Stang Julie, Stensrud Trine, Mowinckel Petter, Carlsen Kai-Håkon
1Department of Sports Medicine, Norwegian School of Sport Sciences, Oslo, NORWAY; 2Department of Pediatrics, Oslo University Hospital, NORWAY; and 3Faculty of Medicine, University of Oslo, NORWAY.
Med Sci Sports Exerc. 2016 Nov;48(11):2100-2107. doi: 10.1249/MSS.0000000000001008.
A high prevalence of asthma and bronchial hyperresponsiveness (BHR) is reported in swimmers and cross-country skiers. It has been suggested that increased parasympathetic nervous activity is involved in asthma development in endurance athletes. We aimed to assess the associations of BHR to parasympathetic activity in healthy and asthmatic swimmers and cross-country skiers and healthy nonathletes.
Parasympathetic activity was measured by pupillometry and heart rate variability at the onset of exercise with the cardiac vagal index calculated in 28 cross-country skiers (♂18/♀10), 29 swimmers (♂17/♀12), and 30 healthy nonathlete controls (♂14/♀16) on two different days. All subjects performed a methacholine bronchial challenge with the provocation dose causing 20% decrease in the forced expiratory volume in 1 s calculated (PD20met). Data were analyzed by robust regression analysis and presented as β coefficients with 95% confidence intervals (CI).
PD20met was negatively associated with cardiac vagal index (-13.9, 95% CI = -26.8 to -1.0) in all subjects. When adjusted to the type of sport, this association was stronger in swimmers (-8.3, 95% CI = -13.0 to -3.6) as compared with controls and nonsignificant in cross-country skiers. Percent pupil constriction was significantly associated with PD20met in swimmers (-9.4, 95% CI = -15.4 to -3.4) only after adjusting for the type of sport. Fourteen swimmers (48%) and 16 cross-country skiers (57%) had doctor-diagnosed asthma in combination with current BHR and/or current use of asthma drugs. Seventy-two percent swimmers, 44% cross-country skiers, and 39% controls had a PD20met ≤8 μmol (P = 0.015). Fourteen swimmers had a PD20met ≤2 μmol as compared with one cross-country skier (P < 0.001).
Parasympathetic activity measured in the heart is more closely related to BHR as compared with parasympathetic activity measured in the pupils. The type of sport influences BHR severity and its relationship to parasympathetic activity.
据报道，游泳运动员和越野滑雪运动员中哮喘和支气管高反应性（BHR）的患病率较高。有人提出，副交感神经活动增加与耐力运动员哮喘的发生有关。我们旨在评估健康和哮喘的游泳运动员、越野滑雪运动员以及健康非运动员中BHR与副交感神经活动的关联。
在两天内，通过瞳孔测量法和运动开始时的心率变异性测量副交感神经活动，并计算28名越野滑雪运动员（男18名/女10名）、29名游泳运动员（男17名/女12名）和30名健康非运动员对照者（男14名/女16名）的心脏迷走神经指数。所有受试者均进行了乙酰甲胆碱支气管激发试验，计算出使1秒用力呼气量下降20%的激发剂量（PD20met）。数据通过稳健回归分析进行分析，并以β系数及其95%置信区间（CI）表示。
在所有受试者中，PD20met与心脏迷走神经指数呈负相关（-13.9，95%CI=-26.8至-1.0）。在根据运动类型进行调整后，与对照组相比，游泳运动员中的这种关联更强（-8.3，95%CI=-13.0至-3.6），而在越野滑雪运动员中不显著。仅在根据运动类型进行调整后，游泳运动员的瞳孔收缩百分比与PD20met显著相关（-9.4，95%CI=-15.4至-3.4）。14名游泳运动员（48%）和16名越野滑雪运动员（57%）经医生诊断患有哮喘，并伴有当前的BHR和/或当前正在使用哮喘药物。72%的游泳运动员、44%的越野滑雪运动员和39%的对照者的PD20met≤8μmol（P=0.015）。与1名越野滑雪运动员相比，有14名游泳运动员的PD20met≤2μmol（P<0.001）。
与瞳孔测量的副交感神经活动相比，心脏测量的副交感神经活动与BHR的关系更密切。运动类型会影响BHR的严重程度及其与副交感神经活动的关系。
