BBC SCIENCE FOCUS MAGAZINE COLLECTION 77GETTY
ARE YOU SLEEP-
DEPRIVED
OR FATIGUED?
Researchers use a sleep
latency test to find out
whether people who are
constantly tired are
sleep-deprived or
fatigued for other
reasons. If you lie down
somewhere quiet during
the day and fall asleep
within a few minutes,
then you are either
lacking sleep or
potentially suffering
from a sleep disorder. If
you’re still awake after
20 minutes, you’re
deemed to be well res ted
with no sleep debt.immune responses. Studies have shown that
low-grade inflammation robs mice of their
energy to run on a wheel. This suggests that
underlying tissue inflammation – whether it’s
in response to a virus, a long-term condition
or a problem with cytokine regulation – can
be enough to make us feel weary. Scientists
in the Netherlands have now started a major
new trial to find out whether anakinra,
an anti-inflammatory drug that blocks a
particular cytokine, brings an improvement
in people with CFS/ME.
Prof Newton is clear that these related
underlying physical vulnerabilities may be a
factor in everyone’s continuing tiredness – not
just CFS/ME sufferers. “The day-to-day fatigue
that GPs see definitely relates to chronic illness.
The two are not separate,” she says.NATURALLY SLEEPY
There’s new research to suggest some of us
may simply have been born with a physical
and psychological susceptibility to tiredness.
Researchers from the University of Edinburgh
analysed the genetic make-up of 111,749 peoplewho indicated they felt tired in the two weeks
before samples were collected for the UK
Biobank. They found a genetic link between
those who reported tiredness and those prone
to diabetes, schizophrenia, high cholesterol or
obesity. “This raises the possibility of a genetic
link between tiredness and vulnerability to
physiological stress,” said the team, led by Prof
Ian Deary. But the researchers also said that the
major it y of people’s d if ferences i n sel f-repor ted
tiredness can be put down to environmental
causes rather than genetic factors. So how we
live our lives and what happens to us, is of the
utmost importance.
Furthermore, the significance of our
relationship to daylight is becoming increasingly
clear. For decades, we’ve been told that
keeping regular habits and sleeping hours is
important. Now, research has confirmed the
importance of a part of the brain called the
suprachiasmatic nucleus (SCN), a group of cells
in the hypothalamus that responds to light
signals fed from the eye. When it’s light, the
SCN messages other parts of the brain to release
hormones that make us feel alert and when 5