Pediatric Endocrine Group
The gonadotropin-releasing hormone stimulation test is
not needed to predict progression of precocious puberty, according to research
presented at the annual scientific meeting of the Canadian Pediatric Endocrine
We wondered if there is a baseline (luteinizing
hormone) value that we could use that would predict if the child will progress
into puberty or not, said Jill Hamilton, MD, FRCPC, study
researcher and pediatric endocrinologist at the Hospital for Sick Children in
Toronto and an associate professor at the University of Toronto.
With assays becoming more sensitive, such as the
third-generation immunochemiluminescence assays, investigators can detect the
luteinizing hormone (LH) at lower levels, potentially
avoiding the need for a gonadotropin-releasing hormone (GnRH) stimulation test,
Hamilton and colleagues retrospectively compared data
from 91 children, 75 girls and 16 boys, who were referred for evaluation of
early signs of puberty. They had not been treated with GnRH analogues and had
been followed for at least 6 months.
We wanted to see how many children progressed in
puberty, and if the (basal) LH level alone could predict who will progress as
opposed to using the (GnRH) stimulated test, Hamilton said.
They found that all patients with a basal LH level of at
least 0.3 IU/L experienced subsequent pubertal progression, whereas 62 of 67
patients with a basal LH level of 0.2 IU/L or less did not progress to puberty,
yielding 100% specificity and 82.2% sensitivity. In contrast, a stimulated LH
level of 5 IU/L showed 96.6% sensitivity and 85.5% specificity.
The researchers concluded that a single basal LH level
of 0.3 IU/L or more is sufficient to expect subsequent pubertal progression in
patients presenting with signs of precocious puberty.
The basal level was as good, and if not better,
in predicting who was going to progress in puberty over the subsequent 6
months, Hamilton said. Normally, patients have to have two blood
tests and undergo an injection. This saves time and costs associated with the
GnRH stimulation test and reduces stress for the patients.
The study was independently conducted.
For more information:
Disclosure: Dr. Hamilton reports no relevant