Table 3.

Relationship between phytoestrogens and plasma sex hormones and SHBG levels

Isoflavones
Equol*
O-DMA
Lignans
β (95% CI)ηp2 (%)Pβ (95% CI)ηp2 (%)Pβ (95% CI)ηp2 (%)Pβ (95% CI)ηp2 (%)P
Estradiol0.010 (−0.008, 0.028)0.10.2670.050 (0.005, 0.094)0.30.0280.035 (0.008, 0.061)0.30.0100.001 (−0.021, 0.023)0.00.946
Estrone0.003 (−0.019, 0.025)0.00.7770.037 (−0.016, 0.090)0.20.1670.002 (−0.031, 0.035)0.00.906−0.021 (−0.047, 0.005)0.20.107
Testosterone0.004 (−0.016, 0.025)0.00.6740.032 (−0.019, 0.082)0.10.219−0.002 (−0.032, 0.028)0.00.912−0.026 (−0.052, −0.001)0.20.042
Androstenedione−0.006 (0.027, 0.016)0.00.6010.028 (−0.022, 0.079)0.10.271-0.001 (−0.032, 0.031)0.00.9610.003 (−0.022, 0.028)0.00.815
SHBG0.011 (−0.004, 0.026)0.10.149−0.016 (−0.053, 0.020)0.00.3790.004 (−0.018, 0.026)0.00.7070.045 (0.027, 0.063)1.2<0.001
Estradiol/SHBG0.000 (−0.023, 0.023)0.00.9910.062 (0.005, 0.119)0.20.0320.032 (−0.002, 0.066)0.20.066−0.043 (−0.072, −0.015)0.50.003
Testosterone/SHBG−0.006 (−0.031, 0.018)0.00.6140.047 (−0.013, 0.108)0.10.124−0.004 (−0.040, 0.033)0.00.848−0.064 (−0.094, −0.034)1.0<0.001
  • NOTE: ANCOVA adjusted for age, BMI, physical activity, time of day at venipuncture, and time interval between last meal and venipuncture. ηp2 is partial η2, which represents the proportion of variance explained by the particular variable after accounting for potential confounders.

  • * Results shown are for the inverse transformation of equol. Hence, where a β coefficient is positive, it indicates a negative association between urinary equol and the particular sex hormone and vice versa.