School of Kinesiology, University of British Columbia, Vancouver, British Columbia, CANADA.
Med Sci Sports Exerc. 2020 Sep;52(9):1855-1861. doi: 10.1249/MSS.0000000000002335.
Swimmers have a high prevalence of exercise-induced bronchoconstriction (EIB), which may be associated with repeated exposure to chlorinated pool water. The eucapnic voluntary hyperpnea (EVH) test is used to diagnose EIB; however, it fails to replicate the environmental conditions experienced by swimmers. The relationship between the composition of the EVH inspired gas and the development of EIB from swim exercise remains unclear.
This study aimed to compare the bronchoconstrictive effect of a chlorinated inspirate EVH test and swim test to a laboratory-based EVH test in swimmers.
Fifteen collegiate swimmers (n = 5 male, n = 10 female; 21 ± 2 yr) completed 3 d of testing in pseudorandom order; a standard EVH test (EVHL), a pool air EVH test (EVHCl), and a swimming test (Swim). Spirometry was measured at baseline, and 3, 5, 10, 15, and 20 min after each test.
EVHL elicited a forced expired volume in 1 s (FEV1) fall index of -9.7% ± 6.4% compared with -6.6% ± 9.2% and -3.0% ± 7.5% after EVHCl and Swim, respectively (P < 0.05). Using Bland-Altman analysis, we found good agreement between EVHL and EVHCl (bias = -2.8, r = 0.79; P < 0.05) with poor agreement between EVHL and Swim (bias = -6.7, r = 0.20) and between EVHCl and Swim (bias = -3.9, r = 0.50; both P < 0.05). Forced expired flow between 25% and 75% lung volume and peak expired flow were significantly reduced by the EVHL compared with the EVHCl and Swim tests (P < 0.05).
EVHL elicits a greater forced expired volume in 1-s fall index compared with EVHCl and Swim. The unique aquatic environment of swimmers potentially protects against bronchoconstriction and should be considered in the determination of EIB.
游泳运动员的运动性支气管收缩（EIB）患病率较高，这可能与反复接触氯化泳池水有关。呼气末正压通气（EVH）试验用于诊断 EIB；然而，它无法复制游泳运动员所经历的环境条件。激发 EVH 气体的组成与游泳运动引起的 EIB 之间的关系尚不清楚。
本研究旨在比较氯化吸入 EVH 试验和游泳试验与游泳运动员基础实验室 EVH 试验对支气管收缩的影响。
15 名大学生游泳运动员（n = 5 名男性，n = 10 名女性；21 ± 2 岁）以随机顺序完成 3 天的测试；标准 EVH 测试（EVHL）、泳池空气 EVH 测试（EVHCl）和游泳测试（Swim）。在每次测试前后 3、5、10、15 和 20 分钟时测量肺活量。
EVHL 引起的 1 秒用力呼气容积（FEV1）下降指数为-9.7% ± 6.4%，而 EVHCl 和 Swim 分别为-6.6% ± 9.2%和-3.0% ± 7.5%（P < 0.05）。通过 Bland-Altman 分析，我们发现 EVHL 与 EVHCl 之间具有良好的一致性（偏差=-2.8，r=0.79；P < 0.05），而 EVHL 与 Swim 之间的一致性较差（偏差=-6.7，r=0.20），EVHCl 与 Swim 之间的一致性也较差（偏差=-3.9，r=0.50；均 P < 0.05）。与 EVHCl 和 Swim 测试相比，EVHL 显著降低了 25%至 75%肺容积之间的呼气流量和呼气峰流量（P < 0.05）。
EVHL 引起的 1 秒用力呼气容积下降指数大于 EVHCl 和 Swim。游泳运动员独特的水上环境可能对支气管收缩有保护作用，在确定 EIB 时应予以考虑。
