THURSDAY, Sept. 30 (HealthDay News) -- Patients battling chronic kidney disease face a higher risk for stroke and heart disease, new research reveals.

The findings are reported in a pair of studies, one from the University of California, Los Angeles, and the second from the University of Cambridge in England, that are published in the Oct. 1 edition of BMJ.com.

Past and current indications of a kidney disease-heart disease link prompted the Cambridge team, which was led by Emanuele Di Angelantonio from the department of public health and primary care, and the UCLA team led by Bruce Ovbiagele of the stroke center and department of neurology, to suggest that early signs of kidney disease should be considered a prime factor when screening for heart disease and stroke risk, alongside blood pressure and cholesterol levels.

However, using kidney disease as a heart disease screening tool is complicated by the fact that kidney disease often goes undiagnosed due to a lack of obvious symptoms, the study authors noted in a news release from the journal's publisher.

In the first instance, the UCLA study, conducted in consort with researchers from Taiwan, focused on the results of 33 studies that looked at the flow rate of fluid filtered through the kidneys of about 280,000 patients.

The team found that those with abnormally low flow rates had a 43 percent greater risk for a future stroke compared with those with normal flow rates.

In addition, as a particular grouping, Asians with low flow rates faced a higher stroke risk than non-Asians with low flow rates, Ovbiagele and colleagues observed.

In the study by Di Angelantonio's team, conducted in collaboration with Icelandic researchers, nearly 17,000 Iceland residents were tracked for almost a quarter of a century.

Noting that even very early signs of kidney disease among the participants was linked to heart disease risk, the team found that by adding kidney disease to traditional screening protocols, heart disease prediction improved "modestly." Specifically, evidence of kidney disease turned out to be half as predictive as a history of diabetes and about one-sixth as predictive as a history of smoking.

Kidney disease was also linked to an increased risk of death from health complications unrelated to either heart disease or cancer.

The research team called for more study into the apparent association between kidney disease and cardiovascular risk, and the usefulness of using kidney disease as a screening indicator.

More information

For more on kidney disease and heart risk, visit the National Kidney Foundation.