Table 1 Characteristics of study children and adolescents
Variables | Total (n = 7981) | Non-current asthma (n = 6957) | Current asthma (n = 1024) | Statistics | P |
|---|---|---|---|---|---|
Age, years, Mean (S.E) | 11.96 (0.06) | 11.92 (0.06) | 12.19 (0.12) | t = − 2.12 | 0.037 |
Age, years, n (%) | χ2 = 3.17 | 0.075 | |||
≤ 12 | 4700 (52.42) | 4114 (52.86) | 586 (49.24) | ||
> 12 | 3281 (47.58) | 2843 (47.14) | 438 (50.76) | ||
Gender, n (%) | χ2 = 0.66 | 0.416 | |||
Male | 4022 (50.87) | 3458 (50.65) | 564 (52.44) | ||
Female | 3959 (49.13) | 3499 (49.35) | 460 (47.56) | ||
Race, n (%) | χ2 = 58.09 | < 0.001 | |||
Non-hispanic White | 2239 (54.43) | 1985 (55.19) | 254 (48.96) | ||
Non-hispanic Black | 1937 (13.87) | 1562 (12.66) | 375 (22.64) | ||
Others | 3805 (31.69) | 3410 (32.15) | 395 (28.40) | ||
Education level, n (%) | χ2 = 1.27 | 0.260 | |||
Less than 9th grade | 6243 (74.57) | 5445 (74.83) | 798 (72.69) | ||
9th grade and above | 1738 (25.43) | 1512 (25.17) | 226 (27.31) | ||
PIR, n (%) | χ2 = 12.99 | 0.002 | |||
≤ 1.3 | 3413 (31.53) | 2930 (30.84) | 483 (36.50) | ||
1.3–3.5 | 2919 (38.61) | 2541 (38.31) | 378 (40.79) | ||
> 3.5 | 1649 (29.86) | 1486 (30.84) | 163 (22.72) | ||
Sedentary time, hours, n (%) | χ2 = 13.38 | < 0.001 | |||
≤ 6 | 4902 (57.62) | 4320 (58.50) | 582 (51.30) | ||
> 6 | 3079 (42.38) | 2637 (41.50) | 442 (48.70) | ||
Physical activity level, n (%) | χ2 = 2.05 | 0.359 | |||
Not ideal physical activity | 2434 (28.69) | 2134 (29.06) | 300 (26.01) | ||
Ideal physical activity | 4510 (57.01) | 3921 (56.73) | 589 (59.01) | ||
Unknown | 1037 (14.30) | 902 (14.20) | 135 (14.98) | ||
Hay fever, n (%) | χ2 = 596.06 | < 0.001 | |||
No | 4069 (49.45) | 3289 (46.47) | 780 (71.02) | ||
Yes | 615 (8.87) | 376 (6.15) | 239 (28.51) | ||
Unknown | 3297 (41.68) | 3292 (47.38) | 5 (0.48) | ||
BMI, kg/m2, Mean (S.E) | 21.42 (0.09) | 21.23 (0.10) | 22.78 (0.24) | t = − 6.40 | < 0.001 |
Overweight, n (%) | χ2 = 20.29 | < 0.001 | |||
No | 4687 (60.72) | 4173 (61.81) | 514 (52.84) | ||
Yes | 3294 (39.28) | 2784 (38.19) | 510 (47.16) | ||
Family education, n (%) | χ2 = 9.81 | 0.002 | |||
High school and below | 6328 (72.13) | 5476 (71.25) | 852 (78.48) | ||
College graduate or above | 1653 (27.87) | 1481 (28.75) | 172 (21.52) | ||
Household smokers, n (%) | χ2 = 16.92 | < 0.001 | |||
No | 7036 (88.90) | 6175 (89.51) | 861 (84.49) | ||
Yes | 945 (11.10) | 782 (10.49) | 163 (15.51) | ||
Asthma in close relative, n (%) | χ2 = 175.36 | < 0.001 | |||
No | 5483 (69.46) | 5137 (74.02) | 346 (36.52) | ||
Yes | 2498 (30.54) | 1820 (25.98) | 678 (63.48) | ||
Total energy, kcal, Mean (S.E) | 1950.74 (11.54) | 1945.15 (11.67) | 1991.05 (32.45) | t = − 1.40 | 0.164 |
Total 25-Hydroxyvitamin D, nmol/L, Mean (S.E) | 66.54 (0.80) | 66.75 (0.80) | 65.06 (1.21) | t = 1.86 | 0.066 |
Vitamin D, mcg, Mean (S.E) | 7.96 (0.33) | 7.76 (0.31) | 9.37 (1.58) | t = − 1.00 | 0.321 |
Calcium, mg, Mean (S.E) | 1042.46 (10.06) | 1042.79 (10.30) | 1040.05 (19.93) | t = 0.14 | 0.888 |
Cotinine, ng/mL, Mean (S.E) | 3.42 (0.43) | 3.18 (0.42) | 5.17 (1.47) | t = − 1.34 | 0.182 |
Cotinine, ng/mL, n (%) | χ2 = 23.06 | < 0.001 | |||
< 0.05 | 4724 (61.61) | 4240 (62.96) | 484 (51.81) | ||
≥ 0.05 | 3257 (38.39) | 2717 (37.04) | 540 (48.19) | ||
Omega-3 PUFAs, g, Mean (S.E) | 1.44 (0.01) | 1.43 (0.01) | 1.47 (0.04) | t = − 1.24 | 0.218 |
Omega-3 PUFAs, g, n (%) | χ2 = 1.71 | 0.191 | |||
> 1.57 | 2630 (33.42) | 2274 (33.06) | 356 (36.07) | ||
≤ 1.57 | 5351 (66.58) | 4683 (66.94) | 668 (63.93) | ||
Omega-6 PUFAs, g, Mean (S.E) | 14.53 (0.12) | 14.48 (0.12) | 14.90 (0.36) | t = − 1.15 | 0.254 |
Omega-6 PUFAs, g, n (%) | χ2 = 1.70 | 0.192 | |||
≤ 16.03 | 5377 (66.72) | 4709 (67.07) | 668 (64.17) | ||
> 16.03 | 2604 (33.28) | 2248 (32.93) | 356 (35.83) |