If you suffer from
cancer, make sure you do not suffer from a sleep disturbance called sleep
apnea. An animal study presented at the
European Association of Urology Congress in Munich demonstrates how sleep apnea
can possibly promote cancer.
Sleep apnea is a condition where a person's breathing stops momentarily during sleep. It commonly occurs due to excessive relaxation of throat muscles during sleep or due to large tonsils, which interfere with breathing. This form of sleep apnea is called obstructive sleep apnea
. Obese individuals often suffer from sleep apnea. Another less common form of sleep apnea is central sleep apnea, which occurs due to a problem in the brain.
‘Indications have shown that patients with cancer may have worse outcomes if they suffer from sleep apnea.’
Sleep apnea influences oxygenation of blood, and therefore the supply of oxygen to various tissues. It causes hypoxia of the brain, that is, oxygen supply to the brain gets cut during the episodes. It predisposes an individual to several conditions like high
, stroke, heart attack and even abnormal heart rhythms
have indicated that patients with cancer may have worse outcomes if they suffer
from sleep apnea. Since the exact mechanism is not known, researchers attempted
to explore the mechanism via animal studies. They conducted the experiment on
mice with kidney tumors. They altered the oxygen levels that the mice were
exposed to, to create a condition similar to the periods of hypoxia experienced
during sleep apnea.
The researchers found that mice that were exposed to
intermittent periods of hypoxia had increased vascular progenitor cells and
cells may contribute to formation of blood vessels. Also, the levels of a hormone called vascular endothelial growth factor (VEGF) in the blood were increased
. This hormone also promotes the formation
of blood vessels. Increased blood vessel formation within the tumor supplies
more blood with oxygen and nutrients to the tumor and helps it to grow.
The researchers do caution that the study was carried
out in mice and therefore the results may not be directly applicable to humans
. However, it does provide possible clues about how sleep apnea can worsen cancer. Further studies may be able to extrapolate the findings to humans. Till then, it may be advisable to treat sleep apnea
wherever possible, irrespective of whether the patient suffers from cancer or not.