Gender Differences in Sleep's Impact on Blood Pressure Explored

Summary: Researchers are examining how sleep characteristics, such as time spent in deep sleep and frequency of nighttime awakenings, influence blood pressure in men and women. The findings suggest that women who spend more time in deep sleep tend to have lower blood pressure, while men who wake up more often during the night are more likely to have higher blood pressure. These results highlight the potential gender-specific benefits of certain sleep stages for heart health and pave the way for further research to explore the underlying mechanisms and possible therapeutic strategies.

Key Takeaways:

Gender Differences in Sleep and Blood Pressure: Women who spend more time in deep sleep are associated with lower blood pressure, whereas men who wake up more frequently during the night have higher blood pressure, demonstrating distinct impacts of sleep characteristics by gender.
Deep Sleep’s Role in Women’s Heart Health: The study suggests deep sleep may be particularly beneficial for women’s cardiovascular health, potentially guiding future therapies to enhance this sleep stage.
Future Research Directions: The findings underscore the need for more studies to determine if modifying sleep stages or patterns can directly improve blood pressure and overall heart health in both men and women.

You may have heard sleep described as something of a magic pill for the body. With the right amount, timing, and quality, it can work wonders—strengthen the immune system, improve blood sugar, even decrease the risk of heart attacks and strokes.

Sleep differences have been reported for some time in men and women, but it is not well known whether the characteristics of sleep serve different functions in one gender over the other, especially as it relates to the heart. New research seeks answers.

Numerous studies over decades have documented a critical role for sleep in heart health. For example, sleep duration is pivotal in maintaining healthy blood pressure levels. In 2018, a National Heart, Lung, and Blood Institute-funded study found that people who slept less than seven hours had higher blood pressure when compared to those who slept at least seven hours.

Exploring Sleep Stages and Cardiovascular Risk

“Sleep is critical for overall health and well-being,” says Marishka Brown, PhD, director of the National Center on Sleep Disorders Research at the National Heart, Lung, and Blood Institute, in a release. “Research is beginning to uncover how sleep characteristics, like time spent in each sleep stage or how often one wakes up at night, contributes to blood pressure control, and also how sex and gender may impact these outcomes, but we still have unanswered questions.”

Kristen Knutson, PhD associate professor of neurology and preventive medicine at Northwestern University Feinberg School of Medicine and National Heart, Lung, and Blood Institute-funded researcher, is trying to help fill these gaps. “We know sleep matters greatly for heart health,” she says in a release. “So, we’re trying to find out more about this connection and also how sleep might be linked to the gender differences we see in cardiovascular disease.” High blood pressure, for example, is more strongly associated with heart attack in women than it is in men.

Knutson and her team recently published a study that focused on the different stages and characteristics of sleep, as opposed to sleep duration, to see what factors, if any, are associated with blood pressure levels in men and women.

Deep Sleep Benefits Women, Night Awakenings Impact Men

The study found that the women who spent more time in deep sleep—the third and deepest stage of sleep—tended to have lower blood pressure than women who spent less time in this stage. In men, however, no comparable association between blood pressure and deep sleep was seen. At the same time, men who wake up more often after falling asleep had higher blood pressure than men who woke up less often, while in women, waking up after falling asleep did not have a comparable association with blood pressure.

The researchers used at-home sleep studies for more than 1,100 adults in Brazil who did not have moderate to severe sleep apnea—conditions already known to be linked with high blood pressure, though some participants did have mild sleep apnea. Study participants ranged from ages 18 to 91, and 64% identified as women.

The researchers recorded one night of sleep using polysomnography. The following morning, they took blood pressure readings and fasting blood samples to measure lipid levels—specifically, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides. They analyzed the data together and also by gender.

Implications and Future Research Directions

They found differences in blood pressure when comparing the sleep experiences of just the men and just the women, and also when comparing the men and women.

But the findings, while intriguing, are only a starting point for other avenues of research, Knutson says in a release. For example, the researchers did not take multiple timepoints for sleep and blood pressure, so they could not determine if someone got more or less sleep at any stage, or waking up during the night, actually made blood pressure levels better or worse. Future studies would need to test whether changing these sleep stages in men and women leads to changes in blood pressure levels.

Still, Knutson says the results of the current study could guide future work that explores the underlying mechanisms that may be making deep sleep in particular more valuable for women. This, in turn, could lead to novel therapies that enhance this sleep stage in women. She also explained that experimental studies could test whether certain modifications in sleep habits can lead to improvements in blood pressure and, ultimately, heart health.

“This study suggests that a better understanding of how specific sleep characteristics could lead to more targeted strategies to help both women and men protect their hearts,” says Brown in a release. “Studies such as this continue to reiterate the critical nature of sleep in the clinical management of hypertension.”