Thyroid disease is the second most common disorder of the endocrine system, second only to diabetes. Thyroid disorders affect roughly 20 million Americans and The American Thyroid Association estimates that nearly 60% of those with thyroid disease are unaware of their condition. Luckily, through simple blood work and regular screening, it can be easily diagnosed and treated with medications.

It is quite common for those with both type 1 and type 2 diabetes to also suffer from a thyroid disorder. On the other hand, if you have a thyroid disorder, you are at a higher risk of developing diabetes. While researchers and doctors are not confident in the exact causes behind diabetes and thyroid disease, there is a large amount of evidence that suggests there is a strong relationship between the two conditions.

The thyroid gland, an important element of our endocrine system, plays a specific role in how our body processes food and in turn, can affect blood sugar management. Untreated thyroid disorders in diabetics can increase the risk of developing diabetic complications such as hyperglycemia.

What Is Your Thyroid Gland and What Does It Do?

The thyroid gland plays a vital role in the endocrine system. It is a small, butterfly-shaped organ that is found in the front of your neck. It is responsible for creating and releasing two types of hormones that play very important roles in regulating your metabolism. Metabolism is the process that takes the food you eat and turns it into energy for the cells and other parts of the body to use. Therefore, the thyroid plays an important role in hunger, digestion, and energy levels.

The thyroid produces two hormones that are responsible for controlling your metabolism – triiodothyronine, also known as T3, and thyroxine, also known as T4. When released by the thyroid, T3 and T4 communicate with the cells to tell them how much energy to use. When too much or too little of these hormones are released, the body’s metabolism can move too fast or too slow, causing conditions such as hypothyroidism and hyperthyroidism.

What Are Common Thyroid Disorders?

Diseases of the thyroid are very common. In fact, according to the Cleveland Clinic, it is estimated that roughly 20 million people in the United States have some kind of thyroid disorder. Thyroid diseases are most commonly caused by an autoimmune response where the body’s immune system attacks the thyroid gland. This attack on the gland can cause your thyroid to act abnormally, which can affect the entire body. Because the thyroid is responsible for controlling the body’s metabolism, too much or too little hormone production by the thyroid gland can cause a broad range of symptoms.

When the thyroid gland produces too many thyroid hormones you can develop a condition called hyperthyroidism. This causes your metabolism to increase and causes symptoms such as:

  • Difficulty sleeping
  • Fast or irregular heartbeat
  • Anxiety and irritability
  • Unexplained weight loss
  • Vision problems and eye irritation
  • Enlarged thyroid gland
  • Irregular menstrual cycles
  • Heat sensitivity
  • Muscle weakness and tremors

Conversely, hypothyroidism is a condition where the thyroid produces too little thyroid hormone. Symptoms are related to a slower metabolism, such as:

  • Feeling tired or exhausted
  • Unexplained weight gain
  • Frequent and/or heavy menstrual cycles
  • Dry and coarse hair
  • Cold intolerance
  • Forgetfulness or mind fog
  • Hoarse voice

Both conditions are serious and should be managed by your healthcare provider, whether or not you have diabetes. If you notice some of these symptoms, notify your doctor immediately so they can perform further testing. If you do have diabetes, it can be even more vital to manage these conditions, as they can greatly affect your blood sugar management and insulin sensitivity.

How Does My Thyroid Affect My Diabetes?

Individuals with diabetes are at an increased risk of developing a thyroid disorder. Researchers are not clear on why there is such a strong association between type 1 diabetes and thyroid disorders, but they believe it has to do with a similar autoimmune response. In general, type 1 diabetics are more likely to develop a thyroid disorder compared to the general population. Since people with one autoimmune condition are at an increased risk of developing a second autoimmune disorder, they have an increased risk of developing an abnormality in their thyroid.

Even though type 2 diabetes is not an autoimmune disorder, evidence proves that type 2 diabetics also suffer from thyroid diseases at a higher rate than the general population, specifically hypothyroidism. Studies suggest there may be indirect factors that with a diagnosis of hypothyroidism, contribute to the development of type 2 diabetes. For example, hypothyroidism can cause you to gain weight, which can put you at a higher risk of developing type 2 diabetes. The exact relationship between thyroid disorders and type 2 diabetes remains unexplained, but researchers continue to explore the possible interactions between gut hormones and carbohydrate metabolism.

Your Thyroid’s Effects on Blood Sugar Management

When the thyroid doesn’t work properly, it can make it very difficult for a diabetic to manage their blood sugar. Since the thyroid is responsible for managing the body’s metabolism, both hypothyroidism and hyperthyroidism affect blood glucose and insulin. One of the first signs that you may be developing a thyroid disorder is that your blood sugar all of a sudden is very difficult to manage.

Hyperthyroidism usually increases the body’s insulin requirements, making it difficult to manage your blood sugar. The excessive amount of thyroid hormone in the blood causes the liver to increase glucose production. This excess glucose production causes the body to become resistant to insulin which is a condition where the body does not use insulin effectively. People with insulin resistance tend to require higher doses of administered insulin, as insulin is metabolized quicker in those with hyperthyroidism. Those with untreated hyperthyroidism will likely require a higher dose of insulin due to their body’s fast metabolism.

Hypothyroidism is less likely to cause significant changes to your blood sugar management, although it can affect how your body metabolizes insulin which can complicate diabetes management. When there is too little thyroid hormone present, the metabolism slows down. When metabolism decreases, the body takes longer to process the insulin that you administer, therefore the insulin stays in your blood longer. Diabetics with untreated hypothyroidism usually have to reduce the amount of insulin they need to give themselves. If hypothyroidism is left undiagnosed or untreated, a diabetic patient is at great risk of hypoglycemia, or low blood sugar, as they are not aware to decrease their standard insulin doses.

Your Thyroid and Other Aspects of Diabetes

An abnormal thyroid can not only affect your blood sugar management but other aspects of your diabetes as well. For example, diabetes increases a person’s risk for heart diseases, such as coronary artery disease or heart failure. Hyperthyroidism can cause symptoms that can worsen heart disease, such as a rapid heart rate or an abnormal heart rhythm. These symptoms can also interfere with the treatment of heart disease, increasing a person’s risk for further medical complications.

Hyperthyroidism can also cause bone loss, which can make the bones very brittle. Having weak bones increases the risk of bone fractures if a person falls. People with diabetes who have peripheral neuropathy also have an increased risk of falling due to poor sensation of their feet. The brittle bones from hypothyroidism along with peripheral neuropathy can elevate the risk of suffering a bone fracture if a person falls. A bone fracture from a fall is a serious injury, and may also lead to further medical complications, especially in the elderly.

Hypothyroidism is known to cause abnormalities in blood lipid levels, specifically LDL (low-density lipoprotein) cholesterol and triglycerides. The same blood lipid abnormalities are also common in type 2 diabetes, which is often worsened by hypothyroidism. These changes in blood lipids can increase the already elevated risk of heart disease and stroke in people with diabetes.

How Can I Manage My Thyroid Disease?

In most cases, it is not possible to prevent thyroid disorders, but luckily, both under and overactive thyroids can be managed with medications. Unfortunately, hypothyroidism and hyperthyroidism generally require lifelong treatment. Hypothyroidism can be managed with T4 replacements which help return your TSH levels to normal. The most common medication prescribed for hypothyroidism is levothyroxine, which is biologically equivalent to thyroxine (T4).

For individuals with hyperthyroidism, there are a few different treatment options ranging from medications to surgery. Medications usually consist of antithyroid drugs which stop your thyroid from making hormones. Commonly used antithyroid drugs are methimazole and propylthiouracil. Radioactive iodine is also used to lower your thyroid hormones by damaging the cells of the thyroid, which in turn, stops your thyroid from making high levels of thyroid hormones. Beta-blockers are also used to manage symptoms associated with hyperthyroidism, such as an elevated heart rate. A more permanent solution would be the surgical removal of your thyroid gland, also known as a thyroidectomy. The removal of the gland will stop all thyroid hormones from being produced, so you will have to take thyroid replacement hormones for the rest of your life.

Importance of Screening

Evidence suggests a strong association between diabetes and thyroid disorders. As thyroid dysfunction affects both a person’s blood glucose levels and insulin, it can negatively impact diabetes control and increase your risk of suffering from a diabetic complication. Due to the complications that can be experienced with untreated thyroid disorders, it is recommended that diabetics are screened regularly to detect abnormalities early and start immediate treatment. If you have type 1 diabetes, it is recommended that you get screened annually. If you have type 2 diabetes, you should get screened upon diagnosis and once every 5 years. Screening frequency should increase as you age since your chances of developing thyroid disease increase with age. If you are over the age of 60, it is recommended you get screened annually for thyroid disease.

If you have already been diagnosed with thyroid disease but do not have diabetes, it is important to implement or continue healthy lifestyle habits to decrease your chances of developing diabetes. Eating a healthy diet, exercising regularly, and managing your blood pressure and cholesterol are all ways to decrease the development of type 2 diabetes. Signs and symptoms of diabetes to watch out for include:

  • Increased thirst and hunger
  • Frequent urination
  • Unexplained weight loss
  • Feeling extremely tired
  • Blurred vision

How Will My Doctor Diagnose a Thyroid Disease?

Symptoms of thyroid diseases can be confused with other conditions. Some signs are similar to normal symptoms experienced during aging or pregnancy. Fortunately, blood tests make it very easy to diagnose a malfunctioning thyroid. The first test your provider will most likely order is a blood test that looks at the amount of thyroid-stimulating hormone (TSH) in your blood. TSH is a hormone produced in the pituitary gland that regulates the number of thyroid hormones in your blood, including T3 and T4. When TSH is high, your thyroid hormones are low, indicating you are suffering from hypothyroidism. Conversely, when TSH is low, your thyroid hormones are high, indicating you are suffering from hyperthyroidism. If your TSH levels are abnormal, your doctor can order further lab tests to determine the severity of your deficiency or excess.