Table 2.

Comparison of plasma Q10 (in ng/mL) levels between breast cancer cases and controls, a nested case-control study within the SWHS, 1997 to 2006

Plasma CoQ10 concentration, ng/mLCasesControlsP value
All women (340 pairs)
Mean ± SD605.4 ± 241.0619.2 ± 185.40.25a
Median (25th, 75th)560.0 (435.0, 728.0)597.0 (500.0, 714.0)0.16b
All women with cases diagnosed more than 1 y after blood draw (303 pairs)
Mean ± SD603.7 ± 242.8622.9 ± 187.40.12a
Median (25th, 75th)553.0 (434.0, 739.0)597.5 (502.5, 714.5)0.09b
Premenopausal women (171 pairs)
Mean ± SD544.6 ± 223.5554.9 ± 153.00.38a
Median (25th, 75th)508.0 (382.0, 649.0)554.0 (450.5, 644.0)0.13b
Postmenopausal women (169 pairs)
Mean ± SD667.0 ± 243.0684.3 ± 192.90.45a
Median (25th, 75th)621.0 (494.0, 788.0)649.5 (550.0, 789.0)0.55b
  • aPaired test using log-transformed values for cases and the average of 2 matched controls.

  • bPaired Wilcoxon signed rank test for cases and the average of 2 matched controls.