Cortés-Télles Arturo, Torre-Bouscoulet Luis, Silva-Cerón Monica, Mejía-Alfaro Roberto, Syed Nafeez, Zavorsky Gerald S, Guenette Jordan A
Respiratory Physiology Department, National Institute of Respiratory Diseases, Mexico City, Mexico.
Respiratory Physiology Department, National Institute of Respiratory Diseases, Mexico City, Mexico.
Respir Med. 2015 Nov;109(11):1397-403. doi: 10.1016/j.rmed.2015.09.010. Epub 2015 Sep 25.
Despite the close link between asthma and obesity, there are no studies that have evaluated the sensory and physiological responses to exercise in obese asthmatics. We recently demonstrated that normal weight asthmatics with well controlled disease have preserved cardiorespiratory and sensory responses to exercise relative to non-asthmatic controls. However, these similarities may not hold true in patients with combined obesity and asthma. Accordingly, we sought to determine if combined asthma and obesity was associated with deleterious effects on cardiorespiratory fitness, exercise performance, dyspnoea, and physiological responses to exercise. Fourteen well-controlled obese asthmatics and fourteen age-matched normal weight asthmatics performed routine spirometry and underwent an incremental cardiopulmonary cycle test to assess the ventilatory, pulmonary gas exchange, cardiovascular, and sensory responses to exercise. Groups were well matched for age, height, spirometry, and asthma control. Obese asthmatics had a significantly greater body mass index (33 ± 3 vs. 23 ± 1 kg/m(2), p < 0.001) and lower self-reported activity levels by 47 % relative to normal weight asthmatics (p < 0.05). Obese asthmatics had a significantly lower maximal oxygen uptake (VO(2)) (82 ± 14 vs. 92 ± 10 %predicted) and work rate (75 ± 8 vs. 89 ± 13 %predicted) relative to normal weight asthmatics (p < 0.05). The anaerobic threshold occurred at a lower VO(2) in obese asthmatics vs. normal weight asthmatics (54 ± 15 vs. 66 ± 16 %predicted, p < 0.05). Ventilatory responses were superimposed throughout exercise with no evidence of a ventilatory limitation in either group. Cardiovascular responses were normal in both groups. Dyspnoea responses were similar but the obese asthmatics experienced greater leg fatigue ratings at submaximal work rates. In conclusion, obese individuals with well controlled asthma have reduced cardiorespiratory fitness and greater leg fatigue ratings relative to normal weight asthmatics. The relatively reduced cardiorespiratory fitness and exercise performance in obese compared to normal weight asthmatics is most likely driven by their more sedentary lifestyle and resultant deconditioning rather than due to respiratory factors.
尽管哮喘与肥胖之间存在密切联系，但尚无研究评估肥胖哮喘患者对运动的感觉和生理反应。我们最近证明，疾病得到良好控制的正常体重哮喘患者相对于非哮喘对照组，对运动的心肺和感觉反应得以保留。然而，这些相似性在合并肥胖和哮喘的患者中可能并不成立。因此，我们试图确定合并哮喘和肥胖是否会对心肺适能、运动表现、呼吸困难及运动的生理反应产生有害影响。14名病情得到良好控制的肥胖哮喘患者和14名年龄匹配的正常体重哮喘患者进行了常规肺功能测定，并接受了递增式心肺循环测试，以评估运动时的通气、肺气体交换、心血管和感觉反应。两组在年龄、身高、肺功能测定和哮喘控制方面匹配良好。肥胖哮喘患者的体重指数显著更高（33±3 vs. 23±1 kg/m²，p<0.001），自我报告的活动水平比正常体重哮喘患者低47%（p<0.05）。相对于正常体重哮喘患者，肥胖哮喘患者的最大摄氧量（VO₂）显著更低（82±14 vs. 92±10%预测值），工作负荷也更低（75±8 vs. 89±13%预测值）（p<0.05）。肥胖哮喘患者的无氧阈相对于正常体重哮喘患者出现在更低的VO₂时（54±15 vs. 66±16%预测值，p<0.05）。两组在整个运动过程中的通气反应均呈叠加状态，且两组均无通气受限的证据。两组的心血管反应均正常。呼吸困难反应相似，但肥胖哮喘患者在次最大工作负荷时腿部疲劳评分更高。总之，与正常体重哮喘患者相比，病情得到良好控制的肥胖哮喘患者心肺适能降低，腿部疲劳评分更高。与正常体重哮喘患者相比，肥胖哮喘患者心肺适能和运动表现相对降低，很可能是由于他们久坐不动的生活方式以及由此导致的身体机能下降，而非呼吸因素所致。
