Figures
- FIGURE 1
Flow chart of the study to obtain a sample of spirometry tests with bronchodilator in the Seinäjoki Adult Asthma Study study.
- FIGURE 2
Percentages of asthma patients fulfilling the commonly used thresholds to define bronchodilator response. ΔFEV1: change in forced expiratory volume in 1 s; FEV1: forced expiratory volume in 1 s.
- FIGURE 3
Venn diagram of the asthma patients (N=219) fulfilling the bronchodilator response thresholds of absolute volume 200 mL, change in forced expiratory volume in 1 s (ΔFEV1) ≥12% of the initial FEV1 and ΔFEV1 % of the predicted FEV1 ≥9%.
Tables
- TABLE 1
Characteristics of the study patients and lung function from spirometry showing the highest reversibility at the diagnostic phase in steroid-naïve patients
Characteristics Study patients (N=219) Age, years 47±15 Age of asthma onset, years 47±15 Female 126 (57.5%) BMI, kg·m-2 27.1 (24.0–30.4) Height, cm 170±10 Smoking history 113 (51.6%) Current smokers 45 (20.5%) Pack-years# 15 (5–22) Atopy¶ 67 (34.3%) Blood eosinophils ×109 per L 0.25 (0.17–0.40) Total IgE, kU·L−1 80 (34–170) Pre-BD FEV1, L 2.77±0.89 Pre-BD FEV1, % predicted 78±17 Post-BD FEV1, L 3.06±0.95 Post-BD FEV1, % predicted 86±17 Pre-BD FVC, L 3.74±1.11 Pre-BD FVC, % predicted 87±16 Post-BD FVC, L 3.95±1.12 Post-BD FVC, % predicted 92±16 Pre-BD FEV1/FVC 0.75 (0.68–0.81) Post-BD FEV1/FVC 0.79 (0.72–0.84) Data are presented as mean±sd, n (%) or median (interquartile range). BMI: body mass index; Ig: immunoglobulin; FEV1: forced expiratory volume in 1 s; BD: bronchodilator; FVC: forced vital capacity. #: Among those with any smoking history. ¶: At least one positive skin prick test for common allergens.
- TABLE 2
Bronchodilator responses in spirometry with the highest reversibility chosen from each steroid-naïve asthma patient (N=219)
Mean±sd Median (IQR) Patients ΔFEV1, mL 294±270 230 (130–400) 219 ΔFVC, mL 210±354 130 (30–300) 219 ΔFEV1, % of the initial FEV1 11.6±10.7 9.5 (4.8–15.3) 219 ΔFVC, % of the initial FVC 6.6±10.9 3.7 (0.8–8.5) 219 ΔFEV1, % of the predicted FEV1 8.3±7.2 7.0 (3.9–10.8) 219 IQR: interquartile range; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity. The data are not normally distributed. The mean values are shown to make it easier to compare results with other studies.
- TABLE 3
Multivariable odds ratios for factors at the diagnostic visit associated with the fulfilment of thresholds of change in forced expiratory value in 1 s (ΔFEV1) >9% of predicted FEV1 and ΔFEV1 ≥12% and 200 mL of the initial FEV1
ΔFEV1 ≥9% of predicted FEV1 p-value ΔFEV1 ≥12% of the initial FEV1+200 mL p-value Age ≥45 years 1.54 (0.73–3.22) 0.258 1.72 (0.77–3.85) 0.190 Male 0.71 (0.33–1.50) 0.365 0.43 (0.19–1.00) 0.050 Symptoms, AQ20 1.10 (0.97–1.14) 0.228 1.02 (0.94–1.11) 0.630 Total IgE <100 kU·L−1 2.06 (0.97–4.37) 0.060 2.84 (1.24–6.51) 0.014 Blood eosinophils >0.25×109 per L 1.90 (0.89–4.10) 0.097 2.55 (1.10–5.88) 0.029 Post-bronchodilator FEV1/FVC<0.7 and ≥10 pack-years 0.26 (0.60–1.11) 0.690 0.39 (0.11–1.43) 0.155 Pre-bronchodilator FEV1 <80% predicted# 6.03 (2.11–17.21) <0.001 15.93 (5.00–50.80) <0.001 Pre-bronchodilator FVC >90% predicted# 4.71 (1.68–13.18) 0.003 2.90 (0.99–8.53) 0.053 Ig: immunoglobulin; FVC: forced vital capacity; FEV1: forced expiratory volume in 1 s; AQ20: Airways Questionnaire 20. #: Measured from the spirometry with highest reversibility. Data are presented as ORs (95% CIs). BMI and smoking were not significantly associated with the thresholds and were excluded from the model. Statistically significant associations are presented in bold.
- TABLE 4
Bronchodilator responses in steroid-naïve asthma patients with pre-bronchodilator (pre-BD) forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) <0.7 versus FEV1/FVC ≥0.7 (N=219)
pre-BD FEV1/FVC ≥0.7 (n=151) pre-BD FEV1/FVC <0.7 (n=68) p-value ΔFEV1, mL 210 (110–370) 285 (180–478) 0.002 ΔFVC, mL 110 (20–240) 200 (90–320) 0.012 ΔFEV1, % of the initial FEV1 7.3 (3.8–12.5) 13.5 (9.3–19.4) <0.001 ΔFVC % of the initial FVC 3.0 (0.5–6.6) 6.4 (2.2–8.5) 0.008 ΔFEV1, % of the predicted FEV1 6.0 (3.2–9.8) 8.9 (5.8–13.2) 0.001 Data are presented as the median (interquartile range). Spirometry showing the highest reversibility chosen from each patient.
- TABLE 5
Different thresholds of bronchodilator response in steroid-naïve asthma patients with pre-bronchodilator forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) <0.7 versus FEV1/FVC ≥0.7 measured from spirometry with the highest reversibility chosen from each patient (N=219)
pre-BD FEV1/FVC ≥0.7 (n=151) pre-BD FEV1/FVC <0.7 (n=68) p-value Absolute change ≥200 mL 80 (53.0%) 48 (70.6%) 0.018 Absolute change ≥400 mL 32 (21.2%) 20 (29.4%) 0.229 ΔFEV1 % of the initial FEV1 ≥12% and 200 mL 40 (26.5%) 38 (55.9%) <0.001 ΔFEV1 % of the initial FEV1 ≥15% and 400 mL 21 (13.9%) 18 (26.5%) 0.035 ΔFEV1 % of the initial FEV1 ≥12% and 400 mL 26 (17.2%) 19 (27.9%) 0.074 ΔFEV1 % of the initial FEV1 ≥15% and 200 mL 27 (17.9%) 30 (44.1%) <0.001 ΔFEV1 % of the predicted FEV1 ≥8% 58 (38.4%) 38 (55.9%) 0.019 ΔFEV1 % of the predicted FEV1 ≥9% 46 (30.5%) 33 (48.5%) 0.015 ΔFEV1 % of the predicted FEV1 ≥10% 37 (24.5%) 29 (42.6%) 0.010 None of the thresholds was fulfilled 70 (46.4%) 19 (27.9%) 0.012 Data are presented as n (%).
Supplementary Material
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Supplementary material 00293-2021.SUPPLEMENT
