Petition: Include thyroid disease in Canada’s chronic diseases list

We are planning to launch a formal federal petition to the Public Health Agency of Canada (PHAC) to add thyroid disease to its list of 20 diseases under surveillance by the Canadian Chronic Disease Surveillance System (CCDSS).

Our first step is to test the waters with this Change.org petition!

Sign the petition at Change.org here: https://www.change.org/p/include-thyroid-diseases-in-canada-s-chronic-diseases-list

Why include thyroid diseases in the CCDSS?

Currently, the majority of thyroid diseases other than thyroid cancer are not included in Canada’s official list of chronic diseases and are not being monitored. 

In other countries that track prevalence rates of thyroid diseases, the combined rate is between 5 and 10% of the population (Reyes Domingo et al, 2019; Crafa et al, 2021).

Several groups of thyroid diseases have much higher prevalence rates among women and older people.

• Globally, rates of autoimmune hypothyroidism are 4 to 10 times higher in women than men, reaching up to 15% of women in countries like Italy (Crafa et al)
• Peak incidence occurs between the ages of 30 and 50 (Chiovato et al, 2019).
• Diseases involving thyroid dysfunction (hyper- and hypothyroidism) affect up to 25% of persons 65 and older (Diab et al, 2019).

Research outside of Canada reveals that thyroid diseases are a significant comorbidity in several other major chronic diseases, such as diabetes, kidney disease, and heart failure, as shown below. Despite this fact, Canada’s government publications on the major chronic diseases cannot give statistics on thyroid disease comorbidity rates.

But prevalence rates across the globe or another country can’t tell Canada’s story. Canada should not have to estimate its rates for Nova Scotia or Nunavut by extrapolating from international rates and fragmentary surveys.

What is the purpose of chronic disease surveillance?  

In short, “to support public health action.”

According to the Government’s website, “The CCDSS enhances the scope of data on chronic diseases in Canada and supports the planning of health resources and the development of health policies and programs.” 

It fits within the broader portfolio of The Public Health Agency of Canada (PHAC), which includes:

• “preventing disease and injuries,
• responding to public health threats,
• promoting good physical and mental health, and
• providing information to support informed decision making.” (PHAC website)

The social burden of thyroid diseases include infertility and pregnancy complications, delayed childhood development, decreased quality of life, and economic impacts (Chiovato et al, 2019).

Wise action begins with data collection. We could begin to reduce the financial cost and human burden of suffering from chronic disease in Canada by adding thyroid disease to the CCDSS.

How does Canada monitor chronic diseases?

Many chronic diseases are tracked by the Canadian Chronic Disease Surveillance System (CCDSS) by using diagnostic codes based on the International Classification of Diseases (ICD).

The CCDSS “collects data on all residents who are eligible for provincial or territorial health insurance. It can generate national estimates and trends over time for over 20 chronic diseases and conditions, and other selected health outcomes.” (Government of Canada, n.d.)

On the website of Canada’s Public Health Agency of Canada, the CCDSS fact sheet shows that our government’s CCDSS monitors the 20 diseases in six categories:

• 4 Cardiovascular diseases,
• 2 Chronic respiratory diseases,
• 3 Mental illnesses,
• Diabetes,
• 6 Muscoskeletal disorders, and
• 4 Neurological conditions.

In addition to age, sex, province, and disease status data, CCDSS collects useful data regarding each disease:

• incidence and prevalence;
• all-cause mortality (death due to any cause);
• health care utilization, such as hospitalizations and physician visits; and
• multimorbidity and comorbidity (having multiple chronic diseases).

If these factors were tracked for thyroid diseases, it could better inform healthy discussions of the net cost-benefit ratio of screening for, treating, and monitoring thyroid diseases in Canada.

Most thyroid diseases are not included in our monitoring programs.

Thyroid cancers are monitored through different systems because it is a type of cancer and it is the only subcategory of thyroid disease that our government does monitor.

However, after a thyroidectomy for thyroid cancer, people living with the resultant hypothyroidism are not under surveillance. As the rates of thyroid cancer climb, so will the rates of lifelong chronic non-autoimmune hypothyroidism.

The Government of Canada does not monitor any of the following thyroid diagnoses:

• Hypothyroidism, autoimmune and non-autoimmune
• Hyperthyroidism, autoimmune and non-autoimmune
• Congenital thyroid disorders,
• Pituitary TSH secretion disorders, including central hypothyroidism
• Toxic and nontoxic nodules and goiter
• Infectious and bacterial thyroiditis
• “Euthyroid sick syndrome,” an illness-induced secondary thyroid hormone metabolism dysregulation, also called “low T3 syndrome” and “nonthyroidal illness syndrome” (NTIS).

All of the above have ICD-11 diagnostic codes that enable them to be monitored through the CCDSS.

Naturally, thyroid belongs in an “endocrine disorders” category alongside its sister disease, which currently stands alone.

• Diabetes and thyroid disease are both endocrine disorders with metabolic manifestations in many organs and tissues.
• Diabetes and thyroid diseases both have significant subpopulations with glandular autoimmunity.
• In pregnancy, we have both gestational diabetes and gestational thyroid disease complications, but thyroid disease incidence spills over into the post-partum phase.
• Research informs us that “thyroid disorders remain the most frequent autoimmune disorders associated with type 1 diabetes” (Hage et al, 2011)
• Both diagnosed and undiagnosed thyroid dysfunction is also highly associated with type 2 diabetes (Khassawneh et al, 2020).

But Canadian statistics on diabetes do not address this significant overlap between the two most prevalent endocrine disorders. That’s because one is on the list and the other is not.

As mentioned above, global prevalence rates are estimated at 5-10% for thyroid diseases (excluding cancer and isolated thyroid nodules). In contrast, according to the CCDSS data tool, as of 2017, these were some of the lower incidence rates of conditions on Canada’s list:

• acute myocardial infarction (<3%)
• stroke (<3%),
• rheumatoid arthritis (<1.5%)
• gout (<1.5%),
• epilepsy (<1%)
• schizophrenia (<1%),
• Parkinsonism (<0.6%), and
• multiple sclerosis (<0.3%)

All-cause “hypothyroidism” alone has high prevalence in the U.S., where it “affects an estimated 4% of women aged 18–24 years and 21% of women older than 74 years; respective values in men are 3% and 16%” (Chiovato et al, 2019).

Rates of thyroid diseases so prevalent in women past childbearing age should be of concern to Canadians. These are our mothers, grandmothers, professionals, and community leaders.

How thyroid diseases and thyroid hormones affect public health

Most physicians should already be aware that thyroid disorders may increase risk in osteoporosis, heart diseases, mental health disorders, infertility, sexual health, and pregnancy. But those conditions are tip of an iceberg.

Thyroid hormones have powerful effects on all organs and tissues in the human body. Scientists have not yet identified a tissue or organ that lacks thyroid hormone transporters or thyroid hormone receptors.

Thyroid autoimmunity is the most prevalent among autoimmune diseases, surpassing type 1 diabetes (Caturegli et al, 2013). It has a strong genetic component, but we can mitigate its harm. A correct and timely autoimmune thyroid diagnosis in one family member can assist in the correct and timely diagnosis of another family member. A strong family history of thyroid autoimmunity may justify screening before pregnancy and appropriate vigilance regarding congenital or childhood thyroid disorders.

When thyroid diseases are undiagnosed or poorly managed, it increases risk to human health in many chronic diseases and acute illnesses. Conversely, illnesses can be secondary causes of dysregulation in thyroid hormone secretion and metabolism in people with or without a thyroid disease diagnosis.

Two areas of research illustrate this two-way street, 1) NTIS and 2) COVID-19:

1) Nonthyroidal illness syndrome (NTIS) / Euthyroid sick syndrome (ESS)

Recently, a very large retrospective study in a multi-state US health region discovered that disease prevalence rates in atrial fibrillation, as well as many other chronic cardiovascular diseases, depression, diabetes, and dementia, were related to thyroid hormone levels within and below range. This was true even in people who were not diagnosed or treated with a thyroid disease who had a normal TSH (Anderson et al, 2020; Appendices).

Surprisingly, in Anderson’s 2020 study, the highest chronic disease prevalence rates were found in cohorts whose Free T3 (FT3) was low while their average TSH and Free T4 (FT4) were normal, the pattern seen in nonthyroidal illness syndrome (NTIS). The second-highest chronic disease prevalence rates were often found in cohorts whose Free T4 (FT4) and/or TSH were within the upper half of the reference range (Anderson et al, 2020; and see the heat maps analyzing their Appendix data by Thyroid Patients Canada, 2021).

Reinforcing Anderson’s findings, in 2018, a study of NTIS in patients with cancers, chronic cardiovascular, neurological, and kidney diseases showed high death rates; and surprisingly, having a mildly high FT4 does not diminish health risk when T3 is concurrently low, but actually increases risk (Ataoglu et al, 2018). A recent review of many studies demonstrated that contrary to widespread belief, “Clinical parameters are more likely to be associated with thyroid hormone levels than with thyrotropin [TSH] levels” (Fitzgerald et al, 2020).

Despite its misleading “nonthyroidal” and “euthyroid” name, “sick euthyroid syndrome” has an ICD diagnostic code categorized under hypothyroidism. This is a logical place for secondary hypo-T3-ism that can inhibit normal TSH response to low thyroid hormones and increase health risk.

Calling this syndrome “nonthyroidal” just because the thyroid gland doesn’t cause it and is not damaged by it is like calling type 2 diabetes a “non-diabetic” syndrome. Just as an acute inflammatory response differs from chronic inflammation, acute low T3 after a myocardial infarction differs from the pathology of chronic low T3 in heart disease (Van den Berghe, 2014; ). It’s not necessarily a transient low T3 that is pathological, but the failure to recover from it in a timely manner.

As a result of the misnaming of this condition, many physicians and scientists have overlooked the fact that people being treated for thyroid diseases are not immune to NTIS. Treated thyroid patients are routinely excluded from research and treatment studies, which is unfairly discriminatory to people with severe thyroid disease who may have more difficulty recovering T3, and recovering health, without TSH-guided thyroid function. Their biochemistry and prognosis may differ under the shadow of their treatment and their thyroid disease.

2) Thyroid diseases and COVID-19

COVID-19 has also illustrated the way that thyroid disease can increase public health risk, and the way a disease can dysregulate thyroid hormone metabolism – there is a “bidirectional impact” (Duntas & Jonklaas, 2021). At the start of the COVID-19 pandemic, thyroid disease and thyroid hormone dysregulation was not on the list of “comorbidities” that increased risk. However, in July 2020, Indonesian scientists Hariyanto and Kurniawan published a meta-analysis of eight COVID-19 studies that had tracked rates of thyroid disease in 2,169 patients. Their title reveals their main finding: “Thyroid disease is associated with severe coronavirus disease 2019 (COVID-19) infection.” The composite odds ratio among the eight studies was 2.48 for the association of thyroid disease with severe COVID-19 disease.

Other researchers have studied Low T3 / non-thyroidal illness syndrome (NTIS) / euthyroid sick syndrome (ESS) in COVID-19. Alas, they did so while following the tradition of excluding patients with thyroid diseases whose disabilities and treatments might mess up the data. Unsurprisingly, morbidity and death rates were found to be higher in COVID-19 patients with low T3 (Lui et al, 2021; Sciacchitano et al, 2021; Calcaterra et al, 2022). Just as many people with chronic heart failure exhibit chronic NTIS (, thyroid hormone abnormalities in “long-COVID” are possible.

Are thyroid diseases “easy” to manage and “cure”?

It’s a common belief that thyroid diseases are “easy” to diagnose and manage. But like type 1 diabetes and rheumatoid arthritis, many types of thyroid diseases are never truly “cured,” and they are not always easy to manage.

Some forms of congenital and acquired thyroid disease are transient or can go into remission, and those require special vigilance regarding the cessation of therapy. But others like thyroid cancer, multinodular goiter, and Graves’ hyperthyroidism are often treated by replacing them with another chronic disease, hypothyroidism, and that’s not a true cure.

As researchers have found in other countries like Korea, treated hypothyroidism has a significant influence on comorbidity rates and death rates, elevating risk to human health in all age and sex groups (Sohn et al, 2021).

Here are some of the variables that make treatment challenging.

Various subgroups of the population may experience more thyroid disease treatment challenges than others, such as patients with congenital hypothyroidism; genetic mutations in thyroid hormone pathways; or severe concurrent chronic heart, liver, or kidney diseases that can dysregulate thyroid hormone metabolism.

Emerging research is facing the challenge of diagnosing and treating “autoimmune polyendocrine syndromes” that combine autoimmune thyroid disease with one or more additional autoimmune diseases like type 1 diabetes, multiple sclerosis, celiac disease, pernicious anemia, lupus, or Addison’s disease (Crafa et al, 2021; Genetic and Rare Diseases Information Center, 2021).

In the history of thyroid therapy, many screening criteria for thyroid disease have often played double duty as therapeutic targets. Since the 1990s, TSH testing has been heralded as the most exquisitely sensitive and specific test. But screening for the presence of a disease in the untreated population is not the same as optimizing a treatment to an individual whose TSH no longer regulates hormone supply.

The drive to simplify thyroid diagnosis and treatment has a downside. It hides the complex truth. The negative feedback loop on TSH secretion is more vulnerable to distortion by disease plus dosing than many realize. Due to lowered FT3:FT4 ratios during levothyroxine therapy in severe hypothyroidism, the TSH-FT3 relationship can become profoundly abnormal (Gullo et al, 2011; Hoermann et al, 2013). TSH-FT4 relationships can be distorted by a myriad of adult-onset pituitary failures, many substances and medications (Haugen et al, 2009), TSH-receptor antibodies (Paragliola et al, 2019), and nonthyroidal illness.

We do not know how many in the Canadian population face therapeutic challenges during thyroid disease, but collecting population data is a foundational way to support researchers, clinicians, health care administrators, and the public at large.

End Canada’s thyroid ignorance; begin surveillance.

In conclusion, thyroid diseases represent a significant disease burden and cost to our society and its health care systems. We can’t fathom just how deeply thyroid diseases affect our communities and how well we are managing them if we don’t perform basic surveillance.

Canadians already living with thyroid diseases, regardless of age, sex, and healthcare region, deserve the best quality of life possible. But thyroid disease statistics will likely vary across regions because of local factors such as provincial testing policies, health care economics, and the availability of practitioners who know a lot about thyroid diseases.

Public health programs and heightened medical awareness can make a difference.

Fortunately, many risk factors of thyroid disease are what the Public Health Agency of Canada can classify as “modifiable,” such as the substitution of iodized salt with sea salt and an understanding of hindrances to levothyroxine medication absorption.

Canadians and sympathetic international citizens call on the Public Health Agency of Canada to put an end to the artificial separation of thyroid disease and thyroid hormone status from other areas of health. Health practitioners need awareness of common comorbidities like various anemias, and patients need accurate information about thyroid endocrine disruptors and dietary influences. It is time to see thyroid disease as a major player in the doctor’s office, emergency room, living room, the workplace, and during a public health crisis.

Once Canadians can see trends in nation-wide data on thyroid disease through the CCDSS program, we can finally set targets to reduce the prevalence and mortality rates in thyroid diseases. We can begin to act to protect disadvantaged Canadians if we can see which demographic groups and health care regions are struggling the most with managing the risk factors thyroid disease diagnosis and/or treatment effectiveness.

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• Tania S. Smith, PhD., President, Thyroid Patients Canada, thyroid patient and thyroid science analyst.
• Thank you to our “Advisory Group” of thyroid patient peer leaders for their assistance in drafting and revising this petition rationale.

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Sign the social media petition at Change.org here: https://www.change.org/p/include-thyroid-diseases-in-canada-s-chronic-diseases-list

• Note: Change.org may ask you for a donation after signing. But that donation does not go to Thyroid Patients Canada. It goes to Change.org to boost our petition post to more users. That will help fund both Change dot org and our petition’s reach. (See “Donations” heading on Wikipedia’s change.org page.)

• To donate directly to Thyroid Patients Canada, please see our Donate and Support page and use the methods provided there. We urgently need dollars to pay our expenses and build sustainability as a nonprofit organization. Thank You!

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