Your thyroid does not exist in a vacuum. Nothing in your body does; it’s all interrelated and interacting in a concerted dance. And hormones, the quintessential “agents of change”, are powerful messengers that absolutely love a noisy party. They want to communicate to one another copiously so they better communicate to you. When considering thyroid health we can’t overlook the rest of the conversation.
The thyroid and its powerful hormones affect every single cell in your body. Ponder that for a moment. All systems, all tissues, all cells, everything. Your body is utterly dependent on thyroid hormones. It’s not like your appendix, although we have learned has more positive function than we had understood previously, but you can still live without it. Ovaries and testicles? Really important, but you could survive their loss. No thyroid? Hang it up, you won’t make it very long.
So the thyroid is sending a message to the body, via its hormones, that MUST be heard. It is one of those hormones that is always invited to the party, guaranteed. And it’s got a lot to say, to everyone.
This article will take up the conversation with some of the key players at the “hormone party” to explore how this may help you on your health journey. What is the thyroid saying to your ovaries? What are they saying back? The testicles want in on the conversation too. What about the gossip with the adrenal glands? And the pancreas with insulin always have something to say. Let’s listen in…
Sex Hormones & Your Thyroid
These two are always chatting. The main sex hormones of estrogen, testosterone, and progesterone are being influenced by the thyroid, and the thyroid is influenced by them as well. One system is strengthening the other. As men and women age, and sex hormones start to decline, the thyroid has to attempt to pick up the slack. And depending on the nutritional state of the thyroid and other environmental factors, the thyroid may blow a gasket, not being able to keep up. In fact, this is a typical outcome for women when they first enter menopause; thyroid dysfunction often coincides with that transition.
Sex Hormones Affecting Thyroid Function
Here is a summary of some of the various effects of sex hormones on Thyroid Binding Globulin (TBG), a protein that binds and potentially minimizes the activity of thyroid hormone.
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Estradiol increases TBG: One of the concerns about estrogen replacement therapy for women is that it lowers the effectiveness of thyroid hormone in the body by increasing TBG. But in the proper balance of testosterone, it shouldn’t be an issue because testosterone lowers TBG.
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Testosterone decreases TBG: A balance of both estrogen and testosterone for women will help keep TBG lowered and keep thyroid hormone readily available. This action of lowering TBG is another reason why testosterone tends to help with increasing metabolic rate through the indirect influence of enhancing thyroid hormone availability.
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Progesterone likely decreases TBG: Less is known about progesterone’s affects on thyroid hormone, but the data is of course growing. Progesterone is important particularly for women in helping to balance the physiological effects of estrogen.
General Effects of Sex Hormones on Thyroid Function
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Estradiol lowers TSH: When women first enter perimenopause and eventually menopause, which is accompanied by lowered estrogen, it is very common to see hypothyroidism (low thyroid) develop, which will usually be marked by an elevation in TSH (Thyroid Stimulating Hormone). Restoring the estrogen levels will help to lower TSH, partially relieving the low thyroid state. But there is more to it…
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Estradiol increases T4 and T3: Estrogen is also directly stimulating the thyroid gland to produce more thyroid hormone, which will also contribute to lowering TSH.
Thyroid Function Affecting Sex Hormone Function
Sometimes sex hormones are deficient or poorly responding because of a hypothyroid (low thyroid) condition. I have had countless patients, particularly younger pre/peri-menopausal women, who have gynecological issues such as menstrual irregularities that were not simply an “ovarian” issue, but a thyroid hormone issue. Correcting the thyroid condition helps with the sex hormone condition, without actually having to replace the sex hormones or consider taking the synthetic birth control pill, the typical gynecological approach for menstrual irregularities.
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T3 increases the sensitivity of Luteinizing Hormone (LH): LH is a pituitary hormone, just like TSH, but stimulates the testicles or ovaries to make sex hormones. The active thyroid hormone T3 has the benefit of making LH more sensitive on the testicles and ovaries, therefore increasing testosterone and estrogen production.
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Low thyroid leads to enlarged and cystic ovaries: Thyroid hormone positively influences a woman’s ovaries, keeping them functioning optimally and clear of waste products that can lead to cysts. Many female gynecological conditions, that seem to be all about ovarian function, really stem from a thyroid condition. (This is another reason, and there are several [see the chapter on Iodine in my book The Hormone Zone], why I always encourage women to take iodine as a part of their thyroid hormone treatment.)
A quick side note. This is an example of how cortisol (the stress hormone) affects sex hormone production and function. I see this a lot in my practice and it is worth noting here:
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Cortisol blocks the production of estrogen and testosterone production at both the ovarian and testicular levels as well as blocking estrogen or testosterone from binding to the cellular receptors. In other words, stress blocks production of sex hormones and the ability for them to stimulate the cell to make you feel your best.
Adrenal Hormones & Your Thyroid
The adrenal/thyroid axis is one of the most important hormone conversations in your body. These are two vital players. They are literally the life of the party. Just as I mentioned that you can’t live without your thyroid, you also can’t live without your adrenal glands. The adrenals produce vital hormones including cortisol, DHEA, aldosterone, adrenaline (epinephrine/norepinephrine), and even sex hormones. These “stress” hormones regulate your response to internal and external stressors, any kind of stimulus big or small, and this keeps you alive and functioning. Adrenal hormones stimulate the thyroid gland, and thyroid hormones stimulate and regulate the adrenal glands. Working to keep both of them optimized is the key to help each of them.
General Effects of Adrenal Hormones on Thyroid Function
Cortisol and Epinephrine/norepinephrine (adrenaline) increases Reverse T3 (rT3): Cortisol and adrenaline are the main stress hormones. When under stress, these adrenal hormones increase and begin to influence the conversion of T4 into active T3 and instead convert T4 to inactive rT3. If inactive rT3 levels are high, then the metabolism lowers and symptoms of hypothyroidism (low thyroid) ensue.
Years ago, I gave little attention to measuring rT3 in patients. One reason is that for the most part, I was able to help most conditions of elevated rT3 by simply increasing the thyroid hormone medication dose. This is still true in general; an increase in dose of high quality thyroid hormone can push past the elevated rT3 and help relieve symptoms. But it does not help everyone, or only helps to an extent. The key for many patients with elevated rT3 is to help guide them to lower it. And this is done by focusing on the adrenal glands and the source of the stress. This is a more comprehensive way to approach thyroid treatment, by adding in a focus towards the adrenals and the patient stress response.
Cortisol decreases TSH: Stress lowers TSH. On the surface, this may sound good. Remember that an elevated TSH is often indicative of hypothyroidism (low thyroid). So if cortisol is lowering TSH, one may assume that the hypothyroid condition is being corrected. But for many, this is not the case. In fact, long term stress, with long term high levels of cortisol, will continually lower TSH and not allow the thyroid to adequately make thyroid hormone, such as T4 and T3. This will hinder the ability for many low thyroid patients to get the proper diagnosis because most doctors only look at the TSH value to make a decision and then prescribe thyroid hormone medication. Cortisol may also be hindering the ability for TSH to be produced by the pituitary and therefore the levels are lowered, making it look like the thyroid is fine. If the stress can be removed, the thyroid may or may not be able to adequately make thyroid hormone in the future.
Insulin Resistance & Your Thyroid
It’s getting late at the party, and you know what that normally means…the crashers show up: the carbohydrates and their friends insulin. It’s not really that they show up, they can be good guys, it’s just that when they show up in a swarm, and it overtakes all the fun, particularly with the thyroid.
Excessive carbohydrates lead to insulin resistance, the condition where cells no longer respond effectively to insulin and blood sugar elevates. This scenario is the hallmark of diabetes. Insulin resistance is an epidemic in this country with nearly 86 million people with the condition, to some varying degree.
Low thyroid decreases the sensitivity of insulin on the cell leading to fat gain (i.e. insulin resistance): One of the common symptoms of hypothyroidism (low thyroid) is weight gain. This is in part due to a lowered metabolic rate. But another factor is due to a lack of thyroid hormone affecting insulin receptors to respond to the insulin hormone. Thyroid hormone normally helps insulin to shuttle glucose (blood sugar) into the cell. This prevents insulin resistance and diabetes.
High thyroid also decreases the sensitivity of insulin on the cell, paradoxically, also leading to fat gain: In hyperthyroidism (high thyroid), excess thyroid hormone, in a very complex process with insulin and glucose (blood sugar) both rising and falling, yields an overall result of insulin resistance. In essence, excessive thyroid hormone is over-communicating with many parts of the body, leading to high blood sugar and insulin resistance.
Excess insulin blocks the conversion of T4 to T3: Again, T3 is the active thyroid hormone, not T4. We make T4 in the thyroid gland, but it is the conversion of T4 to active T3 that helps our cells to function correctly. When we ingest high amounts of carbohydrates thereby stimulating high levels of insulin, we prevent the conversion of T4 to T3. This can of course lead to a lowered metabolic rate and hypothyroidism (low thyroid).
In Summary: What You Can Do About It
The hormone party is like Las Vegas: it’s always going on, it’s always happening, it never stops…and too much of a good thing isn’t always that good. And remember that there are a lot of different players at this party, but in the right balance, they can certainly all get along and have a great time.
So how can you make sure you have the best hormone party going on? Make sure that you see a competent physician who understands the complete intricate dance of hormones happening in your body: thyroid, adrenals, sex hormones, and insulin (and frankly, even more). Be sure you are exploring your options for all of your hormones, including your thyroid. At The Hormone Zone, we focus on providing a world-class comprehensive view of all of your hormones for your thyroid health. We look forward to serving you.
References
- Ann Saudi Med. 2011 Mar-Apr; 31(2): 145–151.PMCID: PMC3102473
- Arner P, Bolinder J, Wennlund A, Ostman J. Influence of thyroid hormone level on insulin action in human adipose tissue. Diabetes. 1984 Apr;33(4):369-75.PubMed PMID: 6423430.
- Endocr Pract. 2009;15(3):254-262. © 2009 American Association of Clinical Endocrinologists
- Journal of Thyroid Research. Volume 2011 (2011), Article ID 152850, 9 pages. http://dx.doi.org/10.4061/2011/152850
- Mechanism of Action and Physiologic Effects of Thyroid Hormones. http://arbl.cvmbs.colostate.edu/hbooks/pathphys/endocrine/thyroid/physio.html
