Abstract 19916: Effect of Whole Soy and Purified Daidzein on Ambulatory Blood Pressure and Endothelial Function-A Six-month Randomized Controlled Trial among Chinese Equol-producing Postmenopausal Women with Prehypertension or Untreated Early Hypertension
Objective: Although observational studies suggest soy foods or isoflavones are cardio-protective, clinical trials on whole soy or isoflavone daidzein (one major isoflavone and also the precursor of equol) on blood pressure (BP) and endothelial function are few and have not been specifically conducted among equol producers,a population most likely to benefit from soy treatment.
Methods: We performed a 6-month double-blind, randomized, placebo-controlled trial to examine the effect of whole soy (soy flour) or purified daidzein on BP, endothelial function and other cardiovascular risk factors in 270 prehypertensive or untreated hypertensive postmenopausal women verified to be equol-producers. Eligible women were randomized to either one of the three treatment groups: 40g soy flour (whole soy group), 40g low-fat milk powder +63mg daidzein (daidzein group) or 40g low-fat milk powder (placebo group) daily, each given as a solid beverage for 6 months. The primary outcome measures were 24h ambulatory BP and endothelial function assessed by ultrasound determined brachial flow mediated dilation.
Results: Total 253 subjects completed the study according to the protocol. Urinary isoflavones indicated a good compliance to the interventions. Intention to treat and per-protocol analysis indicated that there was no significant difference in the 6-month changes or % changes in parameters of ambulatory BP and brachial flow mediated dilation among the 3 treatment groups. A further subgroup analysis among hypertensive women (n=138) did not alter the conclusions.
Conclusion: Whole soy and purified daidzein had no significant effect on BP and vascular function among equol producing postmenopausal women with prehypertension or untreated hypertension.
Author Disclosures: Z. Liu: None. S. Ho: None. J. Woo: None.
- © 2014 by American Heart Association, Inc.