High Cholesterol and Your Thyroid: Hyperlipidemia

Thyroid Problems May Be the Cause of Your High Cholesterol

Cholesterol levels and thyroid disease are linked. istockphoto

Millions of Americans with high cholesterol levels may not know that their cholesterol is elevated due to undiagnosed thyroid problems.

High cholesterol levels affect an estimated half the American population and is a major contributor to heart disease, America's number one killer. But the most commonly-known high cholesterol triggers, such as poor diet or insufficient exercise, are not necessarily the caue for everyone.

Undiagnosed and undertreated hypothyroidism can cause elevated cholesterol, and of the estimated 30+ million Americans with thyroid disease, at least half are undiagnosed and millions more are not sufficiently treated, opening them up to the risk of continued hypothyroidism symptoms despite treatment.

Some experts believe that the numbers of undiagnosed are vastly, underestimated and that the current thyroid diagnostic criteria are too narrow and rigid, and are missing many millions more with subclinical and low-level hypothyroidism.

In 2009, as part of Thyroid Awareness Month, the American Association of Clinical Endocrinologists (AACE) released the results of a survey on the thyroid-cholesterol connection, looking at the connection between undiagnosed hypothyroidism and high cholesterol. The survey had several important findings:

  • Fewer than half of the adults who had been diagnosed with high cholesterol know if they had ever been tested for thyroid disease, despite the well-documented connection between the two conditions.
  • Ninety percent of those surveyed were unaware of the thyroid gland's impact on cholesterol regulation.

According to AACE's president at the time, Richard A. Dickey, M.D.,

Patients who have been diagnosed with high cholesterol should ask their physician about having their thyroid checked. If they have an underlying thyroid condition in addition to their high cholesterol, the cholesterol problem will be difficult to control until normal levels of thyroid hormone are restored.

The National Cholesterol Education Program and the Food and Drug Administration recommend thyroid testing in patients with high cholesterol levels. The prescribing information for the popular cholesterol-lowering drugs also recommends that patients be tested for thyroid disease before beginning cholesterol-lowering drug therapy.

It's unclear why, given that guidelines strongly recommend thyroid testing, all doctors don't insist on comprehensive thyroid testing after identifying high cholesterol in their patients. 

About Cholesterol

Cholesterol is a waxy substance found only in animal foods and is also manufactured in your liver. It is transported by fat-carrying proteins in the blood. Cholesterol helps us make and maintain nerve cells and manufacture natural hormones.

When the body cannot metabolize cholesterol properly, or foods containing too much are consumed, an excess of cholesterol, known as hyperlipidemia or hypercholesterolemia, can occur. Cholesterol can be deposited in the walls of arteries, especially around the heart, and potentially block blood flow, which increases your risk of heart attacks and strokes. High cholesterol is considered a key risk factor for heart disease.

Millions of Americans are trying to lower their cholesterol through improved diet, exercise, and even cholesterol-lowering drugs like statin drugs.

For some of these patients, thyroid testing and subsequent treatment for hypothyroidism could restore the body's metabolism to normal and result in lower cholesterol levels and decreased heart disease risk. If you are one of these people, you may even be able to go off the cholesterol-lowering drugs under your doctor's direction.

About Hypothyroidism

Hypothyroidism refers to a condition where your thyroid gland is underactive. The thyroid, a butterfly-shaped gland located behind and below your Adam's Apple, produces a hormone that helps regulate your metabolism and facilitate the delivery of oxygen and energy to cells, tissues, and organs.

When your thyroid produces too little hormone, your ability to process cholesterol can also be impaired.

Common symptoms of hypothyroidism include:

  • Weight gain, or inability to lose weight
  • Fatigue and exhaustion
  • Feeling run down and sluggish
  • Depression, anxiety, and mood swings
  • Constipation
  • Menstrual irregularities, including more frequent or heavier periods
  • Dry, coarse and/or itchy skin
  • Dry, coarse and thinning hair
  • Feeling cold, especially in the extremities
  • Muscle cramps, joint pain, carpal tunnel or tendonitis

Do You Have Hypothyroidism?

If you are one of the people with high cholesterol levels but you have not yet been diagnosed with a thyroid condition, how can you tell if you are hypothyroid?

  1. First, start by doing the Thyroid Neck Check, which is located at the AACE website. This easy to perform home test may help you determine if you have an enlarged thyroid, one sign of a thyroid condition.
  2. Second, fill out the Hypothyroidism Symptoms Checklist. This detailed checklist helps you review all the risk factors and symptoms of hypothyroidism. You can take this Checklist to your doctor to help get a diagnosis, or make the argument that your hypothyroid symptoms are not resolved by your current treatment.
  3. Third, ask your doctor to run a Thyroid Stimulating Hormone (TSH) test to evaluate your thyroid levels. This test can diagnose hypothyroidism in many people.
  4. Fourth, if your TSH levels are normal but you still suspect hypothyroidism, be aware that there are different ways to interpret the test results that might have an impact on your diagnosis.
  5. Fifth, if TSH levels are normal but you have symptoms or a family history of thyroid disease, you should ask to have your free T4, free T3, and thyroid antibodies tested. Antibodies usually indicate a thyroid that is in the process of autoimmune failure, but not enough to show up in your TSH blood tests. For more info, read Thyroid Antibodies.