Urinary nicotine metabolites (μmol/24 h) in smokers who consumed watercressa
| Urinary metabolite | μmol/24 h (mean ± SD) | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Period 1 (baseline)b | Period 2 (watercress consumption)b | Period 3 (follow-up 1)c | Period 4 (follow-up 2)c | P, Period 1 vs. period 2 | |||||
| Nicotine | 7.24 ± 3.41 | 6.56 ± 5.87 | 8.17 ± 7.23 | 5.91 ± 3.21 | 0.62 | ||||
| Nicotine-Gluc | 1.72 ± 1.03 | 2.48 ± 2.00 | 1.44 ± 0.753 | 1.21 ± 0.947 | 0.13 | ||||
| Cotinine | 10.3 ± 4.67 | 10.0 ± 4.40 | 9.55 ± 7.00 | 7.65 ± 4.01 | 0.76 | ||||
| Cotinine-Gluc | 7.67 ± 5.76 | 9.60 ± 7.36 | 7.24 ± 4.39 | 7.58 ± 5.28 | 0.031 | ||||
| trans-3′-Hydroxycotinine | 34.7 ± 21.8 | 37.5 ± 17.1 | 30.9 ± 21.9 | 28.0 ± 15.4 | 0.50 | ||||
| trans-3′-Hydroxycotinine-Gluc | 8.29 ± 7.16 | 11.0 ± 7.19 | 7.93 ± 7.23 | 7.38 ± 5.78 | 0.0043 | ||||
| Keto acid | 1.49 ± 1.00 | 1.66 ± 0.844 | NAd | NA | 0.31 | ||||
| Hydroxy acid | 6.84 ± 3.86 | 7.22 ± 3.85 | NA | NA | 0.74 | ||||
a Twelve smokers maintained constant smoking habits and avoided cruciferous vegetables except during the watercress consumption period. Twenty-four-h urine samples were collected and analyzed for nicotine metabolites (see Fig. 2<$REFLINK> ).
b For each smoker (n = 12), we determined the mean value of each metabolite (except keto acid and hydroxy acid) for the 3 days of the period. Then, the mean ± SD for the 12 smokers was calculated. Values for keto acid and hydroxy acid were from a single day in the period.
c The same as Footnote b except n = 10 smokers.
d NA, not analyzed.