BIOLOGY AND SHIFT WORK
New
research suggests that biological differences may account for why some
people are "morning people" and others are more energetic at
night.
Emmanuel Mignot, MD,PhD, and his colleagues asked 410 adults when they
like to sleep and work. They wanted to know what their ideal schedule
would be and when they felt most alert. They also drew blood to look at
a gene relating to their genetic "clock" regulating circadian
rhythms, or daily sleep-wake schedules.
They found a link between two different forms of the gene and whether
people were partial to morning or evening activity.
Most people were brightest in the morning but about 25%said they felt
most awake during the late afternoon or evening. These people all had
the same form of the "clock" gene.
This is a preliminary study but it has potential to explain why some people
cannot function well on off shifts and others thrive while working graveyard.
Published Sept 15 1998, Sleep(Vol.21,No.6,p568-576)