Table 2.
Urinary nicotine and nicotine metabolites as a molar percentage of TNE stratified by UGT2B10 phenotypea
| Analytes | Study 1
|
Study 2
|
||||
|---|---|---|---|---|---|---|
| UGT2B10 Null (n = 60) |
UGT2B10 Non-null (n = 735) |
P value | UGT2B10 Null (n = 37) |
UGT2B10 Non-null (n = 614) |
P value | |
|
|
|
|||||
| Total Nicotineb | 20 (21.1) | 18.5 (11.5) | 0.571 | 14.7 (12.6) | 15.2 (10.9) | 0.796 |
| Nicotine-N-oxideb | 8.2 (4.9) | 7 (4.4) | 0.067 | 7.7 (5.4) | 5.6 (4.2) | 0.028 |
| Cotinineb | 21.5 (9.7) | 13.1 (5.9) | < 0.001 | 20.6 (7.9) | 11.4 (5.3) | < 0.001 |
| Cotinine glucuronideb | ND | 17.2 (8.4) | < 0.001 | ND | 16 (7.1) | < 0.001 |
| Total 3-hydroxycotinineb | 52.2 (17.9) | 44.3 (16.2) | 0.002 | 58.3 (19.9) | 51.7 (16.3) | 0.057 |
| C-oxidation (sum of total cotinine and total 3-hydroxycotinine)b | 73.4 (16.4) | 74.5 (13.7) | 0.601 | 77.7 (15.8) | 79.2 (13.6) | 0.582 |
| TNEb (nmol/ml) | 56.6 (36.6) | 57.1 (39.8) | 0.929 | 57.4 (39.1) | 78.8 (53.9) | 0.003 |
| TNEc (nmol/ml) | 45.1 (39.6) | 45.7 (44.8) | 0.895 | 47.3 (45.5) | 62.7 (56.8) | 0.012 |
| Number of African Americans (%) | 45 (75%) | 248 (33.7%) | < 0.001 | 31 (83.8%) | 169 (27.5%) | < 0.001 |
a
UGT2B10 phenotype was characterized by cotinine glucuronidation, smokers with no quantifiable cotinine glucuronide are defined as null, values for each analyte are the percentage of TNE.
b
mean (SD), ND, not detected (nmol total cotinine/nmol cotinine <1.1, based on a coefficient of variation of 9.6%)
c
geometric mean (interquartile range)