New NIH Study Seeks Kidney & Heart Disease Links & Solutions

A consortium has begun a landmark study examining risk factors for rapid loss of kidney function and the link between kidney and heart diseases. The researchers hope to identify ways to prevent or improve the treatment of both problems.

Seven centers have begun enrolling men and women who have mild to moderate kidney disease for the Chronic Renal Insufficiency Cohort (CRIC) Study. This is the first large, prospective, epidemiological study in the United States to look at the health of people with chronic kidney disease. The CRIC Study will help explain why kidney disease gets worse faster in some people and why some are more prone to heart disease. Over 2 years, 3,000 volunteers will be recruited for the study, which is funded by the National Institute of Diabetes and Digestive and Kidney Diseases, part of the National Institutes of Health, U.S. Department of Health and Human Services.

Patients will continue to receive regular health care from their own doctors. At the same time, CRIC investigators will carefully monitor the health of each patient for up to 6 years and perform standard blood, urine and other tests measuring kidney, heart and blood vessel health. About one third of participants will also have a glomerular filtration rate test, a measure of kidney function that is more accurate than standard tests. In addition, some patients will have electron beam tomography, a fairly new test that measures calcium in the heart's arteries and may identify heart disease earlier than standard ECG and EKG tests.

So that findings can be applied to patients in the community, CRIC is recruiting people with varying degrees of kidney function, half of whom will have kidney disease due to diabetes, the leading cause in the United States. In 2000, more than 458,000 people were treated for kidney failure, costing taxpayers, insurers, and patients $19.35 billion. Another 10 to 20 million people have earlier stages of kidney disease. All are at higher-than-average risk for heart attacks, strokes, and other complications.

"The economics of the disease alone warrant a study of this scale, but those of us who care for people with kidney disease never forget the tremendous physical and emotional challenges they face daily," says Thomas Hostetter, M.D., the kidney specialist overseeing the study. "We'd like to make life better for them, and if we can reduce medical costs by preventing kidney and heart failure, that's great too."

Many studies have focused on people with advanced kidney disease, but few have studied those in earlier stages, when there should be a greater opportunity to preserve kidney function or prevent heart disease. The CRIC Study will provide the most thorough review to-date of the relative impact of known risk factors for kidney disease and heart disease �� diabetes, hypertension, high cholesterol, tobacco use, and inactivity �� and factors suspected of contributing to these conditions �� chronic inflammation, infection, oxidative stress, elevated homocysteine, fibrinogen. The CRIC Study should also provide clues to how kidney disease itself contributes to the development of cardiovascular diseases.

Anyone who has diabetes, high blood pressure, or a family member with kidney problems �� especially African Americans, Hispanic Americans, and Native Americans �� is at high risk for getting kidney disease. Hostetter encourages those at high-risk to get a blood or urine test for kidney disease.

"It would be terrific if we could prevent kidney disease. In the meantime, I'd be a lot happier �� and I know patients would be �� if CRIC could show us how to manage it better," said Hostetter.

Editors:

Centers are in Ann Arbor, Michigan; Baltimore; Chicago; Cleveland; New Orleans; Oakland and San Francisco, California; and Philadelphia.

Read more about the CRIC Study at http://www.niddk.nih.gov/patient/cric/cric.htm and www.cristudy.org.

For background on kidney disease see "Your Kidneys and How They Work" and other titles at http://www.niddk.nih.gov/health/kidney/kidney.htm.