LUNG ELASTIC RECOIL IN NORMAL YOUNG-ADULT CHINESE COMPARED WITH CAUCASIANS

Chinese people have smaller total lung capacity (TLC) compared with Ca ucasians of similar age, sex and height, One possible reason would be a higher lung elastic recoil in Chinese, Most published values for lun g elastic recoil viz static lung compliance (CLst), Shape constant K, and maximal static transpulmonary pressure (PLmax) have been from Cauc asian subjects, The aim of our study was to obtain values for lung ela stic recoil in normal young adult Chinese subjects, Static expiratory pressure-volume (P-V) curves were studied in 22 healthy Chinese subjec ts (12 males and 10 females), The P-V curve was fitted using an iterat ive I exponential function least mean squares regression on a computer , according to an exponential equation: V=A - Be--KP, where V is lung volume, P is transpulmonary pressure, and A, B and K are constants. Me an values+/-SD for K, CLst and PLmax were 0.12+/-0.04, 230+/-103 ml . cmH(2)O(-1) and 27.5+/-7.5 cmH(2)O, respectively, The values of CLst a nd K were similar to that of normal Caucasian subjects, whereas values of PLmax were lower, We attributed the lower PLmax partly to weaker i nspiratory muscles in Chinese compared with Caucasians, We conclude th at lung elastic recoil in normal young adult Chinese is similar to tha t of healthy young adult Caucasians. Hence, lung elasticity is unlikel y to explain the racial differences in static lung volumes.