It has long been recognised that there are variations in lung function between people of different ethnic groups. One possible explanation has been that nutritional or socioeconomic factors are largely responsible for the differences. Some of our previous work in which we compared lung function in children of south Asian origin with that of white children confirmed that white children had generally larger values for lung function, but the differences were not explained by any socioeconomic or cultural factors we were able to measure. There is always the chance, however, that there were socioeconomic factors that we could not measure. If this was the case, then we would expect lung function in successive generations of immigrant populations to gradually approach that of the host country.
We were able to explore this idea by comparing lung function in two groups of south Asian children from the Leicester Cohorts; those whose mothers had been born overseas and immigrated to the UK and those whose mothers had been UK-born. We would expect bigger values of lung function in children of UK-born mothers if lung function in migrants gradually approaches that of the native population. We found that there were no differences in lung function between the two groups of children – if anything, offspring of UK-born mothers had slightly smaller values of lung function.
This was a relatively small study and we would welcome more work in the area. It has important implications because it suggests that differences in lung function are, at least in part, attributable to ethnicity and therefore ethnicity-specific prediction equations may continue to be important, even for populations that have been resident away from their region of origin for more than one generation.
Kuehni CE, Strippoli MF, Spycher BD, Silverman M, Beardsmore CS. (2015) Lung function in the children of immigrant and UK-born south-Asian mothers. Eur Respir J. 2015 Jan 8. pii: ERJ-01521-2014. [Epub ahead of print]