Table 5 Covariates of CYP1A2 activity based on maximum R and stepwise regression: premenopausal women

Current smoker?

No (n = 121)

5.35 (4.76–6.03)¹

19.48

<0.0001

Yes (n = 21)

7.69 (6.41–9.23)

SHBG²

0.07 (0.02)

14.21

0.0002

5.23 (4.39–6.22)

6.33 (5.34–7.50)

7.25 (6.11–8.60)

7.06 (6.08–8.21)

0.0004

Total cholesterol (mmol/day)³

-0.77 (0.21)

14.02

0.0003

7.02 (5.75–8.58)

6.39 (5.42–7.54)

6.40 (5.42–7.55)

5.55 (4.66–6.60)

0.04

Insulin (pmol/l)³

0.21 (0.08)

7.24

0.008

5.66 (4.82–6.65)

5.69 (4.75–6.82)

6.63 (5.64–7.78)

7.61 (6.41–9.05)

0.001

Caffeine intake (mg/day)²

0.019 (0.007)

7.59

0.007

5.70 (4.82–6.75)

6.28 (5.31–7.42)

6.59 (5.51–7.87)

7.17 (6.15–8.35)

0.006

Age (years)

0.014 (0.006)

5.00

0.03

5.84 (4.93–6.93)

6.11 (5.11–7.30)

6.63 (5.71–7.70)

6.98 (5.84–8.34)

0.02

Triglycerides (mmol/day)³

0.14 (0.07)

4.18

0.04

6.12 (5.14–7.28)

6.27 (5.35–7.36)

6.34 (5.38–7.48)

7.13 (5.81–8.74)

0.24

BMI

-0.37 (0.18)

4.51

0.04

7.65 (6.49–9.02)

6.25 (5.38–7.27)

5.91 (5.00–6.98)

6.53 (5.41–7.89)

0.01

HDL (mmol/day)

-0.20 (0.14)

2.20

0.14

7.23 (6.11–8.56)

6.20 (5.29–7.27)

6.82 (5.80–8.03)

5.63 (4.77–6.65)

0.05