TABLE 2

Diffusing capacity and biomarker data in study groups

Never and ex-smokers with <10 pack-yearsNon-obstructive patients with ≥10 pack-yearsACOS: ≥10 pack-years FEV1/FVC <0.7p-value#
Subjects n1223234
DLCO % pred97±1691±1585±230.001
DLCO/VA % pred98±1396±1886±22¶,+<0.001
Blood neutrophils ×109 L−13.60 (2.70–4.60)3.85 (2.95–4.98)4.50 (3.50–5.53)0.008
Blood eosinophils ×109 L−10.16 (0.09–0.28)0.14 (0.09–0.22)0.19 (0.10–0.29)0.409
IgE kU·L−159 (25–167)95 (26–199)59 (20–140)0.516
FeNO ppb12 (5–21)8 (5–13)10 (5–15)0.063
hsCRP mg·L−11.24 (0.56–2.33)1.18 (0.74–5.02)0.93 (0.59–3.04)0.369
IL-6 pg·mL−11.52 (1.12–2.48)2.10 (1.09–5.69)2.88 (1.88–4.99)<0.001

Data are presented as mean±sd, or median (interquartile range), unless otherwise stated. Statistically significant p-values are presented in bold. #: p-value across all groups; : as compared to group 1 (never- and ex-smokers with <10 pack-years), p<0.05; +: as compared to group 2 (non-obstructive patients with ≥10 pack-years) p<0.05. ACOS: asthma–chronic obstructive pulmonary disease overlap syndrome; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; DLCO: diffusing capacity of the lung for carbon monoxide; VA: alveolar volume; IgE: immunoglobulin E; FeNO: exhaled nitric oxide fraction; hsCRP: high-sensitivity C-reactive protein; IL-6: interleukin 6.