Diabetes has become remarkably less deadly over the past generation, new research reveals.
In 2009, a Canadian living with diabetes had a life expectancy that was six years less than a comparable person without diabetes. In 1996, the diabetes sufferer would have had an 11-year reduction in life expectancy.
"That's a big difference," Dr. Lorraine Lipscombe, a research scientist at the Women's College Research Institute in Toronto, said in an interview. "But people with diabetes still have a significant reduction in life expectancy."
While the new study did not examine why mortality dropped, Lipscombe said it likely reflects a number of medical advances and societal changes. For example, screening for diabetes is more commonplace and treatment is more aggressive, particularly when it comes to blood pressure control.
As well, the number of people who smoke has dropped, and treatments for heart disease have improved a lot. Diabetes, a disease in which the pancreas does not produce enough insulin or the body does not properly use the insulin it produces, is highly damaging to the heart.
"We're seeing a lot fewer cardiovascular events in the patient population," Lipscombe said. "And when people do have a heart attack, we're a lot better at treating them."
The new research, published Thursday in the medical journal Diabetologia, examined changes in the "excess risk of mortality" among patients with diabetes in Ontario and in the United Kingdom.
In Ontario in 1996, a person living with diabetes was about 90 per cent more likely to die than a comparable person without diabetes. But 2009, that excess risk of mortality had fallen to 51 per cent.
In the U.K., the excess rate of mortality fell to 65 per cent from 214 per cent during that same time period.
The new study also confirmed what earlier research showed, that the number of people living with diabetes is soaring.
In Ontario, the rate of people living with diabetes rose to 11.4 per cent of the total population from 5.4 per cent during the study period.
In the U.K., the rate also doubled, but it increased to 6.9 per cent from 3.2 per cent. The researchers said they could not fully explain the considerable differences, but noted that screening is much more aggressive in Canada, which suggests there may be more people in the U.K. who have diabetes but are undiagnosed.
A person is considered to have diabetes if they have a HbA1C level – a measure of how much sugar has been floating around in the bloodstream for the past three months – of greater than 6.5 per cent. It is determined by a simple blood test that does not require a person to fast. (Previously diabetes was diagnosed using a measure of blood sugars after a person fasted overnight.)
About 2.5-million Canadians have diabetes, a disease characterized by high levels of blood glucose that can cause circulatory, heart and kidney problems. About 40,000 people a year die of diabetes in Canada; it is also the leading cause of amputations and blindness.
There are three distinct forms: Gestational diabetes is a temporary condition that occurs during pregnancy; type 1 diabetes, usually diagnosed in children, occurs when the pancreas is unable to produce insulin; and type 2 diabetes occurs when the pancreas doesn't produce enough insulin or the body doesn't effectively use the insulin it produces.
About 90 per cent of diabetics have type 2, which is usually a consequence of obesity, inactivity, poor diet and aging.