Natural Short Sleepers
Sleep is for the
Weak
–
天賦異稟短睡者
sleepers in 2009,
by a research team
l ed by Dr. Fu Y i ng - hu i at
The University of California, San Francisco who
intended to study a circadian rhythm disorder
called Familial Advanced Sleep Phase syndrome
(FASP). It is a rare condition in which patients
become lethargic in the evening and wake up
unusually early. To their surprise, they found that
the subjects naturally woke up early (around 4
am), but went to bed past midnight, contrary to
what would be expected with sufferers of FASP.
Genetic screening revealed that the subjects
shared a single gene variation, which, once
introduced to lab mice, elicited a short sleep
phenotype as well [2].
Des p i te t hese d i scove r i es , p rog res s i n
identifying the genetic causes and molecular
mechanisms of short sleepers remain marred by
difficulties in finding true short sleepers. The data
is difficult to obtain since short sleeping hours is
hardly a disorder that is cause for a trip to the
clinic.
Before you jump to the conclusion that you may
be a short sleeper, here is something you should
know. Whilst many claim to be short sleepers who
regularly maintain fewer than 7 hours of sleep
per night, most are chronically sleep-deprived. In
fact, for every 100 people who think they do not
need more than five or six hours of sleep every
night, only about 5 can actually function with that
little sleep, while the rest belong to a third of the
All
mammals have to sleep. The necessity
of sleep puts even the most powerful men and
women on their backs. During this sacred time,
tissues replenish and organs recalibrate. Humans
spend roughly a third of their lifetime in serene
slumber – except a small group of “natural short
sleepers” who make up just 1 – 3% of the world’s
population. These super beings are simultaneously
night owls and early birds, potentially working well
into the night and waking up early in the morning,
feeling entirely refreshed without the assistance of
power naps or caffeine.
I
come to life about 11 at
night, if I went to bed earlier, I’d feel
like half my life was missing.
- Linda Cohen, a short sleeper
The s tudy of sho r t s l eepe r s i s a l a rge l y
uncharted area in sleep medicine and what is
responsible for their ability to function on little
sleep is widely disputed. One theory suggests
that some short sleepers may have a mild form
of a psychiatric disorder known as hypomania,
cha racte r i sed by pe r vas i ve eupho r i a and
hyperactivity. In a study from The University of
Pittsburgh Medical Centre, natural short sleepers
scored significantly higher than experimental
controls in test scales for hypomania [1].
There are also possible genetic factors that
influence short sleeping patterns. A variation in
the gene
hDEC2
was discovered in natural short
By David Iu
姚誠鵠
