Insulin-like growth factor I (IGF-I) and IGF-binding protein 3 response to growth hormone is impaired in HIV-infected children.
To better characterize the somatotropic axis in HIV-infected children the circadian rhythm of growth hormone (GH), and basal and stimulated (by an insulin-like growth factor I [IGF-I] generation test) plasma levels of IGF-I and insulin-like growth factor-binding protein 3 (IGFBP-3), were evaluated in 16 children (9 boys and 7 girls; age range, 7-11 years) with HIV infection. All patients were free from active opportunistic infection or liver disease at the time of the study. Sixteen age- and sex-matched healthy children (10 boys and 6 girls; age range, 7-11 years) served as control subjects. GH rhythmometric data were analyzed by single and population mean cosinor analysis. As regards the IGF-I generation test, biosynthetic human GH (hGH, 0.1 IU/kg, 0.033 mg/kg) was administered subcutaneously for 4 days and blood samples were taken from fasting subjects at baseline and on the morning after the last GH injection for measurement of IGF-I and IGFBP-3. Plasma GH levels fell within normal limits in the HIV-seropositive patients and were similar to those of healthy children (1.31 +/- 1.18 vs. 1.57 +/- 1.16 microg/liter, respectively; mean +/- SD). The population mean cosinor analysis shows that the GH circadian rhythm reached statistical significance both in the HIV-seropositive children and in the control group. Despite this, the IGF-I and IGFBP-3 levels were significantly lower in HIV-infected children than in the control group (75.6 +/- 57.2 vs. 233.3 +/- 52.5 ng/ml, p < 0.001 and 2.09 +/- 0.17 vs. 3.89 +/- 0.24 mg/liter, p < 0.01, respectively; mean +/- SD); moreover, the response of IGF-I and IGFBP-3 to the IGF-I generation test was significantly lower in HIV-infected children than in the control group (86.3 +/- 55.8 vs. 257.5 +/- 53.4 ng/ml, p < 0.001 and 3.14 +/- 0.43 mg/liter, p < 0.01, respectively; mean +/- SD). It appears that circadian GH secretion is normal in children with HIV infection, but the response to exogenous GH with regard to IGF-I and IGFBP-3 production is impaired, indicating a degree of GH insensitivity in such children.
Rondanelli
Mariangela
M
Department of Internal Medicine and Medical Therapy, University of Pavia, 27100 Pavia, Italy. ferrari@unipv.it
Caselli
Desiree
D
Aricò
Maurizio
M
Maccabruni
Anna
A
Magnani
Barbara
B
Bacchella
Luisa
L
De Stefano
Anna
A
Maghnie
Mohamed
M
Solerte
Sebastiano Bruno
SB
Minoli
Lorenzo
L
D002648:Child; D015331:Cohort Studies; D005215:Fasting; D005260:Female; D015658:HIV Infections / Q000097:blood*; D006304:Health Status; D019382:Human Growth Hormone / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D006801:Humans; D007279:Injections, Subcutaneous; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood* / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008297:Male; D013997:Time Factors
D018972:Insulin-Like Growth Factor Binding Protein 3; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I