Sex Differences Between Vascular Endothelial Function and Carotid Intima-Media Thickness by Framingham Risk Score

Objectives-To investigate sex differences associated with changes in brachial artery flow-mediated dilatation and carotid intima-media thickness by Framingham Risk Score. Methods-The study included 1083 patients aged 30 to 80 years. According to the Framingham Risk Score, patients were divided into 3 groups: low, mid, and high risk. Traditional cardiovascular risk factors such as age, sex, smoking, diabetes, hypertension, and cholesterol were assessed by Framingham Risk Score, as well as laboratory and vascular parameters, including flow-mediated dilatation and intima-media thickness. Correlations between flow-mediated dilatation, intima-media thickness, and the Framingham Risk Score were analyzed by sex. Results-Compared with women, flow-mediated dilatation in men was significantly lower in the low-risk group (mean +/- SD, 8.31%+/- 2.89% versus 9.76%+/- 3.62%; P < .001) but significantly higher in the mid- and high-risk groups (mid-risk, 7.43%+/- 2.65% versus 6.67%+/- 2.42%; high-risk, 6.41%+/- 2.27% versus 5.78%+/- 2.39%; P < .001). Flow-mediated dilatation decreased-with an increasing Framingham Risk Score in both sexes but especially in women. Although intima-media thickness increased with the Framingham Risk Score in both sexes, there was no significant sex difference between the groups. Univariate analysis showed significant negative correlations between flow-mediated dilatation and the Framingham Risk Score in both sexes (R-men = -0.308; P < .001; R-women = -0.572; P < .001) and flow-mediated dilatation and intima-media thickness (R-men = -0.295; P < .001; R-women = -0.474; P < .001). There was a significant positive correlation between intima-media thickness and the Framingham Risk Score (R-men = -0.571; P < .001; R-women = 0.633; P < .001). Conclusions-A sex difference existed only for flow-mediated dilatation at the same Framingham risk level. Flow-mediated dilatation might be more sensitive than intima-media thickness for detecting sex differences in vascular dysfunction, according to Framingham risk stratification in a Chinese population.