Table 1.
Baseline characteristics in relation to quartiles of FEV1: Males (n = 20,700)
| Overall | Q4 | Q3 | Q2 | Q1 | P value for trend | |
|---|---|---|---|---|---|---|
| FEV1 (L) | 3.52(±0.77) | 4.51(±0.42) | 3.79(±0.14) | 3.31(±0.14) | 2.58(±0.44) | – |
| Number (n) | 20,700 | 4813 | 5176 | 5388 | 5323 | – |
| Age (years) | 43.4 (±6.6) | 40.0 (±6.0) | 42.2 (±6.0) | 44.1 (±6.1) | 46.8 (±6.4) | < 0.001 |
| Height (m) | 1.77(±0.07) | 1.81(±0.06) | 1.78(±0.06) | 1.76(±0.06) | 1.74(±0.06) | < 0.001 |
| BMI (kg/m2) | 24.6 (±3.3) | 24.0 (±2.9) | 24.5 (±3.1) | 24.7 (±3.3) | 25.2 (±3.6) | < 0.001 |
| Baseline eGFR (mL/min/1.73m2) | 88.0(±13.2) | 89.4(±13.3) | 88.2(±13.0) | 87.5(±13.0) | 87.1(±13.3) | < 0.001 |
| Current-smokers (%) | 49.2 | 37.9 | 44.2 | 51.3 | 62.3 | < 0.001 |
| Physical inactivity (%) | 52.5 | 44.7 | 50.1 | 54.1 | 60.3 | < 0.001 |
| Systolic BP (mmHg) | 127 (±15) | 125 (±13) | 126 (±14) | 127 (±15) | 129 (±16) | < 0.001 |
| Anti-hypertensive medication (%) | 3.7 | 1.9 | 2.8 | 3.4 | 6.5 | < 0.001 |
| Cholesterol (mmol/L) | 5.59(±1.07) | 5.39 (±1.02) | 5.56 (±1.03) | 5.66 (±1.08) | 5.73 (±1.10) | < 0.001 |
| History of CVD | 0.9 | 0.3 | 0.5 | 0.9 | 2.0 | < 0.001 |
| History of diabetes | 3.2 | 2.1 | 2.3 | 3.5 | 4.9 | < 0.001 |
| Social class (%) | < 0.001 | |||||
| - Low skilled | 45.0 | 38.4 | 42.2 | 46.5 | 52.2 | |
| - High skilled | 43.6 | 52.1 | 46.9 | 42.0 | 34.2 | |
| - Self-employed | 8.3 | 7.8 | 8.8 | 8.6 | 8.0 | |
| - Other | 3.1 | 1.7 | 2.1 | 2.9 | 5.6 |
Q Quartile, FEV1 Forced expiratory volume in 1 s, eGFR Estimated glomerular filtration rate, BMI Body mass index, BP Blood pressure, CVD Cardiovascular disease. Data consist of mean (±standard deviation) unless otherwise stated. Linear by linear association for chi square tests used for p-value for categorical variables, ANOVA test for linearity used for p-values of continuous variables