“Do you know why, when I immediately wake-up, I get a heat surge through my body?” she asked.
The question took me back in time. A few years ago, when in my early 50s, I experienced the same phenomenon. Many women do, especially as they move into their post-menopause years. The ‘heat surge on waking-up’ moment can be confusing, but there’s a logical reason for this and, if you have client’s complaining about this, despite them being on HRT, I want to explain all about the Cortisol Awakening Response.
What is the Cortisol Awakening Response?
I first heard about cortisol and a phenomenon known as the Cortisol Awakening Response (CAR), when I was studying sport and exercise science and exploring the hormonal and blood pressure changes, which occur in female athletes who over-train.
I never imagined that I would be going back to studying this, during my menopause transition, many, many years later.
You may have heard of Cortisol – it’s one of our chronic stress hormones. As a stress hormone it is made in the adrenal glands and as such, it is known as a ‘glucocorticoid hormone’.
This means it is produced from cholesterol circulating in the blood stream. In this case, cortisol is made from the ‘good’ cholesterol – HDL Cholesterol, in the adrenal glands.
Increased cortisol production occurs when humans wake up, undertake exercise or face a stressful event. As such, the pituitary gland reacts to these situations and sends a signal to the adrenal glands to produce the right amount of cortisol.
This is why the morning wake-up heat production is related to cortisol production. Because this powerful hormone is a glucocorticoid hormone, it also has an effect on the tone or elasticity of the blood vessels.
Cortisol wakes us up. If the awakening response is also linked to sweating or hot flushes (hot flashes), then this is due to higher-than-normal cortisol levels.
For many women, especially those in post-menopause, this can be due to the adrenal glands producing more cortisol. This is turn affects blood pressure, heart rate and breathing.
In turn, these metabolic changes also cause the wave of heat to pass through the body as the blood vessels don’t dilate as readily – a response to the ageing of the blood vessels, a condition known as ‘vascular or arterial stiffness’.
The cortisol awakening response (CAR) is the acute increase of the cortisol level in the 30-45 minutes after awakening.
CAR is believed to act as a “boosting” mechanism, to aid in physiologically preparing one for waking up and getting on with the tasks of our day.
Salivary cortisol increases and reaches a peak 30 minutes after awakening and then decreases to its lowest level at nighttime. This is the normal rhythmic function of the circadian rhythm.
If this circadian rhythm gets out of balance, so too does the balance between melatonin (the sleep hormone) and cortisol. Blood pressure and resting heart rate become elevated, also contributing to the feelings of heat on awakening.
Because the cortisol-awakening-response is driven by both nerves and hormones (neuro-endocrine system), any irregularities depend on how balanced the hypothalamus, pituitary gland and adrenal glands are.
The connection that these three organs have is known as the Hypothalamus-Pituitary-Adrenal Axis (HPA axis). The working of this axis is considered to be influenced by, and sensitive to, a host of psychological conditions and stressors.
All of which affect your cortisol levels throughout the day.
Workplace and personal stress, over-exercising, insomnia, too much fasting, being too thin, or being overweight, as well as menopause hormonal changes, all affect HPA-Axis function, which in turn affects the morning Cortisol-Awakening Response.
Cortisol is widely recognized as one of the chronic stress hormones. Some is good, too much isn’t so good.
Cortisol has a diurnal (day-night) pattern and works in with melatonin, the sleep hormone. Cortisol levels are generally high in the morning and low at night, unless there are disruptions to its normal fluctuations throughout the day, such as when women are busy, exhausted, over-exercising, overweight or stressed.
For women going through menopause, high levels of exercise also affect cortisol levels
It is well known in sport and exercise science, that heavy, intense exercise, cause an elevation of cortisol. During heavy exercise, cortisol concentrations tend to increase, particularly at intensities above 60% of VO2 peak.
This increase is a physiological response to the physical stress of exercise. Whilst most studies have been conducted on males, it seems that moderate-to-high intensity exercise can significantly elevate cortisol levels, with high intensity potentially increasing them by as much as 83% compared to resting levels. [Hill et al., 2008].
Cortisol is an essential hormone in exercise. It’s role is to help free proteins from the muscle, to be used in the liver for the production and use of more glucose (gluconeogenesis).
This is why, for endurance athletes especially, they tend to not have the size of muscles that bodybuilders have. Increased exposure to cortisol increases muscle breakdown or catabolism. This is why both the stress of heavy exercise AND the stressful life of women, accumulate in a phenomenon known as allostatic load.
It’s the same for women doing lots of high-intensity exercise and not sleeping – the greater the exercise intensity, the higher the levels of cortisol.
As I’m always saying to Practitioners who undertake my certified courses, or for women who come onto the MyMT™ programmes,
‘without proper recovery, intense exercise can lead to elevated levels of cortisol in the bloodstream and heightened symptoms of physical stress, even when exercise is not being performed – such as first thing in the morning. For women in menopause, this elevated cortisol, can give them a hot flush on awakening’.
Elevated heart rate and /or elevated cortisol go hand in hand – add on dehydration, inflammation, low blood glucose, low iron levels, and additional stress, then, whether your clients are exercisers or not, elevated cortisol may be the cause of hot flashes in the morning on awakening.
Are your clients waking up to hot flushes in the morning?
Hot flashes and night sweats differ from the general heat women may feel on awakening. Cortisol Awakening Response [CAR], doesn’t generally lead to sweating first thing in the morning.
However, an elevated heart rate, the anticipated stress of the day ahead and overnight insomnia, can contribute to an elevated Cortisol Awakening Response and the feeling of heat moving down the body.
Declining Elasticity and Tone in Blood Vessels Increases CAR
For a number of years, I’ve talked about the changes to blood vessels as women move through menopause.
This is known as arterial or vascular stiffness.
I also introduce you to this phenomenon in the Practitioner Masterclass on Menopause, which is now online for you.
Menopause is the gateway to biological ageing, so, numerous changes are occurring around the body. This includes changes to the blood vessels and other organs.
Hormones travel in the blood. They contact virtually all body tissues, however, most of them have targeted actions specific to the different hormone receptors, including in the blood vessels.
As women’s oestrogen levels naturally decline during menopause, blood vessels are ageing. This leads to vascular or arterial stiffness. Fortunately, this vascular stiffening can be slowed, not only with HRT, but also by looking after the blood vessels. This includes:
- Stress management
- Anti-inflammatory nutrition
- Adequate sleep
- Weight management
- Moderate aerobic exercise
- Not smoking
- Reducing alcohol intake
The declining elasticity in blood vessels and lymphatic vessels, means that blood pressure and heat regulation may get out of balance too.
When women have busy, active lives, the vascular stiffness can leave them feeling exhausted, (especially if they are on their feet all day).
This is why feelings of overwhelm, high cortisol levels, insomnia and burnout, contribute to worsening symptoms as women move through menopause.
How can I manage hot flushes in the morning?
There are simple lifestyle strategies, that Practitioners can share with clients. I go into these in more depth in the Certified Practitioner course, but a couple of these are:
- Calming strategies are helpful. This includes teaching clients specific breathing techniques, which reduce heart rate.
- Resetting the normal circadian day/night cycle. Cortisol should be high in the morning (but not too high) and over the course of the day, it should be lowering as women move into the evening hours.
- Have a focus on strategies to reduce your client’s blood pressure. This is especially important in the evening, before bedtime.
- Help overweight clients lose weight. Increased visceral fat is associated with increased temperature regulation and oxidative stress. Helping clients to lose weight is an important strategy for managing hot flushes.
If you are struggling to get results with your midlife clients, especially with weight loss, then join me on the Certified Menopause Weight Loss Coach Course. You can read about how they work HERE.
Dr Wendy Sweet, MyMT Founder/ Member: Australasian Society of Lifestyle Medicine.
References:
Anderson, T., Wideman, L. Exercise and the Cortisol Awakening Response: A Systematic Review. Sports Med – Open 3, 37 (2017). https://doi.org/10.1186/s40798-017-0102-3
Edwards KM, Mills PJ. Effects of estrogen versus estrogen and progesterone on cortisol and interleukin-6. Maturitas. 2008 Dec 20;61(4):330-3. doi: 10.1016/j.maturitas.2008.09.024.
Elder GJ, Wetherell MA, Barclay NL, Ellis JG. The cortisol awakening response–applications and implications for sleep medicine. Sleep Med Rev. 2014 Jun;18(3):215-24.
Gerber LM, Sievert LL, Schwartz JE. Hot flashes and midlife symptoms in relation to levels of salivary cortisol. Maturitas. 2017 Feb;96:26-32.
Hill EE, Zack E, Battaglini C, Viru M, Viru A, Hackney AC. Exercise and circulating cortisol levels: the intensity threshold effect. J Endocrinol Invest. 2008 Jul;31(7):587-91. doi: 10.1007/BF03345606.
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Nijm, J. & Jonasson, Lena. (2008). Inflammation and cortisol response in coronary artery disease. Annals of Medicine, 41. 224-33. 10.1080/07853890802508934.
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