Circadian secretory pattern of growth hormone, insulin-like growth factor type I, cortisol, adrenocorticotropic hormone, thyroid-stimulating hormone, and prolactin during HIV infection

The circadian rhythms of plasma growth hormone (GH), insulin-like growth factor type I (IGF-I), cortisol, adrenocorticotropic hormone (ACTH), thyroid- stimulating hormone (TSH), and prolactin (PRL) were evaluated in 13 HIV- seropositive patients (8 males and 5 females; mean age [±SD], 30 ± 5 years), classified as CDC C2. Sixteen clinically healthy subjects (9 males and 7 females; mean age [±SD], 32 ± 8 years) were chosen as control group. Samples were taken every 4 hr from 04:00 to 20:00 and every 2 hr from 20:00 to 04:00. Plasma GH was evaluated by IRMA procedure, plasma IGF-I by RIA (after separation of soluble IGF-I from IGF-I-binding proteins, using acid- ethanol extraction), plasma cortisol by a solid-phase RIA, plasma ACTH by double-antibody RIA, and serum TSH and serum PRL by a solid-phase two-site fluoroimmunometric assay. Rhythmometric data were analyzed by single and population mean cortisol analysis; the comparison of the parameters of the rhythm between patients and controls was carried out by the mesor test and the amplitude-acrophase Hotelling test. Alterations of the circadian pattern of GH, IGF-I, cortisol, ACTH, TSH, and PRL were demonstrated in HIV- seropositive patients. In fact, the circadian profiles of these hormones were clearly flattened and no statistically significant 24-hr rhythm was detectable (with the exception of cortisol). These results are consistent with the hypothesis that alterations of the circadian temporal structure may already be present in HIV-seropositive patients without wasting and infectious complications.