Ageing affects sleep patterns in several ways including reducing the quality of sleep and the total hours of sleep. Over 50% of adults who are 65 and plus suffer from some form of chronic sleep-related problem. Natural ageing causes changes in sleep architecture, melatonin secretion, and circadian rhythm - all of which affect sleep. Sometimes, other health concerns and medications may also result in sleep disturbances among the elderly. In this article, we delve into the common factors that affect sleep as we age.
1. Sleep architecture:
Sleep architecture refers to the "distribution of sleep". Generally, we experience two main types of sleep: rapid eye movement (REM) and non-rapid eye movement (NREM). NREM has three different stages – wake, light, and deep sleep. In normal sleep architecture, a person will have four or five sleeping cycles per night. While some cycles may contain all three stages of NREM and REM, not all of them will contain each phase. Ageing causes fragmented of sleep architecture. For instance, as we age, we experience more "light sleep", less "deep restorative sleep" or "slow-wave", but fairly steady REM sleep or "dream sleep".
2. Circadian rhythm:
The circadian rhythm or circadian cycle refers to our internal body clock that runs in a 24-hour period to carry out essential functions and processes. The sleep-wake cycle is one of the most crucial circadian rhythms and is tied to levels of light which help us stay alert during the day. As we age, we are likely to develop circadian rhythm disorder, leading to sleep disturbances. The rhythm shifts earlier, making the elderly more alert during the early morning and sleepy in the early evenings. Patients with circadian rhythm sleep disorder tend to sleep more during the day or have insomnia.
Melatonin is a hormone that causes sleepiness and is usually secreted in the early evenings for promoting sleep at night. However, with age, melatonin secretion is reduced, resulting in insomnia. There are melatonin gummies or supplements available that can be administered for insomnia or jet lags. Although it is generally safe for short-term use and unlikely to result in dependency, common melatonin side effects include headache, dizziness, drowsiness, and nausea.
4. Health Issues and Medications:
As we age, it is common to develop various health issues which disrupt the normal sleep pattern. For example, hypertension, increased urination at night, asthma, chronic pain, and other ailments can keep the elderly up at night. Similarly, intake of various medicines at older ages can also result in insomnia and fragmented sleep. People who take sleeping pills for a prolonged time can also develop dependency and reduced efficacy.
With ageing comes many changes in lifestyle that can affect sleep. For example, retired people are likely to lead a more sedentary lifestyle without much physical activity, or a proper routine, which can create sleeping problems.
The environment also plays a crucial role in promoting a good night's sleep, especially among the elderly. A familiar and comfortable ambience can promote peaceful sleeping while unfamiliar places during travel or holidays can result in insomnia or jet lag. A relaxing environment with proper temperature, low levels of light and noise, and comfortable bedding can greatly improve sleep at night.
"As we age, 3 things happen to our sleep:
- The distribution of sleep stages changes and there is a decline in slow wave sleep (deep sleep), and increase in light stages I and II, and sleep becomes lighter and more easily disrupted.
- The amount of sleep does not necessarily change but the distribution of sleep does and we tend to get less sleep at night and require an afternoon nap.
- Sleep becomes more disturbed by external factors such as pain, chronic disease such as diabetes or heart disease and medications we take from the doctor.
We do not yet know why these things happen, whether they are bad for us or if we can improve the changes as we age."
- Dr. Charles Samuels, M.D., CCFP, DABSM, Medical Director of The Centre for Sleep & Human Performance