Growth hormone and
prolactin blood concentrations were measured in five human volunteers over 28-hour periods including 24 hourly samples (0800 to 0800 hours) followed by an oral
glucose tolerance test (0800 to 1100 hours) 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 degrees C for 2 hours from 1300 to 1500 hours. During all studies, mealtimes (0800 hours, 1130 hours, 1630 hours) and dark phase (2300 to 700 hours) were fixed.
Growth-hormone concentrations were strikingly elevated throughout the 24-hour study done during the febrile period of
Sandfly fever infection (P less than .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 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 less than .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. A nocturnal surge of
growth hormone was still seen in the artificial
hyperthermia study, albeit somewhat delayed.(ABSTRACT TRUNCATED AT 250 WORDS)