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

Table 3

Correlation analysis of PM₁₀ and FeNO by the Pearson correlation and multivariate linear regression analysis according to subgroup.

Subgroup	Number of events	FeNO (ppb)	PM10 ( μg/m^3)	Univariate		Multivariate
				Correlation coefficient	value	B	value
History of respiratory disease
Asthma^†	367	52.3 ± 43.8	48.0 ± 25.7	0.104	0.047	0.093	0.072
Allergic rhinitis^†	242	44.1 ± 37.0	47.8 ± 24.9	0.091	0.160	0.096	0.128
Chronic obstructive pulmonary disease^†	48	33.9 ± 44.8	47.9 ± 22.7	−0.036	0.807	−0.058	0.708
No history of respiratory disease^†	715	23.2 ± 19.8	47.5 ± 25.7	0.081	0.030	0.083	0.024
Pulmonary-related medication before the visit
Pulmonary medication^‡	309	36.3 ± 29.5	46.7 ± 21.2	−0.05	0.926	0.013	0.814
No pulmonary medication^‡	1265	30.8 ± 31.1	47.5 ± 26.1	0.070	0.012	0.053	0.035

PM₁₀, particulate matter with a diameter of less than 10 μm; FeNO, fractional exhaled nitric oxide. B is the regression coefficient, and the positive sign of regression coefficient means that the variables are positively associated. PM₁₀ values were based on two days before the hospital visit. Numbers are presented as mean ± standard deviation. ^†Multivariate linear regression analysis is adjusted for age, sex, pulmonary-related medication before the visit (antihistamine, intranasal corticosteroids, inhaled corticosteroids, and leukotriene receptor antagonist), humidity, and temperature. ^‡Multivariate linear regression analysis is adjusted for age, sex, previous history of respiratory disease (asthma, allergic rhinitis, and chronic obstructive pulmonary disease), humidity, and temperature.