How menopause symptoms may increase risk of heart disease

Vasomotor symptoms, including hot flashes and night sweats, are prevalent in middle-aged women.

A new study published in the journal Menopause reports that socioeconomic factors and a history of depression or migraine in early adulthood may increase the risk of vasomotor symptoms later in life.

In addition, another study, also published in the journal Menopause by the same research team, shows that the combination of vasomotor symptoms and migraine in middle age may increase the risk of cardiovascular disease later in life. The researchers reported that this association persisted after accounting for other cardiovascular disease risk factors.

Although migraine and vasomotor symptoms are individually associated with cardiovascular risk, the new study is one of the first to examine their combined effects on cardiovascular disease.

Dr. Cheng-Han Chen, an interventional cardiologist and medical director of the structural heart program at Memorial Care Saddleback Medical Center in California, who was not involved in the study, said:

"This population-based study suggests that the combination of migraine and vasomotor symptoms may serve as an early indication of a population that could benefit from more intensive intervention and risk factor modification to reduce future risk. Further research could potentially investigate whether more aggressive management of cardiovascular risk factors in this particular population would lead to better health outcomes."

How do menopause and migraine symptoms affect heart health?

Hot flashes and night sweats, called vasomotor symptoms, are common in middle-aged women, affecting nearly 70% of this age group. These symptoms are usually experienced during menopause.

Notably, these vasomotor symptoms tend to be severe or very frequent in about one-third of ill women, negatively affecting their quality of life. Despite the high prevalence of vasomotor symptoms, the risk factors for vasomotor symptoms are poorly understood.

Although vasomotor symptoms are pronounced before and during menopause, factors that influence susceptibility to vasomotor symptoms may occur at an earlier age. In one of two studies published in the journal Menopause, researchers examined risk factors for vasomotor symptoms that may be present in early adulthood.

In addition to their impact on quality of life, studies have shown that vasomotor symptoms are associated with an increased risk of cardiovascular disease. Researchers have also observed a link between migraine and vasomotor symptoms.

Moreover, migraine is also associated with an increased risk of cardiovascular disease. However, it is unknown whether the combination of migraine and a history of vasomotor symptoms can increase the risk of cardiovascular disease.

In addition, it is unclear whether vasomotor symptoms can increase cardiovascular risk given known risk factors such as blood pressure, blood glucose and lipid levels, and smoking. Thus, another study examined the effect of vasomotor symptoms and migraine on cardiovascular risk.

The CARDIA study on cardiovascular disease risk factors in women

Both studies included more than 1,900 women who participated in the Coronary Artery Risk Development in Young Adults (CARDIA Trusted Source) study. This long-term study is designed to assess factors in young adulthood that may increase the risk of cardiovascular disease later in life.

Participants in the CARDIA study were between 18 and 30 years of age at the time of inclusion. Participants were assessed for cardiovascular risk factors at enrollment and then every five years thereafter. The last data collection occurred 35 years after enrollment, when participants were about 60 years old.

The study also collected data on vasomotor symptoms from a visit 15 years after inclusion, when participants were in their early 40s. Data on vasomotor symptoms were then collected every five years.

Researchers determined the presence and severity of vasomotor symptoms based on participants' feelings of hot flashes or night sweats during the three-month period before each assessment. Based on changes in the severity of these symptoms over time, the researchers divided participants into groups that had minimal, increasing, or persistent vasomotor symptoms.

A characteristic feature of these two studies was that, unlike previous studies, they included women undergoing gynecologic procedures or receiving hormone therapy.

How vasomotor symptoms affect cardiovascular risk

In one study, researchers examined the association between the presence of a history of vasomotor symptoms and migraine, either alone or together, with the occurrence of cardiovascular events 15 years after the start of follow-up.

Cardiovascular events accounted for in the study included nonfatal and fatal cardiac events, including myocardial infarctions, heart failure, and strokes. To account for other cardiovascular risk factors, the researchers measured blood pressure, blood cholesterol and glucose levels, body mass index, and tobacco use at 15 years after study entry.

Analysis was adjusted for factors such as age, race, and reproductive factors including gynecologic surgery, use of oral contraceptives, or sex hormone therapy.

Only women who had a history of both migraine and persistent vasomotor symptoms were at twice the risk of cardiovascular events compared with other participants without a history of both conditions. In contrast to previous studies, having either persistent vasomotor symptoms or migraine did not independently increase the likelihood of cardiovascular events.

Additional analyses showed that the inclusion of cardiovascular risk factors, such as smoking and blood glucose and cholesterol levels, attenuated the association between the combination of persistent vasomotor symptoms and migraine and the risk of cardiovascular events. In other words, the presence of both persistent vasomotor symptoms in combination with other risk factors may have increased the risk of cardiovascular events.

Thus, lifestyle changes such as smoking cessation could reduce the overall risk of cardiac events associated with vasomotor symptoms and migraine.

Risk factors for vasomotor symptoms

Given the impact of vasomotor symptoms on women's quality of life, the researchers examined factors that predispose women to persistent vasomotor symptoms in a second study. Specifically, they analyzed factors that might predispose women to persistent symptoms versus infrequent symptoms.

The researchers found that black adults, as well as people who smoked, had less than a high school education, or had symptoms of migraine or depression at baseline or had a hysterectomy 15 years after entry, had an increased risk of persistent vasomotor symptoms. Also, black adults and those with low BMI at baseline showed an association with an increase in vasomotor symptoms with age.

The researchers then conducted an additional analysis, categorizing the women based on whether they experienced persistent interfering vasomotor symptoms or non-interfering symptoms. Women experiencing interfering symptoms shared risk factors similar to those with persistent symptoms.

In addition, the researchers found an association between interfering symptoms and thyroid disease. Although further research is needed, these results suggest that screening for and treatment of thyroid disease could potentially reduce the risk of vasomotor symptoms later in life.

Strengths and weaknesses of the study

Strengths of the two studies included their prospective design, which involved tracking participants over a long period of time. Moreover, both studies took into account several variables, including the use of hormone therapy and gynecologic surgeries, which may have influenced the analysis.

However, both studies were correlational and therefore did not establish a causal relationship. The methods used to classify participants according to the severity of their vasomotor symptoms were also different from those used in the other studies. Thus, using a different classification system for vasomotor symptoms could have led to different results.

Finally, both studies used self-reported migraine and vasomotor symptoms, making these data subject to misrepresentation.