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Cortisol Levels, Thyroid Function and Aging


Diagram depicts the level of Cortisol over a 24 hour cycle

Interview with David Zava, Ph.D.  Originally published in the John R. Lee, M.D. Medical Letter

David Zava, Ph.D. is a biochemist, breast cancer researcher, a much-published author of professional research papers, and the laboratory director of ZRT Laboratory in Portland, OR, which does state-of-the-art saliva hormone assay and blood spot testing. He is also the co-author of What Your Doctor May Not Tell You About Breast Cancer, and a sought-after speaker on the topic of hormones and saliva hormone testing.

JLML: Cortisol is needed for nearly all dynamic processes in the body, from blood pressure regulation and kidney function, to glucose levels and fat building, muscle building, protein synthesis and immune function. You’ve been specifically studying the effects of cortisol on thyroid function.

DTZ: Yes, one of cortisol’s more important functions is to act in concert or synergy with thyroid hormone at the receptor-gene level. Cortisol makes thyroid work more efficiently. A physiologic amount of cortisol—not too high and not too low—is very important for normal thyroid function, which is why a lot of people who have an imbalance in adrenal cortisol levels usually have thyroid-like symptoms but normal thyroid hormone levels.

JLML: Would you explain this thyroid-cortisol relationship in more detail?

DTZ: One way to understand the synergy of cortisol and thyroid is to think of trying to turn on a big round valve with one hand, as opposed to two hands where you can really grip it and turn it on. Both thyroid and cortisol have to be there in the cells, bound to their respective receptors at normal levels, to efficiently turn the valve on and get gene expression. So, when cortisol levels are low, caused by adrenal exhaustion, thyroid is less efficient at doing its job of increasing energy and metabolic activity.

Every cell in the body has receptors for both cortisol and thyroid and nearly every cellular process requires optimal functioning of thyroid.

JLML: And what happens when cortisol levels get too high?

DTZ: Too much cortisol, again caused by the adrenal glands’ response to excessive stressors, causes the tissues to no longer respond to the thyroid hormone signal. It creates a condition of thyroid resistance, meaning that thyroid hormone levels can be normal, but tissues fail to respond as efficiently to the thyroid signal. This resistance to the thyroid hormone signal caused by high cortisol is not just restricted to thyroid hormone but applies to all other hormones such as insulin, progesterone, estrogens, testosterone, and even cortisol itself. When cortisol gets too high, you start getting resistance from the hormone receptors, and it requires more hormones to create the same effect. That’s why chronic stress, which elevates cortisol levels, makes you feel so rotten—none of the hormones are allowed to work at optimal levels.

Insulin resistance is a classic example. It takes more insulin to drive glucose into the cells when cortisol is high. High cortisol and high insulin, resulting in insulin resistance, are going to cause you to gain weight around the waist because your body will store fat there rather than burn it.

JLML: This would certainly be a significant effect when it comes to creating balanced hormone levels.

DTZ: When cortisol is high the brain also is less sensitive to estrogens. That’s why you can have a postmenopausal woman with reasonable amounts of estrogen, but when you put her under a stressor and her cortisol rises, she’ll get hot flashes, which are a symptom of estrogen deficiency. She really doesn’t have an estrogen deficiency, the brain sensors have just been altered. If you then drive the estrogen levels up with supplementation to treat the hot flashes, she’ll start getting symptoms of estrogen dominance like weight gain in the hips, water retention, and moodiness. And the hot flashes usually don’t go away.

This is why you often can’t effectively treat someone with hormonal imbalance symptoms such as hot flashes by simply adding what seems to be the missing hormone, be it thyroid, progesterone, estrogen or testosterone. If your cortisol is chronically high you’ll have overall resistance to your hormones.

JLML: What percentage of the saliva tests for cortisol are high?

DTZ: I’d say it’s as high as ten to twenty percent, but you have to remember that the population that’s sending in saliva hormone tests tends to have health problems. It also depends on the time of year and what’s happening in the world. I saw a lot of high cortisol in the saliva samples that came in after 9/11. Around the winter holidays, cortisol skyrockets, and then after the holidays it takes a nosedive. The adrenals were keeping pace with the holiday stressors and then they collapse because they’re exhausted. That’s a very common pattern. It’s no different with other stressors like exams or war. Most of us can remember how we made it through the stress of exams only to get sick shortly thereafter. Adequate levels of cortisol are necessary to acutely activate the immune system when we are exposed to viruses and when the adrenals are just too tired to make any more cortisol we are vulnerable to viral infections.

Stress is what both high and low cortisol have in common. Stress hits the adrenals and in response they either collapse in fatigue and do not produce enough stress hormones, resulting in a functional thyroid deficiency, or they can go in the other direction where they’re pouring out cortisol and it’s causing overall hormone resistance, including thyroid resistance. Either way, low or high cortisol, and thyroid hormones become inefficient.

JLML: Let’s talk about the good and bad aspects of cortisol.

DTZ: Most people with cortisol problems, high or low, are in the gray zone, meaning that they are outside of a normal physiological range necessary for optimal health. Cortisol helps maintain blood glucose levels by activating gluconeogenesis, the breakdown of tissue protein to amino acids and then to glucose. That’s a good thing, but not in excess. Too much cortisol, caused by stressors, over a prolonged period of time, results in excessive breakdown of all structural tissues of the body including muscle, bone, skin and brain, causing accelerated aging.

In bones, high cortisol activates nearly every biochemical pathway involved in bone resorption. Cortisol specifically inhibits osteoblast activity, or bone building; it suppresses the production of androgens [male hormones] in the gonads [androgens build bone]; it activates osteoclasts which causes bone to be resorbed faster; it decreases mineral absorption in the gut, so you won’t be absorbing the calcium and magnesium you need to build bone; and it increases renal [kidney] tubule spilling of calcium. Calcium supplementation and alendronate-type drugs used to inhibit bone resorption, such as Fosamax, will always fight a losing battle to high cortisol. I frequently see women reporting continued bone loss, despite use of pharmaceutical bone resorption inhibitors, when salivary cortisol levels are very high.

With saliva testing we see that when people have very high cortisol and low androgens they tend to have bone loss even when their progesterone and estrogen are normal. I see the most bone loss in women who have had a total hysterectomy.

JLML: What is the relationship between cortisol and melatonin, yet another hormone?

DTZ: Cortisol is released from the adrenal glands in a rhythmic pattern throughout the day. It’s high in the morning, which energizes you. If you don’t have enough cortisol in the morning you have a hard time getting out of bed. It’s at its lowest levels at two a.m. when melatonin is high. Melatonin and cortisol are inversely related, so when cortisol is down and melatonin is up you’re regenerating your body.

When your cortisol stays high you also won’t produce enough growth hormone or thyroid-stimulating hormone, which are important anabolic [tissue building] hormones. This is why a good sleep is so important. People with high salivary night cortisol levels are usually complaining of sleep problems.

JLML: What are normal saliva cortisol levels for a perimenopausal woman?

DTZ: At ZRT Laboratory a normal morning saliva hormone level for cortisol for a perimenopausal woman is 3 to 8 ng/mL, and by 10 at night it’s 0.5 to 1.5 ng/mL, which is a big drop. Very early in the morning when you’re in a deep sleep it goes even lower, so if you’re not sleeping properly and resting, your cortisol rhythms will be thrown out of balance. This is where progesterone plays an important role because it’s the only natural hormone that actually competes with cortisol for the glucocorticoid receptors. It can counter the stimulating effects of cortisol at night when you need to be sleeping.

JLML: You’re offering this new technology of blood spot testing which is available to the lay consumer—what is it and what can you test with it?

DTZ: It involves a nearly painless finger prick to get a very small amount of blood that is dried on filter paper and mailed back to us with a completed questionnaire. Right now we can test IGF-1, an index of growth hormone activity, a thyroid panel including TSH, free T3, free T4, and thyroid peroxidase (TPO), FSH and LH. In the next month or so we will launch a male panel, which includes PSA, testosterone, and SHBG.

If you're experiencing the symptoms that Dr. Zava discusses above, you may want to consider a blood spot test of your cortisol and/or thyroid levels.

Asperger Syndrome Tied to Low Cortisol Levels
HealthDay News 04.01.09

Finding could steer caregivers away from situations that would add to anxiety

Low levels of a stress hormone may be responsible for the obsession with routine and dislike for new experiences common in children with a certain type of autism.

U.K. researchers found that children with Asperger syndrome (AS) do not experience the normal twofold increase of cortisol upon waking up. Levels of the hormone in their bodies do continue to decrease throughout the day, though, just as they do in those without the syndrome.

The body produces cortisol, among other hormones, in stressful situations. Cortisol increases blood pressure and blood sugar levels, among other duties, to signal the body's need to adapt to changes occurring around it. It's thought that the increase shortly after waking helps jump-start the brain for the day ahead, the researchers said.

People with Asperger syndrome notably have very repetitive or narrow patterns of thought and behavior, such as being obsessed with either a single object or topic. Though tending to become experts in this limited domain, they have otherwise very limited social skills, according to the study.

"Although these are early days, we think this difference in stress hormone levels could be really significant in explaining why children with AS are less able to react and cope with unexpected change," study co-leader Mark Brosnan, from the psychology department at the University of Bath, said in a news release issued by the school.

If these Asperger symptoms are caused primarily by stress, caregivers could learn to steer children away from situations that would add to anxiety, the researchers said.

"This study suggests that children with AS may not adjust normally to the challenge of a new environment on waking," study researcher David Jessop, from the University of Bristol, said in the news release. "This may affect the way they subsequently engage with the world around them."

The researchers, whose findings were published in the journal Psychoneuroendocrinology, will next study if this lack of cortisol upon waking also occurs in children with other types of autism.

Cortisol and Stress: How to Stay Healthy
By Elizabeth Scott, M.S. February 5, 2008

Cortisol is an important hormone in the body, secreted by the adrenal glands and involved in the following functions and more:

Proper glucose metabolism
Regulation of blood pressure
Insulin release for blood sugar maintanence
Immune function
Inflammatory response

Normally, it’s present in the body at higher levels in the morning, and at its lowest at night. Although stress isn’t the only reason that cortisol is secreted into the bloodstream, it has been termed “the stress hormone” because it’s also secreted in higher levels during the body’s ‘fight or flight’ response to stress, and is responsible for several stress-related changes in the body. Small increases of cortisol have some positive effects:

A quick burst of energy for survival reasons
Heightened memory functions
A burst of increased immunity
Lower sensitivity to pain
Helps maintain homeostasis in the body

While cortisol is an important and helpful part of the body’s response to stress, it’s important that the body’s relaxation response to be activated so the body’s functions can return to normal following a stressful event. Unfortunately, in our current high-stress culture, the body’s stress response is activated so often that the body doesn’t always have a chance to return to normal, resulting in a state of chronic stress.

Higher and more prolonged levels of cortisol in the bloodstream (like those associated with chronic stress) have been shown to have negative effects, such as:

Impaired cognitive performance
Suppressed thyroid function
Blood sugar imbalances such as hyperglycemia
Decreased bone density
Decrease in muscle tissue
Higher blood pressure

Lowered immunity and inflammatory responses in the body, slowed wound healing, and other health consequences
Increased abdominal fat, which is associated with a greater amount of health problems than fat deposited in other areas of the body. Some of the health problems associated with increased stomach fat are heart attacks, strokes, the development of , higher levels of “bad” cholesterol (LDL) and lower levels of “good” cholesterol (HDL), which can lead to other health problems!
To keep cortisol levels healthy and under control, the body’s relaxation response should be activated after the fight or flight response occurs. You can learn to relax your body with various stress management techniques, and you can make lifestyle changes in order to keep your body from reacting to stress in the first place. The following have been found by many to be very helpful in relaxing the body and mind, aiding the body in maintaining healthy cortisol levels:

Guided Imagery
Listening to Music
Breathing Exercises
Other Techniques

Cortisol secretion varies among individuals. People are biologically ‘wired’ to react differently to stress. One person may secrete higher levels of cortisol than another in the same situation. Studies have also shown that people who secrete higher levels of cortisol in response to stress also tend to eat more food, and food that is higher in carbohydrates than people who secrete less cortisol. If you’re more sensitive to stress, it’s especially important for you to learn stress management techniques and maintain a low-stress lifestyle.

Cortisol may alleviate chronic fatigue and fibromyalgia symptoms: study
March 19, 2008 CBC News

Sufferers of fibromyalgia and chronic fatigue syndrome may see significant relief from their symptoms when administered the stress hormone cortisol, finds a new study.

A review of 50 published studies conducted by researchers in California has found that people who suffer from chronic fatigue and fibromyalgia have adrenal dysfunction, meaning their adrenal glands, which produce sex hormones and cortisol, don't work effectively.

Chronic fatigue is a condition in which people have debilitating fatigue that may be get worse with activity and is not relieved by rest. Fibromyalgia is a syndrome characterized by multiple pain points in muscles throughout the body and fatigue. Chronic fatigue and fibromyalgia affect 0.5 to five per cent of the population, according to the study's authors.

"My review of existing studies suggests that a treatment protocol of early administration of cortisol may help improve and reduce the symptoms of chronic fatigue syndrome and fibromyalgia," said Dr. Kent Holtorf, medical director of the Holtorf Medical Group Center for Endocrine, Neurological and Infection Related Illness in Torrance, Calif., in a release.

Holtorf also conducted an observational study with 500 patients from his clinic, who received cortisol as part of their treatment. He found that by the fourth visit, 84 per cent reported improvement, with 75 per cent showing "significant improvement," and 62 per cent reporting substantial improvement.

The typical dose of cortisol adminstered to patients was 5 to 15 mg. Concentrations in the body were measured throughout the study using urine analysis.

"Cortisol treatment carries significantly less risk and a greater potential for benefit than treatments considered to be the standard of care for both conditions," said Holtorf.

The study is published in the winter issue of the Journal of Chronic Fatigue Syndrome.

See also
Diabetes and depression
Loneliness Is in the Genes
'Coffeeholics wake the dead'
Sleep Deprivation
Vitamins and minerals
Living with Aspergers

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