Oct. 8 (HealthDay News) -- Exercise may help extend the lives of people with kidney disease, a new study finds.

Many patients with chronic kidney disease (CKD) die prematurely, but many of those deaths aren't directly related to kidney problems, according to background information in the study.

Researchers analyzed data collected from 15,368 adult participants of the U.S. National Health and Nutrition Examination Survey III. Of those people, 5.9 percent had CKD. Based on the frequency and intensity of physical activity, the participants were divided into inactive, insufficiently active and active groups. They were followed for an average of seven to nine years.

The study found that 28 percent of CKD patients were inactive, compared with 13.5 percent of those without CKD. Active and insufficiently active CKD patients were 56 percent and 42 percent less likely to die during the study than inactive CKD patients. Similar exercise-related benefits were noted in those without CKD.

"These data suggest that increased physical activity might have a survival benefit in the CKD population. This is particularly important as most patients with stage III CKD die before they develop end stage renal disease," wrote Dr. Srinivasan Beddhu, of Salt Lake City Veterans Administration Healthcare System and University of Utah, and colleagues.

The study appeared online Oct. 8 in the Clinical Journal of the American Society of Nephrology.

SOURCE: American Society of Nephrology, news release, Oct. 8, 2009