Aldosterone and Thyroid Health
Published June 22 2015
I have written numerous articles and blog posts on adrenal health in the past, and usually I focus on the adrenal hormones cortisol and DHEA. But rarely do I talk about aldosterone, and so I figured I’d dedicate a post to this important hormone. Aldosterone is a mineralcorticoid, and like cortisol and DHEA it is also secreted by the adrenal glands. As a result, if someone has adrenal insufficiency then this not only can lead to a decrease in cortisol levels, but it can also lead to a decrease in aldosterone as well. When someone has problems with blood pressure and/or water retention the hormone aldosterone is usually involved, as I’ll discuss in this article.
In order to have a better understanding of the importance of aldosterone, I’d like to briefly talk about the renin-angiotensin-aldosterone system (RAAS). This system helps to regulate blood pressure and fluid imbalance. As a result, if someone has high or low blood pressure, or problems with water retention, then this system will be involved.
The RAAS is initiated by the secretion of renin, which is an enzyme that catalyzes the chemical breakdown of angiotensinogen, thus forming angiotensin I. Angiotensin is a hormone that causes narrowing of the blood vessels, which in turn leads to an increase in blood pressure. It is also involved in the regulation of aldosterone, which increases blood pressure by allowing the body to retain sodium. So essentially renin is released by the kidneys and in turn leads to the formation of angiotensin, and this in turn stimulates the release of aldosterone from the adrenal cortex.
Aldosterone, Blood Pressure Regulation, and Water Retention
High blood pressure and water retention are two common problems seen in some of my patients with thyroid and autoimmune thyroid conditions. I’ve written a separate article entitled “Blood Pressure and Thyroid Health“, and in this article I explained how aldosterone increases the absorption of sodium and water, while causing the excretion of potassium. This in turn increases blood pressure. I also mentioned how adrenal weakness or in some cases a very high-sodium diet can cause low levels of aldosterone.
So when someone has high blood pressure and/or water retention, this usually is associated with high aldosterone levels. Of course there can be other factors as well, such as a tumor of the adrenal gland. However, it’s important to understand that high aldosterone is frequently a response to these conditions. In other words, if a person has very high blood pressure or narrowing of an artery that supplies the kidneys then this will cause an increase in aldosterone.
Primary vs. Secondary Hyperaldosteronism
Hyperaldosteronism (high aldosterone levels) can be primary or secondary. Primary hyperaldosteronism is when there is a direct problem with the adrenal glands, such as an adrenal adenoma. Secondary hyperaldosteronism is caused by other problems, as it can be due to a genetic problem, dietary factors, high blood pressure, or another condition. Some of the common symptoms of primary and secondary hyperaldosteronism include fatigue, headaches, and muscle weakness.
If a doctor suspects hyperaldosteronism then they usually will start out with some basic tests, such as a comprehensive metabolic profile to determine the sodium and potassium levels in the blood. The aldosterone and renin levels might also be tested. They might also do some imaging of the adrenal glands to see if there is an adenoma. Typically drugs such as spironolactone or eplerenone will be recommended to lower the aldosterone levels, and of course if an adrenal adenoma is found this most likely will be removed.
The sympathetic nervous system can also affect aldosterone production (1) (2). And there is evidence that stress and anxiety can increase aldosterone levels (3). One study discussed how the events preceding myocardial infarction (a heart attack) and heart failure are driven in part by norepinephrine, angiotensin II, and aldosterone (4). The study discusses how overactivity of the mineralocorticoid receptor (which aldosterone binds to) in cardiac muscle cells could be important even when aldosterone isn’t excessively high. And so when one takes a beta blocker, this is affecting the renin-angiotensin system, which in turn is decreasing the aldosterone levels.
Can Taking Too Much Licorice Root Affect Aldosterone Levels?
I’ve spoken about the benefits of licorice root in previous articles. Glycyrrhetic acid is the active metabolite in licorice, and it inhibits the enzyme 11-ß-hydroxysteroid dehydrogenase type 2, which typically results in an elevation of sodium and decrease in potassium levels (5). Many people are familiar with Glycyrrhizin, also known as Glycyrrhizic acid. Glycyrrhetic acid is a 200–1000 times more potent inhibitor of 11-ß-hydroxysteroid dehydrogenase (11-ß-HSD) than glycyrrhizic acid (5). Although taking small amounts of licorice can benefit many people with low cortisol levels, taking large amounts can result in something called pseudo-hyperaldosteronism (5). Keep in mind that deglycyrrhizinated licorice (DGL), which is usually used for digestive orders such as ulcers, does not come with these same risks.
What Can Cause Low Aldosterone Levels?
I have focused primarily on high aldosterone levels thus far, but there are some conditions when aldosterone is low. Low aldosterone can be a factor with compromised adrenals, or with Addison’s disease. Or in some cases a very high sodium diet can lead to low aldosterone levels, although this isn’t too common. As I’ll soon discuss it is also possible that hypothyroidism can lead to decreased aldosterone levels. When aldosterone is too low the kidneys excrete sodium, and this will usually cause low blood pressure and low blood volume. Some of the common symptoms of low aldosterone include salt cravings, dizziness, lightheadedness, and weight loss.
How Does Aldosterone Relate To Thyroid Health?
As I discussed in the article I wrote on blood pressure, thyroid hormone plays a role in blood pressure homeostasis. Alterations of the renin-angiotensin-aldosterone system activity occurs in people with thyroid conditions (6). A study conducted on rats showed that hypothyroidism typically is associated with a decreased renin-angiotensin-aldosterone system and that giving thyroid hormone can cause upregulation of this system (7). According to the study the rats with hypothyroidism had a decrease in plasma renin activity, plasma angiotensin, and aldosterone concentrations. On the other hand, another study looked at the relationship of plasma renin, aldosterone, and thyroid hormones in people with hyperthyroidism, hypothyroidism, and a normal (euthyroid) state (8). This study showed that plasma renin was significantly higher in hyperthyroidism, and was low in those with hypothyroidism. On the other hand, this study showed that the aldosterone levels weren’t different except for one group which had normal free T3 and free T4 levels but suppressed TSH levels, as the aldosterone was higher than normal in this group.
So essentially what this is saying is that hypothyroidism will result in decreased renin, angiotensin, and aldosterone. On the other hand, renin can be high in those with hyperthyroidism, but aldosterone doesn’t seem to be affected in hyperthyroid cases. This does seem to make sense based not only on my personal experience with Graves’ Disease (as I didn’t experience high blood pressure when I was diagnosed), but this is also the case with most of my patients as well. While some of my patients with hyperthyroidism and Graves’ Disease have an increased blood pressure, most people with hyperthyroid conditions that I have worked with have normal blood pressure, although they have an increased heart rate due to the high levels of thyroid hormone.
Are There Natural Solutions For Aldosterone Imbalances?
As for whether high or low aldosterone levels can be addressed naturally, it depends on what the cause of the problem is. For example, if someone has an aldosterone-producing adrenal adenoma which is causing high aldosterone levels, then getting this benign tumor removed through surgery is probably required. On the other hand, if a thyroid hormone imbalance is causing problems with the hormone aldosterone, then obviously it is necessary to correct this imbalance. If someone has adrenal weakness leading to low aldosterone levels, then restoring the health of the adrenals is the solution. If someone is taking large doses of the herb licorice, which in turn is causing a decrease in plasma renin and aldosterone, then of course one needs reduce the dosage or stop taking the licorice.
In summary, when it comes to the adrenals, most doctors focus on cortisol and DHEA. But aldosterone is also important, as this adrenal hormone is involved in blood pressure regulation, and is usually a factor when someone is experiencing water retention. Primary causes of high aldosterone levels are usually a result of a direct problem with the adrenal glands, while other factors cause secondary hyperaldosteronism. Some factors which can lead to low aldosterone levels include problems with the adrenals, including Addison’s disease, hypothyroidism, and taking high doses of the herb licorice.