While research shows that age, gender and body mass index (BMI) play important roles in cardiovascular disease risk, it's not clear why the risk spikes when women are in menopause.
‘Menopause does not change blood pressure but can increase one's cardiovascular disease risk, as seen in changes in harmonic components of the radial pulse.’
Researchers in this study used radial pulse waves, measuring the beat of the heart through the artery at the base of the wrist. Checking radial pulse waves is easy, non-invasive and can offer more data than just looking at systolic or diastolic blood pressures, the researchers said.
They studied 327 premenopausal and postmenopausal women with no history of heart disease, tracking the women's systolic and diastolic blood pressure measurements, as well as 12-second continuous radial pulse data.
"Through mathematical models, we converted the pressure wave of the radial pulse into frequency waves. Each frequency wave was assigned a corresponding harmonic amplitude classification from C1 to C5 which provides different information than pulse rate or blood pressure," said Chi-Wei Chang, Ph.D., the study lead author and director of research and development at the Mii-Ann Medical Research Center in Taipei, Taiwan.
"For example, a violin and clarinet can play the same note but sound different because of the harmonic components of these instruments' overtones," Chang said. "Two people can have a heart rate of 75 beats per minute, but their harmonic amplitudes can vary dramatically. Analyzing the differences between these harmonic components reveals more individualized information about a person's circulatory system."
The researchers found radial pulse wave information reflected changes during menopause that were not evident in systolic or diastolic blood pressure measurements. Specifically, the first and third harmonics -- C1 and C3 -- were impacted. C1 is related to heart attack and heart failure, according to Chang.
They also found:
BMI is the largest factor affecting a woman's blood pressure and risk for hypertension.
Age affects only systolic blood pressure.
Additionally, according to this study, the C1 and C3 harmonics in radial pulse waves may shed light on hormonal changes during menopause that indicate the progression of atherosclerosis, but more work is needed to know for sure, Chang said. This information can be useful in better understanding a woman's cardiovascular disease risk.
"Healthcare providers can measure a menopausal woman's radial pulse to see if the patient's C1 harmonic is affected. If it is, they can monitor a patient's situation more closely and take action to prevent cardiovascular disease from becoming more severe," Chang said.
One of the limitations of the study is this increase in the amplitude of the first and third harmonics of the radial pulse wave only suggests that menopause increases the risk of heart disease by exacerbating atherosclerosis. More research is needed to demonstrate how and why that occurs, Chang said.