Table 3.
Association between early-life exposures and asthma at age 7 years
| No Asthma* | Asthma* | Adjusted OR (95%CI)† |
p-value | |
|---|---|---|---|---|
| Prenatal | ||||
| Mother smoked | 53 (17%) | 27 (21%) | 1.25 (0.74 – 2.13) | 0.41 |
| Umbilical cord plasma cotinine concentration (ng/mL)& | 3.14 ± 3.03 | 4.17 ± 4.17 | 1.76 (1.00 – 3.09) | 0.048 |
| Number of smokers in the home | 0.8 ± 1.0 | 0.7 ± 0.8 | 0.83 (0.66 – 1.04) | 0.11 |
| Maternal perceived stress# | 5.4 ± 3.5 | 5.9 ± 3.3 | 1.05 (0.99 – 1.12) | 0.11 |
| Maternal composite stress$ | 6.0 ± 1.9 | 6.2 ± 1.9 | 1.05 (0.93 – 1.17) | 0.44 |
| Maternal depression% | 7.6 ± 6.1 | 8.9 ± 6.6 | 1.03 (1.00 – 1.06) | 0.08 |
|
| ||||
| Year 1 | ||||
| Mother smoked | 131 (43%) | 47 (37%) | 0.74 (0.48 – 1.15) | 0.18 |
| Number of smokers in home | 1.3 ± 1.3 | 1.5 ± 2.0 | 1.04 (0.91 – 1.19) | 0.55 |
| NO2 (ppb)‡ | 20.4 [12.0, 31.7] | 20.0 [10.9, 32.4] | 0.97 (0.75 – 1.26) | 0.82 |
| Nicotine (ug/g)‡ | 0.4 [0.2, 1.4] | 0.4 [0.2, 1.3] | 0.98 (0.66 – 1.44) | 0.90 |
| Ergosterol (ng/mg)‡ | 3.7 [2.1, 6.1] | 3.1 [2.1, 6.2] | 0.84 (0.61 – 1.15) | 0.27 |
| Endotoxin (EU/mg)‡ | 38.7 [17.5, 90.2] | 29.5 [14.6, 62.2] | 0.74 (0.51 – 1.07) | 0.11 |
| Maternal perceived stress# | 4.4 ± 2.7 | 5.0 ± 2.8 | 1.07 (0.99 – 1.16) | 0.07 |
| Maternal composite stress$ | 7.7 ± 1.0 | 7.8 ± 0.9 | 1.14 (0.92 – 1.42) | 0.23 |
| Maternal depression% | 5.6 ± 5.3 | 7.0 ± 6.5 | 1.04 (1.00 – 1.08) | 0.04 |
| Number of colds | 4.1 ± 2.9 | 4.8 ± 2.7 | 1.07 (0.99 – 1.15) | 0.09 |
|
| ||||
| Year 2 | ||||
| Mother smoked | 124 (41%) | 47 (37%) | 0.83 (0.53 – 1.30) | 0.42 |
| Number of smokers in home | 1.2 ± 1.2 | 1.3 ± 2.2 | 1.02 (0.89 – 1.17) | 0.77 |
| Maternal perceived stress# | 4.4 ± 2.9 | 5.3 ± 3.1 | 1.10 (1.02 – 1.18) | <0.01 |
| Maternal composite stress$ | 6.0 ± 1.8 | 6.3 ± 1.9 | 1.07 (0.95 – 1.20) | 0.26 |
| Maternal depression% | 5.7 ± 6.0 | 7.5 ± 6.8 | 1.04 (1.00 – 1.07) | 0.03 |
| Number of colds | 3.7 ± 2.7 | 5.2 ± 3.8 | 1.13 (1.06 – 1.22) | <0.01 |
|
| ||||
| Year 3 | ||||
| Mother smoked | 125 (40%) | 48 (38%) | 0.80 (0.52 – 1.24) | 0.31 |
| Number of smokers in home | 1.1 ± 1.1 | 1.1 ± 1.4 | 0.99 (0.83 – 1.18) | 0.91 |
| Endotoxin (EU/mg)‡ | 32.0 [17.6, 61.2] | 32.9 [16.2, 58.8] | 0.86 (0.66 – 1.13) | 0.29 |
| Maternal perceived stress# | 4.5 ± 2.8 | 5.3 ± 2.9 | 1.10 (1.02 – 1.18) | 0.01 |
| Maternal composite stress$ | 6.0 ± 1.8 | 6.6 ± 1.8 | 1.16 (1.02 – 1.31) | 0.02 |
| Maternal depression% | 5.2 ± 5.8 | 7.3 ± 6.9 | 1.05 (1.02 – 1.09) | <0.01 |
| Number of colds | 3.5 ± 2.8 | 4.5 ± 3.0 | 1.11 (1.03 – 1.20) | <0.01 |
Values are counts (percentages), means ± standard deviations, or medians [interquartile range] from raw, non-imputed data. The exception is umbilical cord plasma cotinine concentration, which is expressed as geometric mean ± geometric standard deviation because of a highly skewed distribution with many values below the detection limit.
Odds ratios are from a logistic regression model controlling for gender, race, and maternal asthma, averaged across 8 imputed datasets; n=442 for all. Model for number of colds also controlled for maternal stress within each year.
Prior to inclusion in the model, NO2, nicotine, ergosterol, and endotoxin values have been log (base 10) transformed and their estimates represent the odds for an interquartile increase in exposure.
Odds ratio is per 1 geometric standard deviation increase in cord plasma cotinine concentration.
Odds ratio is per unit increase in the maternal Perceived Stress Scale, which ranges from 0 to 4.
Odds ratio is per unit increase in the composite stress scale, as described in text, which ranges from 0 to 9.
Odds ration per unit increase in the maternal Edinburgh Postpartuem Depression Scale, which ranges from 0 to 30.