Type 2 diabetes

Type 2 diabetes is a disease characterized by chronic hyperglycemia, that is, by having too much glucose (sugar) in the blood. This disease usually occurs in older adults, and more commonly affects people who are obese or overweight.

Type 2 diabetes: understand it all in 2 min

In a healthy individual, blood sugar is controlled by insulin, a hormone secreted by the pancreas. Insulin allows sugar to enter cells for use as fuel, especially in muscles and the liver. In a person with type 2 diabetes, the body becomes unable to regulate blood sugar, which is the level of glucose in the blood. This is when blood sugar levels rise (this is called hyperglycemia). In the long term, if blood sugar is not lowered by treatment, it can cause serious health problems, especially cardiovascular problems.

This chronic disease requires individualized treatment and close monitoring by the affected person and the medical team. Healthy lifestyles are the basis of treatment. If these habits are not enough to lower blood sugar, drugs can be used.

There are 2 main forms of diabetes, type 1 diabetes and type 2 diabetes, both characterized by chronic hyperglycemia.

Type 1 diabetes occurs in young people and often develops in childhood. It is caused by the autoimmune destruction of the pancreas that no longer produces insulin. The cause is poorly understood and there is currently no possible prevention. People with the condition are therefore dependent on insulin, which must be given by injection.

As for type 2 diabetes, which accounts for 90% of diabetes cases, it occurs later in life. It is mainly due to a state of insulin resistance and is associated with being overweight.

A rapidly growing disease

The number of people with type 2 diabetes is growing steadily, and this trend is attributed to the “western” lifestyle, which is associated with a sedentary lifestyle and obesity, as well as an ageing population. Globally, the International Diabetes Federation predicts that the number of people with diabetes could increase from 285 million in 2010 to 438 million in 2030.

In Canada, in 2009, 6% of people over the age of 12 reported having diabetes. This rate increases with age, reaching almost 18% among those 65 and over. In total, more than 9 million Canadians have diabetes or prediabetes, including 650,000 Quebecers. In addition, many cases of diabetes are unknown because they go undetected.

Type 2 diabetes usually begins after the age of 40 but is now affecting more children and adolescents, due to obesity affecting more and more young people.

Causes

Diabetes results from a combination of genetic and environmental factors, as well as lifestyle factors. In general, each person carries hereditary baggage which predisposes them to suffer from diabetes or, on the contrary, protects them. Researchers now know several genes that put an individual at risk for developing type 2 diabetes. In people genetically predisposed to the disease, it is generally overweight and particularly the accumulation of fat in the organs of the body. Abdomen that leads to insulin resistance, the first step to type 2 diabetes.

Initially, to compensate for insulin resistance, the pancreas begins to produce more insulin. However, over time the pancreas becomes exhausted and insulin secretion decreases. There is therefore a relative lack of insulin and blood sugar levels remain continuously elevated.

Type 2 diabetes is therefore the result of two phenomena: first, insulin resistance, then exhaustion of the pancreas.

Diagnostic

Because type 2 diabetes is rarely accompanied by symptoms in the early stages, it is often discovered incidentally during a routine medical examination.

Blood glucose tests can be used to detect this: a fasting or random blood sugar test and, sometimes, a test for induced hyperglycemia. This last test consists of a blood glucose reading 2 hours after having ingested a sweet juice containing 75 g of glucose. Often, fasting blood sugar gradually rises over the years from a normal level to an intermediate state of prediabetes and then to the threshold for diabetes.

Blood sugar can be measured by a blood test or estimated with a blood glucose meter (glucometer), which allows blood sugar levels to be analyzed on a drop of blood taken from the fingertip.

Even if the results are normal, it is usually recommended that you have these tests at regular intervals in order to find the disease as soon as possible.

Possible complications

For information on acute complications (hypoglycemia and hyperglycemia caused by adjustment of treatment and hyperosmolar hyperglycemia syndrome in untreated diabetics), see our Diabetes fact sheet (overview).

In the long term, many diabetics see their condition worsen as a result of their disease, especially if the diabetes is not well controlled and monitored. This is because chronically high blood sugar gradually damages nerves and blood vessels, mainly in the eyes and kidneys. Diabetes can therefore be the cause of cardiovascular disease, irreversible vision loss, pain due to nerve damage or kidney failure. For more information, see our Complications of Diabetes fact sheet.