Opiate use is a well-recognised cause of hypogonadotrophic hypogonadism. Adrenocorticotrophic hormone and growth hormone deficiencies are much rarer.
A 56-year-old female presented with weight loss, lethargy, and nausea of ~3 years duration. She had received treatment with morphine sulphate 100 mg twice daily for ~15 years for back pain due to disc prolapse and osteoarthritis. A 0900 h cortisol of 110 nmol/l requested by her general practitioner had resulted in her referral. She was receiving no hormonal treatment.
Investigations: short Synacthen test cortisol levels 0 min 109 nmol/l, 30 min 610 nmol/l, and 60 min 713 nmol/l. ACTH 12.5 ng/l, fT4 12.8 pmol/l, fT3 5.6 pmol/l, TSH 1.36 mU/l, prolactin 446 μIU/ml, FSH 17.4 U/l, LH 2.9 U/l, and IGF1 10.2 nmol/l all performed at 0900 h. An insulin tolerance test, during which adequate hypoglycaemia was achieved with a blood glucose level of 1.1 mmol/l coincidental with autonomic nervous system and neuroglycopenic symptoms, produced peak cortisol levels of 169 nmol/l and GH 0.93 μg/l. MRI of pituitary was normal.
This case highlights the need to consider pituitary insufficiency in patients receiving opiate therapy who have otherwise unexplained symptoms. The limits of the short Synacthen test in assessing the integrity of the hypothalamo-pituitaryadrenal axis are also demonstrated. She is asymptomatic at present receiving hydrocortisone and GH treatment.