Episode - Elevated Liver Enzymes and Hyperthyroidism


It’s common for people with hyperthyroidism to have elevated liver markers. The reason why elevated liver markers are a concern is because this indicates that liver damage is taking place.  In this episode I will discuss why these markers are commonly elevated in those with hyperthyroidism, and I’ll also talk about the different options you have.

During this episode you’ll learn:

  • When you should be concerned about elevated liver enzymes
  • Some basics about liver enzymes, including factors that can cause them to be elevated
  • The three main enzymes that commonly increase during hyperthyroidism
  • Why an elevated alkaline phosphatase doesn’t always indicate problems with the liver
  • Two common causes of elevated liver enzymes in those with hyperthyroidism, along with a few other potential causes
  • Why the liver enzymes need to be tested whenever someone takes antithyroid medication
  • 3 options you have to address elevated liver enzymes

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Here is the transcript for this episode:

Welcome back to the Save My Thyroid podcast. This is Dr. Eric Osansky, and because it’s common for people who have hyperthyroidism to have elevated liver enzymes, in this episode, I am going to discuss some of the most common reasons for this and what you can do to address this problem.

Let’s go ahead and start by discussing some basics about liver enzymes. Once again, a lot of people with hyperthyroidism have elevated liver markers. Of course, there are people without hyperthyroidism who have elevated liver markers, but the focus of this episode will be on those with hyperthyroidism. When I talk about liver enzymes, I will specifically be talking about the ALT, AST, and alkaline phosphatase. I will get into more specifics about these enzymes shortly.

What causes these liver enzymes to be elevated? This is something I will be discussing in greater detail. Let’s talk about testing right now. The way I test for elevated liver enzyme markers is by doing what’s called a comprehensive metabolic panel, or a CMP. The good news is most endocrinologists will order this test for their hyperthyroid patients, or at least those who are on antithyroid medication because it is common for antithyroid medication to increase liver enzymes. Just about every endocrinologist will do regular liver enzyme panels as long as the person is taking antithyroid medication.

That being said, I’d like to go into greater detail about the three liver markers: ALT, AST, and alkaline phosphatase. Let’s start with ALT, which is alanine aminotransferase. This is also known as serum glutamatic-pyruvic transaminase, or SGPT. ALT is more commonly elevated than AST. ALT is mainly found in hepatocytes, which are liver cells. When damage to the liver occurs, ALT is released from injured liver cells. This causes an elevation in serum ALT. ALT is also present in muscles, adipose tissue, the intestines, colon, prostate, and brain. It is also worth mentioning that extreme exertion can cause a temporary elevation of the liver enzymes. For example, if someone runs a marathon and then gets a CMP, there is a good chance that the liver enzymes will be elevated, including ALT.

I am going to discuss aspartate aminotransferase, or AST. This is also known as serum glutamic oxaloacetic transaminase, or SGOT. In addition to being found in the liver, AST is also located in the heart, kidneys, brain, and skeletal muscles. Whereas ALT can increase up to 50 times greater than normal when liver damage is present, AST levels will typically rise to 10-20 times greater than normal. One reason for this is because ALT is more specific to the liver. If ALT is elevated, this is usually a pretty good indication of liver damage. On the other hand, if AST is elevated and ALT is normal, chances are that damage is happening to a different area of the body, such as the skeletal muscles.

Now let’s go ahead and discuss alkaline phosphatase. This is an enzyme found in the bloodstream and plays a key role in metabolism within the liver. However, if it is elevated, not only can it indicate problems with the liver, but it can also indicate a problem with the bones. Even sometimes the gallbladder. Elevated alkaline phosphatase can not only be an indication of hyperthyroidism, but other health problems as well such as hepatitis, cirrhosis, cholecystitis, a blocked bile duct, osteomalacia, bone cancer, or hyperparathyroidism.

Let’s discuss why these liver markers become elevated. A common cause is hyperthyroidism. And I should say why they become elevated here. If someone just in general does a liver panel or CMP, and they see one of these markers are elevated, this doesn’t necessarily mean- hyperthyroidism probably isn’t the most common cause. Especially alkaline phosphatase. I should point out that ALT, AST, sometimes we see elevated ALT or AST in people with hyperthyroidism who are not taking antithyroid medication, but I need to point out that alkaline phosphatase is elevated in most people with hyperthyroidism, even those who are not taking antithyroid medication. I see sometimes the alkaline phosphatase quite high. It’s something I wouldn’t get too alarmed about, at least initially. If it’s not decreasing over time, then it might be some cause for concern.

The second common cause is antithyroid medication. Elevated liver enzymes are common in people taking methimazole, PTU, and carbimazole (for those who are overseas), which converts into methimazole. This doesn’t always cause an elevation in the liver enzymes, but it is quite common for this to happen.

I should also mention when it comes to the different types of antithyroid medications, it is more common to see this with PTU. There is concern of the effects that PTU has on the liver in some people. Some people take PTU, and they are perfectly fine. Especially for pregnant women in the first trimester, typically endocrinologists will give PTU instead of methimazole. On average, PTU puts more stress on the liver when compared to methimazole and carbimazole, which is why usually most endocrinologists will recommend others over PTU.

There is research that shows that PTU related to liver toxicity is likely to occur in about 1% of treated patients. This is why the liver enzymes need to be tested, regardless of what type of antithyroid medication is taking. You still want to test the liver enzymes regularly no matter what type of medication you’re on. At least every couple of months. However, if someone is just starting the medication, test them maybe a month later to see how they’re doing. If they’re looking okay, I would still keep an eye on them, but not as frequently. If the liver enzymes are elevated after the first month when you start antithyroid medication, you might want to keep an eye on the liver enzymes every month. Maybe do a CMP every 4-6 weeks.

Alkaline phosphatase, this is very common for people who have hyperthyroidism, even if they are not taking antithyroid medication. For those who are taking antithyroid medication, this doesn’t usually cause it to increase further. It’s usually already increased by the time someone is taking antithyroid medication, but it won’t usually drive it up further. I wouldn’t get too concerned initially about an elevated alkaline phosphatase. However, if it doesn’t decrease soon after normalization of the thyroid hormones, this may indicate another problem and is a greater cause for concern. I will say that it could take some time to decrease. If the thyroid hormone levels are normal, and you do a CMP a month later and alkaline phosphatase is still high, I wouldn’t get too concerned unless if it’s increasing, or perhaps if it’s extremely high.  It depends on the situation.

Let’s discuss other reasons for elevated liver enzymes. Viral hepatitis can be a potential cause. With viral hepatitis, the liver enzymes can stay elevated for a few months. They will be really high in cases of hepatitis. Chronic hepatitis will also present with elevated liver enzymes although not quite as high as acute viral hepatitis.

Frequent alcohol consumption. Most people who listen to this probably know that alcohol puts stress on the liver. If you are drinking alcohol frequently, this could also cause the liver enzymes to be elevated.

Having a family history of liver disease makes it more likely.

Also, in addition to antithyroid medications that could also cause elevated liver enzymes, if you start a certain medication, and you notice that your liver enzymes, whether it’s ALT or AST, are elevated, and it coincided with you starting a certain medication, it could very well be related to that, even if it’s not antithyroid medication. Or maybe you are taking antithyroid medication, and it doesn’t elevate your liver enzymes, but a few months later, you have a different health condition, and you take a different type of medication, and your liver enzymes increase. It could be related to the antithyroid medication, but you will usually see that increase relatively quickly.

As far as specific medications, there are too many medications to mention here that could potentially raise liver enzymes. Aspirin could. Acetaminophen puts a good amount of stress on the liver. Ibuprofen. Antibiotics can sometimes. Antifungal medication. Antiseizure medication. Statins, as well as other cardiovascular drugs.

Nonalcoholic fatty liver disease can sometimes cause elevated liver enzymes. Although not everyone with nonalcoholic fatty liver disease does, I will say that many people with this condition do have elevated liver enzymes, with ALT usually being higher than AST. I mentioned earlier that ALT is more specific to the liver.

Other common findings include high triglycerides, low HDL levels, and higher normal hemoglobin A1C (related to blood sugar) levels. They are the average glucose levels over a 2–4-month period. Some other factors which can lead to elevated liver enzymes are hemochromatosis, a few different types of hepatitis, autoimmune hepatitis, Celiac disease (sometimes), muscle injury.

When should you be concerned about elevated liver enzymes? I wouldn’t get too concerned if they are slightly above the lab reference range. If the liver enzymes are approaching are or over triple digits, I’m talking about specifically AST and ALT—alkaline phosphatase is not a concern to be in triple digits. It is very common to be in triple digits. For AST and ALT, if these are in triple digits, then this is usually a cause for concern. I wouldn’t panic. If it is due to the antithyroid medication, stopping or reducing your dose of antithyroid medication will often resolve the problem. The reference range for AST, according to LabCorp is between 0-40 international units per liter. For ALT, it’s between 0-32 international units per liter. If someone’s levels are close to 100 IUs/liter or greater, then this is usually a cause for concern. I would not panic, but I also would not ignore it.

As I mentioned earlier, if the elevation of the liver enzymes is due to antithyroid medication putting stress on the liver, then the endocrinologist will probably tell you to stop the medication. Or they may tell you to take a lower dose. If you are taking 40mg of methimazole, then maybe they will lower it to 20mg and do another CMP, and see what the liver enzymes look like. If they are a little bit high but not too bad, they may tell you to stick to the 20mg. Everything comes down to risk vs benefits, so of course they want you to be safe when dealing with hyperthyroidism. They don’t want you to have problems with your liver, but they also don’t want you to have unmanaged hyperthyroidism.

Sometimes someone will have elevated liver enzymes when taking one type of antithyroid medication, but not another. Even though PTU has a greater tendency to put more stress on the liver, this isn’t the case with everyone. There are some people who take methimazole, and it raises the liver enzymes, and for whatever reason, they switch to PTU, and it doesn’t put the stress on the liver enzymes. So that’s another solution, too. The endocrinologist might decrease the antithyroid medication dosage, but if that doesn’t help, then he/she might switch to a different type of antithyroid medication and see if that has a similar effect.

The bad news is many endocrinologists will recommend radioactive iodine or thyroid surgery if the liver enzymes elevate in response to taking antithyroid medication. Some of them won’t switch the person to PTU because they will argue that the liver enzymes may very well be increased with PTU. That could be the case, but radioactive iodine and thyroid surgery in my opinion should be a last resort. I think it’s worth looking into switching to a different type of antithyroid medication.

Of course, my approach also is to look into natural methods whenever necessary. This is not related to this episode, but you could find my story and discussion about herbs such as bugleweed. When I dealt with Graves’, I personally took bugleweed. That is another option, too is to consider taking an herbal approach. That doesn’t work for everyone. And again, that is not the focus of this episode. But I did want to mention that if someone is unable to take antithyroid medication, there are alternative options.

When should someone be concerned by an elevated alkaline phosphatase? I did mention that it is frequently elevated to the high thyroid hormone levels. As the thyroid hormone levels decrease, the marker should also decrease over time. The average reference range for alkaline phosphatase is 20-140 IUs/liter. LabCorp uses a range of 39-117 IUs/liter. It is common to see hyperthyroid patients with levels exceeding 200 IUs/liter. Even that isn’t a cause for concern. As the thyroid hormone levels decrease, this number usually would decrease. I would be concerned if the alkaline phosphatase does not start decreasing after the thyroid hormone levels are normal.

What options do you have? Option #1 is if antithyroid medication is causing the elevated liver enzymes, then you could replace antithyroid medication with bugleweed. Also, one thing I didn’t mention here is low dose naltrexone (LDN) is something else to consider. Same thing with cholestyramine. I won’t get into great detail here, but cholestyramine can bind to thyroid hormone. I have only had a few patients take it, but I have seen it work in hyperthyroid patients, so it is an option to consider. Also, LDN modulates the immune system. It is hit or miss. And again, bugleweed doesn’t work in everyone, too. You might have difficulty getting a prescription for cholestyramine. None of these do anything to address the cause of the problem, but we’re not talking about that in this episode. We’re talking about being safe while trying to address the cause. If your liver enzymes are getting really high, we want to do everything we can to avoid radioactive iodine and thyroid surgery.  So these are just some other options.

Option #2 is lower the thyroid hormone levels. That is what we’re trying to accomplish through the antithyroid medication, and things such as bugleweed, Cholestyramine, and even LDN indirectly.

Support the liver with natural agents. That is another option. You could try taking agents such as milk thistle; NAC, which is a precursor to glutathione, which is the master antioxidant. That is very important for optimal liver health. Or you can take a liposomal or acetylated glutathione. Even turmeric might help. So these are some of the things you can consider doing if you have elevated liver enzymes.

That’s all I want to cover with regard to addressing elevated liver enzymes. I hope you found this episode to be extremely valuable. I look forward to seeing you in the next episode.