a BMI of 41 kg/m² with evidence of easy bruising, abdominal striae, and lower limb proximal myopathy. There was no evidence of androgen excess. Following resolution of DKA she underwent routine blood tests, overnight low-dose dexamethasone suppression test (LDDST), 24-hour urine free cortisol (UFC), adrenal computed tomography (CT), 24-hour urine metanephrines, magnetic resonance imaging pituitary. Significant findings were an IFCC-HbA1C (glycated haemoglobin) 102 mmol/mol on admission (30 mmol/mol 6 months earlier) and an overnight LDDST with a non-suppressed cortisol level 163 nmol/L (normal < 50 nmol/L). Total urine cortisol was 472 nmol in 24hours, confirming hypercortisolemia. Adrenal CT revealed a 2.6 cm right-adrenal adenoma (absolute washout =69%). 24-hour urine metanephrines (repeated), plasma aldosterone-renin-ratio and androgens were all within normal range; adrenocorticotropic hormone (ACTH) level 15.9 ng/L (0–46 ng/L). An MRI pituitary confirmed no evidence of visible adenoma. She was discharged on insulin, metformin 500 mg twice daily and regular anti-hypertensives. Insulin was eventually stopped two months following discharge. The HbA1C has remained in the non-diabetic range with a well-controlled BP. Repeat outpatient overnight LDDST (twice) showed serum cortisol levels of 65 and 37 nmol/L. Multiple UFCs have been normal for 12 months since hospital discharge. A repeat CT-adrenals confirmed unchanged appearances of the right adrenal mass. This patient had convincing history, signs and investigation results of hypercortisolism likely leading to development of life-threatening malignant hypertension and DKA. Glucose intolerance associated with Cushing’s syndrome is usually only mild to moderate in severity and marked hyperglycaemia with ketosis is very rare. Cyclical Cushing’s is a poorly understood phenomenon and the mechanisms causing such abnormality have yet to be discovered. This condition has recently been recognised as occurring much more frequently than initially thought. A high index of suspicion of the syndrome is required in patients with symptoms or signs of Cushing’s syndrome but with normal cortisol values. This patient remains under endocrine follow up with periodic UFC measurements.