Table 5.

Creatinine-corrected urinary levels of SPMAa in hookah smokers and non-smokers (≥18 years) pre and post hookah-only social events in hookah lounge versus home (N = 208)

Creatinine-corrected SPMA valuesHookah loungeHome
Hookah-only social event (n = 108)Hookah-only social event (n = 100)
pmol/mg creatininepmol/mg creatinine
Pre eventPost eventRatiobPcPre eventPost eventRatiobPdPePf
All hookah smokers (n = 105)
 M (±SD)g0.43 (±0.61)1.56 (±2.03)<0.0010.75 (±1.44)1.27 (±2.05)0.0030.1760.034
 GM (95% CI)h0.18 (0.12 -0.27)0.62 (0.40–0.96)3.40.26 (0.17–0.41)0.58 (0.40–0.83)2.2
 Median (5–95 percentile)0.20 (0.02–1.62)0.83 (0.03–6.12)4.20.32 (0.02–3.34)0.60 (0.11–7.10)1.9
 (Minimum–maximum)(0.02–3.24)(0.02–9.05)(0.02–9.30)(0.02–9.42)
 % above LODi (Freq/n)j77% (41/53)94% (51/54)86% (43/50)94% (47/50)
Daily hookah smokers
 M (±SD)0.59 (±0.81)3.05 (±2.25)0.0431.43 (±2.36)2.22 (±2.95)0.0230.5130.040
 GM (95% CI)0.29 (0.05–1.58)2.26 (0.71–7.22)7.80.47 (0.17–1.32)1.30 (0.76–2.24)2.8
 Median (5–95 percentile)0.25 (0.05–2.02)3.56 (0.80–6.12)14.20.49 (0.02–9.30)1.24 (0.30–9.42)2.5
 (Minimum–maximum)(0.05–2.02)(0.80–6.12)(0.02–9.30)(0.30–9.42)
 % above LOD (Freq/n)100% (5/5)100% (5/5)87% (13/15)100% (15/15)
Weekly hookah smokers
 M (±SD)0.29 (±0.41)1.62 (±2.05)0.0020.40 (±0.67)1.08 (±1.56)0.0010.3640.138
 GM (95% CI)0.11 (0.05–0.23)0.60 (0.26–1.36)5.50.17 (0.10–0.31)0.55 (0.35–0.87)3.2
 Median (5–95 percentile)0.18 (0.02–1.29)0.48 (0.03–5.81)2.70.19 (0.02–1.33)0.52 (0.13–4.38)2.7
 (Minimum–maximum)(0.02–1.58)(0.02–6.30)(0.02–3.34)(0.11–7.10)
 % above LOD (Freq/n)55% (11/20)95% (19/20)81% (21/26)92% (24/26)
Occasional hookah smokers
 M (±SD)0.51 (±0.68)1.26 (±1.92)0.0030.62 (±0.59)0.25 (±0.20)0.1390.4360.006
 GM (95% CI)0.23 (0.14–0.39)0.51 (0.28–0.92)2.20.34 (0.13–0.93)0.17 (0.08–0.38)0.5
 Median (5–95 percentile)0.21 (0.02–1.62)0.91 (0.03–5.82)4.30.51 (0.06–1.68)0.19 (0.02–0.62)0.4
 (Minimum–maximum)(0.02–3.24)(0.02–9.05)(0.06–1.68)(0.02–0.62)
 % above LOD (Freq/n)89% (25/28)93% (27/29)100% (9/9)89% (8/9)
Non-smokers (n = 103)
 M (±SD)0.19 (±0.46)0.38 (±0.82)0.0550.37 (±0.59)0.36 (±0.62)0.9330.0510.172
 GM (95% CI)0.06 (0.04–0.09)0.09 (0.06–0.15)1.50.11 (0.07–0.19)0.12 (0.07–0.20)1.1
 Median (5–95 percentile)0.05 (0.02–0.64)0.13 (0.02–1.26)2.60.14 (0.02–1.81)0.16 (0.02–1.49)1.1
 (Minimum–maximum)(0.02–3.16)(0.02–4.77)(0.02–2.89)(0.02–3.84)
 % above LOD (Freq/n)46% (24/52)56% (29/52)59% (29/49)64% (32/50)
PkPkPLPkPkPL
 Daily vs. weekly0.2770.0890.1350.0260.0160.705
 Daily vs. occasional0.8020.0760.0310.571<0.0010.006
 Daily vs. non-smoker0.0340.0010.0010.011<0.0010.014
 Weekly vs. occasional0.1320.8230.2280.2130.0210.002
 Weekly vs. non-smoker0.105<0.0010.0010.361<0.0010.007
 Occasional vs. non-smoker<0.001<0.0010.0860.0800.6430.201
  • aSPMA = S-Phenylmercapturic acid, a metabolite of benzene, in pmol/mL.

  • bRatio = ratio of post to pre hookah event SPMA GMs and medians.

  • cP Hookah lounge: pre vs. post event; P Home: pre vs. post event.

  • c,dP values were derived from Wilcoxon signed-rank tests; two-tailed α level P < 0.05.

  • eP pre event: hookah lounge vs. home.

  • fP change in SPMA hookah lounge vs. home.

    e,f,k,LP values were derived from Mann–Whitney U tests; two-tailed α level P < 0.05.

  • gM (±SD) = arithmetic mean and SD.

  • hGM (95% CI) = geometric mean and 95% confidence interval. All SPMA values and percentages are rounded up.

  • i% above LOD = percentage of urine samples above the limit of detection: SPMA LOD = 0.03 pmol/mL.

  • jFreq/n = frequency of samples with levels above the LOD/n size of samples per group; nondetectable values of SPMA were replaced with (LOD/2 = 0.015 pmol/mL).

  • kP SPMA levels by smoking frequency status.

  • LP pre to post event change in SPMA levels by smoking frequency status; P significant levels are shown in bold.