An Unusual Case of a Primary Hyperparathyroidism Mimic
Wynn, T.; Marath, H.; Brahma, A.; Rajagopal, V.
Acute Medicine 22(4): 261-263
2023
ISSN/ISBN: 1747-4892 PMID: 38284639 Document Number: 18341
A 32-year-old lady with a history of bulimia nervosa was noted to have a raised adjusted calcium of 2.94mmol/L associated with high parathyroid hormone (PTH) 17.2pmol/L. On review, she had an apparent hypercalcaemia for at least three years, and also had a chronic, severe alkalosis with a bicarbonate up to 81.9mEQ/L. Ionised calcium during that time had actually been low, down to 1.03mmol/L. This case highlights the effects of alkalosis on calcium, as more albumin is available for binding to ionised calcium. This results in a low ionised calcium, which triggers PTH release and overall leads to raised adjusted calcium levels. Clinicians may misdiagnose a similar patient with primary hyperparathyroidism and treatment would cause worsening of true hypocalcaemia.
Document emailed within 1 workday
