How often have you heard that, “Older people are supposed to sleep less.” Is this true or is it a myth? Are changes seen in sleep part of normal aging, or is there something else going on that causes older adults to sleep poorly?
Complaints of sleeping difficulties do increase with age. Older people complain about getting less sleep at night, waking up more often during the night, waking up too early in the morning and being sleepy during the day. The amount of deep sleep (called stage 3 and 4 sleep or slow wave sleep) seen in younger adults is reduced as we age. The resulting sleep of older adults is less deep, hence they are more likely to be bothered and awakened by outside noise.
Tests of daytime sleepiness indicate that older people are sleepy during the day, suggestive of not getting enough sleep at night. That older people are sleepier in the day than their younger counterparts suggests that it is not the need to sleep that is reduced, but rather the ability to sleep.
There are many reasons that the ability to sleep decreases with age.
- Circadian rhythm changes
- The presence of sleep disorders (such as sleep disordered breathing)
- Medical illness including dementia
- Medication use
Circadian Rhythm Changes: The sleep/wake cycle is controlled by our biological clock or circadian rhythm. The average younger adult gets sleepy at around 10:00 – 11:00pm and sleeps for about eight hours, waking between 6:00-8:00am. As we age, our circadian clock advances causing advanced sleep phase syndrome. People with advanced sleep phase get sleepy early in the evening, for example, around 8:00-9:00pm. If they went to bed at that time, they would still sleep for about 8 hours, which means they would wake at 4-5:00am. Although they get sleepy earlier in the evening, people with advanced sleep phase still try to stay up until 10:00 or 11:00pm. Their bodies however, still wake up at 4-5:00am, which means they are only able to get 5-6 hours of sleep, because they are only in bed that long before their advanced sleep/wake cycle wakes them up. Advanced sleep phase is very common in older adults and is one of the primary reasons behind complaints of waking early in the morning and being unable to get backto sleep.
The best treatment of advanced sleep phase is bright light exposure in the early evening or late afternoon. Older people need to spend more time out of doors being exposed to bright sun light. Light is the best stabilizer of circadian rhythms.
Sleep Disordered Breathing: Another reason the ability to sleep is decreased may be “sleep disordered breathing”, or “sleep apnea” not a rare finding in the elderly, in which the individual cannot breath and sleep at the same time. Symptoms of sleep disordered breathing include:
- Excessive daytime sleepiness (such as falling asleep or fighting to stay awake while working at a desk, visiting with friends or while driving)
- Loud snoring (which is heard throughout the house)
- Gasping, or choking during sleep
- Nocturnal hypertension and arhythmias
- Waking with a morning headache
- Waking up confused or with intellectual deterioration.
Treatment of sleep apnea improves all the symptoms, including the cognitive impairment. The treatment of choice at this time is Continuous Positive Airway Pressure (CPAP) where a machine, with a nose piece connected to a hose, pushes positive pressure into the airway and acts as a splint to keep the airway open. Research from our laboratory has shown that about 25% of older adults have sleep disordered breathing with the prevalence increasing to over 50% in patients with dementia.
Medical Illness and Medicacation: Other factors which affect how an older person sleeps include medical illness and medication use. The pain of arthritis or heart disease, as well as psychiatric illness (such as depression), can interfere with sleep. The key is to treat the primary problem first as resolution of the primary problem should improve the sleep complaint. Many medications can affect sleep either by being depressants and causing daytime sleepiness or by being stimulants and causing insomnia. Having the physician adjust the time of day medication is taken, or the dose can improve sleep.
Dementia: Patients with dementia have very disturbed sleep which effects both them and their caregivers. One of the reasons is the high prevalence of sleep disordered breathing in this group of patients. Since it is known that treating sleep disordered breathing in younger adults improves memory, the University of California San Diego is conducting research on whether treating sleep disordered breathing in patients with mild to moderate Alzheimer’s disease will also improve their memory. They are also studying the effect of caregiving on sleep of the caregiver. The hope is that the results of these studies will help improve the quality of life of both the patient with Alzheimer’s disease and of their caregivers.
Copyrighted by Sonia Ancoli-Israel, Ph.D
