Archive for May 2013

Less Sleep Associated With High Blood Pressure In Middle Age

May 29, 2013

Middle-aged adults who sleep fewer hours appear more likely
to have high blood pressure and to experience adverse changes
in blood pressure over time, according to a report in the June 8 issue
of Archives of Internal Medicine, one of the JAMA/Archives journals.

Almost one-third of Americans have hypertension or high blood pressure,
a condition that contributes to 7 million deaths worldwide each year,
according to background information in the article. “Identifying a novel
lifestyle risk factor for high blood pressure could lead to new interventions
to prevent or reduce high blood pressure,” the authors write. “Laboratory
studies of short-term sleep deprivation have suggested potential mechanisms
for a causal link between sleep loss and hypertension.” Sleep deprivation is
associated with increased activity in the sympathetic nervous system, which
controls the body’s stress response. Over time, this activation could contribute
to high blood pressure.

Researchers from the University of Chicago studied 578 adults who first had
their blood pressure and other clinical, demographic and health variables
measured between 2000 and 2001. In 2003 and 2005, sleep duration was
measured using surveys and a wrist actigraphy mechanism, 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; only
seven (1 percent) averaged eight or more hours of sleep. After excluding
patients taking medication for high blood pressure and controlling for age,
race and sex, the researchers found that individuals who slept fewer hours
were significantly more likely to have higher systolic (top number) and diastolic
(bottom number) blood pressure.

Sleeping less also predicted increases in blood pressure over five years,
along with the onset of hypertension. Each hour of reduction in sleep duration
was associated with a 37 percent increase in the odds of developing high
blood pressure.

The researchers summarized the present study provides evidence for a link
between the duration and quality of sleep and high blood pressure levels
using objectively measured sleep characteristics. Further studies are
planned to determine whether optimizing sleep duration and quality can
reduce the risk of increased blood pressure.

Research for this study was supported by a grant from the National Institute
on Aging. The Coronary Artery Risk Development in Young Adults (CARDIA)
study is supported by U.S. Public Health Service contracts from the National
Heart, Lung and Blood Institute.

Journal reference:
1. Association Between Sleep and Blood Pressure in Midlife:
The CARDIA Sleep Study. Archives of Internal Medicine, 2009;