Circadian Growth Hormone and Prolactin Blood Concentration during a Self-Limited Viral Infection and Artificial Hyperthermia in Man

摘要

Growth hormone and prolactin blood concentrations were measured in five human volunteers over 28-hour periods including 24 hourly samples (0800 h to 0800 h) followed by an oral glucose tolerance test (0800 h- 1100 h) both preexposure and during the peak febrile phase of a self limited viral infection, Sandfly fever. Several months after recovery, three of the subjects were studied for 24 hour periods while they sat in a tub of water at 41 C for 2 hours from 1300 to 1500 hours. During all studies, meal times (0800 h, 1130 h, 1630 h) and dark phase (2300 h-0700 h) were fixed. Growth hormone concentrations were strikingly elevated throughout the 24 hours study done during the febrile period of Sandfly fever infection (P<.01) except for the period of normal nocturnal release when they were not significantly different from the baseline study. No additional nocturnal surge was noted above the already elevated growth hormone values during the viral induced fever. Growth hormone values tended to decline slowly during the night but increased considerably during the glucose tolerance test the following morning. These changes were similar to responses previously reported in patients with cases of malnutrition. A clear cut increase in growth hormone concentrations (P<.001) was also seen during a brief 2 hour period of artificial hyperthermia, suggesting that elevated body temperature alone may explain part of the increase in growth hormone values seen during the fever of infection.