June 9 -- MONDAY, June 8 (HealthDay News) -- Middle-aged adults who don't get enough sleep are at increased risk of developing high blood pressure, a new study has found.
Over the course of five years, Kristen L. Knutson of the University of Chicago and colleagues collected health information, such as blood pressure readings, and measured the sleep duration of 578 adults with an average age of 40. Sleep duration was measured using surveys and a sensor worn on the wrist that records periods of rest and activity.
Adults who slept fewer hours than other study participants were significantly more likely to have higher blood pressure readings, the researchers found.
Adults who slept less were also more likely to develop high blood pressure as time passed. After five years, each hour of reduction in sleep duration was associated with a 37-percent increase in the odds of developing high blood pressure, or hypertension, according to the study findings published in the June 8 issue of the Archives of Internal Medicine.
The average amount of sleep a night among study participants was six hours. Only 1 percent averaged eight or more hours per night, the researchers said.
"Identifying a novel lifestyle risk factor for high blood pressure could lead to new interventions to prevent or reduce high blood pressure," Knutson's team wrote. "Laboratory studies of short-term sleep deprivation have suggested potential mechanisms for a causal link between sleep loss and hypertension."
High blood pressure contributes to 7 million deaths worldwide each year, and the condition affects one-third of Americans, according to background information provided in the report.
The authors also pointed out that sleep deprivation affects the body's stress response, which can raise the risks of developing high blood pressure.
The study, which excluded patients taking medication for high blood pressure and controlled for age, race and sex, also found that black men had higher blood pressure levels than women or white men. In addition, black men tended to get fewer hours of sleep, the researchers found.
"These two observations suggested the intriguing possibility that the well-documented higher blood pressure in African Americans and men might be partly related to sleep duration," the study authors concluded.
The National Heart, Lung and Blood Institute has tips on lowering blood pressure.
SOURCE: University of Chicago, news release, June 8, 2009