Washington August 2000 - Disrupted sleep
may be weakening the immune systems
elderly widows and
new findings suggest.
Researchers at the University of Pittsburgh Medical Center
Systems (UPMC) Western Psychiatric Institute and
studied 29 patients aged 40 to 78
Each patient spent three nights in a sleep lab as part of a
placebo-controlled study of the treatment of
depression between 1995 and 1996.
had any infectious illnesses at the time
and all were
first lifetime episode of
Analysis of their blood samples showed that those whose sleep
been disrupted had decreased levels of natural killer cells (NKCs),
which take their name from the way they help destroy illness-causing
cells. A decreased NKC count indicates a
system and a body more vulnerable to illness.
The study, published in the January-February issue of
Medicine, provides the first direct evidence that
are associated with the stress-immune
relationship in humans, the
"Stress-related intrusive thoughts and avoidance behaviours
associated with greater time spent awake during the
cycle which, in turn, was associated with lower numbers
The findings prove that maintaining good sleep is important for
to maintain health, according to the primary author,
of the University of Pittsburgh Medical
department of psychiatry.
She said the findings
importance of developing interventions
by stress-related sleep disruptions.
Although sleep disruptions associated with bereavement or other
stressful life events may play an important role in illness
Hall said, it is not yet known whether doctors can
health by improving their sleep.
"We know that it is better to treat the underlying problem,
bereavement-related depression, than to simply treat the symptom,
disturbed sleep, with a sleeping pill," Hall said.
"The potential health
benefits of treating bereavement-related
depression, including its
sleep disruptions, is one of the
research avenues we are now