Kidney disease accounts for most of the increased risk of dying early among diabetics

One in every 10 Americans has diabetes, and a third or more of those with the condition will develop kidney disease. It may be possible to live a long and healthy life with diabetes, but once kidney disease develops, the risk of dying prematurely increases significantly, according to a study appearing in an upcoming issue of the Journal of the American Society of Nephrology (JASN). The findings have significant clinical implications for the prevention and treatment of kidney disease in people with diabetes.

Because people with diabetes have an increased likelihood of dying prematurely as well as an increased likelihood of developing kidney disease, Maryam Afkarian, MD, PhD (University of Washington) and her colleagues looked to see how the former affects the latter. In other words, how much does kidney disease contribute to diabetics' increased risk of dying early?

The researchers examined 10-year mortality rates in 15,046 US adults. Kidney disease was present in 9.4% and 42.3% of individuals without and with type 2 diabetes, respectively.

Among the major findings:

• Among people without diabetes or kidney disease, 10-year mortality was 7.7%.
• Among individuals with diabetes but without kidney disease, mortality was 11.5%.
• Among individuals with both diabetes and kidney disease, mortality was 31.1%.

"People with type 2 diabetes have many other risk factors for cardiovascular disease and mortality, so we expected that kidney disease would predict a part, but not a majority, of higher mortality associated with type 2 diabetes. To our surprise, we found that even in the medically complex patients with type 2 diabetes, kidney disease is a very powerful predictor of premature death," said Dr. Afkarian.

She noted that the findings have important implications. "First, among people with type 2 diabetes, the subgroup with kidney disease carries most of the mortality risk, so targeting intensive risk factor modification on this subgroup is likely to have the highest impact on overall mortality of people with diabetes. Secondly, preventing kidney disease may be a powerful way of reducing mortality in people with diabetes," said Dr. Afkarian.