Getting
too little sleep during the week can increase some risk factors for
diabetes, but sleeping late on weekends might help improve the picture, a
small U.S. study suggests.
Researchers
conducted a sleep experiment with 19 healthy young men and found just
four nights of sleep deprivation were linked to changes in their blood
suggesting their bodies weren’t handling sugar as well as usual.
But
then, when they let the men get extra sleep for the next two nights,
their blood tests returned to normal, countering the effect of the
short-term sleep deprivation.
“It
gives us some hope that if there is no way to extend sleep during the
week, people should try very hard to protect their sleep when they do
get an opportunity to sleep in and sleep as much as possible to pay back
the sleep debt,” said lead study author Josaine Broussard of the
University of Colorado Boulder.
The
study doesn’t prove sleeping late every weekend can counter the ill
effects of insufficient rest every other night of the week, Broussard
cautioned.
And it doesn’t prove that catching up on sleep will prevent diabetes, reports Reuters Health.
“We
don’t know if people can recover if the behaviour is repeated every
week,” Broussard added by email.
“It is likely though that if any group
of people suffer from sleep loss, getting extra sleep will be
beneficial.”
To
assess the impact of sleep on diabetes risk, Broussard and colleagues
focused on what’s known as insulin sensitivity, or the body’s ability to
use the hormone insulin to regulate blood sugar. Impaired insulin
sensitivity is one risk factor for type 2 diabetes, which is associated
with age and obesity and happens when the body can’t properly convert
blood sugar into energy.
The
researchers did two brief sleep experiments. On one occasion, the
volunteers were permitted just 4.5 hours of rest for four nights,
followed by two evenings of extended sleep that amounted to 9.7 hours on
average. On another occasion, the same men were allowed to sleep 8.5
hours for four nights.
After
the four nights of sleep deprivation, the volunteers’ insulin
sensitivity had fallen by 23 percent and their bodies had started to
produce extra insulin. But when researchers checked again after two
nights of extended rest, the men’s insulin sensitivity, and the amount
of insulin their bodies produced, had returned to normal, mirroring what
was seen during the portion of the experiment when the volunteers
consistently got a good nights’ rest.
The
volunteers were given a calorie-controlled diet to limit the potential
for their food and drink choices to influence the outcomes. In the real
world, when people don’t get enough sleep they tend to overeat, which
may limit how much results from this lab experiment might happen in
reality, the authors note in a report scheduled for publication in the
journal Diabetes Care.
“The
results from the present study are unlikely to be fully reflective of
what may occur in persons who are older, overweight or obese, or have
other potent risk factors for diabetes,” said James Gangwisch, a
researcher at Columbia University who wasn’t involved in the study.
Chronically
sleep-deprived people are more likely to develop other health problems,
though, ranging from obesity to high blood pressure to cognitive
deficits, the study authors point out.
“By
catching up on sleep on the weekends, people are reducing average
extent and severity of the effects of sleep deprivation,” Gangwisch
added by email. “Ideally, we would all get sufficient sleep on a nightly
basis.”