Anastrozole delays bone maturation in kids with congenital adrenal hyperplasia
The aromatase inhibitor anastrozole shows promise in the treatment of children with congenital adrenal hyperplasia (CAH), reducing bone age advancement without adversely affecting bone mineral density (BMD) and visceral adipose tissue (VAT), as shown in a recent study.
Researchers looked at 25 anastrozole-treated paediatric CAH patients (mean age, 11.3 years; 56 percent boys) and 31 paediatric CAH controls not treated with the drug (mean age, 13.5 years; 29 percent boys). All participants underwent a pubertal exam, bone age X‐ray and dual X‐ray absorptiometry (DXA) scan.
Children in the anastrozole group had received the drug for an average of 5.2 years. Both the anastrozole and control groups had also been receiving chronic glucocorticoid replacement therapy and inevitably had periods of intermittent hyperandrogenaemia, as shown by the elevated bone age Z-scores.
Anastrozole produced a significant decrease in the average bone age z‐score, from 4.3 standard deviation score (SDs) at treatment initiation to 1.9 SDs at the time of DXA exam, which was conducted a mean of 5.2 years later (p=0.0004).
The anastrozole and control groups did not significantly differ in terms of total BMD z‐scores (p=0.51), L2‐L4 BMD z‐scores (p=0.66), VAT (p=0.38), total BMD adjusted for height-for-age z-scores (TMBDHAZ; p=0.66) and L2‐L4HAZ z-scores (p=0.41).
According to the researchers, the similarity in BMD observed between children receiving vs not receiving anastrozole indicates that “the direct effect of potentially higher androgen levels from blocking aromatization in children treated with anastrozole may compensate for the effect of decreased oestrogen levels on bone and may offset some of the negative effects of glucocorticoids.”
The described effect could also explain the absence of difference in VAT between the two patient groups, they added.