Circadian Rhythm and Sleep in Perimenopause

By Suzanne Fenske, MD, FACOG, ABOIM, MSCP

Circadian Rhythm and Sleep in Perimenopause

The circadian rhythm aligns every cell in the body with the natural world. It promotes sleep at night and alertness during the day. When your rhythm falls out of alignment, as can be the case during perimenopause, you’ll feel it as insomnia, anxiety, and low energy. And when you don’t sleep well, it affects everything, even exacerbating other perimenopausal symptoms.

Today’s article will dive into circadian science, how it changes in midlife, and what you can do to support your body’s natural rhythms to feel and function better during this life transition. Keep reading as we explore:

• What is the circadian rhythm?
• The role of cortisol and melatonin
• Health impacts of circadian disruptions
• Sleep and rhythm changes in perimenopause
• Circadian and sleep-supportive habits

What is the Circadian Rhythm?

Everybody has an internal circadian clock, a system that adapts to external cues and regulates physiologic systems. The suprachiasmatic nucleus (SCN) is the master pacemaker in the brain that synchronizes the peripheral clocks in every cell in the body. The SCN receives light signals from the eye, which coordinates the diurnal, sleep-wake rhythm of the body. This 24-hour rhythm determines the rhythm of cell cycles, metabolism, immunity, blood pressure, hormones, and more.

Blue light is the strongest stimulus and regulator of the circadian rhythm, keeping the system synchronized. Blue light from the sun during the day supports wellbeing, alertness, cognitive performance, hormonal balance, and more. However, chronic low-intensity blue light exposure from technological devices and indoor lighting, especially in the evening after sunset, negatively impacts circadian cycles.

In addition to blue light, the daily circadian rhythm is influenced by:

• Stress
• Physical activity
• Social environment
• Temperature
• Food intake

The Role of Melatonin and Cortisol

Melatonin and cortisol are two key circadian hormones, both following a diurnal, daily pattern. Cortisol rises in the morning and falls in the evening, whereas melatonin is high at night and low during the day.

Melatonin, the sleep hormone, is suppressed by blue light exposure during the day and then increases in the evening after dark to promote drowsiness and sleep through the night. Disruption of the melatonin pattern or levels impacts sleep and contributes to circadian issues.

Melatonin levels decline with aging and the menopausal transition, accounting for at least some of the sleep disturbances women face at that time.

Cortisol works in opposition to melatonin. Cortisol is low at night, spikes in the morning (called the cortisol awakening response), and then declines throughout the day. This predictable pattern supports daytime alternes, energy, and activity, while giving way to melatonin at night. If cortisol is high at night when it’s supposed to be low, often because of stress, it may be hard to fall and stay asleep.

Circadian Rhythm and Health

Disruptions in the circadian rhythm affect sleep, metabolism, and cognitive function. Symptoms may include:

• Difficulty falling asleep
• Difficulty staying asleep
• Feeling tired, but wired
• Sleeping, but not feeling rested
• Daytime fatigue
• Mood changes

Over time, disruptions contribute to aging and chronic diseases, including cancer, cardiovascular disease, and metabolic disorders.

The Effect of Perimenopause

Estrogen has many roles, and one is the regulation of circadian gene expression within cells. Ovulation requires estrogen coordination with SCN signals, and as estrogen declines in late perimenopause and beyond, not only does it lead to the cessation of ovulation and fertility, but it can also disrupt sleep and the circadian rhythm. Changes in estrogen mean changes in the circadian rhythm, hormones, metabolism, body temperature, heart rate, and more. 

Because of the hormonal landscape, women have more circadian changes and more extreme symptoms than men.  Women experience higher rates of insomnia than men. Perimenopause only amplifies these changes.

Sleep disturbances are one of the most common perimenopausal symptoms, affecting nearly 56% of perimenopausal women. Not only do the circadian rhythm changes and declining melatonin levels contribute, but perimenopausal symptoms themselves can disrupt sleep. Urinary frequency, night sweats, depression, and other symptoms associated with the transition make it more challenging to get enough, high-quality sleep.

In a study comparing young women to postmenopausal women, the postmenopausal women had worse sleep based on all parameters measured. They had a harder time falling asleep, less total sleep time, more nighttime alertness, and worse circadian melatonin variations.

How to Support Your Circadian Rhythm

Perimenopause drives circadian changes, which can in turn reinforce hormonal disruptions. What is a woman to do? Luckily, the circadian rhythm responds to various external and internal factors that you can influence with lifestyle habits, including these:

• Take cues from the sun. In the morning and throughout the day, expose your eyes to natural sunlight. You can sit by an open window and take a walk outside. In the evening, dim indoor lights and limit blue lights from devices. Try the night setting on your phone or wearing blue light-blocking glasses while watching TV.

• Create rhythm with daily activities. Go to bed around the same time each night and get up around the same time each day. Eat meals at regular times throughout the day and limit food intake before bed. Try exercising early in the day. Create routines that your body adapts to over time.

• Gather personal information. TārāMD offers comprehensive and advanced testing. Let us take a close look at your daily cortisol pattern, melatonin levels, estrogen status, and more. With this information, we can target imbalances with a personalized approach.

• Support a healthy cortisol curve with a whole food, protein-rich diet, limiting sugar and ultra-processed foods. Increase nutrients, including B vitamins, vitamin C, and magnesium. Be mindful of exercising too much or not enough. And most importantly, manage stress like your sleep and life depend on it. Learn more about cortisol and adrenal health here.

• Focus on plant-rich foods in your diet. Recent research looked at the effects that including more fiber in the diet had on sleep quality. While fiber is known to support digestion, it seems its impact on sleep is also positive. Adults with higher intake of plant foods experienced less disrupted sleep at night.

• Support healthy melatonin levels by creating a relaxing bedtime routine and limiting blue light before bed. Sleep in a dark room (hello blackout curtains). Increase melatonin-rich foods, such as pistachios and tart cherries, or discuss low-dose melatonin supplementation or other sleep supplements with your TārāMD

• Consider bioidentical hormone replacement therapy. BHRT, both estrogen and progesterone, support a healthy circadian rhythm and sleep. While there is much misinformation about hormone therapy, the truth is that it’s very safe and effective for addressing symptoms and long-term consequences of hormone deficiency. Read more here.

The circadian rhythm is foundational for life; it’s how the body synchronizes with the natural world, maintains a sleep-wake pattern, adjusts to the seasons, and maintains internal body rhythms. However, for many women, perimenopause may disrupt the circadian rhythm, leading to sleep challenges and other symptoms. Restoring and supporting the body’s natural rhythm improves sleep and eases perimenopausal discomfort, and we can help. Reach out to TārāMD today.

References

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