Study on small airway function in asthmatics with fractional exhaled nitric oxide and impulse oscillometry.
OBJECTIVE
The invasive techniques can be direct and objective to assess small airway function, but they have significant risks and inconveniences for patients and cannot be repeated often. Some sophisticated techniques such as fractional exhaled nitric oxide (FeNO) and impulse oscillometry (IOS) may surmount such restrictions. Therefore, we investigated the relation among FeNO, IOS, and small airway function in asthmatic patients.


METHODS
We recruited 140 asthmatic patients including 69 patients with small airway normal function and 71 patients with small airway dysfunction. FeNO, eosinophil（EOS）count and total immunoglobulin E (IgE) in peripheral blood, pulmonary function, as well as IOS were measured.


RESULTS
The levels of FeNO, the reactance area (AX), the resonant frequency Fres and EOS were significantly increased in small airway dysfunction group compared with small airway normal function group (P < 0.01 respectively). A multiple regression model showed that FeNO, AX and Fres were correlative factors of mid forced expiratory flow of percentages of predicted values [FEF25-75 (%pred)] (P < 0.01, respectively). A receiver operating characteristic (ROC) analysis showed that the combination of FeNO, AX and Fres had a greater area under the ROC curve (AUC) than each of them (AUC: 0.881, P < .001, 95％CI: 0.815-0.929).


CONCLUSIONS
FeNO and IOS are helpful in diagnosis of small airway dysfunction with high sensitivity and specificity, and FeNO combined with IOS can better evaluate the small airway function in asthmatic patients.
Department of Pulmonary Medicine, Qilu Hospital of Shandong University, Jinan, 250012, P.R. China.
Lin
L
Liu
Department of Pulmonary Medicine, Qilu Hospital of Shandong University, Jinan, 250012, P.R. China.|Department of Cadre Health Care, The Second Hospital of Shandong University, Jinan, 250033, P.R. China.
Wen
W
Liu
Department of Pulmonary Medicine, Qilu Hospital of Shandong University, Jinan, 250012, P.R. China.
Chunhong
C
Liu
Department of Pulmonary Medicine, Qilu Hospital of Shandong University, Jinan, 250012, P.R. China.
Dexiang
D
Wang
Department of Pulmonary Medicine, Qilu Hospital of Shandong University, Jinan, 250012, P.R. China.
Jiping
J
Zhao
Department of Pulmonary Medicine, Qilu Hospital of Shandong University, Jinan, 250012, P.R. China.
Junfei
J
Wang
Department of Pulmonary Medicine, Qilu Hospital of Shandong University, Jinan, 250012, P.R. China.
Jinxiang
J
Wu
Department of Pulmonary Medicine, Qilu Hospital of Shandong University, Jinan, 250012, P.R. China.
Tian
T
Liu
Department of Pulmonary Medicine, Qilu Hospital of Shandong University, Jinan, 250012, P.R. China.
Yuanyuan
Y
Zhang
Department of Pulmonary Medicine, Qilu Hospital of Shandong University, Jinan, 250012, P.R. China.
Yahui
Y
Liu
Department of Pulmonary Medicine, Qilu Hospital of Shandong University, Jinan, 250012, P.R. China.
Liuzhao
L
Cao
Department of Pulmonary Medicine, Qilu Hospital of Shandong University, Jinan, 250012, P.R. China.
Liang
L
Dong
D000328:Adult; D056151:Airway Remodeling / Q000502:physiology*; D001249:Asthma / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D015415:Biomarkers / Q000097:blood; D002681:China / Q000453:epidemiology; D004804:Eosinophils / Q000166:cytology; D045853:Exhalation / Q000502:physiology; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D008168:Lung / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000032:analysis*; D009991:Oscillometry / Q000295:instrumentation*; D011237:Predictive Value of Tests; D012129:Respiratory Function Tests / Q000379:methods
D015415:Biomarkers; D009569:Nitric Oxide; D007073:Immunoglobulin E
asthma; fractional exhaled nitric oxide; impulse oscillometry; small airway dysfunction