Table 1.

Mean Salivary Cytokine and Cotinine Concentrations Stratified by Participant Tobacco Use

Analyte	NS	CS	HS	EU	P value
IL-2 (pg/ml)	1.1 ± 0.3	0.4 ± 0.1	0.5 ± 0.1	0.4 ± 0.1	0.92
IL-4 (pg/ml)	0.1 ± 0.03	0.1 ± 0.01	0.1 ± 0.01	0.1 ± 0.01	0.93
IL-6 (pg/ml)	1.4 ± 0.4	1.0 ± 0.4	0.6 ± 0.2	1.1 ± 0.5	0.83
IL-8 (pg/ml)	347.4 ± 94.0	82.3 ± 39.7	51.8 ± 23.1	21.2 ± 6.9	0.13
IL-10 (pg/ml)	0.6 ± 0.2	0.1 ± 0.03	0.1 ± 0.02	0.1 ± 0.02	0.74
IL-12p70 (pg/ml)	0.2 ± 0.06	0.2 ± 0.05	0.2 ± 0.06	0.2 ± 0.03	0.83
IL-13 (pg/ml)	2.6 ± 0.7	1.1 ± 0.4	1.3 ± 0.3	1.1 ± 0.3	0.89
IL-1β (pg/ml)	26.5 ± 6.8	23.8 ± 6.8	24.8 ± 9.9	14.6 ± 5.4	0.44
IFN-γ (pg/ml)	1.4 ± 0.3	1.9 ± 0.5	1.1 ± 0.4	1.6 ± 0.4	0.57
TNF-α (pg/ml)	1.8 ± 0.6	0.4 ± 0.10	0.4 ± 0.1	0.4 ± 0.1	0.86
Cotinine (ng/ml)	N.D.	23.8 ± 6.18****	2.88 ± 0.61†	19.1 ± 4.57***	<0.01

Definition of abbreviations: ATP = alternative tobacco product; CS = cigarette smoker; EU = e-cigarette user; HS = hookah smoker; N.D. = nondetectable (all samples below the lower limit of detection of 0.4 ng/ml); NS = nonsmoker.

Analyte aggregate means ± SEM by tobacco product use. Because salivary data failed normality tests, analytes were analyzed with nonparametric Kruskal-Wallis tests. When P ⩽ 0.05 (in bold), a Dunn’s multiple comparison test was performed post hoc to identify where statistically significant differences occurred.

Asterisks indicate when tobacco product differs from nonsmoking outcome (negative reference group). ***P ⩽ 0.001, and ****P ⩽ 0.0001.

^† Indicates when ATP groups differ from cigarettes (i.e., positive reference group).