Prediabetes in Canada: what PHAC says about your risk

About 3.7 million people in Canada were living with diagnosed diabetes in 2020-21, according to the Public Health Agency of Canada (PHAC). With November marking Diabetes Awareness Month, the agency’s guidance on prediabetes, the stage before type 2 diabetes, is a useful place to start for anyone who has wondered about their own risk.

PHAC’s most recent national snapshot, published in late 2023, found that 9.4 per cent of people aged one and older had diagnosed diabetes. The rate was 10.1 per cent among males and 8.7 per cent among females. It rises sharply with age: 0.3 per cent for those aged one to 19, 1.7 per cent for ages 20 to 39, 10.9 per cent for ages 40 to 64, and 27 per cent for people 65 and older. These are the figures for the 2020-21 data year, and newer numbers may be released later.

Most of those cases are type 2. PHAC says type 2 diabetes makes up 90 to 95 per cent of cases, while type 1 accounts for 5 to 10 per cent. The two are quite different. Type 1 is an autoimmune condition that requires insulin therapy for life, and PHAC states that it is not preventable. Type 2, by contrast, is described as potentially preventable, or at least delayable.

That is where prediabetes comes in. In the snapshot, PHAC defines prediabetes as an HbA1c (a blood test that reflects average blood sugar over recent months) of 6.0 per cent or higher but below 6.5 per cent, in a person who has no diabetes diagnosis and takes no glucose-lowering medication. Among adults aged 20 to 79, 6.3 per cent had prediabetes, based on survey data collected between 2007 and 2019. The agency notes that prediabetes can progress into type 2 diabetes over time, and that lowering your risk of prediabetes and managing blood glucose can help prevent or delay type 2 diabetes later in life.

One of the less obvious findings is how often diabetes goes unnoticed. In the same survey data, 1.9 per cent of adults aged 20 to 79 had undiagnosed diabetes. Put another way, PHAC reports that 22.5 per cent of people who met the criteria for diabetes were unaware of their condition. That is the main reason the agency advises regular screening.

Who is more likely to develop type 2 diabetes? PHAC’s prevention page lists several risk factors: prediabetes itself, advanced age, high cholesterol, physical inactivity, high blood pressure, being overweight or obese, a history of gestational diabetes, and a family history of type 2 diabetes. For prediabetes specifically, the page points to abdominal obesity and a family history of type 2 diabetes. Some of these, such as genetics and older age, cannot be changed, a point the snapshot makes directly.

The agency also says type 2 and gestational diabetes are more common among Indigenous Peoples and among people of African, East Asian and South Asian backgrounds. It attributes this in part to family history, cultural differences and inequities, and differences in opportunities and access to care. Other conditions linked to higher risk include polycystic ovary syndrome, vascular disease and schizophrenia. More broadly, PHAC reports that people facing social and economic disadvantage are more likely to develop type 2 diabetes, and that rates differ by income, education level and employment status.

Gestational diabetes, which develops during pregnancy, affects about 10 per cent of women who give birth, according to the snapshot. It is associated with a higher risk of developing type 2 diabetes later in life, which is why it appears on the risk list.

On prevention, PHAC’s advice is practical rather than dramatic. A healthy lifestyle can lower the risk of prediabetes and type 2 diabetes and help prevent or delay complications. The agency’s list of habits is: don’t smoke, maintain a healthy weight, limit alcohol, get enough sleep and rest, eat a variety of healthy foods, be physically active every day, and manage high blood pressure, cholesterol and glucose. The snapshot sums it up as regular physical activity, healthy eating, weight management and being smoke-free.

The stakes of not catching it early are laid out plainly. Complications of diabetes can include heart disease, diabetic ketoacidosis, foot ulcers and lower-limb amputations, and damage to the eyes, kidneys and nerves. People with diabetes are also at higher risk of severe outcomes from influenza and COVID-19. PHAC adds that, in many cases, the earlier a health condition is detected, the easier it is to treat.

The agency’s advice on testing is to get screened for diabetes regularly and to report any new signs and symptoms to a health care provider. How often that should happen for a given person depends on individual factors, which is a conversation for a doctor, nurse practitioner or pharmacist rather than something a news article can settle.

It is also worth remembering what the numbers do and do not say. The national figures are population estimates, not predictions for any one person, and having one or more risk factors does not mean someone will develop diabetes. Likewise, PHAC’s lifestyle guidance is meant to lower risk and delay onset, not to promise a particular outcome.

This article is based on official guidance from the Public Health Agency of Canada and is provided for general public information. It’s not a substitute for medical advice, if you have questions about how this applies to you, talk to your doctor or pharmacist.

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Sources: Public Health Agency of Canada, Diabetes: Prevention and risk factors; Public Health Agency of Canada, Snapshot of Diabetes in Canada, 2023.