Figure 1. Sputum Neutrophil Percentages (A) and Eosinophil Percentages (B) in Lean And

(a) (b)

Figure 1. Sputum neutrophil percentages (a) and eosinophil percentages (b) in lean and overweight/obese subjects with stable asthma. Horizontal bars represent mean (a) and median (b) concentrations.

Figure 2. Proportion of neutrophilic asthma (sputum neutrophils ≥ 61%) in overweight/obese versus lean asthma subjects.

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Figure 3. Sputum (a) and plasma IL-17 (b) concentrations in lean and overweight/obese patients with stable asthma. Horizontal bars represent median concentrations.

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(b)

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Figure 4. Association of sputum IL-17concentrations with sputum neutrophlil percentages (a) and sputum eosinophil percentages (b) and association of plasma IL-17 concentrations with sputum neutrophlil percentage (c) and eosinophil percentage (d) in patients with stable persistent asthma.

Figure 5. Sputum neutrophil percentages (a) and eosinophil percentages (b) in lean and overweight/obese subjects with acute asthma. Horizontal bars represent mean (a) and median (b) concentrations.

Figure 6. Sputum (a) and plasma IL-17 (b) concentrations in lean and overweight/obese patients with acute asthma. Horizontal bars represent median concentrations.

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(b)

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Figure 7. Association of sputum IL-17concentrations with sputum neutrophlil percentages (a) and sputum eosinophil percentages (b) and association of plasma IL-17 concentrations with sputum neutrophlil percentage (c) and eosinophil percentage (d) in patients with acute asthma.

Table 1. Characteristics of lean (BMI 24 kg/m2) and overweight/obese (BMI ≥ 24 kg/m2) patients with stable persistent asthma.

BMI 24 kg/m2 / BMI ≥ 24 kg/m2 / P value
Female (%) / 29 (48.3) / 45 (59.2) / 0.206
Age (year) / 41.5 (31.5, 51.8) / 44.0 (34.0, 54.8) / 0.314
BMI (kg/m2) / 22.3 (21.2, 23.1) / 31.7 (26.7, 36.1) / 0.000
Smoking (%) / 18 (30.0) / 17 (22.4) / 0.312
Plasma IL-17 (pg/ml) / 8.725 (5.205, 18.088) / 12.458 (6.712, 22.468) / 0.072
Sputum IL-17 (pg/ml) / 3.552 (2.306, 5.920) / 5.047 (2.955, 8.461) / 0.015
FEV1% predicted / 86.9 (15.6) / 85.4(15.3) / 0.565
FVC% predicted / 95.3 (14.1) / 92.1 (14.0) / 0.190
Sputum neutrophils (%) / 42.1(18.9) / 48.1(21.3) / 0.091
Neutrophilic asthma (%) / 11 (18.3) / 26 (34.2) / 0.039
Sputum eosinophils (%) / 1.9 (0.3, 7.6) / 1.8 (0.3, 4.5) / 0.654
Eosinophilic asthma (%) / 24 (40.0) / 26 (34.2) / 0.487
OSAS (%) / 5 (8.3) / 14 (18.4) / 0.092
GER (%) / 13 (21.7) / 27 (35.5) / 0.078
BDI II score / 8.0 (5.0, 12.8) / 9.0 (7.0, 15.8) / 0.056
ICS use (%) / 8 (13.3) / 12 (15.8) / 0.688
ICS dose# (g/d) / 0 (0, 0) / 0 (0, 0) / 0.636
ACQ-5 score / 0.9 (0.6, 1.4) / 1.2 (0.7, 1.6) / 0.082

Data are presented as mean (standard deviation) or median (interquartile range) or number (percentage). BMI: body mass index; FEV1: forced expiratory volume in 1 second; FVC: forced vital capacity; OSA, obstructive sleep apnea; GER, gastro-esophageal reflux; BDI, Beck Depression Inventory; ICS: inhaled corticosteroid; ACQ: Asthma Control Questionnaire; #: Beclomethasone equivalents.

Table 2. Multiple linear regression model for predicting sputum neutrophil percentage using sputum IL-17, sex, age, BMI, smoking status, ICS dose as covariates.

Unadjusted model / Adjusted model
β coefficient / Standard error / P value / β coefficient / Standard error / P value
Female (yes/no) / -1.184 / 4.199 / 0.778
Age (year) / 0.191 / 0.145 / 0.189
BMI ≥ 24 kg/m2 (yes/no) / 4.107 / 3.465 / 0.238
Smoking (yes/no) / 2.794 / 4.846 / 0.565
ICS dose (g/d) / 0.003 / 0.005 / 0.596
Sputum IL-17 (pg/ml) / 1.032 / 0.340 / 0.003 / 1.191 / 0.325 / < 0.001

BMI: body mass index; ICS: inhaled corticosteroid.

Table 3. Multiple linear regression model for predicting sputum neutrophil percentage using plasma IL-17, sex, age, BMI, smoking status, ICS dose as covariates.

Unadjusted model / Adjusted model
β coefficient / Standard error / P value / β coefficient / Standard error / P value
Female (yes/no) / 0.899 / 4.279 / 0.834
Age (year) / 0.254 / 0.146 / 0.084 / 0.287 / 0.140 / 0.042
BMI ≥ 24 kg/m2 (yes/no) / 4.894 / 3.532 / 0.168
Smoking (yes/no) / 2.645 / 4.964 / 0.595
ICS dose (g/d) / 0.004 / 0.006 / 0.498
Sputum IL-17 (pg/ml) / 0.167 / 0.097 / 0.088

BMI: body mass index; ICS: inhaled corticosteroid.

Table 4. Correlation between sputum and plasma IL-17 and existence of OAS, GER and depression.

Sputum IL-17 / Plasma IL-17
Rs / P value / Rs / P value
OSA / 0.010 / 0.906 / 0.086 / 0.322
GER / 0.048 / 0.580 / 0.087 / 0.314
BDI II score / 0.111 / 0.198 / 0.325 / < 0.001

OSA, obstructive sleep apnea; GER, gastro-esophageal reflux; BDI, Beck Depression Inventory.

Table 5. Characteristics of lean (BMI 24 kg/m2) and overweight/obese (BMI ≥ 24 kg/m2) patients with acute asthma.

BMI 24 kg/m2 / BMI ≥ 24 kg/m2 / P value
Female (%) / 52.0 / 61.9 / 0.500
Age (year) / 35.0 (9.3) / 42.1(11.3) / 0.022
BMI (kg/m2) / 22.2 (21.5, 23.3) / 33.2(27.6, 38.2) / 0.000
Smoking (%) / 24.0 / 33.3 / 0.484
Plasma IL-17 (pg/ml) / 26.276 (12.889, 57.974) / 23.057 (11.466, 64.438) / 0.903
Sputum IL-17 (pg/ml) / 10.161 (5.207, 18.862) / 11.053 (7.230, 21.196) / 0.544
Sputum eosinophils (%) / 8.0 (5.3, 33.5) / 9.0 (4.3, 24.3) / 0.766
Sputum neutrophils (%) / 55.7 (21.7) / 55.3 (17.5) / 0.941
Pulse (beat/min) / 104.0 (14.4) / 102.6 (13.3) / 0.746
Respiratory rate (breaths/min) / 23.6 (4.8) / 23.9 (5.0) / 0.861
Accessory muscle use (%) / 7 (28.0) / 5 (23.8) / 0.747
Wheezing (%) / 24 (96.0) / 19 (90.5) / 0.450
Diaphoresis (%) / 3 (12.0) / 2 (9.5) / 0.788
Initial FEV1 % predicted / 50.5 (12.8) / 53.7 (11.5) / 0.379
SaO2 (%) / 95.0 (93.5, 96.0) / 95.0 (94.0, 96.0) / 0.937
Duration of exacerbation / 0.874
Less than 1 day (%) / 15 (60.0) / 11 (52.4)
1 - 2 days (%) / 8 (32.0) / 8 (38.1)
More than 2 days (%) / 2 (8.0) / 2 (9.5)
Cause of asthma exacerbation
Upper respiratory infections (%) / 14 (56.0) / 14 (66.7) / 0.460
Exposure to allergens (%) / 8 (32.0) / 5 (23.8) / 0.539
Therapy interruption (%) / 1 (4.0) / 2 (9.5) / 0.876
Others (%) / 2 (8.0) / 0 (0) / 0.549
Inhaled β-agonists (%) / 25 (100.0) / 21 (100.0) / 1.000
Inhaled anticholinergics (%) / 5 (20.0) / 2 (9.5) / 0.566
Systemic corticosteroids (%) / 23 (92.0) / 21 (100.0) / 0.549
Intravenous magnesium (%) / 0 (0) / 2 (9.5) / 0.394

Data are presented as mean (standard deviation) or median (interquartile range) or number (percentage). BMI: body mass index; FEV1: forced expiratory volume in 1 second; SaO2: arterial oxygen saturation; ICS: inhaled corticosteroid.