In a large U.S. study, people who
tended to get less than six hours of sleep nightly were more
likely to have high blood pressure, high cholesterol,
diabetes and to be obese. The research is the first to look
at differences in risk between racial and ethnic groups, and
also finds the strongest effect among Black and Hispanic
Americans. "This is important, since racial minorities are
generally at increased risk of cardiovascular disease,
diabetes and obesity," lead author said. "And if they also
tend to have more sleep difficulties, that could be making
things worse." Using nationwide survey data from 2008,
researchers divided results from more than 5,000 respondents
representing the U.S. population into three groups. Very
short sleepers got less than five hours per night, short
sleepers got between five and six hours and long sleepers
got more than nine hours. Very short and short sleep were
both linked to poor health, research team reports. Very
short sleepers were twice as likely to have high blood
pressure and high cholesterol, compared to people who slept
around seven to eight hours. Very short sleepers were also
75 percent more likely to have diabetes and 50 percent more
likely to be obese. Short sleepers were about 20 percent
more likely than normal sleepers to report high blood
pressure and obesity. Blacks were most likely to report
sleeping less than five hours and very short sleep was most
strongly linked to obesity among Blacks. Short sleep was
strongly linked to high blood pressure among Blacks, Whites
and non-Mexican Hispanics, while people of Asian descent had
the strongest link between short sleep and high cholesterol.
Long sleepers did not appear to experience any negative
health effects once researchers adjusted for other factors.
"Like most aspects of health, too little is bad for you and
too much is also likely bad for you," lead author said. "It
is hard to say that short sleep is worse than long - it's
just that we currently have a better idea of why short sleep
is detrimental to health," he added. Quantity of sleep isn't
the only important factor though, he said. Insomnia, sleep
apnea and waking frequently during the night may be related
to heart disease, diabetes and obesity, he said. Sleep and
health are likely linked in a two-way relationship, he said.
Less sleep may negatively impact health, and certain health
conditions like obesity might make sleep more difficult.
"Lack of sleep limits your body's ability to keep itself
healthy, increasing risk for disease, which puts stress on
the body, making sleep harder," he said. "It is likely a
cycle like this." |