A study spanning over two decades and six countries links sleeping less than seven hours to an increased risk of hypertension, particularly highlighting a greater susceptibility among females.

Summary: A global analysis of 16 studies involving over a million participants reveals that sleeping fewer than seven hours significantly raises the risk of developing high blood pressure, with the risk intensifying for those who sleep under five hours. This association was notably stronger in females. Despite varied definitions of short sleep across studies, the findings underscore the importance of adequate sleep for heart health. The study calls for further research using more precise sleep measurement methods to explore this link.

Key Takeaways: 

  • Sleeping fewer than seven hours is linked to a 7% increased risk of developing high blood pressure, which rises to 11% for those sleeping under five hours.
  • The association between short sleep duration and hypertension risk is particularly pronounced in females, who face a 7% greater risk compared to males.
  • The research findings will be presented at the American College of Cardiology’s Annual Scientific Session on Sunday, April 7.

Sleeping fewer than seven hours is associated with a higher risk of developing high blood pressure over time—especially for women, according to a study recently presented at the American College of Cardiology’s Annual Scientific Session.

While the association between sleep patterns and high blood pressure has been reported, evidence about the nature of this relationship has been inconsistent, according to researchers. 

The current analysis pools data from 16 studies conducted between January 2000 and May 2023, evaluating hypertension incidence in 1,044,035 people from six countries who did not have a prior history of high blood pressure over a median follow-up of five years (follow-up ranged from 2.4 to 18 years). 

Short sleep duration was significantly associated with a higher risk of developing hypertension after adjusting for demographic and cardiovascular risk factors, including age, sex, education, BMI, blood pressure, smoking status, etc. Furthermore, the association was found to be even stronger for those getting fewer than five hours of sleep.

The Risks of Short Sleep

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“Based on the most updated data, the less you sleep—that is less than seven hours a day—the more likely you will develop high blood pressure in the future,” says Kaveh Hosseini, MD, assistant professor of cardiology at the Tehran Heart Center in Iran and principal investigator of the study, in a release. “We saw a trend between longer sleep durations and a greater occurrence of high blood pressure, but it was not statistically significant. Getting seven to eight hours of sleep, as is recommended by sleep experts, may be the best for your heart too.”

The study found that sleeping fewer than seven hours was associated with a 7% increased risk of developing high blood pressure, which increased to 11% when reported sleep duration was less than five hours. By comparison, diabetes and smoking are known to heighten one’s risk of hypertension by at least 20%, Hosseini says in a release.

While the study did not look at why this might be the case, Hosseini says that disrupted sleep could be to blame. For example, he says lifestyle habits or comorbid conditions such as overeating, alcohol use, nightshift work, certain medication use, anxiety, depression, sleep apnea, or other sleep disorders may be factors.

Researchers were surprised there were no age-based differences in the association between sleep duration and hypertension given that sleep patterns tend to shift with age. The age of the participants ranged from 35.4 years to 60.9 years, and more than half (61%) were female. When compared with men, females who reported less than seven hours of sleep had a 7% greater risk of developing high blood pressure.

Gender Differences and Future Research

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“Getting too little sleep appears to be riskier in females,” Hosseini says in a release. “The difference is statistically significant, though we are not sure it’s clinically significant and should be further studied. What we do see is that lack of good sleep patterns may increase the risk of high blood pressure, which we know can set the stage for heart disease and stroke.”

This study has several limitations, including that sleep duration was based on self-reported questionnaires, so changes in sleep duration over the follow-up period were not assessed. Moreover, there were variations in how short sleep duration was defined between the studies (fewer than five or six hours).

“Further research is required to evaluate the association between sleep duration and high blood pressure using more accurate methods like polysomnography, a method for evaluating sleep quality more precisely,” Hosseini says in a release. “Moreover, the variations in reference sleep duration underline the need for standardized definition in sleep research to enhance the comparability and generalizability of findings across diverse studies.”

Aayushi Sood, MD, lead author and medical resident at The Wright Center for Graduate Medical Education, presented the study, “Sleep Duration and Hypertension Incidence: Systematic Review and Meta-Analysis,” on April 7.

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