Kidney disease may up risk of diabetes: Study

The risk may be attributed to the rising level of urea -- the nitrogen-containing waste product in blood, which comes from the breakdown of protein in foods. 

Kidneys normally remove urea from the blood, but it can build up when kidney function slows down, resulting in greater insulin resistance as well as secretion in the body.

"We have known for a long time that diabetes is a major risk factor for kidney disease, but now we have a better understanding that kidney disease, through elevated levels of urea, also raises the risk of diabetes," said the Ziyad Al-Aly, Assistant Professor at the Washington University in St. Louis. 

"When urea builds up in the blood because of kidney dysfunction, it often results in increased insulin resistance and impaired insulin secretion," Ziyad added.

The findings, published in the journal Kidney International, are significant because urea levels can be lowered through medication, diet -- for example, by eating less protein -- and other means, thereby allowing for improved treatment and possible prevention of diabetes, the researchers said.

For the study, the team evaluated the records of 1.3 million adults without diabetes over a five-year period, beginning in 2003.

Out of these, 117,000 of those without diabetes -- or 9 per cent -- had elevated urea levels, signalling poor kidney function and were at 23 per cent higher risk of developing diabetes.