Association of Airway Eosinophilia with Small Airway Dysfunction in Patients with Mild and at Risk for COPD

Figures & data

Table 1 Clinical and Lung Physiology Characteristics in Patients Stratified According to Sputum Eosinophils Count

Characteristic	Eosinophil-Low	Eosinophil-High	P-value
	n = 56	n = 13
Age, year	65±6	64 ±7	0.81
Male sex, n (%)	32 (56)	6 (46)	0.54
BMI, kg/m^2	27.8 ±4.6	26.4 ±4.4	0.33
Height, cm	172 ±11	172 ±10	0.99
Ex-smokers, n (%)	24 (44)	4 (30)	0.53
Smoking quantity, PY	45±25	43±16	0.67
Sputum eosinophils, %	0.35 (0–0.62)	3.0 (2.8–4.5)	<0.001
Sputum neutrophils, %	75 (59–81)	74 (64–81)	0.93
Blood eosinophils, /μL	179 (117–226)	274 (235–368)	<0.001
FeNO, ppb	12 (7–16)	9 (7–39)	0.82
Inhaled therapies, n (%)
Corticosteroids	11 (19)	2 (15)	1.0
Long-acting beta agonist	16 (28)	7 (53)	0.10
Long-acting muscarinic antagonist	10 (17)	8 (61)	<0.01
Pre-BD FEV1, %	83 ±13	75 ±12	0.046
Post-BD FEV1, %	88 ±12	79 ±12	0.037
Post-BD FEV1 reversibility, %	5 ±5	6 ±4	0.88
Pre-BD FEV1/FVC %	62 ±8	58 ±9	0.20
Post-BD FEV1/FVC %	65 ±8	60 ±9	0.14
Pre-BD FVC, %	102 ±13	99 ±14	0.45
Post-BD FVC, %	104 13	102 16	0.61
Pre-BD MEF25, %	30 ±14	24 ±9	0.084
Post-BD MEF25,%	33 ±15	26 ±14	0.093
Pre-BD MEF50, %	45 ±20	35 ±15	0.064
Post-BD MEF50, %	51 ±23	38 ±17	0.021
Pre-BD MEF75, %	69 ±24	52 ±19	0.01
Post-BD MEF75, %	75 ±25	56 ±23	0.017
sRtot, %	73.5 ±63	100.5 ±80	0.26
FRC, %	116 ±23	135 ±32	0.036
RV, %	120 (112–140)	147 (116–163)	0.043
RV/TLC %	42±7	48±7.0	<0.01
IC, L	2.8 ±0.72	2.31 ±0.65	0.023
IC/TLC%	42 ±6	34 ±7	<0.01
R5–19, %	107 (54–199)	174 (31–208)	0.89
AX, %	501 ±500	599 ±1101	0.34
LCI	9.6 ±1.5	10.6 ±1.2	0.026
Sacin, L^−1	0.32 (0.21–0.39)	0.58 (0.38–0.75)	0.032
Scond, L^−1	0.056 (0.03–0.13)	0.062 (0.04–0.12)	0.77
SGRQ-c total score	22.2 ±14	24.3 ±13	0.61
CAT total score	14.1 ±5	14.2 ±7	0.88

Note: Values are presented in mean ±SD and if skewed in median (IQR).

Abbreviations: FVC, forced vital capacity; FEV1, forced expiratory volume in 1 second; MEF, maximal expiratory flow at 25% (MEF50), 50% (MEF50) and 75% (MEF75) of forced vital capacity; FRC, functional residual capacity; RV, residual volume; TLC, total lung capacity; s_Rtot, total specific airway resistance; IC, inspiratory capacity; R5–19, frequency dependence of resistance between 5 Hz and 19 Hz; AX, area under the reactance curve; LCI, lung clearance index from MBW that continued until the expired end-tidal SF6 concentration reached <2.5% of the starting concentration; S_acin and S_cond, acinar and conductive ventilation inhomogeneity both measured by MBW; BD, bronchodilation until 400 µg salbutamol; SGRQ-c, George’s Respiratory Questionnaire for COPD patients; CAT, COPD Assessment Test.

Figure 1 Predictors of lung function in early COPD: a heatmap illustrating the power of predictors (x-axis) expressed as standardized estimates (coefficient) from linear multivariate regressions for lung function measures (y-axis). Colors indicate the positive (red) and negative (violet) impact of the predictor on each lung function measure.

Abbreviations: FEV1, forced expiratory volume in 1 second; MEF, maximal expiratory flow at 25% (MEF50), 50% (MEF50) and 75% (MEF75) of forced vital capacity; FRC, functional residual capacity; RV, residual volume; TLC, total lung capacity; sRtot, total specific airway resistance; IC, inspiratory capacity; LCI, lung clearance index; S_acin and S_cond, acinar and conductive ventilation inhomogeneity.