Unreliability of classic provocative tests for the diagnosis of growth hormone deficiency

Area of Science:

• Pediatric Endocrinology
• Growth Hormone Physiology
• Diagnostic Endocrinology

Background:

• Prepubertal children may exhibit blunted growth hormone (GH) response to standard stimuli despite normal growth.
• Accurate diagnosis of GH deficiency is crucial for timely and appropriate intervention.

Purpose of the Study:

• To evaluate the utility of the GHRH plus arginine test in children with blunted GH response and normal auxological parameters.
• To differentiate true GH deficiency from other causes of blunted GH response.

Main Methods:

• Investigated 9 prepubertal children with blunted GH response to classic stimuli.
• Administered GHRH plus arginine as a supraphysiologic stimulus to assess pituitary reserve.
• Measured serum GH, prolactin (PRL), IGF-I, and insulin levels using immunometric assays.

Main Results:

• Seven out of 9 children showed a normal GH response to GHRH plus arginine.
• All children exhibited normal serum PRL, IGF-I, and insulin levels with normal insulin sensitivity.
• Growth rate improved significantly in all patients after one year, reaching near-normal values.

Conclusions:

• The GHRH plus arginine test is valuable in identifying false GH deficiency in children with normal growth.
• Decisions for initiating GH replacement therapy should integrate auxological data with laboratory findings.
• This test aids in avoiding unnecessary GH therapy by accurately assessing pituitary function.