Exercise induces gastric ischemia in healthy volunteers: a tonometry study

Heavy physical exercise may cause gastrointestinal signs and symptoms, and, although splanchnic blood flow may decrease through redistribution by more than 50%, it is unclear whether these signs and symptoms relate to gastroi ntestinal ischemia. In 10 healthy volunteers, we studied the effect of exer cise on gastric mucosal perfusion adequacy using air tonometry. Two relativ ely short (10 min) exercise stages were conducted on a cycle ergometer, aim ing for 80 and 100% of maximum heart rate, respectively. The intragastric-a rterial PCO2 gradient (Delta PCO2) was elevated by 1.1 +/-1.0 kPa over base line values (-0.1 +/-0.3 kPa) only after maximal exercise (P < 0.001). <Del ta>PCO2 positively correlated with the arterial lactate level taken as an i ndex of exercise intensity (Spearman's rank test: r = 0.76, P < 0.0001). By bilinear regression analysis, a lactate level of 12 mmol/l, above which a sharp rise in the <Delta>PCO2 occurred, was calculated. We conclude that, i n healthy volunteers with normal splanchnic vasculature, gastric ischemia m ay develop during maximal exercise as judged from intragastric PCO2 tonomet ry.