April 8 (HealthDay News) -- Older women with malfunctioning kidneys are at increased risk for sudden cardiac death, says a U.S. study.

Researchers analyzed data on 2,760 postmenopausal women, average age 67, with a history of some heart disease to learn whether less serious, unrecognized kidney function deficiencies increased the risk of sudden cardiac death (SCD). They found that the risk of SCD was 3.16 times higher in women with advanced kidney dysfunction than in those with normal kidney function.

This increased risk was evident after the researchers controlled for several baseline risk factors including heart failure, age, smoking, heart rate and level of HDL, or "good," cholesterol.

Of the 135 women who suffered SCD over 6.8 years, 36 (3.5 percent) had normal kidney function, 69 (4.6 percent) had moderate kidney dysfunction, and 30 (13 percent) had advanced kidney dysfunction.

"We already know that patients with kidney disease are at greater risk of heart attack, heart failure and stroke. This study extends that concern to SCD and supports previous recommendations that people with kidney disease be monitored aggressively for cardiac risk factors," study author Dr. Rajat Deo, a fellow in cardiac electrophysiology at Johns Hopkins Hospital in Baltimore, said in a prepared statement.

The study was published in the April 8 issue of Hypertension.

While these findings about a link between kidney dysfunction and SCD were made in women, Deo and his colleagues believe they also apply to men. They're preparing an analysis of kidney function and SCD risk in elderly men and women.

"Sudden cardiac death is an important public health problem, but it is poorly understood and understudied, especially in women," Deo said.

SCD -- which kills about 310,000 American adults a year -- occurs when the heart abruptly and unexpectedly stops beating. SCD commonly strikes people with heart disease or heart disease risk factors, people with end-stage kidney disease and those with chronic kidney disease.

SOURCE: American Heart Association, news release, April 7, 2008