Table 1.
Fold changes for the metabolites involved in caffeine metabolism among SMK, MSC, and NTC.
| Biochemical name | Fold changes |
||||||||
|---|---|---|---|---|---|---|---|---|---|
| Plasma |
Urine |
Saliva |
|||||||
| MSC/NTC | SMK/NTC | SMK/MSC | MSC/NTC | SMK/NTC | SMK/MSC | MSC/NTC | SMK/NTC | SMK/MSC | |
| Caffeine | 1.79 | 0.52 | 0.29 | 1.47 | 1.35 | 0.92 | 1.55 | 0.42 | 0.27 |
| Paraxanthine | 1.19 | 0.82 | 0.69 | 1.09 | 1.48 | 1.37 | 1.15 | 0.86 | 0.74 |
| Theobromine | 1.06 | 0.43 | 0.41 | 1.05 | 0.74 | 0.70 | 0.79 | 0.44 | 0.56 |
| 1-methylurate | ND | ND | ND | 1.02 | 1.34 | 1.32 | ND | ND | ND |
| 1,3-dimethylurate | ND | ND | ND | 0.97 | 1.71 | 1.75 | ND | ND | ND |
| 1,7-dimethylurate | 1.24 | 0.89 | 0.70 | 1.19 | 1.26 | 1.06 | 1.1 | 1.05 | 0.95 |
| 3,7-dimethylurate | ND | ND | ND | 0.88 | 0.62 | 0.71 | ND | ND | ND |
| 1,3,7-trimethylurate | ND | ND | ND | 1.13 | 1.11 | 0.98 | ND | ND | ND |
| 1-methylxanthine | 1.03 | 1.23 | 1.20 | 1.03 | 1.64 | 1.59 | ND | ND | ND |
| 3-methylxanthine | 0.90 | 0.81 | 0.90 | 0.98 | 0.88 | 0.89 | ND | ND | ND |
| 7-methylxanthine | 0.91 | 0.81 | 0.88 | 0.90 | 0.94 | 1.05 | 0.69 | 0.91 | 1.32 |
| 5-acetylamino-6-amino-3-methyluracil | ND | ND | ND | 0.97 | 1.93 | 2.00 | ND | ND | ND |
| 5-acetylamino-6-formylamino-3-methyluracil | ND | ND | ND | 0.94 | 2.07 | 2.20 | ND | ND | ND |
| Theophylline | 1.24 | 0.91 | 0.74 | ND | ND | ND | 1.23 | 0.89 | 0.72 |
The statistical significance P < .05 is highlighted by shaded and bolded “fold change” values; bolded fold of change values indicate .05 < P < .1. Abbreviations: MSC, moist snuff consumers; ND, not detected; NTC, non-tobacco consumers; SMK, cigarette smokers.