Table 2.

Distributions of urinary metabolites of nicotine, NNK, and [pyridine-D4]NNK of study subjects by the treatment sequence assignment at the end of smoking adaptation (visit #2), The PEITC Intervention Study 2008–2013

Treatment sequence assignment
Urinary metabolites of nicotine and NNKPEITC-PlaceboPlacebo-PEITCPaTotal
Number of subjects40b4182
[pyridine-D4]NNK cigarettes/day, mean (SD)c21.6 (8.5)20.1 (7.1)0.41920.9 (7.8)
Urinary metabolites, geometric mean (95% CI)
 Total nicotine, ng/mg Cr2,114 (1,670–2,676)3,015 (2,389–3,806)0.0392,530 (2,136–2,997)
 Total cotinine, ng/mg Cr2,839 (2,368–3,402)3,371 (2,819–4,031)0.1903,096 (2,725–3519)
 Total 3′-hydroxycotinine, ng/mg Cr6,638 (5,355–8,227)6,993 (5,657–8,646)0.7366,815 (5,866–7,919)
 Total nicotine equivalents, nmol/mg Cr45.1 (37.6–54.0)58.1 (48.6–69.5)0.05451.2 (45.0–58.3)
 Total 3′-hydroxycotinine:total cotinine ratio2.34 (1.96–2.79)2.07 (1.74–2.47)0.3482.20 (1.94–2.49)
 Total NNAL, pmol/mg Cr0.85 (0.65–1.10)0.94 (0.73–1.22)0.5670.89 (0.75–1.07)
 Free NNAL, pmol/mg Cr0.24 (0.19–0.30)0.29 (0.23–0.36)0.2760.26 (0.22–0.31)
 Total [pyridine-D4]NNAL, pmol/mg Cr0.24 (0.19–0.31)0.26 (0.20–0.33)0.6970.25 (0.21–0.30)
 Free [pyridine-D4]NNAL, pmol/mg Cr0.08 (0.06–0.10)0.09 (0.07–0.11)0.5460.08 (0.07–0.10)
 [pyridine-D4]Hydroxy acid, pmol/mg Cr0.11 (0.09–0.14)0.13 (0.11–0.17)0.2620.12 (0.11–0.14)
 [pyridine-D4]Hydroxy acid:total [pyridine-D4]NNAL ratio0.47 (0.39–0.55)0.52 (0.44–0.62)0.3980.49 (0.44–0.56)
  • aTwo-sided P for the difference between the two treatment assignment groups based on the two-group t test.

  • bOne subject did not provide the 24-hour urine sample at visit 2, and thus was excluded from the analysis.

  • cSix subjects were excluded from analysis due to missing data (1 in PEITC-Placebo and 5 in Placebo-PEITC group).