Persistence of human growth hormone circadian rhythm in patients with homozygous beta-thalassemia
Pasqualetti, P.; Collacciani, A.; Natali, G.F.; Colantonio, D.; Casale, R.
Panminerva Medica 34(3): 124-127
1992
ISSN/ISBN: 0031-0808 PMID: 1491871 Document Number: 390644
Plasma levels of human growth hormone (hGH) were measured for an entire day every two hours, starting from midnight, in 6 healthy male subjects and in 6 male patients with homozygous beta-thalassemia, without evidence of any endocrine disease. The data were analyzed by the "cosinor" method, and the results show the presence of a significant (p < 0.05) circadian rhythm for hGH in both groups. Whereas no differences were found in mesors and acrophases between the two studied groups (p > 0.05), a statistically-significant (p < 0.05) difference was observed regarding amplitudes, being higher in the controls. These data suggest that in patients with beta-thalassemia major without evidence of any endocrine abnormality, the circadian secretory pattern of hGH is preserved, even if the rhythm amplitude is reduced: this could be a compensatory mechanism in order to stimulate growth.