Type 2 Diabetes Risk: Signs, Tests and How to Lower Your Risk

Know your type 2 diabetes risk factors, the A1C and fasting glucose numbers used in Canada, when to get screened, and proven steps that lower your risk.

Type 2 diabetes develops gradually, often over years, and many people have no symptoms at first. The good news is that knowing your risk early gives you time to act, and research shows that lifestyle changes can greatly lower the chance of developing it.

Take our free diabetes risk test to get a sense of your risk in a few minutes. It is based on the American Diabetes Association's risk test. In Canada, the government-developed CANRISK questionnaire is also widely used. Neither can diagnose diabetes, but both can tell you whether it is time to get tested.

Who is at higher risk?

Risk factors for type 2 diabetes include:

• Age: risk rises from age 40, though younger people can develop it.
• Family history: a parent, brother or sister with type 2 diabetes.
• Ethnicity: higher risk for people of Indigenous, South Asian, Asian, African, Hispanic or Caribbean heritage.
• Gestational diabetes: having had diabetes during pregnancy, or a baby weighing over 4 kg at birth.
• PCOS (now also called PMOS): polycystic ovary syndrome, recently renamed polyendocrine metabolic ovarian syndrome, is closely linked with insulin resistance.
• Prediabetes: blood sugar above normal but not yet in the diabetes range.
• Body weight and waist size, especially extra weight around the abdomen.
• High blood pressure or high cholesterol, low physical activity and sleep apnea.
• Some medications, such as long-term steroid use, and certain mental health conditions.

Possible signs and symptoms

Many people have no symptoms. When they do appear, they can include:

• feeling unusually thirsty and urinating more often
• tiredness or low energy
• blurred vision
• cuts or sores that heal slowly, or frequent infections, including yeast infections
• tingling or numbness in the hands or feet
• unexplained weight loss

How diabetes is tested in Canada

Diabetes Canada uses these blood test results (in Canadian units, mmol/L):

• A1C: 6.5% or higher suggests diabetes. A1C reflects your average blood sugar over about the past three months.
• Fasting plasma glucose: 7.0 mmol/L or higher, after not eating for at least eight hours.
• Two-hour glucose tolerance test: 11.1 mmol/L or higher two hours after a sugary drink.

Without symptoms, a result usually needs to be confirmed with a repeat test on another day.

Prediabetes

Prediabetes means blood sugar is higher than normal but below the diabetes range. Diabetes Canada defines it as an A1C of 6.0% to 6.4%, a fasting glucose of 6.1 to 6.9 mmol/L, or a two-hour glucose tolerance result of 7.8 to 11.0 mmol/L. Prediabetes is an important window: not everyone with it goes on to develop diabetes, and many people can bring their levels back to normal.

When should you be screened?

Diabetes Canada recommends:

• screening every three years from age 40, using a fasting glucose and/or A1C test
• earlier and more frequent testing, every 6 to 12 months, for people at very high risk or with several risk factors
• an annual check of your risk factors with your health care provider

If you had gestational diabetes, follow-up testing after your baby is born, and regularly after that, is especially important.

How to lower your risk

The landmark US Diabetes Prevention Program found that people with prediabetes who made lifestyle changes, aiming for about 7% weight loss and 150 minutes of activity a week, reduced their risk of developing type 2 diabetes by 58% over about three years. You do not need to change everything at once. Steps that help include:

• Move more: work up to 150 minutes of moderate activity a week, such as brisk walking, plus strength training a couple of times a week.
• Eat more fibre: vegetables, legumes, whole grains, nuts and seeds help steady blood sugar.
• Swap sugary drinks for water, milk or unsweetened options.
• Aim for modest weight loss if you carry extra weight. Even 5% to 7% of your body weight can make a difference.
• Sleep well and stop smoking if you smoke.

When to get medical advice

Book an appointment with your doctor or nurse practitioner to ask about testing if:

• your risk test result is moderate or high
• you are 40 or older and have not had a blood sugar test in the past three years
• you have had gestational diabetes or have PCOS/PMOS
• you notice any of the symptoms above

Get urgent care if you have extreme thirst and urination with vomiting, stomach pain, rapid breathing, confusion or drowsiness. These can be signs of dangerously high blood sugar. Call 9-1-1 in an emergency.