The Association between Plasma Concentration of Phytoestrogens and Hypertension within the Korean Multicenter Cancer Cohort

In order to examine the association between plasma phytoestrogen concentration (genistein, daidzein, equol and enterolactone) and hypertension, we conducted a nested case-control study for 229 hypertension cases including 112 prehypertension and 159 healthy controls derived from the Korean Multi-center Cancer Cohort (KMCC). The concentration of plasma phytoestrogens was measured using time-resolved fluoroimmunoassay. We assessed the association between plasma phytoestrogens and hypertension using logistic regression models using odds ratio (OR) and 95% confidence interval (95%CI). The highest tertile of plasma equol and enterolactone concentration exhibited a significantly decreased risk of hypertension (equol, OR = 0.34, 95%CI 0.20-0.57; enterolactone, OR = 0.32, 95%CI 0.18-0.57), compared with the lowest tertile. Equol and enterolactone showed reduced ORs for prehypertension (the highest tertile relative to the lowest tertile, OR = 0.50, 95%CI 0.26-0.96; OR = 0.38, 95%CI 0.19-0.75, respectively) and hypertension (OR = 0.42, 95%CI 0.22-0.81; OR = 0.28, 95%CI 0.14-0.54, respectively). There was a stronger association in hypertension (the highest tertile relative to the lowest tertile in obesity vs. non-obesity; equol, OR = 0.06 vs. 0.63; enterolactone, OR = 0.07 vs. 0.46; both p-heterogeneity < 0.01). This study suggests that equol and enterolactone may contribute to prevent primarily prehypertension and hypertension, and control cardiovascular disease (CVD) based on the continuum of hypertension and CVD. Further study to assess hypertension risk based on useful biomarkers, including phytoestrogens, may contribute to primary prevention of hypertension.