Diagnostic strategy for growth hormone deficiency: relevance of IGF-1 determination as a screening test.

Abstract

BACKGROUND:

Adult growth hormone (GH) deficiency must be diagnosed before prescribing therapeutic recombinant human GH. We studied the clinical relevance of a diagnostic strategy for growth hormone deficiency (GHD) using IGF-1 determination as a first step.

METHODS:

In 2000 and 2001, we tested 142 adult patients with hypothalamo-pituitary disorders for somatotropic function using Insulin Tolerance Test (ITT), the reference test for the diagnosis of GHD, with concomitant Insulin-like growth factor-1 (IGF-1) determination, a marker of somatotropic function. Patients were classified as GHD (peak GH concentration<3 ng/ml with the ITT) or normal.

SETTING:

Monocenter prospective study in a tertiary referral center.

RESULTS:

GHD was diagnosed in 61 subjects. Using a ROC curve, a threshold IGF-1 concentration of 175 ng/ml yielded a negative predictive value of 89+/-5%. A diagnostic strategy with IGF-1 determination as the first step followed by ITT for patients with an IGF-1 concentration below 175 ng/ml missed five of the 61 GHD patients, avoided 46/142 ITT and reduced the cost of diagnosis by 15%.

CONCLUSION:

We propose the use of a strategy consisting of IGF-1 determination followed, if below 175 ng/ml by confirmatory ITT to diagnose GHD in adults.

• Authors: S Hadjadj, C Faure-Gerard, S Ragot, C Millet, F Duengler, F Torremocha, G Chatellier, B Bataille, R Marechaud
• Journal: Annales d'endocrinologie (Ann Endocrinol (Paris)) Vol. 68 Issue 6 Pg. 449-55 (Dec 2007) ISSN: 0003-4266 [Print] France
• PMID: 17991453 (Publication Type: Journal Article)

Chemical References

• Biomarkers
• Insulin-Like Growth Factor I
• Growth Hormone

Topics

• Adult
• Aged
• Biomarkers (blood)
• False Negative Reactions
• False Positive Reactions
• Female
• Growth Hormone (deficiency)
• Humans
• Hypothalamic Diseases (blood, diagnosis)
• Insulin-Like Growth Factor I (metabolism)
• Male
• Middle Aged
• Pituitary Diseases (blood, diagnosis)
• Prospective Studies
• Sensitivity and Specificity