Relationship between Particulate Matter (PM₁₀) and Airway Inflammation Measured with Exhaled Nitric Oxide Test in Seoul, Korea

Table 1

Baseline characteristics.

	Events
No. of outpatient clinic visits/patients	1,574/1,439
Age (years)	48.3 ± 16.1
Gender
Male^†	688 (43.7%)
Female^†	886 (56.3%)
History of respiratory disease
Asthma^†	367 (23.3%)
Chronic obstructive pulmonary disease^†	48 (3.0%)
Allergic rhinitis^†	242 (15.4%)
Pulmonary-related medication before the visit
INS^†	82 (5.2%)
ICS^†	204 (13.0%)
LABA or LAMA^†	201 (12.8%)
LTRA^†	153 (9.7%)
Antihistamine^†	187 (11.9%)
Base-line spirometry after bronchodilation
FEV1 (liters)	2.8 ± 0.8
FEV1 (% of predicted value)	87.5 ± 14.6
FVC (liters)	3.5 ± 1.0
FVC (% of predicted value)	90.1 ± 12.9
Ratio of FEV1 to FVC (%)	77.9 ± 10.1
Bronchodilator response (positive)^†	273 (17.3%)
Asthma provocation test (positive)^†	105 (6.7%)

INS, intranasal corticosteroids; ICS, inhaled corticosteroid; LABA, long-acting B agonist bronchodilator; LAMA, long-acting antimuscarinic agent bronchodilator; LTRA, leukotriene receptor antagonist; FEV1, forced expiratory volume in one second; FVC, forced vital capacity. Numbers are presented as average ± standard deviation. ^†Numbers are presented as n (%).