medwireNews: Anastrozole decreases the rate of bone maturation leading to significant gains in growth potential in children with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21OHD), US research shows.
Kyriakie Sarafoglou and colleagues, from the University of Minnesota in Minneapolis, say their data suggest that “anastrozole could have a role as an adjunct therapy in children with CAH and advanced bone age.”
They explain in The Journal of Clinical Endocrinology & Metabolism that although third-generation aromatase inhibitors like anastrozole have been shown to effectively treat children with other disorders of puberty and growth, there are no adequately powered studies examining the use of these drugs in children with CAH with advanced bone age and reduced predicted adult height (PAH).
To address this, they reviewed the medical records of 60 children (57% boys) with CAH due to 21OHD and an advanced bone age, defined as greater than 2 standard deviations (SD) above the mean.
All children were treated with anastrozole 1 mg/day in addition to their regular dose of hydrocortisone, with or without fludrocortisone depending on their salt wasting status. They began treatment at 7.7 years of age, on average, and continued for a mean of 4.9 years. Anastrozole was discontinued when a patient’s bone age reached 14 years in girls and 16 years in boys.
The researchers report that when the children started on anastrozole therapy they had a mean bone age z score of 4.2. This fell significantly over time, reaching 2.0 at 4 years and 1.3 at 6 years.
In line with this, PAH z score improved significantly over time from –2.1 at baseline to –0.45 at 4 years and 0.18 at 6 years.
The improvements in PAH z score corresponded to a mean PAH increase from 156 cm at baseline to 168 cm and 173 cm at 4 years and 6 years, respectively. After adjustment for age at diagnosis, CAH type, sex, average hydrocortisone dose before starting anastrozole, and average hydrocortisone dose during follow-up, Sarafoglou and team estimate that PAH increased by a significant mean 2.08 cm during the first year of anastrozole therapy, and by a significant 19.46 cm over 6 years of treatment.
The positive effect of anastrozole treatment remained significant when height z scores were corrected for bone age and was consistent when the children were stratified by sex and whether they received a gonadotropin-releasing hormone analog.
The researchers also note that there were no significant changes in bone mineral density over the course of treatment and there was no need for increased doses of hydrocortisone.
Finally, patients and their parents did not report any increases in clinical symptoms associated with androgen excess such as hair growth, acne, or increased virilization.
Sarafoglou et al conclude: “Based on our results, anastrozole can be an effective adjunctive therapy in children with CAH and advanced bone age to optimize their growth.”
However, they add that “a longitudinal randomized controlled clinical trial is needed to assess long term outcomes.”
medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2024 Springer Healthcare Ltd, part of the Springer Nature Group
