INVOLVEMENT OF HORMONAL CIRCADIAN SECRETION IN THE GROWTH OF HIV-INFECTED CHILDREN

Objective: To evaluate the circadian secretion of hormones involved in the regulation of growth in childhood, namely growth hormone, insulin -like growth factor (IGF)- I, cortisol, adrenocorticotropin hormone (A CTH), and thyroid-stimulating hormone (TSH) in HIV-infected children. Design: The circadian secretory pattern of growth hormone, IGF-I, cort isol, ACTH and TSH was evaluated in 14 HIV-infected children; 13 healt hy age- and sex-matched children were chosen as controls. Methods: Sam pling was performed every 4 h from 0400 h to 2000 h and every 2 h from 2000 h to 0400 h. Rhythmometric data were analysed by single and popu lation mean cosinor methods and by analysis of variance. Results: A st atistically significant circadian rhythm for growth hormone, IGF-I and cortisol was detectable in HIV-seropositive children, but the mean ba sal IGF-I levels were below the normal range for age in 12 patients. A statistically significant circadian rhythm was not detectable for ACT H or TSH. Conclusion: These results show that there is a loss of the p hysiological regulation of growth hormone-IGF-I axis and a modificatio n of 24 h TSH profile in our HIV- infected children. These abnormaliti es might be involved in the altered growth mechanism leading to the fa ilure to thrive that is a peculiar feature of HIV-infected children. ( C) 1998 Lippincott Williams & Wilkins.