Hot Flashes Signal Heart Risk

A new study has determined that women who endure regular hot flashes between the ages of 40 and 53 might be more prone to insufficient vascular function. The likelihood of poor vascular function is independent of cardiovascular disease risk factors as well as estradiol levels. The study's findings were recently published in Menopause. The study was funded by the University of Pittsburgh Clinical and Translational Science Institute, the National Heart Lung and Blood Institute and the National Institutes of Health.

Study Details

Researchers studied data from 272 women between age 40 and 69. Each study participant was a non-smoker. These women were in the late perimenopausal stage of 2-12 months amenorrhea or the postmenopausal stage. The study did not include pregnant women or those with cardiovascular disease, hysterectomy, neoplasia, kidney failure, Raynaud's phenomenon, Parkinson's disease, seizures and/or bilateral oophorectomy. Potential study participants who recently used reproductive hormone agents, insulin, reuptake inhibitors and/or cardiovascular drugs were not included. The average age of the typical study participant was 54. The average study participant was also characterized by the following features: Caucasian, college educated, postmenopausal and a fairly favorable cardiovascular disease risk factor profile.

Each participant underwent a physical exam and brachial artery flow-mediated dilation (FMD) to determine endothelial function. The participants also underwent carotid artery ultrasound, ambulatory flash monitoring and a blood draw. The study also made use of a wrist actigraph for three days, an electronic hot flash diary for three days and a physiologic hot flash monitor for 24 hours. Menopause status was determined according to menstrual bleeding patterns. Estradiol levels, triglycerides, insulin, total cholesterol, high-density lipoprotein cholesterol, interleukin 6 and C-reactive protein were evaluated.

Study Findings

Younger women between the ages of 40 and 53 who endured hot flashes had a low FMD compared to those who did not endure hot flashes. This lower FMD stayed true even after controlling for additional cardiovascular disease risk factors. It is an indication of comparably poor endothelial function.

The research team also found that a higher frequency of physiologically monitored hot flashes was linked to poor FMD. The study's authors noted that the FMD of the youngest women who endured hot flashes was similar to that of women in the oldest tertile analyzed in the study (54-60 years-old). A link between hot flashes and FMD could not be established amongst these older women.

In terms of the role of E2, the research team determined that levels were not significantly linked with FMD and did not decrease the association between hot flashes and FMD in the study's young women (40-53 years-old). The study's findings indicate that menopausal hot flashes are linked to inferior endothelial function regardless of E2. However, this finding is strictly limited to young women.

The research team noted that prior studies have linked an association between early hot flashes and a heightened cardiovascular disease risk. The researchers believe the different cardiovascular risk disease markers might indicate different temporal relations to hot flashes that progress from endothelial dysfunction to atherosclerosis all the way to clinical cardiovascular disease events. However, the pathophysiologic mechanism underlying this association is not crystal clear.

In the end, the study's findings point to the possible value of considering the role of hormones as well as hot flashes in cardiovascular health changes that take place early on during the menopause transition. The findings also lend credence to the role endothelium might play in the physiology of hot flashes that take place in comparably young women.

Study Limitations

The research team acknowledges various study limitations including insufficient data from women in the early perimenopausal stage and women in other racial/ethnic groups.

"These findings point to the potential value in considering the role of not only hormones, but also hot flashes, in the cardiovascular changes that occur early in the menopause transition, while also underscoring the potential role that the endothelium may play in the physiology of early hot flashes," stated Dr. Thurston and colleagues.