Researchers Add
Colon Cancer to List of Physical Problems Possible from Lack of Sleep
Inadequate sleep
previously associated with higher risks of obesity, heart disease,
diabetes, and death
Feb. 8, 2011 - A
new study finds individuals who averaged less than six hours of sleep at
night had an almost 50 percent increase in the risk of colorectal
adenomas - a precursor to cancer tumors - compared with those sleeping
at least seven hours per night. Untreated adenomas polyps can become malignant.
An inadequate
amount of sleep has previously been associated with higher risks of
obesity, heart disease, diabetes, and death. Now colon cancer can be
added to the list.
Men with moderate to severe sleep apnea were nearly
three times more likely to have a stroke than men with no or mild sleep
apnea - watch video - April 9, 2010
As we age, the lens in the eye thickens and the pupil
shrinks, reducing the amount of light passing through to the retina;
earlier study opted for gold glasses to block blue light
"To our
knowledge, this is the first study to report a significant association
of sleep duration and colorectal adenomas," said Li Li, MD, PhD, the
study's principal investigator, family medicine physician in the
Department of Family Medicine at UH Case Medical Center and Associate
Professor of Family Medicine, Epidemiology and Biostatistics at Case
Western Reserve University School of Medicine.
"A short amount
of sleep can now be viewed as a new risk factor for the development of
the development of colon cancer."
In the study,
patients were surveyed by phone prior to coming into the hospital for
scheduled colonoscopies at UH Case Medical Center. They were asked
demographic information as well as questions from the Pittsburg Sleep
Quality Index (PSQI), which obtains information about the patient's
overall sleep quality during the past month. The PSQI asks for such
information as how frequently one has trouble sleeping and how much
sleep one has had per night.
The study was
funded by the National Cancer Institute through Case Western Reserve
University School of Medicine.
Senior
Citizens and Sleep Problems
Older adults need about the same amount of sleep
as younger adults (7 to 9 hours nightly), according to Mayo
Clinic sleep specialist Timothy Morgenthaler, M.D.
Although, a
study published in the February, 2010, issue of the journal
SLEEP, reported older adults sleep about 20 minutes less than
middle-aged adults, who sleep 23 minutes less than young adults.
“As you get older, however, your sleeping
patterns may change. Older adults tend to sleep more lightly and
awaken more frequently during the night than do younger adults.
This may create a need for or tendency toward daytime napping,”
Dr. Morgenthaler
writes in a
Mayo Clinic Q&A.
“If your sleep is frequently interrupted or cut
short, you're not getting quality sleep — and the quality of
your sleep is just as important as the quantity,” he adds.
Dr. Morgenthaler points out that lack of sleep
can affect your immune system.
“Studies show that people who don't get a good
night's sleep or who don't get enough sleep are more likely to
get sick after being exposed to a virus, such as the common
cold. Lack of sleep can also affect how fast you recover if you
do get sick,” he says.
“During sleep, your immune system releases
proteins called cytokines. These substances increase in the
presence of an infection, inflammation and stress. Increased
cytokines are necessary in fighting infection and regulating
deeper sleep. In addition, other infection-fighting cells are
reduced during periods of sleep deprivation. So, your body needs
sleep to fight infectious diseases.
“How much sleep do you need to bolster your
immune system? The optimal amount of sleep for most adults is
seven to eight hours a night. School-aged children and
adolescents need nine or more hours of sleep a night.
“But be careful; more sleep is not always better.
For adults, sleeping more than nine to 10 hours a night has been
associated with weight gain, heart problems, stroke, sleep
disorders, depression and other health concerns.”
Of the 1,240
patients, 338 were diagnosed with colorectal adenomas at their
colonoscopy. The patients with adenomas were found in general to have
reported sleeping less than six hours compared to compared to those
patients without adenomas (control) patients, and the association
between amount of sleep and adenomas remained even when adjusted for
family history, smoking, and waist-to-hip ratio (a measurement of
obesity).
The researchers
also found a slightly stronger association of sleep duration with
adenomas with women compared to men, but the difference was not
statistically significant.
Dr Li said the
magnitude of the increase in risk due to less hours of sleep is
comparable to the risk associated with having a first-degree relative
(parent or sibling) with colon cancer, as well as with high, red meat
intake.
"Short sleep
duration is a public health hazard leading not only to obesity, diabetes
and coronary heart disease, but also, as we now have shown in this
study, colon adenomas," he said.
"Effective
intervention to increase duration of sleep and improve quality of sleep
could be an under-appreciated avenue for prevention of colorectal
cancer."
Although why
fewer hours of sleep may lead to colon cancer is unknown, Dr. Li said
some of theories include that less sleep may mean less production of
melatonin, a natural hormone that in animals has been linked to DNA
repair, or that insulin resistance may underlie the link between sleep
disturbance and cancer development.
The study by
researchers from University Hospitals (UH) Case Medical Center and Case
Western Reserve University School of Medicine is published in the Feb.
15, 2011 issue of the journal Cancer.
Dr. Li and other
researchers on the study are also associated with the UH Seidman Cancer
Center, the Case Comprehensive Cancer Center, the Department of
Epidemiology and Biostatistics at Case Western Reserve University, the
Center for Clinical Investigation at Case Western Reserve, and the
Department of Medicine at UH and Case Western Reserve University School
of Medicine.