The IGFBP-3 Stimulation Test: A New Tool for the Diagnosis of Growth Hormone Deficiency in Children.

The diagnosis of growth hormone deficiency is problematic, given the shortcoming of the standard growth hormone stimulation test. This study is designed to investigate a new tool for the diagnosis of growth hormone deficiency.

Ten short, prepubertal children, who fulfill the inclusion criteria, will undergo a two-secretagogue standard growth hormone stimulation test, and an insulin like growth factor binding protein-3 (IGFBP-3) stimulation test simultaneously. During this test, components of the ternary complex moieties, viz, insulin-like growth factor-I (IGF-I), IGFBP-3 and acid labile subunit (ALS) will also be measured along with growth hormone.

The aim of this study is to detect an acute rise in IGFBP-3 of >15% from baseline.

The importance of this study is that it inculcates the specificity and improved sensitivity of stimulated IGFBP-3 in the diagnosis of growth hormone deficiency.

Inclusion criteria

• Bone age < 10 years female, < 12 years male
• Pubertal status: Girls: Tanner I for breast development. Boys: testicular volume of ≤ 3 cc, as measured by the standardized orchidometer (Prader type). The onset of pubic hair development up to and including Tanner III is allowed in the study.
• Adequate nutrition: body mass index ≥ 25th percentile for gender.

Exclusion criteria

• Syndromic short stature
• Chronic illnesses.
• Other disorders, including osteo- or chondrodystrophies, and endocrine causes of short stature such as Cushing syndrome, and untreated hypothyroidism.