Sleep Problems: Nuisance or Serious Health Problem?
Sleep disturbances may be bad for your health.
Posted Sep 20, 2011
Have you developed sleep difficulties as you have grown older? Experts say that with age a person is more like to have trouble getting to sleep and staying asleep without interruption through the night.
Does it matter? I mean, besides the inconvenience, how can this be a big problem? Recent research indicates that fragmented sleep harms memory. We all know that our memories start to slip as we get older. Now we know that fragmented sleep could be one of the causes.
Animal studies at Stanford revealed that disrupting sleep made it harder for the animals to recognize familiar objects, even though the experimental disruption was done in a way that total sleep time was about the same as normal. Comparable studies need to be done in humans.
Common natural causes of fragmented sleep in older humans are alcohol abuse and sleep apnea. Also, in males, enlarged prostate causes a need for frequent urination.
As I have explained in several of my learning and memory blog posts (thankyoubrain.blogspot.com), learning events during the day are consolidated into lasting form during the sleep at night of the same day. We don't know exactly how sleep helps, but obviously, you have far fewer mental distractions during sleep - unless, of course you keep waking up.
Alzheimer's Disease also causes fragmented sleep. So, it is no surprise that the brain degeneration by the disease would cause memory problems. But maybe, just maybe, it is the fragmented sleep that accelerates onset of Alzheimer's disease. Remember from my last column, I presented evidence that most older people have the brain lesions of Alzheimer's Disease, even though they may not yet be clinically ill.
Now, this seemingly ridiculous possibility has to be taken seriously in light of new research showing that sleep-disordered breathing, as in sleep apnea, seems to increase the risk of mental decline and even dementia in older women. As we age, tissue in the back of the throat tends to lose muscle tone and during sleep, and the muscle tone may collapse during sleep to thus allow the tissues to blanket the airway to the lungs. The reflex system controlling breathing may also shut down. When such things happen in sleep, the brain fails to get its needed oxygen supply, and reflex responses set in to compensate, such as raising blood pressure. This pressure rise can damage kidneys and reset the brainstem control settings so that blood pressure is always high. When brain oxygen is too low for too long, it triggers a frantic brain arousal state to wake up enough to breathe, lest you die of asphyxiation.
These transient interruptions of sleep may occur numerous times at night, but a patient doesn't remember it, because they typically go back to sleep, which prevents remembering the awakening.
A recent research report reveals that apnea-caused fragmented sleep is a special problem in older women. In a study spread out over as long as six years the investigators examined all-night sleep patterns in 298 women and then years later tested their cognitive function. The number who had apnea numbered 105, while 193 had normal sleep. Data analysis was adjusted for age, race, body-mass index, education level, smoking status, presence of diabetes, presence of hypertension, medication use (antidepressants, benzodiazepines or other tranquilizers), and baseline cognitive scores.
After an average of 4.7 years, almost half of the women who had been diagnosed with apnea developed cognitive impairment or even dementia, while 31.1% of women the non-apnea women later developed cognitive impairment. The effect apparently was not due to the amount of fragmentation as such but rather to the extent of oxygen depletion and the total sleep time spent in apnea.
So the practical matter seems to be you needn't worry just because you wake up frequently during the night. But, if you do wake up often, you probably should go to a sleep lab and find out if you have an apnea problem.
The treatment is simple (though uncomfortable at first): you simply sleep with a mask that delivers pressurized air throughout the night. It is worth the nuisance to lower your blood pressure, save the wear and tear on heart and kidneys, and reduce the odds of becoming demented.