Sleep patterns change with age

The gradual changes in our bodies that occur as part of the aging process also affect our sleep. Even in healthy older people, sleep becomes more fragile. It becomes harder to settle into sleep, and more awakenings occur throughout the night.

These changes have been demonstrated in sleep laboratory studies. Sleep efficiency (the time spent asleep compared to time in bed), falls from its high values in youth (95 to 98%) to 70 to 80% in older age. Also, the amount of light sleep increases with age, and the amount of deep sleep is reduced. Some research has demonstrated that we need less sleep as we age, but most experts believe that we need just as much. And although as we age we may sleep less at night, we are taking more naps or dozing while reading or watching TV.

Additionally, the arousal threshold falls as we age, so that sounds and other interruptions are more likely to awaken us.

Another aspect of aging is that the normal circadian pattern (24-hour rhythm) of sleep gradually weakens, and sleep tends increasingly to be spread across the 24-hour day rather than being consolidated in the nighttime sleep period. All of these changes result in the common complaint of seniors: that sleep is shorter and less restorative than it was in their youth.

Most seniors notice that their sleep is interrupted by other changes in their bodies. For example, muscle or joint pains may make it difficult to get comfortable, and most people over the age of 65 must visit the bathroom at least once during the night. However, these are normal aspects of aging.

The most problematic and long-term sleep difficulties in seniors are due to medical conditions (e.g., lung disease, arthritis, reflux and heart disease) and mental health issues such as depression and dementia. In addition, specific sleep disorders such as sleep apnea and periodic limb movement disorder are also associated with age, and affect sleep.

Since disturbed sleep is common in seniors, it can be difficult to distinguish between a normal aging process and a disease state. Therefore, a medical check-up is needed to determine the cause when older individuals experience persistent trouble in falling or staying asleep that is associated with daytime problems (e.g., marked sleepiness, mood changes, pronounced fatigue, forgetfulness, loss of interest or pleasure).

Good lifestyle habits result in better sleep

Poor sleep habits can worsen the sleep changes associated with aging. Therefore, by simply changing these habits, the sleep problem may be reduced or eliminated, resulting in a better quality of life. Helpful strategies include reducing caffeine intake, avoiding large, heavy meals late at night, and reducing daytime naps.

Also, active seniors report fewer sleep problems than their inactive counterparts. Physical exercise such as walking briskly for 30 to 40 minutes has beneficial effects on sleep, regardless of age.

Specific sleep disorders

Just as medical and mental health issues become more common as we age, specific sleep disorders are also more common and affect the amount and quality of sleep.

One example is sleep apnea, which is breathing problems during sleep. In obstructive sleep apnea, loud snoring and pauses in breathing are noticed by the bed partner, but the sleeper may have no complaints apart from sleepiness in the day. Obstructive sleep apnea is due to narrowing or closure of the airway during sleep. It is caused by many factors, including obesity. The breathing disturbance causes brief awakenings, which disrupt sleep but are not usually recalled in the morning. Common associated symptoms are difficulty with memory, concentration and thinking, and daytime sleepiness, including sleepiness while driving.

Obstructive sleep apnea requires treatment such as use of a device that uses air pressure to keep the throat open, plus other strategies such as weight loss. Treatment is necessary because obstructive sleep apnea has been linked to several conditions such as heart disease, depression, and headaches.

The second, less common type of breathing disturbance associated with age is called central sleep apnea. This type of sleep apnea is caused by a failure, during sleep, of the brain's control of the breathing process. In this condition, snoring is usually absent. Sighing breaths or shallow breathing may be noted by the bed partner. Unlike people with obstructive sleep apnea, those with central sleep apnea are more likely to remember their awakenings and complain of light and fragmented sleep.

Periodic limb movement disorder

About half of all people aged 65 or over experience twitching in the legs and sometimes the arms during the night. When these twitches and jerks are prominent and frequent, the condition is called periodic limb movement disorder (PLMD). Diagnosis of periodic limb movement disorder requires a sleep laboratory evaluation to confirm the presence of the movements and their effects on sleep. Commonly, these movements occur in "batches," and can occur as frequently as 2 or 3 times a minute. People with periodic limb movement disorder may complain of marked sleep disruption, or may not be aware of it at all. Periodic limb movement disorder usually causes insomnia and, more rarely, excessive daytime sleepiness.

People with periodic limb movement disorder may also experience "restless legs" when awake. Restless legs syndrome is present when a peculiar and difficult-to-describe sensation occurs in the calves or thighs while at rest. Characteristically, it is relieved by movement but recurs on resting again. Both periodic limb movement disorder and restless legs syndrome can be treated with non-medication and medication approaches.

REM sleep behaviour disorder

Normally, during the dreaming part of sleep (called the rapid eye movement or REM part of sleep), the body is paralyzed. However, for people with REM sleep behaviour disorder, this does not occur, resulting in an enactment of dreams. A variety of behaviours can occur associated with dream enactment (striking out, swearing, falling, etc.), and self-injury or injury of the bed partner may occur. This disorder is more common in men over the age of 60, and can be associated with other neurological disorders.

original article by Jon Fleming, MD,
with revisions by the MediResource Clinical Team