Home' Trinidad and Tobago Guardian : April 4th 2017 Contents A22 body & soul
guardian.co.tt Tuesday, April 4, 2017
Prolonged sleep disturbance can
lead to lower bone formation
Insufficient sleep, a common problem that has
been linked to chronic disease risk, might also be
an unrecognised risk factor for bone loss. Results
of a new study will be presented this Saturday at
the Endocrine Society's 99th annual meeting in
Orlando, Florida, US.
The study investigators found that healthy men had
reduced levels of a marker of bone formation in their
blood after three weeks of cumulative sleep restriction
and circadian disruption, similar to that seen in jet lag or
shift work, while a biological marker of bone resorption,
or breakdown, was unchanged.
"This altered bone balance creates a potential bone
loss window that could lead to osteoporosis and bone
fractures," lead investigator Christine Swanson, MD, an
assistant professor at the University of Colorado in Auro-
ra, Colorado, said. Swanson completed the research while
she was a fellow at Oregon Health & Science University in
Portland, Oregon, with Drs Eric Orwoll and Steven Shea.
Inadequate sleep is also prevalent, affecting more
than 25 per cent of the US population occasionally and
10 per cent frequently, the Centers for Disease Control
and Prevention report.
The ten men in this study were part of a larger study
that some of Swanson's co-authors conducted in 2012
at Brigham and Women's Hospital in Boston, Massa-
chusetts. That study evaluated health consequences of
sleep restriction combined with circadian disruption.
Swanson defined circadian disruption as "a mismatch
between your internal body clock and the environment
caused by living on a shorter or longer day than 24 hours."
Study subjects stayed in a lab, where for three weeks
they went to sleep each day four hours later than the prior
day, resulting in a 28-hour "day." Swanson likened this
change to "flying four time zones west every day for three
weeks." The men were allowed to sleep only 5.6 hours
per 24-hour period, since short sleep is also common
for night and shift workers. While awake, the men ate
the same amounts of calories and nutrients throughout
the study. Blood samples were obtained at baseline and
again after the three weeks of sleep manipulation for
measurement of bone biomarkers. Six of the men were
ages 20 to 27, and the other four were ages 55 to 65. Lim-
ited funding prevented the examination of serum from
the women in this study initially, but the group plans to
investigate sex differences in the sleep-bone relationship
in subsequent studies.
US Zika vaccine begins
second phase of testing
Researchers have begun the second phase of
testing of a Zika vaccine developed by US gov-
ernment scientists in a trial that could yield
preliminary results as early as the end of 2017.
Dr Anthony Fauci, director of the National Insti-
tutes of Allergy and Infectious Diseases (NIAID), said
the US$100 million trial has already been funded and
will proceed, despite the US$7 billion in cuts to the
National Institutes of Health (NIH) budget proposed
by the Trump Administration over the next 18 months.
Fauci said the current Zika vaccine candidate had
cleared preliminary safety hurdles, and would now
enter testing for efficacy, which would occur in two
The first phase will continue testing for safety and
evaluate the vaccine's ability to stimulate the immune
system to develop antibodies to fight Zika. It will also
test different doses to see which works best.
The second phase, set to begin in June, will attempt
to determine if the vaccine can actually prevent Zika
In the NIAID study, researchers aim to enroll at least
2,490 healthy volunteers in areas with confirmed or
potential active transmission of Zika by mosquitoes.
These include parts of the continental United States,
Puerto Rico, Brazil, Peru, Costa Rica, Panama and
Mexico. They will receive either the vaccine, or a
placebo, and be followed for two years.
If enough people are exposed to the virus, Fauci
said they could get an effectiveness signal as early
as the end of this year. The trial is expected to be
completed by 2019. (Reuters)
A study finds
of a marker of
in their blood
similar to that
seen in jet lag or
After three weeks, all men had significantly reduced
levels of a bone formation marker called P1NP compared
with baseline, the researchers reported. This decline was
greater for the younger men than the older men: a 27 per
cent versus 18 per cent decrease. She added that levels of
the bone resorption marker CTX remained unchanged,
an indication that old bone could break down without
new bone being formed.
(The Endocrine Society, via Science Daily)
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