SLEEP
Washington August 2000 - Disrupted sleep
may be weakening the immune systems
of
elderly widows and
widowers,
new findings suggest.
Researchers at the University of Pittsburgh Medical Center
Health
Systems (UPMC) Western Psychiatric Institute and
Clinic in
Pittsburgh, PA.,
studied 29 patients aged 40 to 78
who were
seeking treatment
for bereavement-related
depression.
Each patient spent three nights in a sleep lab as part of a
double-blind,
placebo-controlled study of the treatment of
bereavement-related
depression between 1995 and 1996.
None of
the subjects
had any infectious illnesses at the time
and all were
experiencing their
first lifetime episode of
major depression.
Analysis of their blood samples showed that those whose sleep
had
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
weakened immune
system and a body more vulnerable to illness.
The study, published in the January-February issue of
Psychosomatic
Medicine, provides the first direct evidence that
sleep disruptions
are associated with the stress-immune
relationship in humans, the
researchers explained.
"Stress-related intrusive thoughts and avoidance behaviours
were
associated with greater time spent awake during the
first sleep
cycle which, in turn, was associated with lower numbers
of
circulating
NKCs."
The findings prove that maintaining good sleep is important for
the
elderly
to maintain health, according to the primary author,
Martica
Hall, PhD,
of the University of Pittsburgh Medical
College's
department of psychiatry.
She said the findings
show the
importance of developing interventions
that reduce
illnesses caused
by stress-related sleep disruptions.
Although sleep disruptions associated with bereavement or other
stressful life events may play an important role in illness
susceptibility,
Hall said, it is not yet known whether doctors can
improve patients'
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
following."
