Abstract
Appropriate paediatric lung function reference equations for ethnic minorities are lacking. We investigated the extent to which differences in body proportions as indicated by the sitting/standing height ratio(Sit/Stand Ht) explain ethnic differences in FEV1.
Methods: As part of the SLIC study (commenced 2011), standard anthropometry including sitting height and spirometry were assessed in multi-ethnic London school children. FEV1 was expressed in Z scores to adjust for sex, age and height (Stanojevic2009). Statistical analysis was by univariable and multivariable regression.
Results: 379 healthy children (age: 5-10y, 43% boys; 31% White, 44% Black; 13% Asian, 12% mixed/other) performed successful spirometry. Compared with Whites, FEV1 was significantly lower in Black, Asian & “Other” children. On univariable analysis ethnicity accounted for 28% and Sit/Stand Ht for 25% zFEV1 variation. In a multivariable model the combined contribution was 35% with ethnicity contribution falling to 10%(Table).
Table: Linear regression showing ethnic differences in FEV1 before & after adjustment for sit/stand height
Conclusion: This study shows that Sit/Stand Ht accounts for some of the differences amongst ethnicities in FEV1 and provides further evidence that sitting height should be an essential part of standard anthropometry. Further work to explore the extent to which differences in body shape, size and composition contribute to ethnic differences in lung function is in progress.
- © 2012 ERS
