Most of us feel like we need more sleep, but as a species, we have evolved to sleep less than any other primate. The most promising discovery for this theory is that whilst humans have evolved to spend less time sleeping, they have also evolved to sleep very deeply. When you think about the bedroom with the closed door, dark room and quiet area, it makes more sense that we would sleep deeper than if we were on the grass or up a tree. It also makes more sense that those who are anxious or light sleepers, feel that they need more hours of sleep per night.
Sleep is a mysterious yet necessary process that all humans, ranging from those who are very rich, to those who are very poor, require on a regular basis in order to function adequately. While most people take sleep for granted and some of us consider it to be ‘wasted time’, it isn’t until we start to feel the effects of poor sleep that we begin to understand the vast importance of deep, restful, high quality sleep.
Sleep places the body into a relaxed state, we all know that, but did you know that it is involved in modulating the metabolic processes, detoxification, thermoregulation, growth, neurotransmitter function and development, immune system defence responses, and learning and memory acquisition? Sleep is a process that is necessary to sustain life, and sanity, with a disruption of this cyclical wheel being a recipe for disaster, in every aspect of a human’s wellbeing.
A good night’s sleep consists of four to six 90-120 minute cycles of various stages and levels of sleep. Five stages of sleep have been identified, with most cycles involving all five stages. Stage 1 and 2 are considered to be relatively ‘light’ stages of sleep, and if you are woken in this time you may report that you were not actually asleep. This is the transition from wakefulness and sleep, with the slightest event bringing you back to wakefulness. Stage 1 represents about 5% of our sleep time, and stage 2 represents about 50% of our sleep time. Towards the end of stage 2, our body prepares to enter deep sleep. Stage 3 and 4 are considered to be ‘deep sleep’ stages covering approximately 20% of our total sleep time. During these stages, it is difficult to be awakened by external events, and if woken, you may be confused, disorientated or frightened. This is the time that mental and physical recuperation and regeneration occurs, along with possible sleep walking and sleep talking. Once you reach stage 4 in your sleep cycle, you then go back to stage 3, stage 2 and sometimes stage 1. Near the end of each sleep cycle you enter REM sleep (rapid eye movement sleep). This is our lightest stage of sleep, and is associated with sudden and dramatic loss of muscle tone, heightened brain activity and rapid eye movement. It is in this time that most dreaming occurs with the first period of REM lasting 10mins, lengthening with each cycle, with the final one lasting about an hour. Typically, after our last REM stage we wake, with some people being aware of their intense dream time. It is common to wake 2-3 times per night, often without the knowledge of wake.
The above is considered to be what happens during a good night’s sleep. Unfortunately, not everyone gets a good night’s sleep. Identifying why your sleep is interrupted is key to achieving quality sleep.
When looking at sleep problems, we must consider what some people believe is the obvious; pain, noise, bladder, stress or light. However, approximately 20% of menopausal women sleep less than 6 hours per night. Many have difficulty maintaining sleep due to hot flushes or night sweats, and others have trouble getting to sleep due to a seemingly unknown reason. The classical problem with controlling the core body temperature can not only cause the obvious hot flushes and interrupted sleep, but an increased body temperature prior to sleep and during sleep has been significantly correlated with poorer sleep efficiency, even in women who are not experiencing the wrath of hot flushes and night sweats. An inability to reach stage 3 or 4 of the sleep cycle can lead to a less rejuvenating and less restful sleep, affecting quality of life on multiple levels.
If hot flushes or night sweats are the cause of your poor sleep, the Australian Menopause Centre can help. However, if you are one of those unlucky women who are waking or having trouble getting to sleep due to an unknown cause, further investigation and digging must be done.
Progesterone, known as the calming hormone, is believed to influence sleep. It is produced by ovulation, and during perimenopause and menopause, ovulation is often erratic, and then absent. Progesterone has several functions, but one of its thoroughly missed functions is its ability to calm the mind, and thus calm the body. When a person wakes for no known reason through menopause, or develops a sleep disorder that primarily started from her mid-40s, hormones and essentially progesterone deficiency must be suspected. Poor quality sleep during peri-menopause and menopause can quite often be settled with the introduction of progesterone supplementation.
One under-investigated aspect of how menopause can affect your sleep, is the development of sleep disordered breathing (SDB). SDB refers to a number of sleep related breathing difficulties including obstructive sleep apnoea, central sleep apnoea and complex sleep apnoea. It has been suggested that with all the changes that occur through peri-menopause and menopause the possibility of developing a sleep disordered breathing condition may not be so obvious as they can develop over a period of years. The classical symptoms of SDB include dozing off during the day, fatigue, excess sleepiness, poor concentration, waking unrefreshed, snoring or nocturnal choking. Those with excess weight, particularly around their abdomen, and a reduced muscle tone (both common in menopause) are at a higher risk of developing one of these sleep related breathing conditions. In fact, compared to pre-menopausal women, postmenopausal women are 2.6 times more likely to have sleep disordered breathing.
Another aspect to consider in menopause is melatonin. Melatonin is a hormone that is produced in the brain in response to darkness. It is the hormone that comes out when the sun goes down and leads you to feel sleepy. In ageing women, the level of melatonin produced at night progressively declines, reaching minimum levels in menopause. This progressive decline in night time melatonin can not only result in a lack of sleepiness and thus insomnia, but it can cause a desynchronization of the circadian rhythm leading to the onset and progression of menopause and sleep problems. Melatonin is often used for initiating sleep, regulating the circadian rhythm and maintaining sleep. Furthermore, it has been suggested that there is a cause-effect relationship between the decline in nocturnal levels of melatonin and the onset of menopause.
Habitual natural sleep time varies greatly with individuals. In an average adult, normal sleep time averages 8.3 hours and normal sleep latency is 10 minutes. Total sleep time decreases with age, along with napping occurring at the beginning and end of life. Whilst there are numerous possible reasons you may not be sleeping adequately, if you are on this site, it is possible, and likely that your hormones and menopause are contributing to your picture. If you are not happy with the length or quality of your sleep, contact us today. The Australian Menopause Centre is able to expertly assess how your hormonal imbalance may be contributing to your insomnia.