Ethnic differences in adolescent lung function: anthropometric, socioeconomic, and psychosocial factors

The relative contribution of body proportion and social exposures to ethnic differences in lung function has not previously been reported in the United Kingdom.

To examine ethnic differences in lung function in relation to anthropometry and social and psychosocial factors in early adolescence.

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.

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.

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.