Volume 184 - Issue 1
Severe renal failure and nephrocalcinosis in anorexia nervosa
Authors: Matthew A Roberts, Campbell R Thorpe, Duncan P MacGregor, Nick Paoletti and Francesco L Ierino
Med J Aust 2006; 184 (1): 46. || doi: 10.5694/j.1326-5377.2006.tb00104.x
Published online: 2 January 2006
Published online: 2 January 2006
Matthew A Roberts,* Campbell R Thorpe,† Duncan P MacGregor,‡ Nick Paoletti,§ Francesco L Ierino¶
* Nephrologist, ‡ Director of Anatomical Pathology, § Psychiatrist, ¶ Deputy Director of Nephrology, Austin Health, Studley Road, Heidelberg, VIC 3084; † Psychiatrist, Child and Adolescent Mental Health Service, The Alfred Hospital, Melbourne, VIC. frank.ierinoATaustin.org.au
In reply: Disturbances of calcium metabolism in anorexia nervosa are complex, particularly with associated renal insufficiency. Although hypocalcaemia is observed in patients with anorexia nervosa, our article attempted to highlight nephrocalcinosis and hypercalcaemia.
We agree that hypercalcaemia is not in itself a diagnosis, and identifying the underlying pathology is essential. Ingestion of vitamin D preparation remains a likely explanation for the hypercalcaemia observed in Patient 1; however, primary hyperparathyroidism was considered as a possible differential diagnosis. Patient 1 had two normal parathyroid hormone tests in the setting of hypercalcaemia and renal impairment. This is consistent with secondary hyperparathyroidism and vitamin D ingestion as documented. The coexistence of primary hyperparathyroidism cannot be excluded. Ionised calcium may be a useful measure if the patient had hypoalbuminaemia, and this would be our normal practice.
Patient 2 had ionised calcium measured twice (one result high, one low), but these added little to the case description and message of the article. Faecal electrolytes were not measured in Patient 2. However, we acknowledge the potential utility of this investigation when interpreting electrolyte disorders. We also agree that familial or genetic conditions should be considered if clinically appropriate.