The amount of sleep an individual needs varies; most adults require seven to eight hours each night. In addition to quantity, sleep quality matters, too. Waking frequently, or fragmented sleep, interrupts the sleep cycle and can contribute to an inability to achieve periods of deep and REM sleep, the stages associated with restful and restorative sleep.
Older adults are at higher risk for sleep deficiencytending toward fewer sleeping hours and a different sleep-cycle pattern. Deep-sleep stages become very short or stop completely. Several factors likely play a role, including normal aging, medications or a medical condition that can cause pain or discomfort during the night such as arthritis, hot flashes, frequent nighttime urination, cancer or lung disease.
A small study published in March 2013 in Nature Neuroscience explored the relationship of poor-quality sleep with changes in the brain’s prefrontal cortex (where long-term memories are stored) associated with aging, which both led to reduced slow-wave activity during non-REM sleep.
Researchers concluded that the lack of deep sleep in older adults combined with these structural brain changes is linked to impaired memory and age-related cognitive decline but couldn’t establish a direct, causal connection.
What are the consequences of inadequate sleep?
Sleep deprivation is associated with:
- Cognitive impairment. Sleep deficiency impedes learning, focusing, reacting, memory, judgment, decision making and the ability to perform mathematical computations.
- Poor mental status. Sleep deficiency leads to low energy, decreased libido and depression and anxiety symptoms, not to mention crankiness and irritability. Sleep problems are common among people with mental illness, and extreme sleep deprivation can trigger paranoia and hallucinations in healthy people.
- Physical health risks. Chronic sleep problems are linked with high blood pressure, stroke, heart disease, heart failure and diabetes. They're also associated with an increased risk of falls and broken bones in older adults.
- Immune dysfunction. The ability to fend off viruses like colds is affected by lack of sleep.
- Obesity. Lack of sleep affects the appetite hormones, causing higher levels of the hormone ghrelin, which make you feel hungry, and lower levels of leptin, which make you feel full. This leads to overeating and an increased appetite for high-carbohydrate, calorie-dense foods.
- Declining quality of life. Nearly 40 percent of adults report falling asleep during the day without meaning to, at least once a month. Inappropriate drowsiness and napping, embarrassing enough, may affect relationships. Lack of energy may lead to withdrawal from activities and socializing.
Are you sleep deficient?
So many people suffer from poor sleep that sleep deficiency has become the new normal, and you may not associate the above problems with a lack of sleep. You could be sleep deficient if you often feel as if you might nod off while reading, sitting in a meeting, watching a movie in a theater or while riding in a car or sitting in traffic.
If you're experiencing health or cognitive problems that could be related to poor sleep or if you're not feeling well rested, keep a sleep diary for a few weeks by recording the amount of sleep you get each night and how alert or sleepy you feel during the day. Then show the diary to your doctor, who, after ruling out any underlying medical reasons for poor sleep, should be able to help you.
Source: Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50