Department of Health and Kinesiology, Center for Translational Research in Aging & Longevity, Texas A&M University, College Station, Texas.
J Appl Physiol (1985). 2021 Feb 1;130(2):435-444. doi: 10.1152/japplphysiol.00783.2020. Epub 2020 Nov 19.
Gut-related symptoms and an increase in markers of gut dysfunction have been observed in patients with chronic obstructive pulmonary disease (COPD). It remains unclear whether exercise, in relation to inducing hypoxia, plays a role in disturbances in protein digestion and amino acid absorption and whole body protein kinetics. Sixteen clinically stable patients with moderate-to-very severe COPD and 12 matched healthy subjects completed the study. Protein digestion and amino acid absorption, whole body protein kinetics were measured in the postabsorptive state via a continuous infusion of stable tracers in combination with orally administered stable tracer sips during 20 min of walking exercise and up to 4 h post exercise. In addition, concentrations of short-chain fatty acid (SCFA) and amino acids were measured. Patients with COPD completed one study day, walking at maximal speed, whereas healthy subjects completed two, one matched to the speed of a patient with COPD and one at maximal speed. The patients with COPD tolerated 20 min of vigorous intensity walking with an elevated heart rate ( < 0.0001) and substantial desaturation ( = 0.006). During exercise, we observed lower protein digestion ( = 0.04) and higher SCFA acetate ( = 0.04) and propionate ( = 0.02) concentrations on max speed study days, lower amino acid absorption ( = 0.004) in subjects with oxygen desaturation, and lower net protein breakdown ( = 0.03) and propionate concentrations ( = 0.04) in patients with COPD. During late recovery from exercise, amino acid absorption ( = 0.02) and net protein breakdown ( = 0.02) were lower in patients with COPD. Our data suggest that 20 min of walking exercise is sufficient to cause perturbations in gut function and whole body protein metabolism during and up to 4 h post exercise in older adults and in patients with COPD with exercise-induced hypoxia. Gut function is disturbed in older adults with COPD. As exercise is the cornerstone of pulmonary rehabilitation in COPD, knowledge of the response of the gut to aerobic exercise is of importance.
在慢性阻塞性肺疾病（COPD）患者中，已经观察到与肠道相关的症状和肠道功能障碍标志物的增加。目前尚不清楚运动（与缺氧有关）是否在蛋白质消化和氨基酸吸收以及全身蛋白质动力学的紊乱中发挥作用。16 名临床稳定的中重度 COPD 患者和 12 名匹配的健康受试者完成了这项研究。在 20 分钟的步行运动期间和运动后 4 小时内，通过连续输注稳定示踪剂并口服稳定示踪剂滴注，在吸收后状态下测量蛋白质消化和氨基酸吸收以及全身蛋白质动力学。此外，还测量了短链脂肪酸（SCFA）和氨基酸的浓度。COPD 患者完成了一天的研究，以最大速度行走，而健康受试者完成了两天的研究，一天与 COPD 患者的速度相匹配，另一天以最大速度进行。COPD 患者能够耐受 20 分钟的剧烈强度步行，心率升高（<0.0001）和明显的血氧饱和度下降（=0.006）。在运动过程中，我们观察到在最大速度研究日，蛋白质消化较低（=0.04），SCFA 乙酸盐（=0.04）和丙酸盐（=0.02）浓度较高，在有血氧饱和度下降的受试者中，氨基酸吸收较低（=0.004），在 COPD 患者中，净蛋白分解（=0.03）和丙酸盐浓度较低（=0.04）。在运动后的晚期恢复期间，COPD 患者的氨基酸吸收（=0.02）和净蛋白分解（=0.02）较低。我们的数据表明，20 分钟的步行运动足以在老年人和运动诱导缺氧的 COPD 患者中引起运动期间和运动后 4 小时内肠道功能和全身蛋白质代谢的紊乱。在 COPD 老年患者中，肠道功能受到干扰。由于运动是 COPD 肺康复的基石，因此了解肠道对有氧运动的反应非常重要。
