Impaired thermoregulation in adults with growth hormone deficiency during heat exposure and exercise.
OBJECTIVE
It has recently been shown that patients with growth hormone deficiency have a reduced sweating capacity. We hypothesize that reduced sweating might affect thermoregulation in growth hormone deficiency patients. In the present study we have examined thermoregulation in growth hormone deficiency patients.


METHODS
Six adult growth hormone deficiency patients and six matched controls were exposed to a 90-minute heat period (40 degrees C). On a second day the subjects exercised for 30 minutes under standardized conditions.


METHODS
On both occasions changes in GH secretion, sweating and temperature were registered. Heat storage and evaporation were calculated from these data.


RESULTS
We found that during the moderate heat exposure, evaporation was less (56.7 vs 115.6 W, P = 0.0037) and heat storage greater (60.7 vs 37.0 W, P = 0.025) in growth hormone deficiency patients compared to their matched controls. Two of the six patients reacted with severe clinical symptoms of heat exhaustion, whereas the controls were unaffected. After exercise the patients reached significantly higher core temperatures than their matched controls (38.1 vs 37.8 degrees C, P = 0.0097).


CONCLUSIONS
Thus, our findings are indicative of a reduced thermoregulatory function in some patients with GH deficiency.
Juul
A
A
University Department of Growth and Reproduction GR, Rigshospitalet, University of Copenhagen, Denmark.
Behrenscheer
A
A
Tims
T
T
Nielsen
B
B
Halkjaer-Kristensen
J
J
Skakkebaek
N E
NE
D000328:Adult; D001833:Body Temperature Regulation / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D013006:Growth Hormone / Q000097:blood / Q000172:deficiency*; D006339:Heart Rate / Q000502:physiology; D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D008297:Male; D012881:Skin Temperature / Q000502:physiology; D013546:Sweating / Q000502:physiology
D013006:Growth Hormone