Table 2.
Interindividual variability in CYP1A2 activity in young and elderly healthy subjects.
| PAX/CAF ratio (MR) | Coefficient of variation (%) | Lowest MR | Highest MR | Highest/lowest MR | |
|---|---|---|---|---|---|
| Young subjects | |||||
| Test 1 | 0.56 ± 0.29 | 52.3 | 0.16 | 1.35 | 8.44 |
| Test 2 | 0.51 ± 0.25 | 48.0 | 0.21 | 1.05 | 5.00 |
| Test 3 | 0.49 ± 0.23 | 46.3 | 0.16 | 1.03 | 6.44 |
| Test 4 | 0.51 ± 0.26 | 50.2 | 0.25 | 1.03 | 4.12 |
| Test 5 | 0.55 ± 0.24 | 43.9 | 0.24 | 0.99 | 4.13 |
| Mean±s.d. | 48.1 ± 2.9* | 5.62 ± 1.64 | |||
| Elderly subjects | |||||
| Test 1 | 0.33 ± 0.12 | 37.9 | 0.12 | 0.52 | 4.33 |
| Test 2 | 0.32 ± 0.13 | 40.4 | 0.10 | 0.55 | 5.50 |
| Test 3 | 0.36 ± 0.16 | 44.0 | 0.10 | 0.62 | 6.20 |
| Test 4 | 0.35 ± 0.17 | 48.6 | 0.10 | 0.70 | 7.00 |
| Test 5 | 0.35 ± 0.15 | 42.6 | 0.09 | 0.62 | 6.89 |
| Mean±s.d. | 42.7 ± 3.6* | 5.98 ± 0.99 | |||
Data are expressed as mean value±s.d. The metabolic ratio is the mean value of five consecutive measures over a 12 week period. The lowest and the highest measure at each test are presented with the ratio.
*
Interindividual CV was similar in young and elderly subjects.