Skimpy Sleep May Up Blood Pressure

April 3, 2006 -- Middle-aged adults may help their blood pressure by getting at least six nightly hours of sleep.

In Hypertension, experts report that middle-aged adults are more likely to be diagnosed with high blood pressure (hypertension) if they slept less than six hours per night.

Blood pressure falls during sleep. Short nightly sleep may mean higher average blood pressure over 24 hours.

In other words, skimping on nightly sleep in middle age may deprive the body of an overnight blood pressure break, eventually making high blood pressure more likely.

The findings need to be confirmed. Meanwhile, there's plenty of reason to get enough sleep, says researcher James Gangwisch, PhD, of Columbia University's Mailman School of Public Health.

"A good night's sleep is very important for good health," Gangwisch says in an American Heart Association news release.

About the Study

Gangwisch and colleagues studied data on about 4,800 people who took a national health survey in 1982 and also did follow-up surveys until 1992.

In the first survey, participants reported their nightly sleep and factors that might affect blood pressure. Those factors included smoking, alcohol use, salt consumption, physical activity, age, sex, and diabetes. Participants were also screened for depression, which often affects sleep.

In follow-up surveys, participants reported any diagnosis of high blood pressure.

Among people aged 32-59, those who reported getting less than six hours of nightly sleep in the original survey were twice as likely to have been diagnosed with high blood pressure by 1992.

Obesity and diabetes partly accounted for the findings, but sleep still mattered, the study shows.

Cause Unclear

The study doesn't prove that participants' sleep habits affected their blood pressure.

Sleep habits were only checked once. Changes in those habits might affect the results, the researchers note.

High blood pressure is common. Nearly one in three U.S. adults has high blood pressure and almost a third of them don't know it, states the American Heart Association.

Participants' medical records weren't checked. If some participants had undiagnosed high blood pressure, the results might be off, write Gangwisch and colleagues. They call for more studies on skimpy sleep, high blood pressure, and ways to fix those problems.