DeLorey D S, Wyrick B L, Babb T G
Institute for Exercise and Environmental Medicine, Presbyterian Hospital of Dallas, TX 75231, USA.
Int J Obes (Lond). 2005 Sep;29(9):1039-47. doi: 10.1038/sj.ijo.0803003.
To investigate the effect of mild-to-moderate obesity on respiratory mechanics at rest and during exercise in obese men. We hypothesized that the simple mass loading of obesity would alter both end-expiratory lung volume (EELV) and respiratory pressures (gastric, P(ga) and transpulmonary, P(TP)) in resting body positions and during graded cycle ergometry to exhaustion.
A total of 10 obese (38+/-5% body fat; mean+/-s.d.) and nine lean (18+/-4%) men were studied.
Body composition (by body circumferences and hydrostatic weighing) and pulmonary function were measured at rest. Breathing mechanics were measured at rest in the upright-seated position, supine, and during cycling exercise. Data were analyzed by independent t-test.
EELV was significantly lower in the obese men in the supine (30+/-4 vs 37+/-6% total lung capacity (TLC)) and seated (39+/-6 vs 47+/-5%TLC) positions and at ventilatory threshold (35+/-5 vs 45+/-7%TLC) (P<0.01). In contrast, at peak exercise, EELV was not different between groups. Respiratory pressures (P(ga) and P(TP)) were elevated (P<0.05) during one or more phases of the breathing cycle at rest and during exercise in obese men.
These data demonstrate that mild-to-moderate obesity in young men results in reduced lung volumes and alterations in respiratory mechanics when supine, seated at rest, and during exercise. During moderate exercise, obesity does not appear to limit changes in EELV; however, the regulation of EELV during heavy exercise appears to be affected.
研究轻度至中度肥胖对肥胖男性静息及运动时呼吸力学的影响。我们假设，肥胖所带来的单纯体重增加会改变静息体位及分级蹬车运动至力竭过程中的呼气末肺容积（EELV）和呼吸压力（胃内压，P(ga)和跨肺压，P(TP)）。
共研究了10名肥胖男性（体脂率38±5%；均值±标准差）和9名瘦男性（体脂率18±4%）。
静息时测量身体成分（通过身体周长和水下称重法）及肺功能。在静息时的直立坐姿、仰卧位以及骑车运动过程中测量呼吸力学。数据采用独立样本t检验进行分析。
肥胖男性在仰卧位（30±4 vs 37±6%肺总量（TLC））、坐位（39±6 vs 47±5%TLC）以及通气阈值时（35±5 vs 45±7%TLC）的EELV显著降低（P<0.01）。相比之下，在运动峰值时，两组之间的EELV并无差异。肥胖男性在静息和运动时的呼吸周期的一个或多个阶段中，呼吸压力（P(ga)和P(TP)）升高（P<0.05）。
这些数据表明，年轻男性的轻度至中度肥胖会导致肺容积减少，以及在仰卧位、静息坐位和运动时呼吸力学的改变。在中等强度运动期间，肥胖似乎并不限制EELV的变化；然而，剧烈运动期间EELV的调节似乎受到影响。
