RELATIONSHIP BETWEEN CLINICAL SEVERITY AND SYMPTOMS OF ASTHMA WITH DEGREE OF CHANGES IN DISTAL AND PROXIMAL AIRWAY FUNCTION

The peripheral parts of the lung are known as the main place of airflow
obstruction in asthmatic patients; but the symptoms of asthma with the location of airway obstruction
are still unknown. The aim of this study was to evaluate the association between asthma symptoms and
severity of asthma and proximal and distal airways using function tests.
Materials & Methods: Ninety-two asthma patients who were diagnosed on the basis of ATS criteria
were enrolled in this study. After full history and physical examination, asthma symptoms and asthma
severity was measured for each patient using asthma control test (ACT provided by GINA). Impulse
oscillometry and lung volume studies (using body- plethysmograph and IOS both provide by Jaeger,
Germany) were performed. Total Airway Resistance (TAWR) indicated by resistance at 5Hz and Central
Airway Resistance (CAWR) were indicated by resistance at 20 Hz. The relationship between the
presence of asthma symptoms, post nasal discharge, ACT score and parameters of lung function were
analyzed.
Results: Clinical asthma symptoms such as cough, dyspnea, wheezing, postnasal drip (PND) with distal
and proximal airway parameters of pulmonary function tests didn’t correlate. (P=0.05). Cough were
found in 59.8% of patients with uncontrolled asthma (ACT score≤19) and 40.2% of controlled asthma
(ACT score≥20) patients. There was a significant association with asthma severity (Value=0.02). Other
asthma symptoms such as dyspnea, wheezing, postnasal drip (PND) with clinical asthma severity had
no significant correlation with degree of changes in distal and proximal pulmonary airway function test
parameters (P=0.05).
Conclusion: Clinical symptoms of asthma could not differentiate the prominent site of airway
involvement