Findings from recently published research indicate that doctors can safely continue to use clonidine testing for the diagnosis of patients with growth hormone deficiency (GHD).
Diagnosis of very low levels of growth hormone in the body is typically done with the aid of at least two stimulation tests. It mainly involves testing for clonidine and arginine, with this believed to produce results doctors can work with.
However, there is insufficient evidence on the accuracy of clonidine testing for GHD diagnosis despite the popularity of use.
New research published in Clinical Endocrinology (Oxford) shows that the test offers a reliable approach for diagnosing GHD in children and adolescents. It is also safe and puberty does not have an effect on growth hormone response to the substance.
The researchers reached their conclusions after analyzing data of 327 children and adolescents with growth issues. These manifested poor growth velocity, short stature, or both. The data of the participants were collected between 2005 and 2013.
These subjects were assessed for growth hormone deficiency through the use of oral clonidine. This was after they had been made to fast overnight.
The testing showed that 87 of the study participants suffered from growth hormone deficiency. Of these, 50 cases were idiopathic and 37 organic.
Growth hormone peak following the testing was less than 7 micrograms per liter (ug/L) in 73 of the prepubertal children and 25 of the adolescents. The GH median peaks for both prepubertal and pubertal children having GHD were similar. There was also no significant difference between the median GH peaks of prepubertal and pubertal subjects who had no GHD.
The authors of the investigational study noted that oral clonidine testing was safe and easy to perform. They suggested that it can be used as the first stimulation test for diagnosing children with short stature suspected of having GHD.
The standard testing procedure for growth hormone deficiency normally lasts about 90 minutes for arginine and 120 minutes for clonidine. Prior to the tests, a patient must go without food for hours – possibly up to about 16 hours.
Another group of researchers found in another study presented at the scientific meeting of the Canadian Pediatric Endocrine Group in 2015 that a shortened combined clonidine and arginine test can reduce the period of fasting required when diagnosing suspected GHD.