Thyroid diagnosis & therapy in Native Canadian populations: Too many unanswered questions

How have thyroid diseases and our Canadian thyroid diagnosis & treatment policies affected Native American people in Canada?

This is an unanswered question. I can’t find any published research about it yet.

It’s just the perfect piece of “thyroid ignorance” to contemplate today in Canada.

Today, Sept. 30, as we Canadians know, is a relatively new holiday instituted here in Canada: “National Day for Truth & Reconciliation.”

It is to commemorate the loss of children who never returned from the “residential schools” that Native American children were required to attend.

Today is a day to imagine what it might be like to be torn away from your family as a young child and forced to attend and live in a school far away, where you couldn’t speak your native language.

According to the Government of Canada website on this holiday,

“There were 140 federally run residential schools in Canada that operated between 1867 and 1996.”

The institution of these schools resulted in not only the deaths of children, but irreparable harms to mental health, families, and Native American communities.

It makes one wonder, how many of those children had undiagnosed or poorly managed thyroid disease during their “schooling”?

I’m doubtful the health care was very good for those children, but don’t we have any data at all on their thyroid diagnoses and treatment from the school records? Can those records be compared with the records of populations of children at similar ages attending non-residential schools in towns and cities?

And how unequal is Native American people’s and communities’ access to thyroid healthcare options today, compared to those who are not Native American, and those who do not live on reservations in the more remote areas of Canada? We still do not know as Canadians, although those who have lived in those communities with thyroid disease know what they have personally experienced.

In contrast with thyroid diseases, we know a lot more about diabetes in Canadian indigenous populations:

“Established in 1999, the Aboriginal Diabetes Initiative (ADI) had initial funding of $58 million over 5 years. It was then expanded in 2005 with a budget of $190 million over 5 years. Currently, Health Canada is investing over $50 million per year to support the ADI’s third phase, as the Government continues supporting health promotion and diabetes prevention activities and services.” (from “Diabetes” page, Indigenous Services Canada, Government of Canada)

Because of this amazing research initiative, we know some dismal facts about diabetes in Indigenous communities:

“First Nations on reserve have a rate of diabetes three to five times higher than that of other Canadians. Rates of diabetes among the Inuit are expected to rise significantly in the future given that risk factors such as obesity, physical inactivity, and unhealthy eating patterns are high.”

Of course, not every type of diabetes is caused by the risk factors mentioned above. Type 1 diabetes (T1D) is autoimmune, similar to autoimmune hypothyroidism. But unlike Hashimoto’s thyroiditis, whose age of onset is usually over 30, T1D often appears in children and youth.

“Anyone can get T1D at any age, although 10-14 is the most common age of onset in most populations.” (JDRF Canada)

So we know a lot about Canadian Indigenous Diabetes prevalence rates, though more ressearch needs to be done in children.

Even if we did have data on diabetes in Indigenous children, it’s not easy to compare diabetes to thyroid diseases in Indigenous children. Thyroid diseases are much more diverse than diabetes in their types, causes, treatments, severity, and their health risks before and during treatment. What kinds of thyroid diseases could have affected Indigenous children attending residential schools, and Indigenous children today?

1. Iodine deficiency hypothyroidism, and perhaps also some cases of excess iodine-induced hypo-and hyperthyroidism. When was the use of iodized salt instituted in residential schools? What were their dietary sources of iodine at residential school compared to at home with their families?
2. Autoimmune thyroid diseases (Graves’ Disease, Hashimoto’s thyroiditis, and Atrophic thyroiditis), which can affect school-aged children even though their peak ages of onset are in adulthood;
3. Congenital hypothyroidism (from birth), including thyroid agenesis/dysgenesis and dyshormonogenesis, and central hypothyroidism (TSH deficiency). Their detection requires screening programs including both TSH and T4, shortly after the TSH falls from its temporary surge after birth.
4. Thyroid cancers. According to one secondary medical source, “Thyroid cancer is an uncommon cancer in childhood: Fewer than one in 100,000 children develop thyroid cancer each year. Although it can occur at any age, childhood thyroid cancer is most common in the teenage years, and it is the second most common cancer among adolescents ages 15 to 19.” (“Thyroid Cancer in Children,” Boston Children’s Hospital)

Why are we still so ignorant of the risks faced by Indigenous children with thyroid disease, both in the past and the present?

Untreated childhood hypothyroidism in particular has severe impacts on health for the rest of a person’s life:

“Undiagnosed hypothyroid children may experience slowed growth rate. Additional symptoms include sluggishness, pallor, dry and itchy scalp, increased sensitivity to cold and constipation. If untreated, the condition may have devastating effects, such as stunted physical growth and mental retardation.” (“Hypothyroidsim in Children,” John Hopkins Medicine)

Hypothyroidism is the most common thyroid dysfunction, and it is also the result of the most definitive treatments for thyroid cancer (total thyroidectomy) and hyperthyroidism (total thyroidectomy, or radioiodine ablation).

So we urgently require knowledge of undiagnosed and poorly treated hypothyroidism in Indigenous children.

Why don’t we have this knowledge yet? It’s not just because of lack of attention to “Indigenous Healthcare” in general, something which the government and researchers have been trying to improve.

The main reason for our thyroid ignorance in the Canadian Indigenous population is that thyroid research in Canada is in a dismal state in general.

We have very little population-wide thyroid health data with which to compare data specifically from Indigenous populations. Some regional data exists, but Canada-wide regional data is lacking.

Below, in the “Biblography,” is all the research I have found on the prevalence of thyroid diseases in Canada. FOUR scientific articles. That’s all!

In fact, some widely advertised prevalence rates of thyroid diseases in Canada are mythological claims. There is NO scientific basis on which any organization can make a dubious claim like this — “Studies have estimated that 1 in 10 Canadians suffer from a thyroid disorder and about 50% of the affected population in Canada is undiagnosed”?? — Ah, but what studies? This a highly questionable claim advertised by “ThyForLife,” the startup led by Natalia Lumen. They could have gotten this mythological claim from the Thyroid Foundation of Canada website, where it is also claimed (also without any citations or references) that “Studies indicate that 1 in 10 Canadians suffer from a thyroid condition of one type or another and are 4 to 7 times more common in women.” — What studies? And how do you know you’ve included all forms of thyroid disease in that statistic? Are you irresponsibly taking research from another country and misapplying it to Canada? It is wrong to spread such health misinformation. It makes it seem like there are a lot of “studies” on thyroid disease prevalence in Canada.

According to one publication in 2019, NO STUDIES have ever made such claims.

“No studies [prior to 2019] have examined the frequency of thyroid screening in the Canadian population, and whether thyroid screening and medication use vary by sex, race, income, and preexisting health conditions. … The majority of published studies about thyroid disease in Canada examine the prevalence and treatment of thyroid cancer.” (Stoll et al, 2019)

So, in honor of “truth” as well as reconciliation, we should first stop making “false” claims of Canadian thyroid disease prevalence rates! We actually have no idea whether certain thyroid diseases are more prevalent in northern Ontario than they are in coastal British Columbia, New Brunswick, Yukon or Nunavut, much less whether the Indigenous peoples in those regions experience “thyroid healthcare inequities.”

We don’t even have our own thyroid journal in Canada — which tells you how few Canadian thyroidologists there must be. Our publishing thyroid scientists put their articles in journals like the American Thyroid Assocciation’s journal called “Thyroid,” and other publications. See what journals the four articles in the Bibliography were published in.

Action is needed

You can’t get to “reconciliation” when you don’t even have a grasp of the “truth.”

To improve our knowledge of Canadian Indigenous Thyroid Healthcare, both past and present, we must improve our knowledge of Canadian Thyroid Healthcare in general, both past and present.

Canadian thyroidologists, and Government of Canada — when are you going to get started on filling this gap in population health research?

For more on our Canadian holiday, see the Government of Canada website: https://www.canada.ca/en/canadian-heritage/campaigns/national-day-truth-reconciliation.html

Bibliography: Canadian Thyroid disease prevalence and treatment

• Gagnon, F., Langlois, M.-F., Michaud, I., Gingras, S., Duchesne, J.-F., & Lévesque, B. (2006). Spatio-temporal distribution of hypothyroidism in Quebec. Chronic Diseases in Canada, 27(1), 1–8. https://pubmed-ncbi-nlm-nih-gov.ezproxy.lib.ucalgary.ca/16672134/
• Sarkar, A., Knight, J. C., Babichuk, N. A., & Mulay, S. (2015). Skewed distribution of hypothyroidism in the coastal communities of Newfoundland, Canada. Environment International, 83, 171–175. https://doi.org/10.1016/j.envint.2015.05.017
• Shah, B. R., Griffiths, R., & Hall, S. F. (2017). Thyroid cancer incidence among Asian immigrants to Ontario, Canada: A population-based cohort study. Cancer, 123(17), 3320–3325. https://doi.org/10.1002/cncr.30746
• Stoll, K. (2019). Disparities in Thyroid Screening and Medication Use in Quebec, Canada. Health Equity, 3(1), 328–335. https://doi.org/10.1089/heq.2018.0051

Government publications:

• Government of Canada, Statistics Canada. (2010, July 27). Healthy aging indicators [self-reported chronic diseases, sleep, social participation, thyroid condition, but only in citizens >45 years old]. https://www150.statcan.gc.ca/t1/tbl1/en/tv.action?pid=1310046601

Not focused on prevalence rates, but makes claims based on the government statistics above from 2010, and recommends NOT screening:

• Birtwhistle, R., Morissette, K., Dickinson, J. A., Reynolds, D. L., Avey, M. T., Domingo, F. R., Rodin, R., & Thombs, B. D. (2019). Recommendation on screening adults for asymptomatic thyroid dysfunction in primary care. CMAJ, 191(46), E1274–E1280. https://doi.org/10.1503/cmaj.190395