Hot flashes are experienced by most midlife women. Emerging data indicate that they may be associated with endothelial dysfunction. No studies have tested whether hot flashes are associated with endothelial function using physiologic measures of hot flashes. We tested whether physiologically-assessed hot flashes were associated with poorer endothelial function. We also considered whether age modified associations.
272 nonsmoking women reporting either daily hot flashes or no hot flashes, aged 40-60, and free of clinical cardiovascular disease underwent ambulatory physiologic hot flash and diary hot flash monitoring; a blood draw; and ultrasound measurement of brachial artery flow mediated dilation to assess endothelial function. Associations between hot flashes and flow mediated dilation were tested in linear regression models controlling for lumen diameter, demographics, cardiovascular disease risk factors, and estradiol.
In multivariable models incorporating cardiovascular disease risk factors, significant interactions by age (p<.05) indicated that among the younger tertile of women in the sample (ages 40-53), the presence of hot flashes [beta(standard error)=-2.07 (.79), p=.01], and more frequent physiologic hot flashes were associated with lower flow mediated dilation [for each hot flash: beta(standard error)=-.10(.05), p=.03, multivariable]. Associations were not accounted for by estradiol. Associations were not observed among the older women (ages 54-60) or for prospective-reported hot flash frequency, severity, or bother. Among the younger women, hot flashes explained more variance in flow mediated dilation than standard cardiovascular disease risk factors or estradiol.
Among younger midlife women, frequent hot flashes were associated with poorer endothelial function and may provide information about women's vascular status beyond cardiovascular disease risk factors and estradiol.