Lower income groups diagnosed with diabetes continue to have a higher mortality rate, an Ontario study suggests.

According to the Diabetes Association of Canada the number of people diagnosed with diabetes in Canada was expected to double between 2000 and 2010, from 1.3 million to 2.5 million.

Researchers found although deaths from diabetes had come down by 30 per cent between 1995 and 2006 in Ontario but diabetics from lower-income groups saw lesser improvement.

According to a report in this week's issue of the Canadian Medical Association Journal there was a 40 per cent widening gap in the mortality ratio in those aged 30 to 64 between the poorest and richest groups of diabetics.

Principal investigator Dr Lorraine Lipscombe of Women's College Hospital in Toronto and the Institute for Clinical Evaluative Sciences (ICES) said

"Our findings illustrate the widening impact of income on the health of diabetes patients, even in a publicly funded health system."

A reason cited for this gap was diabetes management had become more complex and costly. Advanced treatment advances have improved survival but it can pose financial burden.

"Income is a well-known predictor of survival. Improved treatments, such as new insulin and blood pressure drugs can be costly and lower income groups are less likely to have an access to them,” said Lipscombe.

By 2006 mortality rates for higher income people was .64, or six in 1,000 people and for lower income adults was .96, or about 10 in 1,000.

"Our worry is that there are differences in access to treatments among incomes," said Lipscombe.