Insomnia in older people

Insomnia in older people

The article below is from Sleepdex an online resource which has lots of information about sleep, but as insomnia appears to get worse with age – there is some quite interesting stuff as to possible causes. If you are over 60 and suffering from insomnia, then I’m sure you will find it an interesting read.

Insomnia is a common complaint in older adults. Chronic sleep difficulties affect older people more often than younger adults. The homoeostatic regulation of sleep changes as we age. Older adults typically have shallower sleep, and fragmentation is more common. Doctors prescribe sleeping aids to the elderly much more often than for young adults or kids.

Factors that contribute to insomnia in seniors may include medical illnesses and medication use, both of which are more common in older adults. Older people also have too little physical activity and reduced exposure to bright light.

There is also a fundamental age-related alteration in the neurobiology of circadian
rhythms, although scientists haven’t figured it all out.

Older people, even healthy ones, often complain about decreased sleep quality, and polysomnographic measurements of physiological indicators have confirmed the reality of these claims. Deep sleep, as a percentage of total sleep, decreases as people age, along with a decrease in growth hormone levels. During late life, REM sleep in a typical night declines about 10 minutes per decade. Wake time during the nocturnal period, a measure of sleep fragmentation, increases about 30 minutes per decade.

There’s also a chicken-and-egg question of the relationship between declining sleep quality and development of chronic illness in older adults. Does low quality sleep contribute to other physical problems or do illnesses cause the low quality sleep?

It can be unclear for any individual, and the two factors are intertwined in most people.

It is worth pointing out the distinction between insomnia and disturbed sleep. Insomnia refers to a subjective inability to fall or stay asleep, and chronic insomnia is due to circadian dysrhythmia, homeostatic dysregulation and hyperarousal.

A person can have insomnia but not disturbed sleep. When the person finally gets to sleep, he or she can sleep soundly. Young adults more typically have trouble falling asleep while old people have trouble staying asleep.

Insomnia, by this classification, often results in increased risk of depression, overall decreased productivity at work and in daytimes activities. Disturbed sleep results in symptoms like those of sleep deprivation.

As people get older, they are more apt to experience secondary insomnia due to medical conditions, and to experience sleep disorders such as apnea, restless leg syndrome, and circadian rhythm disorder. Primary insomnia and insomnia due to psychiatric problems do not increase with age.

Some common poor sleep habits are more prevalent in elderly populations – staying in bed all night even when not sleeping (leading to poor sleep efficiency) and daytime napping. This can be due to retirement or boredom. Good sleep practices can help.

Sleep medication use in the elderly differs from that in younger people only in the longer retention time in the body. A drug's half-life – the time it takes for the body to eliminate half the drug from the bloodstream – is higher in the elderly.

This means sleep inertia due to residual sleeping pills is more likely in older people.

In general, older people are more prone to movement during sleep and sedative drugs increase the risk of falls. This is why doctors take into account a patient's age when selecting a sleeping aid. Chloral hydrate is also used in the elderly more often than in young people.

WHAT SCIENTISTS KNOW
There’s a difference in the sexes. Men lose more of the deep sleep (stages 3 and 4) than women. Daytime sleepiness is more frequent in older men than in older women.
Young and middle-aged adults typically complain of difficulty falling asleep, seniors more often experience nocturnal awakening, early morning awakenings, and non-refreshing sleep.

Some of the sleep hygiene practices recommended for insomniacs are often ignored by older people. Retired people without the regular schedule of a job are more likely to engage in daytime napping, irregular arising time, and increased time in bed compared to employed people. These practices are not conducive to trying to beat insomnia.

Insomnia affects a third of older Americans. Restless leg syndrome and sleep-disordered breathing/apnea are also more common in older people. Sleep-disordered breathing is particularly of interest because there is evidence that connects it will dementia and cognitive deficits in the elderly.

It used to be believed that the human circadian clock had a period of about 25.25 hours and that this period declined as people got older. This explained why teenagers had trouble waking up in the morning while seniors get sleepy early in the evening. However, circadian rhythm amplitude sometime stays strong in very healthy older people. Now scientists think that the intrinsic period of endogenous human circadian pacemaker is not significantly different between health old and young adults and is much closer to 24 hours. Deterioration in the suprachiasmatic nucleus may represent a pathologic rather than a normal change. Another view is that older people tend to have a narrower window in the circadian cycle to get to sleep. They are literally more set in their ways. Young people can go to bed at a different time each night and move their sleep times around much more flexibility.

Older people spend more time in bed than younger ones, but nighttime sleep is typically shallow and fragmented. Scientific measurements confirm subjective reports of decline in sleep quality with age in otherwise healthy older people. Deep sleep decreased from 18.9% during young adulthood (ages 16 to 25) to 3.4% in midlife (36 to 50). The decrease in slow-wave sleep was accompanied by decreases in growth hormone levels.

During late life, REM sleep declines gradually by about 10 minutes per decade. Sleep fragmentation, as measured by wake time, increases by 30 minutes per decade during late life.

THERMOREGULATION AND THE ELDERLY
Dutch scientists have found that elderly bodies are less capable of thermoregulation than younger ones, and give the effect of skin temperature on the ability to fall asleep and stay asleep, this may explain increased insomnia rates in seniors. (More on thermoregulation and sleep.)

The prevailing hypothesis in sleep models is the two-process model, in which sleep is a affected by circadian and homeostatic processes . The decline in sleep quality that goes along with getting old is thought to be due to alterations in both processes. Researchers at Cornell's Laboratory of Human Chronobiology found that the homeostatic process starts to go off-kilter before the circadian process as we age.
They found this by studying people of different ages.

They also found that while young adults sleep longer than middle-aged and older adults, daytime napping is essentially unchanged as we age, in the absense of other restrictions (such as retirement.)

RESEARCH
When the U.S. government started the National Insitute on Aging in the 1970s, sleep was a low priority in the medical funding community. In the past few decades the importance of sleep has been recognized, both as an important part of quality of life and as a contributor to and symptom of diseases.

The most recent National Sleep Disorders Research Plan (2003) concedes that most of the research on sleep is conducted on young adults and that there has not been enough scientific exploration of how age affects sleep. There isn’t widespread agreement on what is “normal” age-related changes in sleep patterns and therefore no going agreement on whether any medical treatment is desirable.

Dan Kennedy has written a free ebook on how to Cure Your Insomnia. To download it visit www.cure-your-insomnia.com