September 3


How High Glucose Levels Affect the Thyroid

By Gabriela

September 3, 2021

In general, thyroid disorders are common in the U.S. population. It affects around 27 million Americans and half are undiagnosed.

Diabetes is first, and thyroid disorder comes as the second most common disease of the endocrine system.

An endocrine system is a group of glands; these glands secrete a hormone that helps in the regulation of nutrient use, growth, and reproduction of the cells.

The thyroid gland has a particular role, and that is to regulate metabolism. On the other hand, abnormal function of the thyroid can have a great impact on diabetes control.

Also, if a thyroid disorder is not treated, it can aggravate certain diabetes symptoms and increase the risk of related complications. The good news is that we can diagnose it through a blood test and there is treatment available.

Those with this chronic disease should do a screening for thyroid disorder from time to time.

Symptoms of Thyroid Problems

The symptoms vary with gender and age. According to Dr. Wu, hyperthyroidism in older women can lead to sweating, hot flashes, weight changes, and mood swings, and these symptoms might be confused with those of menopause.

Other typical symptoms are shaky hands, irritability, decreased energy level, fast heart rate, insomnia, weight loss even if we experience increased appetite, and frequent bowel movements. These symptoms are similar to Type I diabetes symptoms.

Hypothyroid has opposite symptoms, according to Amy Campbell, nutritionist CDE, RD, those are constipation, feeling tired, dry skin and hair, feeling cold, depression, and weight gain. We will notice that the symptoms are similar to those of type II diabetes.

Hypothyroid and hyperthyroid can lead to ‘goiter’,  i.e. swollen neck since the thyroid grows bigger. It is believed that hyper and hypo can lead to osteoporosis, which is a condition that leads to weak bones, and because of that possible fractures.

Diabetes and Thyroid Disorder

In those with this chronic disease, the prevalence of thyroid disorders increases to 10 percent. They have an increased chance of developing a thyroid disorder.

In the population, around 6 percent of people experience a certain form of thyroid disease.

According to a study, there is an overall prevalence of thyroid diseases of 13.4 percent in those with diabetes. The highest incidence is in women with type I diabetes (T1D), and that is 31.4 percent.

Females with T1D have a 1 in 3 chance of developing a thyroid disorder.

According to researchers, that’s because T1D is an autoimmune disease, and people that have an autoimmune disease are more prone to thyroid disease.

Individuals with type II diabetes (T2D) are at risk of developing thyroid disease the same as those with T1D. However, the risk of type II is not as high as the risk of type I.

Around 12 % of those with type II have a thyroid disorder. The researchers are not sure what is the connection between these two conditions. They think it might be because of the aging process.

Effect of Thyroid on Blood Glucose Control

The proper function of the thyroid is to regulate metabolism and its energy. And in turn, the abnormal role of the thyroid may lead to profound effects on the control of blood sugar.

Both hypothyroidism and hyperthyroidism can affect diabetes and its course, but they have different effects.


This is typically linked with increased insulin needs and worsening control of blood glucose.

This excessive thyroid hormone can lead to increased insulin resistance, increased production of glucose in the liver, and fast absorption of glucose with the use of the intestines.

We can consider underlying thyroid disease in case we experience increased requirements of insulin, deterioration in the control of the blood sugar, and unexplained loss of weight.

Those with diabetes have an increased risk of heart disease. Moreover, many of them have certain heart conditions like heart failure or coronary heart disease.

Hyperthyroidism can increase the chance of abnormal heart rhythm, fast heart rate, chest pain i.e. angina, increase the chance of other heart problems, interfere with treating heart failure, or worsen heart failure.

Untreated and prolonged hyperthyroidism can lead to excessive bone loss and cause osteoporosis i.e. bone thinning.

Osteoporosis makes falling more dangerous since it raises the chance of bone fractures. Those with diabetes and peripheral neuropathy have increased chances of falls, because of loss of proprioception and poor foot sensation.


Hypothyroidism rarely leads to significant changes in the control of blood sugar. But it can lower the clearance of insulin from the bloodstream and in that way the insulin dose can be reduced.

With hypothyroidism, there are different abnormalities in the blood lipid levels. Like increased triglyceride levels, increased LDL cholesterol levels, and increased total cholesterol.

Hypothyroidism worsens the abnormal lipid pattern which is typical of T2D (high amount of dense and small  LDL particles, low HDL cholesterol, high triglycerides).

These particular changes raise the already high chance of cardiovascular diseases like stroke and heart disease among those with T1D or T2D.

Managing Thyroid Problems

To help with thyroid, we need to do 3 things, and that is to eat properly, get tested, and take suitable medicine.


Proper food makes a difference. An essential nutrient for the thyroid is iodine. The iodine is added to the salt in the U.S.

In case we do not use salt or maybe we use alternative salts, we will need to get the necessary amount of iodine. The best sources are sea animals and seaweed, i.e., sea vegetables.

According to the nutritionist, Amy Campbell certain foods can help with thyroid problems. Those foods are low-fat dairy foods, poultry, seeds, seafood, avocados, lean meat, almonds, whole grains, beans, and onions.


The guidelines from ADA say that people with T2D should do some tests. Also, every five years after they do the tests they should test for the TSH levels. Those with T1D should be screened one time per year.

In case we are experiencing any unexplained changes in our glucose levels or other symptoms, we need to check our thyroid levels as soon as possible and do it frequently.


We can treat hypothyroidism with a replacement hormone known as levothyroxine. It takes months to do testing and to get the right dose, but when that happens, we will hopefully feel better.

But there are other medicines besides levothyroxine, and that is liothyronine. For the proper medication seeing a doctor is a must.

It is crucial to take drugs for the thyroid daily at the same time. For hyperthyroid, there are surgical and medical treatments.

Supplements of fiber, calcium, and iron do not heal and can block the absorption of the drugs we take for the thyroid. We need to take our thyroid drugs a few hours away from the time we take these supplements.

For the best information on this, we should see our doctor. Diabetes and thyroid are closely related, and it is said that maybe someday the thyroid hormones will be used to treat the other condition.

But for now, what we need to do is be aware of our thyroid stats and see a doctor in case it is too high or maybe too low.

Source Verywell Health | Diabetes Council | Diabetes Spectrum | NCBI


  • Gabriela

    Co-Founder & Editor-in-Chief of Diabetes Health Page, Fitness trainer and instructor has dedicated her career to educating and informing people for over 10 years. As one of the most passionate diabetes advocates, Gabi has worked tirelessly to ensure that those people receive the education and support they need to properly manage their diabetes and achieve their health, fitness and weight loss goals.

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