Spirometry and flow-volume curves in healthy, normal Pakistanis.

Previous studies have indicated that lung volumes in healthy, normal Pakistani adults are smaller than measurements reported in comparable healthy European populations; in order to confirm these findings and to examine the relationship of maximal expiratory flow rates to lung volumes, we studied 250 non-smoking healthy subjects (116 men and 114 women) between the ages of 18 and 65 years. The population sample was drawn from urban and rural areas of Pakistan, with low levels of air pollution. The results indicate that the forced vital capacity (FVC) and forced expired volume in 1 second (FEV1) were lower in the Pakistani population compared to European populations and North American populations of European descent. These data are in conformity with previous studies; however, in Pakistani men the effects of age on FVC and FEV1 were slight so that, after the fourth decade, the FVC and FEV1 values are very comparable between the European and Pakistani populations. Amongst Pakistani women, on the other hand, FVC and FEV1 remained lower than in their European counterparts throughout adult life. Maximal expiratory flow rates amongst the men did not correlate with age, and these values were very similar to those reported in age-matched European populations. In women, however, there was a significant correlation of maximal flow rates with age and height, and the maximal expiratory flows were decreased compared to European populations. These data indicate that in Pakistani men pulmonary mechanics may be different to their European counterparts, allowing for higher maximal expiratory flows at any given lung volume.