Lung volumes in normal Cantonese subjects: preliminary studies.

Abstract

Chuan and Chia (1969) in Singapore and by Wu and Yang (1962) in Taiwan. Significant differences, however, are noted for FRC, TLC, RV, and RV/TLC between our findings and those of Chuan and Chia. Our series is unbalanced because of an uneven distribution of age groups. In fact in none of the reported studies on Chinese subjects, including that of da Costa (1971), is the series large or balanced. Clearly, further research is required in this ethnic group to get more reliable predictive formulae for lung volumes.In clinical practice, lung function is usually assessed by simple measurement of lung volumes and ventilation. Predicted, that is, 'normal', values are calculated from formulae derived from studies of healthy populations. There is evidence of ethnic differences, average values for Chinese subjects being below those for Caucasians. The present study was designed to explore further these reported ethnic differences in lung volumes. Material and methodsA total of 331 Cantonese subjects, ranging in age from 17 to 56 years, were studied. There were 134 male and 197 female subjects in the group. Most of the men were hospital employees who performed manual work but a number of young men, ranging in age from 18 to 25 years, were trainees from the Police Training College. The 197 women were nurses or manual workers in the hospital, and, of the total, 124 were young student nurses ranging in age from 17 to 25 years. All the subjects had normal chest radiographs within the sixmonth period before the testing and all were clinically free from chest diseases or any other disorders that could affect the results.A smoking history was obtained in all of the male subjects, 70 of whom were non-smokers (52%) while 64 (48%) smoked. The smokers were divided into three groups: smoked fewer than 10 cigarettes per day-light smokers; smoked 10 to 20 cigarettes per day-moderate smokers; and smoked more than 20 cigarettes per day-heavy smokers. Among the female subjects a smoking history was obtained in only a few subjects.Measurements of ventilatory capacity were made on the Pulmonet 114 apparatus which has a 9-litre spirometer bell of light weight. All subjects cooperated well in the tests which were performed with the subjects sitting after rest but not at basal condition.

Spirometric reference values in a large Middle Eastern population

“…larger trunkto-leg ratio) at a given height [7,8], corresponding to vital capacities that are larger by 10-15% for a given standing height [3]. Ethnic differences in lung function have also been suggested for many other groups [5,7,9], specifically Asians [6,[10][11][12]. There is a lack of information concerning spirometric reference values for people living in the Middle East.…”

Residual lung volume of female Thai adults

“…1a). The pRV from Goldman and Becklake 13 was overestimated whereas those from Ching and Horsfall 10 and Demura et al 14 were underestimated.…”

“…Chin et al equation 7 gave the pRV of 1.18 ± 0.12 l that was very similar to Thai mRV with p = 0.46. On the other hand, both Demura, Yamaji, and Kitabayashi equation 14 and Ching and Horsfall equation 10 gave much lower pRV than Thai with p < 0.001. Fig.…”

“…In support of this possible explanation, Fulambarker et al 19 recently showed that the USborn Asian Indians have higher lung functions than the comparable immigrant counterparts. Further, it has been reported that Cantonese 10 and Taiwanese Chinese 8 , but not Singaporean Chinese 9 , have similar lung volumes. Results in the present study that reveal similar RV to that of the Singaporean Chinese also corroborate this notion.…”

“…Furthermore, previous studies have shown that the RV of Asian populations are different depending on their ancestry, i.e., Chinese, Malay, or Indian Singaporean 7 , and geography, i.e., Cantonese, Singaporean Chinese, or Taiwanese [8][9][10] . Thus a prediction equation is valid only for a specific population.…”