hPP and gastrin response to a liquid meal and oral glucose during prolonged severe exercise, caloric deficit, and sleep deprivation.

Sixteen young healthy military cadets were subjected to prolonged severe exercise, caloric supply deficiency, and sleep deprivation during a 5-day ranger training course. Several cadets complained of gastric discomfort. The fasting and postprandial human pancreatic polypeptide (hPP) and gastrin levels induced by a liquid meal (no. = 9) and peroral glucose load (no. = 7) were measured during normal school activities (control) and on the third day during the course. The results showed that the fasting level of hhPP was significantly increased during the course. Both during meal and glucose stimulation the hPP level during the course was significantly higher at most registrations than during control conditions. The fasting level of gastrin was not changed. The maximal level of gastrin during meal stimulation was higher during the course than during the control period. Glucose loading, on the other hand, did not change the gastrin response. The integrated response of hPP and gastrin were not changed during the course either for the liquid meal or for the peroral glucose load.