Table 1.

Demographics and baseline biomarkers by sex

CharacteristicFemalesMalesAll subjects
n (%)24 (43.6)31 (56.4)55 (100)
Age (mean, range)22.7 (19–33)25.9 (18–48)a24.5 (18–48)
BMI (mean, range)22.4 (17.7–33.3)24.0 (18.3–32.3)a23.3 (17.7–33.3)
Race (n, %)
 Asian4 (7.3)5 (9.1)a9 (16.4)
 Black2 (3.6)2 (3.6)4 (7.3)
 White10 (18.2)22 (40.0)32 (58.2)
 Mixed8 (14.6)2 (3.6)10 (18.2)
Suspected cigarette smoker
 No (n, %)22 (40.0)25 (45.5)47 (85.5)
 Yes (n, %)2 (3.6)6 (10.9)8 (14.5)
Hookah use classification
 Daily (n, %)1 (1.8)2 (3.6)3 (5.5)
 Weekly (n, %)4 (7.3)6 (10.9)10 (18.2)
 Monthly (n, %)11 (20.0)11 (20)22 (40.0)
 Yearly (n, %)4 (7.3)3 (5.5)7 (12.7)
 Not reported (n, %)4 (7.3)9 (16.4)13 (23.6)
Marijuana use
 No (n, %)15 (27.3)18 (32.7)33 (60.0)
 Yes (n, %)9 (16.4)13 (23.6)22 (40.0)
Time in bar (min)b108 (80–128)95 (60–120)101 (75–120)
Smoking duration (min)b71 (55–75)76 (45–80)74 (45–80)
Number of bowls usedb1.3 (1.0–2.0)1.5 (1.0–2.0)1.5 (1.0–2.0)
Number of shared usersb2.9 (2.0–4.0)2.8 (2.0–4.0)2.9 (2.0–4.0)
Bowls per userb0.6 (0.3–0.8)0.6 (0.3–0.7)0.6 (0.3–0.7)
Prior SHS (h)c3.0 (1.0–5.0)4.0 (2.0–5.0)3.0 (1.6–5.0)
 No (n, %)13 (23.6)18 (32.7)31 (56.4)
 Yes (n, %)11 (20.0)13 (23.6)24 (43.6)
Bar SHS (min)c8.5 (5.0–21.0)8.5 (4.0–27.5)8.5 (5.0–27.5)
 No (n, %)20 (36.4)23 (41.8)43 (78.2)
 Yes (n, %)4 (7.3)8 (14.6)12 (21.8)
Biomarkersd
 Expired CO (ppm)2.5 (1.0–3.0)4.1 (2.0–6.0)a3.4 (2.0–4.0)
 Cotinine (ng/mg creat)14.3 (9.30–22.0)13.1 (9.13–18.7)13.6 (10.4–17.7)
 Nicotine (ng/mg creat)2.19 (0.99–4.88)2.45 (1.23–4.88)2.34 (1.41–3.87)
 NNAL (pg/mg creat)1.03 (0.55–1.90)1.23 (0.73–2.07)1.14 (0.78–1.67)
VOC mercapturic acid metabolites (ng/mg creatinine)
 2-OH-propyl37.0 (26.3–52.2)40.6 (27.2–60.5)40.0 (30.0–50.7)
 3-OH-propyl315.1 (217.0–457.7)353.2 (255.1–489.2)336.1 (264.9–426.3)
 2-Carbamoylethyl96.8 (73.8–127.0)98.2 (75.7–127.5)97.6 (81.3–117.2)
 Cyanoethyl4.56 (2.38–8.74)5.92 (3.04–11.5)5.28 (3.34–8.35)
 MHBMA0.242 (0.166–0.354)0.198 (0.143–0.273)0.216 (0.170–0.274)
 OH-ethyl3.30 (2.63–4.15)2.73 (2.19–3.41)2.97 (2.54–3.47)
 Phenyl0.199 (0.137–0.290)0.188 (0.132–0.267)0.193 (0.150–0.247)

NOTES: “Suspected cigarette smoker” if urine cotinine > 30 ng/mL; “smoking duration,” total time spent smoking hookah; “prior SHS,” total time exposed to secondhand cigarette smoke in past 7 days (hours); “bar SHS,” time exposed to secondhand cigarette smoke while in hookah bar (min); creat, creatinine; daily, approximately daily use or 3 or more times per week; weekly, approximately weekly use (1–2 times per week); monthly, approximately monthly use (several times per month but not weekly); yearly, several times per year or less; NNAL, 4–(methylnitrosamino)-1-(3-pyridyl)-1-butanol; VOC mercapturic acid metabolites and parent compounds: 2-hydroxypropyl (propylene oxide), 3-hydroxypropyl (acrolein), 2-carbamoylethyl (acrylamide), cyanoethyl (acrylonitrile), 2-hydroxy-3-buten-1-yl or isomer(s) [abbrev. MHBMA] (1,3-butadiene), 2-hydroxyethyl (ethylene oxide), and phenyl (benzene).

  • aSignificant difference between females and males (P < 0.05).

  • bPresented as mean (interquartile range).

  • cStatistics for “yes” only.

  • dGeometric mean (95% CI).