Ethnic group
People are allocated to different ethnic groups on the basis of differences in skin, physical characteristics and geographical location. In Europe one deals mostly with Caucasians, Negroid, Mongoloid and Polynesian people, and those from the Indian subcontinent. Ethnic differences in lung function are in part due to differences in body build. The lungs are contained in the thorax, so that it would be logical to predict lung volumes from the dimensions of the chest cage or trunk. In practice predictions are based on total standing height, i.e. including the skull, neck, thoracic and lumbar spine, and legs. For the same length Negroid people usually have shorter trunks than Caucasians, whilst Mongoloid people have a longer trunk. Therefore prediction equations for Caucasians are not necessarily valid for other ethnic groups. One should keep in mind that even among black people there are important differences in body build; a fixed correction factor for an ethnic group does not, therefore, conclusively resolve ethnic differences in lung function (ref. 1). There are differences between white and black people in the relationship between sitting and standing height (ref. 3). Similar differences have been noted between Ethiopians and Japanese (ref. 4).
There is no evidence for differences in lung function among Caucasians in Europe. In general, in people of mixed ethnic descent lung volumes are intermediate between that of the parents’ ethnic groups (ref. 5).
Differences in lung function between inhabitants of the northern and southern part of the Indian subcontinent are attributed to diet and ethnic admixture. A protein rich diet leads to an increased body size, and there is some evidence that with the adoption of a western lifestyle differences in lung function with Caucasians diminish. Ethnic admixture similarly causes differences to become smaller. FEV1%FVC is by and large independent of ethnic group.
Predicting lung function in non-Caucasians is a gray area; some practical recommendations are given in another chapter. An excellent review is given by Cotes (ref. 2).
See also:
Reference values for FEV1, FVC
and FEV1%FVC in children and adolescents
SpirXpert software
| Ref. 1 - Fixed correction factor for ethnic group | |
| The following studies suggest that a fixed correction factor for an ethnic group is not based on a firm scientific basis. | |
| 1 | Schoenberg JB, Beck GJ, Bouhuys A. Growth and decay of pulmonary function in healthy blacks and whites. Respir Physiol 1978; 33: 367-393. |
| 2 | Corey PN, Ashley MJ, Chan-Yeung M. Racial differences in lung function: search for proportional relationships. J Occup Med 1979; 21: 395-398. |
| 3 | White NW, Hanley JH, Lalloo UG, Becklake MR. Review and analysis of variation between spirometric values reported in 29 studies of healthy African adults. Am J Respir Crit Care Med 1994; 150: 348-355. |
| Ref. 2 - Review of ethnic differences | |
| Cotes JE. Lung Function. Assessment and application in medicine. Ed. 5, Blackwell Scientific Publications, Oxford, 1993 | |
| Ref. 3 - Leg length and sitting height | |
| Negroid subjects in general have longer legs for trunk length: | |
| 1 | Verghese KP, Scott RB, Teixeirea G, Ferguson AD. Studies in growth and development. XII. Physical growth of northern American Negro children. Paediatrics 1966; 44: 243-247. |
| 2 | Van de Wal BW, Erasmus LD, Hechter R. Stem and standing heights in Bantu and white South Africans: their significance in relation to pulmonary function values. S Afr J Lab Clin Med 1971; 45 (suppl.): 568-570. |
| 3 | Rossiter CE, Weill H. Ethnic differences in lung function: evidence for proportional difference. Intern J Epidem 1974; 3: 55-61. |
| Standing height leads to a slightly higher explained variance than sitting height: | |
| 1 | Damon A. Negro-white differences in pulmonary function. Vital capacity, timed vital capacity and expiratory flow rates. Human Biol 1966; 38: 380-393. |
| 2 | Van de Wal: see above. |
| Sitting height cannot be measured with the same accuracy as standing height, so that it is not practically useful in prediction equations: | |
| Tanner JM. Growth at adolescence. Ed. 2. Blackwell, Oxford, 1978. | |
| Ref. 4 - Differences in body build | |
| 1 | Bibi H, Goldsmith JR, Vardi H. Racial or ethnic variation in spirometric lung function norms. Recommendations based on study of Ethiopian Jews. Chest 1988; 93: 1026-1030. |
| 2 | Massey DG, Fournier-Massey G. Japanese-Americans pulmonary reference values: influence of environment on anthropology and physiology. Env Res 1986; 39: 418-433. |
| Ref. 5 - Genetic and ethnic factors | |
| Reed TE. Caucasian genes in American Negroes. Science 1969: 165: 762-768. | |