Table 1.

Subject Demographics and Biomarkers of Nicotine and Tobacco Use

	All (N = 49)	E-Cigarette Users (n = 15)	Cigarette Smokers (n = 14)	Nonsmokers (n = 20)
BMI, mean ± SD	26.3 ± 5.8	26.4 ± 6.3	26.5 ± 6.0	26.1 ± 5.6
Age, mean ± SD	27.5 ± 7.6	22.8 ± 4.8	31.3 ± 6.4	28.3 ± 8.4
Sex, n, F/M	22/27	3/12	5/9	14/6
Race, n, African American/white/other	9/34/6	1/11/3	6/7/1	2/16/2
Cigarettes/d, mean ± SD (range)	—	0.0 ± 0.1 (0.0–0.1)	9.8 ± 5.3 (3.8–20)*	—
Cotinine, mean ± SD	—	99.6 ± 132.0†	121.7 ± 125.3*	2.0 ± 7.5
NNAL/creatinine, mean ± SD	—	4.7 ± 9.5	98.1 ± 89.7*	1.2 ± 3.9

Definition of abbreviations: BMI = body mass index; e-cigarette = electronic-cigarette; NNAL = 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol.

^*P  ≤  0.0001.

^†P  ≤  0.001, compared with nonsmokers.