Professor Kaye is taking a break this month, so I’m going solo to talk about something that we can all relate to……..sleep. Earlier in my career I was a sleep researcher, studying sleep in diseases of aging, such as Alzheimer’s and Parkinson’s diseases. So sleep is something I like to talk about. But then again, sleep is something everyone likes to talk about. Everyone does it. Some do it with ease; some struggle with fitful effort. And although we all know that a person’s age affects sleep in many ways……..not many are aware of new research that tells us that sleep actually affects aging itself. Let’s first look at some basic facts about sleep and aging.
Aging affects sleep in lots of ways, although it doesn’t actually change sleep requirement, at least not for most people. Adults generally needs less sleep than children and adolescents, and older adults on average need as much sleep as younger adults. But getting that “sleep requirement”, usually between 6 and 10 hours, becomes more challenging as we get older. Less sleep at night is often compensated for by daytime napping. Sleep also becomes “lighter”, with less of the deep sleep that is the most restful and restorative. And older adults are more likely to have health conditions that cause frequent awakenings…….painful joints, twitchy legs, obstructing airways and frequent need for bladder breaks. The net result is lower sleep efficiency…….less time sleeping for the time in bed. Aging also can change the function of the “body clock” in the hypothalamus of the brain. The body clock regulates the body’s many rhythms and cycles, especially the daily (circadian) rhythms such as sleep and wakefulness. Through adulthood, there is tendency for sleepiness to come earlier in the evening, so that “night owls” become “morning larks”, although that certainly doesn’t happen in everyone. In the very old, there may be weaker signals from the body clock for nighttime sleep and daytime alertness. In advanced dementia, sleep occurs in random episodes day or night or even complete day-night reversal. Loss of eyesight may exacerbate the loss of normal day-night cycles of sleep, as the body clock relies on light-dark data from the retina.
Insomnia is more common in older adults too, caused not only by chronic health conditions, but by worry, medications (both prescribed and over the counter) and poor sleep habits developed over years of struggling to sleep. Habits that reinforce restless sleep include going to bed too early because of boredom and spending too much time in bed not sleeping, either watching TV and reading or just lying there hoping to fall asleep. Alcohol in the evening can disrupt sleep in the second half of the night. Consuming coffee, tea and other caffeinated drinks in the afternoon disrupts sleep drive in most people. Daytime napping, lack of physical activity and insufficient exposure to natural outdoor light can all also contribute to insomnia.
Insomnia is not a medical emergency, but sleep deprivation leads to fatigue, poor concentration and crankiness. That much you knew, but what you probably didn’t know is that over time, insomnia increases risk of diabetes, inflammatory diseases, depression and dementia. Like diet and exercise, getting adequate sleep is essential for slowing the onset of chronic diseases.
What to do about insomnia? An evaluation by your primary care provider to rule out medical and psychological conditions that contribute to restless sleep is a good start. A referral to a sleep disorder center is a must if your primary problem is severe daytime fatigue or excessive sleepiness. If you habitually doze easily when sitting during the day, falling asleep within 10 or 15 minutes of sitting, you may have a serious sleep disorder such as obstructive apnea or narcolepsy. Excessive daytime sleepiness is actually a more urgent matter than insomnia. If fatigue and excessive sleepiness started recently, it may be due to a new medication or medical problem or just simple sleep deprivation. Strange behaviors during sleep, such as kicking, punching and yelling, may be signs of other serious sleep disturbances associated with neurologic disorders and also warrant a referral to a sleep specialist.
Sleep medications are helpful for many people with insomnia, but they increase the risk of falling, confusion, memory lapses and problems with nighttime breathing. Melatonin supplements are safe and worth trying, but are often not as effective for seniors. Sedating antidepressants and antihistamines may be effective for sleep, but come with their own side effects. Which is not to say medications shouldn’t be used……many people do fine with them and have improved daytime function as a result, as least in the short term. Nighttime doses of analgesics for pain and going to bed with an empty stomach (to avoid heartburn from reflux) are other important measures. Cognitive behavior therapy is probably the best long term approach for improving sleep efficiency. The simple principles of this therapy are to restrict time in bed to the time you actually sleep, to limit time in bed (and bedroom) to sleep and sex, reduce daytime napping, reduce caffeine and alcohol intake, increase physical activity and exposure to natural light and practice relaxation techniques to help with anxiety and worry. These are not easy steps to take, but in the long run they are the most effective approach to insomnia. The National Sleep Foundation website (sleepfoundation.org) is a great resource for more information.