Table 3.

Linear mixed effect models: blood cells, IL-8 and TNF-α

Independent variable	Time interval	B	95% CI	P value
Log (leucocytes, 109/L)	0–12 hours	0.00	-0.01–0.01	0.44
Log (neutrophils, 109/L)	0–12 hours	0.00	-0.01–0.02	0.58
Log (monocytes, 109/L)	0–1 hour	0.04	-0.10–0.19	0.55
Log (eosinophils, 109/L)	0– 3 hours	-0.11	-0.18 – -0.03	0.01
Log (lymphocytes, 109/L)	0–12 hours	-0.00	-0.01–0.01	0.65
Log (IL-8, pg/ml)*	0–3 hours	0.09	0.04–0.14	0.001
Log (TNF-α, pg/ml)**	0–3 hours	0.02	-0.08–0.12	0.75

The time intervals of the above parameters were selected based on visual inspection of the plots. The slopes of the parameters were estimated using linear mixed effect models [11] by including the variables time (hours), smoking (yes or no) and their interaction. B: regression coefficient for the variable time (for further information see the method section). * Release from whole blood cells after lipopolysacharide (LPS) stimulation. ** Spontaneous release from whole blood cells IL: interleukin, TNF-α: tumor necrosis factor-α