Sleepeducation.com Research Summary

Study Title

Association of Usual Sleep Duration with Hypertension: The Sleep Heart Health Study

Publication

The August 1, 2006, issue of the journal Sleep

Goal

To examine the relationship between usual sleep duration and high blood pressure

Importance

Studies have shown that short-term sleep restriction elevates blood pressure. But little is known about usual sleep duration and high blood pressure. More than one-third of people sleep for less than seven hours per night. This short sleep often results from personal choices such as watching TV, using the Internet or working.

Results

The median sleep duration of study group members was seven hours per night. Results show the percent of participants whose usual sleep duration fell in the following ranges:

• Less than six hours — 9.2%
• Six to less than seven hours — 20.4%
• Seven to less than eight hours — 34.2%
• Eight to less than nine hours — 28.6%
• Nine or more hours — 7.6%

People who sleep for seven to less than eight hours per night were compared with those in the other sleep ranges. Results show that high blood pressure is more likely in adults who sleep for either less than seven hours per night or eight or more hours per night. This link is strongest among people who have a usual sleep duration of less than six hours.

Results were adjusted for other factors such as age, sex, obesity and cigarette smoking. The link between high blood pressure and sleep duration remained after adjustment. Results were similar between men and women.

People who get the least or most sleep are more likely to have depressive symptoms or heart disease. Insomnia is more common in people with shorter sleep durations. People with long sleep durations are more likely to consume high amounts of alcohol.

What it Means to You

• Sleeping for either more or less than seven to eight hours each night may lead to high blood pressure.
  
  
• High blood pressure increases your risk for heart disease.
  
  
• Most people should obtain an average of seven to eight hours of sleep per night to promote good health.
  
  
• People with high blood pressure should make sure that they get enough sleep each night.

Participants

The study involved 5,910 adults with an average age of 63.1 years. This group was composed of 3,097 women and 2,813 men.

Study Design

Cross-sectional, observational study

Study Methods

Members of the study group completed a Sleep Habits Questionnaire between 1995 and 1998. Their responses were used to calculate their usual sleep duration. Blood pressure was measured during an evening home visit or an earlier clinic visit. Participants also had their sleep evaluated during an overnight sleep study. This was done by unattended, in-home polysomnography.

Limits of the Study

• The study involved only middle-aged adults and older adults. Results may not be the same for younger people.
  
  
• Usual sleep duration was obtained by self-report. These times are only estimates.
  
  
• The study did not measure some factors such as exercise and diet.

Lead Author

Daniel J. Gottlieb, MD, MPH, of the Boston University School of Medicine and VA Boston Healthcare System in Massachusetts

Conflicts of Interest

This was not an industry supported study.

Funding/Support

The study was supported by the National Heart, Lung and Blood Institute.

View the study abstract online.

Reviewed by David A. Kristo, MD
Updated August 2, 2006