Table 5. Comparison of inflammatory mediators between smokers with low K_CO and those with normal K_CO.

	Smokers without COPD
	Normal KCO (n = 50)	KCO<80% (n = 39)	P value†
Leukocytes, Giga/L	6.3 [5.1–7.8]	6.9 [6,0–8.4]	0.19
IL-6, pg/mL	15.1 [12.9–18,5]	16.9 [13,3–18.5]	0.46
IL-8, pg/mL	44.7 [38,9–51.6]	47.5 [41,8–51.6]	0.30
MCP-1, pg/mL	35,8 [26.6–50,0]	38.7 [27.3–50,2]	0.62
TNF-α, pg/mL	66.5 [55.5–74.8]	70.0 [59.5–85.9]	0.35
Eotaxin, pg/mL	127 [92–185]	125 [61–171]	0.39

K_CO, transfer factor coefficient of the lung for carbon monoxide; IL, interleukin; MCP-1, monocyte chemotactic protein-1; TNF-α, tumor necrosis factor alpha

Data are median [interquartile range].

† P value by nonparametric Kruskal-Wallis test