Abstract
RATIONALE: The relative contribution of body proportion and social exposures to ethnic differences in lung function has not previously been reported in the United Kingdom. OBJECTIVES: To examine ethnic differences in lung function in relation to anthropometry and social and psychosocial factors in early adolescence. METHODS: The subjects of this study were 3,924 pupils aged 11 to 13 years, of whom 80% were ethnic minorities with satisfactory lung function measures. Data were collected on economic disadvantage, psychological well-being, tobacco exposure, height, FEV(1), and FVC. MEASUREMENTS AND MAIN RESULTS: The lowest FEV(1) was observed for Black Caribbean/African children after adjusting for standing height (SH) (white boys: 2.475 L; 95% confidence interval [CI], 2.442-2.509; white girls: 2.449 L; 95% CI, 2.464-2.535]; Black Caribbean boys: -14% [95% CI, -16 to -12]; Black Caribbean girls: -13% [95% CI, -16 to -11]; Black African boys: -15% [95% CI, -17 to -13]; Black African girls: -17% [95% CI, -19 to -14]; Indian boys: -13% [95% CI, -16 to -11]; Indian girls: -11% [95% CI, -14 to -8]; Pakistani/Bangladeshi boys: -7% [95% CI, -9 to -5]; Pakistani/Bangladeshi girls: -9% [95% CI, -11 to -6]). Adjustment for upper body segment instead of SH achieved a further reduction in ethnic differences of 41 to 51% for children of Black African origin and 26 to 39% for the other groups. Overcrowding (boys) and poor psychological well-being (boys and girls) were independent correlates of FEV(1), explaining up to a further 10% of ethnic differences. Similar patterns were observed for FVC. Social exposures were also related to height components. CONCLUSIONS: Differences in upper body segment explained more of the ethnic differences in lung function than SH, particularly among Black Caribbeans/African subjects. Social correlates had a smaller but significant impact. Future research needs to consider how differential development of lung capacity is compromised by the social patterning of growth trajectories.