TUESDAY, Feb. 21 (HealthDay News) -- People with type 2 diabetes have a higher risk of death than people without the disease, but a new study suggests that if they also have kidney damage their risk of dying is even greater.

In an analysis of 22 studies, researchers from Brigham and Women's Hospital in Boston found that the annual risk of death for people with type 2 diabetes ranged from 0.28 per 100 patient years to 8.24 per 100 patient years. And, in studies with those with more advanced kidney disease, the risk of death was between 5.9 per 100 patient years to 8.24 per 100 patient years.

"It's no surprise that those with kidney disease have a higher mortality risk," said Dr. Vivian Fonseca, president of medicine and science for the American Diabetes Association. "People with type 2 diabetes often don't know they have the disease, and have many years of poor blood sugar control before they're diagnosed. That means they're likely to have nerve damage and visual damage, which make managing kidney disease more complicated."

The current analysis is published online Feb. 21 in the journal Cardiovascular and Cerebrovascular Disease.

There were almost 92,000 people and nearly 7,000 deaths included in the new analysis. All of the studies were randomized clinical trials including people with type 2 diabetes. The trials had to last at least a year to be included.

Overall, there was approximately a 30-fold difference in the annual risk of death across the various trials, suggesting that people with type 2 diabetes are very diverse, and that some people are at much higher risk of complications and death than others.

The researchers found that those with the lowest risk of death were people under the age of 59 with fewer signs of kidney damage.

Those with the highest risk of death were older, had diabetes for a longer period of time (average of about 15 years), had high blood pressure and signs of kidney disease. The authors found that presence of chronic kidney disease was associated with the highest mortality rates.

"This analysis shows that having a high creatinine level is a very high marker for mortality," said Dr. Joel Zonszein, director of the clinical diabetes center at Montefiore Medical Center in New York City.

Creatinine levels indicate the health of your kidneys. The higher this level is, the less effectively your kidneys are working.

Both experts said it's important to try to prevent kidney damage, because the more it progresses, the harder it becomes to control.

Controlling blood sugar and blood pressure levels are essential to keeping the kidneys healthy, Zonszein said.

"I see much less progression to late-stage kidney disease in patients who are treated aggressively for high blood pressure, especially with ACE inhibitors or ARBs. Patients need to get the proper amounts of these medications to bring their blood pressure to normal," he said.

ACE inhibitors and ARBs are two different types of blood-pressure lowering medications.

"We really can slow the progress of kidney disease, but we have to treat patients correctly early in the disease," Zonszein said.

Fonseca agreed. "Do everything you can to prevent late-stage kidney disease. Get good control of your blood pressure and good control of your diabetes. Make sure you have screening for kidney problems," Fonseca said.

Both also agreed that once late-stage kidney disease has set in, it becomes much harder to control blood pressure and other complications. "This group is a huge challenge and we haven't really found the answers yet. We need new therapies for this particular patient population," Fonseca said.

More information

Learn more about keeping your kidneys healthy if you have diabetes from the U.S. National Institute of Diabetes and Digestive ... Kidney Diseases.