Table 1

 Baseline characteristics of study population

Cross-sectional population 1991Cross-sectional population 2000
TotalProvided blood for CRPTotalProvided blood for CRP
BMI, body mass index; CRP, C-reactive protein; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; IQR, interquartile range.
Number of participants2633244213461301
Men, N (%)1312 (50)1224 (50)668 (50)647 (50)
Mean (SD) age (years)44.4 (13.6)44.7 (13.5)56.1 (12.4)56.1 (12.3)
Mean (SD) height (m)1.68 (0.1)1.68 (0.1)1.68 (0.1)1.68 (0.1)
Mean (SD) BMI (kg/m2)25.5 (4.0)25.5 (4.0)26.8 (4.4)26.8 (4.4)
n = 2614n = 2425
Smoking status, N (%)
    Never1306 (50)1201 (49)680 (51)654 (50)
    Ex730 (28)681 (28)510 (38)494 (38)
    Current597 (23)560 (23)156 (12)153 (12)
Mean (SD) FEV1 (l)3.19 (0.92)3.18 (0.93)2.84 (0.85)2.84 (0.85)
N = 1343N = 1298
Mean (SD) FEV1 in 1991 (l)3.2 (0.84)3.18 (0.85)
Mean (SD) FVC (l)3.94 (1.08)3.94 (1.08)3.67 (1.01)3.67 (1.01)
N = 1342N = 1297
Mean (SD) FVC in 1991 (l)3.94 (1.00)3.94 (1.01)
Wheeze in past 12 months, n (%)632 (24)596 (24)343 (25)271 (21)
Median (IQR) CRP (mg/l)1.14 (0.55–2.42)1.69 (0.80–3.79)
Response in 2000 by deciles of CRP in 1991 (% total)
    1116 (9.4)
    2129 (10.4)
    3123 (10.0)
    4132 (10.7)
    5125 (10.1)
    6133 (10.8)
    7129 (10.4)
    8125 (10.1)
    9115 (9.3)
    10107 (8.7)