Diagnosis of growth-hormone deficiency in adults

• Published in: The Lancet (British edition) Vol. 343; no. 8905; pp. 1064 - 1068
• Main Authors: Hoffman, D.M, O'Sullivan, A.J, Ho, K.K.Y, Baxter, R.C
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 30.04.1994; Lancet; Elsevier Limited
• Subjects: Adolescent; Adult; Adults; Aged; Biological and medical sciences; Body Mass Index; Carrier Proteins - blood; Diagnostic systems; Female; Functional investigation of endocrine glands and genital system; Glucose Tolerance Test; Growth Disorders - diagnosis; Growth factors; Growth hormone; Growth Hormone - blood; Growth Hormone - deficiency; Hormones; Humans; Hypoglycemia; Hypopituitarism - blood; Indexing; Insulin; Insulin - administration & dosage; Insulin-Like Growth Factor Binding Proteins; Insulin-like growth factor I; Insulin-Like Growth Factor I - analysis; Insulin-like growth factor-binding protein 3; Insulin-like growth factors; Investigative techniques, diagnostic techniques (general aspects); Male; Medical diagnosis; Medical disorders; Medical research; Medical sciences; Middle Aged; Physical growth; Pituitary; Proteins; Radioimmunoassay; Sensitivity and Specificity; Endocrinopathy; Human; Pituitary hormone; Somatomedin C; Secretion; Deficiency; STH; Adult; Exploration; Hormonal investigation; Hormone releasing factor
• ISSN: 0140-6736; 1474-547X
• DOI: 10.1016/S0140-6736(94)90181-3

There is no consensus as to the most appropriate method of diagnosing growth-hormone (GH) deficiency in adults. We have evaluated the relative diagnostic merits of measuring peak GH response to insulin-induced hypoglycaemia (insulin tolerance test), mean 24 h GH concentration derived from 20 min sampling, serum insulin-like growth factor I (IGF-I) concentrations, and serum IGF binding protein 3 (IGFBP-3) concentrations. These tests were undertaken in 23 patients considered GH deficient from extensive organic pituitary disease, and in 35 sex-matched normal subjects of similar age and body-mass index. Hypopituitary subjects had significantly lower stimulated peak GH, mean 24 h GH, IGF-I, and IGFBP-3 concentrations than normal subjects. The ranges of stimulated peak GH responses were clearly separated between the hypopituitary (<0·2-3·1 ng/mL) and normal (5·3-42·5 ng/mL) groups, but mean 24 h GH, IGF-I, and IGFBP-3 concentrations overlapped. Mean 24 h GH concentrations were below assay sensitivity in 80% of hypopituitary subjects and 16% of normal subjects. 70% and 72%, respectively, of the IGF-I and IGFBP-3 values in hypopituitary subjects were within the range for normal subjects. We conclude that GH deficiency in adults is most reliably identified by stimulatory testing, and that IGF-I and IGFBP-3 are poor diagnostic tests of adult GH deficiency.