Table I.
Demographic and Clinical Characteristics of the Study Samples in 1996 – 1997 and 2006 – 2009. For mean values, the standard deviation is presented in parentheses; for median values, the first and third inter-quartile values are presented in parentheses.
| Unaffected | Symptoms Only |
BHR Only |
Asthma | All | |
|---|---|---|---|---|---|
| A. 1996 – 1997 | N=395 | N=62 | N=73 | N=45 | N=597 |
| % Female | 54 | 48 | 53 | 40 | 52 |
| Age, yrs | 27 (17, 41) | 33 (20, 42) | 17 (12, 33) | 22 (10, 37) | 26 (16, 41) |
| BMI, kg/m2 | 24 (20, 28) | 26 (23, 31) | 23 (17, 27) | 24 (17, 27) | 24 (20, 28) |
| % Predicted FEV1 | 103 (15) | 100 (12) | 96 (18) | 94 (10) | 101 (15) |
| % Predicted FVC | 107 (15) | 104 (11) | 104 (17) | 105 (11) | 106 (14) |
| Mean FEV1/FVC | 82 (8) | 82 (8) | 80 (11) | 78 (9) | 81 (9) |
| Total IgE, kU/L | 20 (9, 50) | 31 (8, 93) | 14 (6, 36) | 96 (24, 350) | 23 (10, 77) |
| N (%) ≥1 +SPT | 161 (41) | 32 (52) | 39 (53) | 20 (45) | 252 (44) |
| N (%) ≥3 +SPT | 76 (19) | 16 (26) | 20 (27) | 12 (27) | 124 (22) |
| N (%) Asthmatic Mother | 20 (8) | 2 (5) | 6 (12) | 7 (22) | 35 (8) |
| N (%) Asthmatic Father | 30 (12) | 8 (18) | 9 (20) | 9 (27) | 58 (15) |
| # Older siblings | 3 (1, 6) | 3 (1, 7) | 3 (2, 6) | 2 (1, 4) | 3 (1, 5) |
| B. 2006 –2009 | N=243 | N=78 | N=119 | N=59 | N=532 |
| % Female | 50 | 64 | 51 | 54 | 54 |
| Age, yrs | 19 (14, 38) | 49 (17, 32) | 11 (9, 16) | 20 (10, 14) | 17 (12, 35) |
| BMI, kg/m2 | 23 (20, 28) | 26 (20, 30) | 19 (17, 23) | 22 (17, 24) | 22 (19, 27) |
| % Predicted FEV1 | 101 (13) | 97 (13) | 95 (12) | 94 (12) | 98 (13) |
| % Predicted FVC | 104 (14) | 98 (14) | 96 (12) | 103 (13) | 102 (14) |
| Mean FEV1/FVC | 85 (7) | 85 (7) | 87 (8) | 83 (8) | 85 (8) |
| Total IgE, kU/L | 8 (18, 44) | 9 (18, 43) | 26 (8, 66) | 62 (23, 298) | 23 (9, 61) |
| N (%) ≥1 +SPT | 105 (43) | 35 (45) | 47 (39) | 36 (61) | 223 (45) |
| N (%) ≥3 +SPT | 71 (29) | 25 (32) | 33 (28) | 35 (59) | 164 (33) |
| N (%) Asthmatic Mother | 9 (6) | 2 (5) | 10 (10) | 13 (32) | 37 (10) |
| N (%) Asthmatic Father | 9 (5) | 3 (7) | 17 (17) | 11 (27) | 42 (11) |
| # Older siblings | 3 (1, 5) | 2 (1, 5) | 2 (1, 4) | 2 (1, 4) | 3 (1, 5) |
BHR = bronchial hyperresponsiveness; BMI = body mass index; FEV1 = forced expiratory volume the first second; FVC = forced vital capacity; SPT = skin prick test.