Low Functioning Thyroid Can Result in Elevated Cholesterol

Patients with abnormal lipid profiles (including cholesterol) are often put onto cholesterol-lowering medications. I often tell my patients that their thyroid health directly affects their blood-cholesterol levels. Many patients are surprised as their primary physician may not have investigated this connection.

The Claim: Your Cholesterol May be High Due to Low Thyroid Function

You’ll see it’s absolutely possible. Any patient with elevated cholesterol needs to investigate why it’s high before commencing any treatment, especially cholesterol-lowering medications.

Cholesterol and it Connection to Heart Disease

Click here for a full review on LDL-cholesterol and here for one on HDL-Cholesterol. You’ll see that LDL-Cholesterol is more susceptible to oxidization and damage, and that’s why it’s considered ‘bad’.

The reason LDL-C is associated with heart disease is when we look at clogged arteries, cholesterol is found within the clog, along with other things. Although cholesterol doesn’t cause heart disease, it’s associated in this manner. The driving forces of heart disease are oxidation and inflammation. Check out my other articles on this topic for more details.

Thyroid Hormones are required for LDL Metabolism

Our muscles and liver (and many other cells) have LDL-receptors on them to allow LDL to enter cells [1]. If, for some reason LDL molecules can’t enter the cells, they will stay in the blood. In all mammals, including humans, thyroid hormone depletion leads to decreased LDL receptor expression and elevated cholesterol in the blood. This phenomenon has been known since the 1920’s [2]. In fact, it’s well documented that low functioning thyroid can and will directly affect total cholesterol and LDL in the blood [2].

Treating Thyroid May Help with Cholesterol

This will only help for some people. Not everyone with high cholesterol has low functioning thyroid; but it certainly warrants investigation.

In many studies, giving T3 and T4 (thyroid hormones) have lowered total cholesterol and LDL-cholesterol in the blood [2]. In other research, mice induced with hypothyroidism saw cholesterol levels increase over time. Then when treated for their low functioning thyroid, their cholesterol levels dropped again. [2].

If your Cholesterol is High, Check Your Thyroid

Cholesterol is quite important for life, so taking a cholesterol-lowering medication (such as a statin), can be quite dangerous if it wasn’t needed in the first place. Asking your doctor to investigate why your cholesterol is high is a fair request. Looking at a full thyroid panel would be helpful, such as TSH, T3, T4 and reverseT3. Your naturopath would be able to assist you in a full work up.