Hot flashes disrupting REM sleep linked to heart disease risk

Hot flashes disrupting REM sleep linked to heart disease risk | Image Credit: © stokkete - © stokkete - stock.adobe.com.

The risk of heart disease is increased among women experiencing nocturnal hot flashes during the second half of the night when REM sleep typically occurs, according to a recent study presented at the 2024 Annual Meeting of The Menopause Society.¹

A sharp decline in women’s hormone levels during the perimenopausal period often leads to the onset of hot flashes and other menopause symptoms. Of symptoms experienced among women transitioning to menopause, nocturnal hot flashes are one of the most common.

During the perimenopausal period, women also experience a significant increase in cardiovascular disease risk, possibly caused by fluctuating hormone levels. Estrogen helps keep the blood vessels open and relaxed, as well as managing cholesterol levels and reducing the risk of plaque buildup in the arteries, but this hormone declines during menopause.

Blood vessels may be vulnerable as estrogen levels decline, and the arteries may be at risk of plague buildup. This increases the risks of heart attack, stroke, and coronary heart disease.

The risk of heart disease is also significantly increased when REM sleep, also known as the deepest sleep when dreams often occur, is disrupted. Data has indicated REM sleep mainly occurring in the second half of the night and thermoregulation being reduced during this time.

Information about heart health among women is vital, as according to Natalie Bello, MD, MPH, FACC, heart disease is the leading cause of death among women.² However, awareness about this fact has decreased among women between 2009 and 2019.

Declines in awareness are greater among younger women and those who are Hispanic or non-Hispanic Black, despite these groups being at an increased risk of heart disease. Approximately 80% of heart disease cases can be prevented by identification and treatment of risk factors, making knowledge of these factors crucial.

Currently, data about whether hot flashes occur more often during the first or second half of the night is lacking.¹ However, this information may be key to understanding the impact on cardiovascular disease risk.

In a recent study, investigators evaluated differences in objectively measured hot flashes in the first vs second half of the night among 60 participants. These participants included healthy, perimenopausal women aged 43 to 54 years without heart disease and not taking hormone therapy or other medications that impact hot flashes.

Objective measuring of hot flashes was performed using sternal skin conductance. Forty-one percent of hot flashes experienced by participants occurred during the first half of the night, while 59% occurred during the second half. This indicates a higher prevalence of hot flashes during the second half of the night, increasing cardiovascular disease risk.

Sarah Witkowski, PhD, MS, BS, whose lab led the study, noted that this data is preliminary and obtained from a small sample. Witkowski also recommended additional research about the association between hot flashes, sleep disruptions, and cardiovascular risk.

Further details will be discussed at the 2024 Annual Meeting of The Menopause Society during the presentation, “Potential implications for cardiovascular disease in perimenopausal people: Investigating differences in nocturnal hot flashes in the first vs. second half of the night."

"The results of this small study are interesting as hot flashes are one of the most common symptoms of menopause," said Stephanie Faubion, MD, MBA, medical director for The Menopause Society. "Further research into the potential association between sleep disruption and an increased risk of developing cardiovascular disease will be important to women and their healthcare professionals."

References

1. Timing of nocturnal hot flashes may affect risk of heart disease for perimenopausal women. The Menopause Society. September 10, 2024. Accessed September 10, 2024. https://menopause.org/press-releases/timing-of-nocturnal-hot-flashes-may-affect-risk-of-heart-disease-for-perimenopausal-women
2. Krewson C. Exploring the intersection of heart health and women's health. Contemporary OB/GYN. February 12, 2024. Accessed September 10, 2024.