Table 3.

Associations between smoking intensity and markers levels among current smokers

Markers	Cigarettes per day				P trend*
	1–10	11–20	21–30	31
	(n = 49; weighted N = 836)	(n = 165; weighted N = 1875)	(n = 109; weighted N = 1760)	(n = 91; weighted N = 894)
		OR (95% CI)	OR (95% CI)	OR (95% CI)
Acute phase protein
CRP	1.0	0.91 (0.27 to 3.13)	1.00 (0.28 to 3.58)	2.76 (0.69 to 11.0)	.16
Chemokines
CCL17/TARC	1.0	1.29 (0.35 to 4.72)	0.58 (0.14 to 2.51)	2.24 (0.52 to 9.64)	.57
CCL11/ EOTAXIN	1.0	1.27 (0.35 to 4.65)	2.40 (0.57 to 10.1)	1.69 (0.31 to 9.17)	.38
Cytokines
IL-15†	1.0	0.20 (0.04 to 1.02)	0.08 (0.01 to 0.91)	1.33 (0.29 to 6.08)	.33
IL-1RA†	1.0	0.22 (0.05 to 1.06)	0.10 (0.02 to 0.59)	0.72 (0.17 to 3.12)	.82
IL-1Β	1.0	0.24 (0.06 to 0.99)	0.11 (0.02 to 0.61)	0.76 (0.19 to 3.06)	.87
IL-16	1.0	1.97 (0.55 to 7.11)	1.18 (0.33 to 4.27)	1.25 (0.31 to 5.12)	.84
SCF	1.0	1.97 (0.59 to 6.60)	1.49 (0.47 to 4.77)	0.95 (0.28 to 3.21)	.57
Soluble receptors
sIL-6R	1.0	0.19 (0.05 to 0.67)	0.33 (0.09 to 1.19)	1.17 (0.31 to 4.41)	.36
sVEGFR3	1.0	0.99 (0.27 to 3.55)	0.74 (0.17 to 3.14)	2.25 (0.47 to 10.9)	.34

* 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, and year of serum collection. P _trend calculated by including categories of cigarettes per day 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.