At the Menopause Centre, we treat thousands of women and one of the most common complaints with either perimenopause or menopause, is without a doubt, sleep disturbances. It is very rare that we speak to a patient, who does not have some sort of sleep deficit occurring. Sleep is so multifactorial and multifaceted, there isn’t just one factor that will negatively or positively impact our sleep patterns.
When we talk about sleep there is one major biological process that occurs that has a huge influence on not only our ability to fall asleep but also on the quality of our sleep. This is called the circadian rhythm.
Put quite simply, the circadian rhythm is essentially our sleep/wake cycle. It is our 24 hour internal body clock and it cycles between sleepiness and alertness. On average, most adults experience the biggest drop in their energy levels between 2-4am and luckily for most, we’re sleeping during this time. Another dip occurs between 1-3pm and this is quite often where we long for a post lunch nap. These times will of course vary depending on whether you’re a night owl or an early bird. These dips in energy levels should not generally be felt, especially if you’re caught up on sleep and will only really be felt if you’re sleep deprived. (1)
A portion of the brain, called the pineal gland, controls our circadian rhythm and its functionality is very much dependant on darkness and light. The major hormone that is produced by the pineal gland is called melatonin.
When there is an abundance of light, the pineal gland turns off its production of melatonin and when there is enough darkness, melatonin production increases. It is this light/dark and dark/light transition that resets our circadian rhythm.
As we age, all aspects of our biological functionality tend to deteriorate and the circadian rhythm is no exception. Melatonin production has been found to commence its decline by the 5th-6th decade of life.
Aging is associated with both impairments of the circadian rhythm and subsequently, reduction in melatonin secretion. Quite often subclinical changes in these areas occur during middle life however, quite frequently, diagnosis is missed.
It has been found that some mental health conditions, such as depression and bipolar can result in decreases in production of melatonin. There tends to be a defect in the amount of melatonin that is produced.
Chronic obstructive pulmonary disease and fibromyalgia are becoming common conditions that many peri/menopausal women are experiencing. Evidence is suggesting atypical levels of melatonin are produced, therefore, negatively influencing sleep.
Although the circadian rhythm and melatonin isn’t directly correlated to the perimenopause/menopause, it has been speculated that they may assist in improving wellbeing and moods.
Surprisingly, melatonin has a positive influence on bone density, through the synchronization of bone turnover. As a result, lack of melatonin production may play a role in the development of postmenopausal osteoporosis. A study of perimenopausal women taking 3mg of melatonin per day, over 6 months, showed improvements in markers of bone turnover. (2)
There are of course, multiple factors during the menopausal transition that can impact our sleep however, the role of the circadian rhythm and melatonin should not be undermined or forgotten. It is important to determine whether sleep disturbances are related to reproductive hormones such as progesterone deficiencies or, if your circadian rhythm needs a reset!
- Jeahn S, Louis G, Zizi F et al. Sleep, Melatonin and the menopausal transition. What are the links? Sleep Science. 2017; 10(1): 11-18.
- Kotlarczyk MP, Lassila HC, O’Neil CK, D’Amico F, Enderby LT, Witt- Enderby PA, et al. Melatonin osteoporosis prevention study (MOPS): a randomized, double-blind, placebo-controlled study examining the effects of melatonin on bone health and quality of life in perimenopausal women. J Pineal Res. 2012;52(4):414-26.