Living your best life by sleeping better
Written by Jessica Binkley Lain
Inadequate sleep doesn’t just cause sleepiness and poor concentration. It can also degrade the body over time and age us quicker.
We’ve all been told how essential sleep is to our health. But in our busy, often over-worked lives, many feel it’s worth the risk to scrimp on sleep. “I’ll sleep when I’m dead” is an all-too-common response for many when asked about their sleep habits.
That mentality is dead wrong, explains Vincent Mysliwiec, MD, FAASM, a professor of research and director of sleep medicine at UT Health Science Center San Antonio. Sleep is a biological requirement that helps the body to recover physically and mentally, to process emotions and consolidate memories, Mysliwiec said. Without sleep, memory and emotions do not function properly, and health suffers. Worse, too little sleep can even lead to an early death.
“We have seen studies where individuals with a short sleep duration were shown to have higher rates of mortality,” he said, noting that while it’s not a direct cause-and-effect relationship, poor sleep causes hormonal imbalances that can lead to detrimental effects on health. Imbalances caused by insufficient sleep can lead to unintentional weight gain. This happens because poor sleep decreases production of the hormone leptin, which decreases appetite. Lack of sleep also increases ghrelin, the hormone that triggers the feeling of hunger, Mysliwiec said.
“When those two hormones are imbalanced, it can contribute to poor eating practices, which then, along with many other factors at play, can lead to obesity, hypertension or cardiovascular disease,” he said.
There have also been substantial advances in understanding the critical role of sleep for brain health. During sleep, the toxic metabolic byproducts of the brain are cleared away through the glymphatic system, Mysliwiec stated. Similar to the body’s lymphatic system, the glymphatic system is responsible for eliminating metabolic waste from the brain, helping to prevent the accumulation of tau and amyloid beta, which are linked to Alzheimer’s disease. In other words, good sleep can help stave off dementia.
Drilling down on a unique demographic
Mysliwiec’s research has focused on sleep and sleep disorders in military personnel.
“We have learned that the rigors of military service, which include long duty days, frequent changes in sleep patterns, short sleep duration, sleeping in austere environments and periods of stress from deployments and leadership positions contribute to the development of sleep disorders,” he said.
Mysliwiec’s findings have established that the most prevalent sleep disorder in military personnel is the co-occurrence of insomnia and obstructive sleep apnea, also known as COMISA. Military personnel with COMISA have higher rates of mental health disorders such as anxiety, depression and PTSD.
“Sleep disorders are more common with age, and sleep apnea is typically diagnosed in middle-aged adults,” Mysliwiec said. “The finding that these complex sleep disorders are present in younger military personnel supports that military service may be a distinct risk factor for sleep disorders, which may also be present earlier than expected.”
The reason for earlier diagnosis in military personnel is, in part, due to short sleep duration, as military personnel typically sleep less than six hours per night, he said.
Sleep cycles and stages
Sleep occurs in cycles of about 90–110 minutes, with four stages for each cycle. Dreaming can occur in each stage. In general, most people need five cycles per night to achieve the full benefits of sleep — hence the well-known recommendation for getting eight hours of sleep each night.
Because each stage of sleep does something helpful, uninterrupted sleep cycles are important to hit every stage. For example, the deepest sleep occurs in Stage 3, where the body can adjust hormones, metabolism and the immune system. Waking during this stage may lead to grogginess the next day.
The last stage of a sleep cycle, Stage 4, is called rapid eye movement, or REM sleep. It’s in this stage that the brain processes new information and commits it to long-term memory.
How aging impacts sleep
Sleep needs do shift slightly with age, with adults over 60 typically going to bed earlier and waking earlier, known as an advanced sleep phase, Mysliwiec explained. Their sleep cycles are slightly shorter in length, but no less important to complete. They still need a full night’s rest to maintain good health and functionality. Older adults typically need about 30 minutes less sleep a night than younger and middle-aged adults because of these shorter sleep cycles. But very often, older people are not getting the sleep they need.
The reason for this is that the sleep of older adults is often fragmented, waking multiple times a night, often in the middle of a sleep cycle, Mysliwiec said. This can be due to sleep disorders as well as medical disorders such as nocturia, or using the restroom at night from prostate enlargement in men or incontinence in women.
Chronic pain also can wake a person in the middle of a sleep cycle and often make it difficult to fall back asleep. This loss of sleep can make chronic pain worse, implementing a vicious cycle. Pain control is essential for good sleep but should be achieved with as little opioid use as possible. That drug class interferes with the REM sleep cycle stage and can worsen pain.
Sleep disorders are seen at a much higher rate among older adults than in younger adults, with the two most prevalent disorders being insomnia and obstructive sleep apnea, said Mysliwiec. Insomnia is present in at least 25% of older adults, with a greater prevalence in women compared to men, and approximately 50% of older adults have obstructive sleep apnea, seen more frequently in men, he said.
However, there are challenges to studying sleep disorders for those of advanced age.
“The current standard for evaluating sleep stages and architecture is based on human scoring, which does not necessarily account for the changes that occur to the electroencephalography [EEG] pattern of older individuals,” Mysliwiec said, noting that to better understand age-related changes in sleep, specific sleep characteristics need to be compared at the individual level to filter out masking variables, such as skull thickness.
More longitudinal studies to assess EEG-based changes over time are also needed to allow researchers to determine if changes in sleep patterns in older adults are in fact consistent with an underlying sleep or brain disorder or inherent to the normal aging process, he said.
Mysliwiec advised that early diagnosis, intervention and preventative measures can protect individuals from the degrading effects of insufficient sleep. Treating sleep disorders not only helps prevent dementia and obesity, but it also increases productive cognition during the day and decreases the risk of infection.
“There are healthy sleep habits we can adopt, as well as treatments and interventions available for sleep disorders to help someone get the good sleep they need,” he said. “Getting the best sleep you can get earlier in life is going to pay dividends later in life.”
