Table 2.
Population Characteristics and Lung Function According to Place of Residence
| UK Indian | Indian Urban | Indian Semiurban | Indian Rural | |
|---|---|---|---|---|
| Subjects, n (% boys) | 311 (50) | 382 (68)* | 188 (43) | 158 (51) |
| Age, yr | 8.1 (1.6) | 9.0 (1.9) | 10.8 (1.8) | 9.8 (1.9) |
| z Height† | 0.34 (1.0) | 0.07 (0.9) | −1.19 (1.0) | −1.24 (0.9) |
| z Weight† | 0.13 (1.0) | 0.13 (0.9) | −1.31 (0.9) | −1.38 (0.9) |
| z BMI† | −0.04 (1.0) | 0.12 (0.9) | −0.98 (0.8) | −1.02 (0.8) |
| FAS | ||||
| High FAS (5–6), n (%) | 77 (25) | 42 (11) | 0 | 0 |
| Medium FAS (2–4), n (%) | 206 (67) | 308 (81) | 45 (24) | 0 |
| Low FAS (0–1), n (%) | 24 (8) | 32 (8) | 143 (76) | 158 (100) |
| Exposure to household tobacco smoking, n (%) | 42 (14) | 34 (9) | 78 (42) | 57 (36) |
| Exposure to indoor biomass smoke, n (%)‡ | 0 (0) | 0 (0) | NA | 142 (90) |
| z FEV1 | 0.04 (0.94) | 0.02 (0.95) | −0.52 (0.85) | −0.88 (0.99) |
| z FVC | 0.01 (0.96) | −0.00 (0.99) | −0.56 (0.89) | −0.91 (1.22) |
| z FEV1/FVC | 0.16 (1.03) | 0.11 (0.93) | 0.11 (0.89) | 0.26 (1.28) |
| Respiratory symptoms§ | 18 (6) | 52 (14) | 49 (26) | 30 (19) |
| Prior asthma | 0 | 14 (4) | 2 (1) | 1 (1) |
Definition of abbreviations: BMI = body mass index; FAS = family affluence score; NA = not available.
Results are expressed as mean (SD), unless otherwise specified; P values were derived from analysis of variance or Chi-square test as appropriate. FAS was grouped in three categories due to the large variation in scores according to area of residence (data were missing in four UK-Indian children).
Data from three children with current asthma were excluded.
z Height, z weight, and z BMI are based on Indian growth charts (25).
Data on biomass smoke exposure were not available for the semiurban group. Spirometry results are adjusted for age, height, and sex based on recently derived Global Lung Function Initiative–2012 coefficients for Indian children (28); at this age 1 z score for FEV1 and FVC equates to a difference of ∼11% (28).
Respiratory symptoms included runny nose, mild cough, and upper respiratory tract infections on the day of testing. Inclusion of data from these children did not impact overall lung function results as summarized in Table E2.