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Table 3 CYP1A2 activity and malondialdehyde levels

From: Cytochrome P450 1A2 (CYP1A2) activity, mammographic density, and oxidative stress: a cross-sectional study

     Quartiles of CMR: mean MDA (95% confidence interval)  
  CMR1β (SE) F P Q1 Q2 Q3 Q4 P for trend
Premenopausal (n = 146)3         
   Serum MDA (μmol/l)1 0.15 (0.07) 4.59 0.03 1.37 (1.15–1.63) 1.52 (1.30–1.77) 1.50 (1.28–1.74) 1.62 (1.38–1.91) 0.06
   Serum MDA adjusted for antioxidants (μmol/l)2 0.14 (0.07) 4.23 0.04 1.33 (1.12–1.57) 1.39 (1.19–1.62) 1.47 (1.27–1.71) 1.53 (1.31–1.79) 0.05
   Total urinary MDA (μmol/day)1 0.23 (0.11) 4.24 0.04 2.35 (1.81–3.06) 2.44 (1.92–3.09) 3.06 (2.44–3.84) 2.78 (2.18–3.53) 0.06
   Total urinary MDA adjusted for antioxidants (mol/day) 0.24 (0.11) 4.36 0.04 2.33 (1.78–3.05) 2.37 (1.81–3.09) 2.90 (2.29–3.68) 2.75 (2.14–3.54) 0.08
   dG-MDA (ρ mol/mg DNA)1 -0.13 (0.15) 0.72 0.40 186.8 (126.5–275.9) 160.1 (112.5–227.6) 157.0 (111.6–220.8) 153.6 (106.9–220.6) 0.29
   dG-MDA adjusted for antioxidants (ρ mol/mg DNA) -0.09 (0.16) 0.35 0.55 187.2 (126.0–278.1) 164.7 (115.0–235.7) 143.9 (101.7–203.6) 163.0 (113.0–235.2) 0.35
Postmenopausal (n = 149)4         
   Serum MDA (μmol/l)1 -0.00 (0.09) 0.00 0.99 1.73 (1.45–2.07) 1.63 (1.36–1.95) 1.55 (1.31–1.83) 1.72 (1.49–1.99) 0.86
   Serum MDA adjusted for antioxidants (μmol/l) 0.08 (0.09) 0.73 0.39 1.71 (1.42–2.04) 1.66 (1.38–1.99) 1.62 (1.35–1.94) 1.81 (1.55–2.1 0) 0.52
   Total urinary MDA (μmol/day)1 -0.06 (0.11) 0.31 0.58 4.06 (3.24–5.09) 3.75 (2.97–4.72) 3.77 (3.05–4.65) 3.69 (3.62–3.76) 0.43
   Total urinary MDA adjusted for antioxidants (μmol/day) -0.12 (0.11) 1.11 0.29 4.02 (3.20–5.04) 3.82 (3.03–4.80) 4.08 (3.25–5.11) 3.70 (3.06–4.47) 0.20
   dG-MDA (ρ mol/mg DNA)1 0.16 (0.16) 0.93 0.34 141.2 (101.4–196.6) 135.1 (96.6–188.9) 133.9 (98.2–182.5) 156.8 (119.4–205.9) 0.57
   dG-MDA adjusted for antioxidants (ρ mol/mg DNA) 0.17 (0.17) 0.98 0.32 153.7 (109.3–216.2) 143.9 (101.9–203.2) 147.1 (105.2–205.6) 167.0 (125.4–222.3) 0.56
  1. 1Log transformed. All statistical models are adjusted for age, ethnicity, body mass index (BMI), waist–hip ratio (WHR), and smoking status. 2Models are further adjusted for serum levels of the antioxidants tocopherol, retinal, β-carotene, β-cryptoxanthin, lycopene, and lutein. 3 n = 143 for serum malondialdehyde (MDA) with adjustment for antioxidants; n = 141 for urinary MDA and n = 138 with adjustment for antioxidants; and n = 141 for malondialdehyde–deoxyguanosine (dG-MDA) adducts and n = 139 with adjustment for antioxidants. 4 n = 145 for dG-MDA. CMR, caffeine metabolic ratio.