van Nieuwenhoven M A, Vriens B E, Brummer R J, Brouns F
Department of Gastroenterology, University Hospital Maastricht, The Netherlands.
Eur J Appl Physiol. 2000 Dec;83(6):578-84. doi: 10.1007/s004210000305.
Dehydration leads to the aggravation of gastrointestinal (GI) complaints during exercise. The aim of this study was to examine the effect of dehydration on various GI parameters during strenuous exercise. Ten healthy well-trained men were investigated in dehydrated and in euhydrated conditions. Dehydration took place before the experiments using a dehydration regimen in a sauna leading to a 3% loss of body mass. Each experiment consisted of 1 h pre-exercise rest, 1.5 h cycling at 70% maximal exercise intensity, and 3.5 h post-exercise rest. During cycling, liquid gastric emptying (GE), orocaecal transit time (OCTT) and intestinal permeability and glucose absorption were measured. The GI-symptoms were scored using a questionnaire. Body temperature, plasma volume and vasopressin were measured before and after cycling. The GE was significantly slower during dehydration [median time to peak 13C enrichment in the breath sample (13C-TTP) 23.6 min, range 13.7-50.0 min, P = 0.02] than in the control situation (median 13C-TTP 17.1 min, range 9.8-38.4 min). The OCTT was unchanged (median 173 min, range 98-263 min compared to median 128 min, range 98-195 min, P = 0.18). Dehydration did not change intestinal permeability, glucose absorption, plasma volume, rectal temperature or plasma vasopressin concentration. In the dehydration experiment, exercise induced a significant increase in nausea (P = 0.01) and epigastric cramps (P = 0.05), in contrast to the control situation. In both experiments, exercise led to a significant increase in rectal temperature and plasma vasopressin concentration, and a significant decrease in plasma volume. The increase in plasma vasopressin concentration was significantly higher in the dehydration experiment (P = 0.015). No significant differences in either the post-exercise rectal temperatures or in plasma volumes was observed. The difference in GE between the two experiments was significantly correlated with the difference in nausea score (r = 0.87, P = 0.002). We concluded that dehydration leads to a delayed GE but not to differences in OCTT, intestinal permeability or glucose uptake during intense cycling. The delay in GE is significantly associated with an increase in exercise-induced nausea.
脱水会导致运动期间胃肠道（GI）不适加重。本研究旨在探讨脱水对剧烈运动期间各种胃肠道参数的影响。对10名健康且训练有素的男性在脱水和正常水合状态下进行了研究。在实验前，通过在桑拿房进行脱水方案使体重减轻3%来实现脱水。每个实验包括1小时运动前休息、以最大运动强度的70%进行1.5小时骑行以及3.5小时运动后休息。在骑行过程中，测量液体胃排空（GE）、口盲肠传输时间（OCTT）、肠道通透性和葡萄糖吸收。使用问卷对胃肠道症状进行评分。在骑行前后测量体温、血浆容量和血管加压素。与对照情况相比，脱水期间胃排空明显减慢[呼气样本中13C富集达到峰值的中位时间（13C-TTP）为23.6分钟，范围为13.7 - 50.0分钟，P = 0.02]（对照情况的中位13C-TTP为17.1分钟，范围为9.8 - 38.4分钟）。口盲肠传输时间未改变（中位时间为173分钟，范围为98 - 263分钟，对照情况的中位时间为128分钟，范围为98 - 195分钟，P = 0.18）。脱水并未改变肠道通透性、葡萄糖吸收、血浆容量、直肠温度或血浆血管加压素浓度。在脱水实验中，与对照情况相比，运动导致恶心显著增加（P = 0.01）和上腹部绞痛显著增加（P = 0.05）。在两个实验中，运动均导致直肠温度和血浆血管加压素浓度显著升高，以及血浆容量显著降低。脱水实验中血浆血管加压素浓度的升高显著更高（P = 0.015）。运动后直肠温度或血浆容量均未观察到显著差异。两个实验之间胃排空的差异与恶心评分差异显著相关（r = 0.87，P = 0.002）。我们得出结论，脱水会导致胃排空延迟，但在剧烈骑行期间对口盲肠传输时间、肠道通透性或葡萄糖摄取没有影响。胃排空延迟与运动诱发的恶心增加显著相关。
