ACTH testing still best option in identifying risk for adrenal insufficiency
Canadian Pediatric Endocrine Group
TORONTO — Biomedical and clinical variables are not helpful to predict recovery of the hypothalamic-pituitary-adrenal axis in patients who received supraphysiological doses of glucocorticoids and who underwent low-dose adrenocorticotropic hormone stimulation testing, according to research presented here at the Canadian Pediatric Endocrine Group 2011 Scientific Meeting.
“Physicians must continue to screen patients with adrenocorticotropin-releasing hormone testing and maintain a state of vigilance for the risk of acute adrenal failure under situations of stress,” said pediatric endocrinology fellow Stefanie Wildi-Runge, MD, and colleagues at CHU Sainte-Justine, University of Montreal.
Almost half of the patients who take moderate or high doses of glucocorticoids may develop adrenal insufficiency, so the ability to predict hypothalamic-pituitary-adrenal (HPA) suppression is important, according to Wildi-Runge.
“We wanted to assess adrenal function in children who take high doses of glucocorticoids. Recovery of the HPA axis is very difficult to predict in children,” she said. “The symptoms [of adrenal insufficiency] are difficult to recognize and are non-specific.”
The researchers examined data from 104 patients who underwent 107 low-dose adrenocorticotropic hormone (ACTH) stimulation tests (1 mcg) between October 2008 and June 2010. All had received at least 1 month of supraphysiological doses of glucocorticoids. The median age of the patients was 8.4 years, and 57 were girls.
The study goal was to determine which biomedical values, such as 8 a.m. cortisol and peak cortisol, or clinical variables — patient and pretest factors — could predict recovery of the HPA axis.
According to the retrospective review, 77 patients had a normal cortisol (≥193 nmol/L) on the day of testing and 63 patients had a normal response to ACTH stimulation (peak cortisol ≥500 nmol/L). The researchers found no relationship between baseline cortisol, length of treatment or cumulative dose of glucocorticoids, and a normal baseline cortisol did not exclude subnormal response to ACTH (21%).
Clinical signs of hypoadrenalism were rare; however, the researchers observed growth deceleration (37%) and excessive weight gain (33%). Overall, although some patients tended to have a better response, the researchers saw no statistical difference among subgroups of patients categorized by underlying disease, Wildi-Runge said. She noted that ACTH testing should continue to be used to screen patients, given the lack of clinical and biomedical predictors.
“ACTH testing is important to identify patients most at risk for adrenal insufficiency,” Wildi-Runge said. – by Louise Gagnon
For more information:
- Wildi-Runge S. Oral Abstract 10. Presented at: the Canadian Pediatric Endocrine Group 2011 Scientific Meeting; Feb. 10-12, 2011; Toronto.
Disclosure: The researchers report no relevant financial disclosures.
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