Table 4.

Associations between smoking duration and markers levels among current smokers

Markers	Smoking duration, y				P trend*
	≤40	40–44	45–49	50
	(n = 67; weighted N = 1453)	n = 126; weighted N = 2461)	(n = 124; weighted N = 1124)	(n = 97; weighted N = 627)
		OR (95% CI)	OR (95% CI)	OR (95% CI)
Acute phase Protein
CRP	1.0	0.43 (0.14 to 1.36)	0.28 (0.08 to 1.00)	0.42 (0.07 to 2.67)	.15
Chemokines
CCL17/TARC	1.0	3.22 (0.73 to 13.2)	3.10 (0.73 to 13.2)	5.01 (0.93 to 26.9)	.09
CCL11/ EOTAXIN	1.0	1.05 (0.29 to 3.86)	0.74 (0.16 to 3.35)	2.56 (0.27 to 24.1)	.69
Cytokines
IL-15†	1.0	1.12 (0.14 to 8.92)	1.55 (0.15 to 16.1)	3.22 (0.14 to 75.4)	.61
IL-1RA†	1.0	0.64 (0.10 to 4.20)	1.31 (0.18 to 9.54)	0.87 (0.05 to 14.2)	1.00
IL-1Β	1.0	0.51 (0.09 to 2.89)	0.94 (0.16 to 5.67)	1.37 (0.11 to 16.6)	.94
IL-16	1.0	0.53 (0.14 to 1.96)	0.36 (0.08 to 1.71)	0.56 (0.08 to 4.01)	.37
SCF	1.0	1.88 (0.67 to 5.29)	3.46 (0.86 to 14.0)	6.61 (1.00 to 43.9)	.03
Soluble receptors
sIL-6R	1.0	4.64 (1.22 to 17.6)	5.20 (0.98 to 27.7)	8.76 (1.30 to 58.9)	.01
sVEGFR3	1.0	2.82 (0.91 to 8.74)	3.48 (0.86 to 14.0)	1.61 (0.21 to 12.5)	.39

* Estimated with weighted logistic regression. All models adjusted for age, sex, history of chronic bronchitis or emphysema, history of coronary heart disease or heart attack, body mass index, case-control study of origin, year of serum collection. P _trend calculated by including categories of years smoked in the model as a continuous variable with a two-sided Wald Test. CCL = C-C motif ligand; TARC = thymus and activation regulated chemokine; CI = confidence interval; CRP = C-reactive protein; IL = interleukin; OR = odds ratio; SCF = stem cell factor; sIL-6R = soluble interleukin 6 receptor; sVEGFR3 = soluble vascular endothelial growth factor receptor 3.

† Categorized as detectable/undetectable.