Dietary intake of isoflavones is associated with a lower prevalence of subclinical cardiovascular disease in postmenopausal women: cross-sectional study.

Abstract

Menopause has been associated with an increased risk of cardiovascular disease. It has been shown that isoflavones protect vascular endothelial cells against induced oxidative stress injury. Therefore, the present study aimed to investigate the association between the dietary intake of isoflavones and the presence of subclinical cardiovascular disease (CVD) in postmenopausal women. Ninety-six postmenopausal women [mean (SD) age 55.2(4.9)years, body mass index (BMI) 27.2(4.6)kgm-2 ] completed the study protocol. Habitual physical activity was assessed using a digital pedometer, resting metabolic rate was measured by indirect calorimetry and dietary intake was assessed via a validated food frequency questionnaire. Subclinical CVD was defined as carotid artery intima-media thickness (C-IMT) >0.9mm and/or the presence of one or more atherosclerotic plaques in any of the studied segments. Mean (SD) C-IMT was 0.74(0.2)mm, 25% of participants were found to have atherosclerotic plaques and the prevalence of subclinical CVD was 35%. Participants with subclinical CVD were more likely to consume less selenium, magnesium, folate and isoflavones, even after adjusting for total energy intake. A multivariate-adjusted regression model showed that a BMI >27kgm-2 was associated with 90% higher risk of having ≥1 plaque and/or C-IMT >0.9mm (P=0.017). Higher oestradiol levels (P=0.004) and isoflavone intake (P=0.021) were independently associated with a lower risk of having subclinical CVD. In the present study, we observed that a higher isoflavone dietary intake was associated with a lower risk of subclinical CVD in postmenopausal women, independent of BMI and endogenous oestradiol levels.