June 9, 2009

Blood pressure may rise with less sleep

Middle-aged adults who slept an average of six hours per night were more likely to have high blood pressure, U.S. researchers found.

Kristen L. Knutson of the University of Chicago and colleagues studied 578 adults who first had their blood pressure and other clinical, demographic and health variables measured from 2000-2001.

In 2003 and 2005, sleep duration was measured using surveys and wrist actigraphy, in which a sensor is worn on the wrist to record periods of rest and activity. Blood pressure, demographic and self-reported sleep information were measured again in 2005 and 2006.

Participants -- average age 40 -- slept an average of six hours per night; while 1 percent averaged eight or more hours of sleep.

The study, published in the Archives of Internal Medicine, found that after excluding patients taking medication for high blood pressure and controlling for age, race and sex, individuals who slept fewer hours were significantly more likely to have higher systolic -- top number -- and diastolic -- bottom number -- blood pressure.

The study also found that each hour of sleep reduction was associated with a 37 percent increase in the odds of developing high blood pressure.