Ask the Doctor
Questions about kidney disease? Risk factors? Signs and symptoms? Are you concerned about yourself, a friend or family member? Ask Dr. Spry.
February 5 , 2002
More than 20 million Americans-one in nine adults-have chronic kidney disease, and most don't even know it. More than 20 million others are at increased risk. This surprising surge in prevalence is among several major findings included in new clinical practice guidelines from the National Kidney Foundation (NKF) to help physicians diagnose this under-treated medical condition earlier and more easily than ever before.
"Americans who have diabetes, high blood pressure or a family history of kidney disease should ask their physicians for routine blood and urine tests to diagnose chronic kidney disease," urged NKF president William F. Keane, MD, at a press conference to announce publication of the guidelines in the February issue of the American Journal of Kidney Diseases. "These tests can detect chronic kidney disease in its early stages when lifestyle changes and medication can be prescribed to delay or prevent the progression of kidney disease and its complications, including the development of heart disease." Left untreated, chronic kidney disease may ultimately lead to kidney failure, requiring transplant or dialysis for survival. With the number of kidney failure patients expected to more than double to 650,000 by 2010-at a projected cost to taxpayers of $28 billion- the guidelines could not come at a better time.
The National Kidney Foundation recommends that all individuals who are at increased risk for chronic kidney disease have their blood pressure measured, and their blood and urine tested for signs of impaired kidney function. In addition to people with diabetes, high blood pressure or a family history of kidney disease, the guidelines identify older Americans, African-Americans, Hispanics, Asians and Pacific Islanders as being at increased risk.
"Recent research indicates that kidney failure can be prevented or delayed if chronic kidney disease is diagnosed early enough in its progression and treated properly," said Andrew S. Levey, MD, chair of the work group which developed the evidence-based guidelines . "Three routine tests-blood for creatinine, urine for protein, and measurement of blood pressure-enable providers to detect kidney disease in its early stages. The guidelines also include a five-stage clinical action plan based on the severity of kidney disease, which offers all physicians-not just kidney specialists-a powerful tool similar to those used for managing other chronic conditions."
"Our new definition also provided us with criteria for analyzing data from the third National Health and Nutrition Examination Survey and calculating the first-ever prevalence figures for each stage of the disease," continued Dr. Levey, who is a professor of medicine at the Tufts University School of Medicine and chief of nephrology at the New England Medical Center in Boston.
The guidelines recommend estimating glomerular filtration rate, or GFR, from the level of creatinine in the blood, and checking for persistent protein in a patient's urine-known as proteinuria-as the best way to diagnose early kidney damage. The widespread belief that measurement of GFR and the detection of proteinuria require a 24-hour urine collection has discouraged care providers from making these tests part of routine medical practice. Evidence cited in the guidelines indicates that the level of GFR and persistent proteinuria can be estimated just as accurately from blood and urine tests collected during a routine office visit.
The clinical practice guidelines for chronic kidney disease , which also will be accessible on NKF's website at www.kidney.org and in book and CD-ROM formats, are the newest set of guidelines to be developed by the National Kidney Foundation through its Kidney Disease Outcomes Quality Initiative or K/DOQI. Building on the continuing success of its guidelines to improve outcomes for dialysis patients, NKF broadened the scope of the project in 2000 to include chronic kidney disease.
"With the release of these new guidelines , the potential benefit of K/DOQI will expand from 300,000 dialysis patients to more than 40 million Americans who have chronic kidney disease or who are at increased risk for developing it," observed Garabed Eknoyan, MD, K/DOQI co-chair and a professor of medicine at Baylor College of Medicine in Houston.
The guidelines are the culmination of two years' work by volunteer experts in nephrology, pediatric nephrology, epidemiology, laboratory medicine, nutrition, gerontology and social work who conducted a systematic study of evidence published in peer-reviewed medical journals. Once the work group achieved consensus, the K/DOQI Advisory Board, a large number of professional organizations and societies, federal officials and selected experts and interested members of the public were invited to review the draft guidelines. This process communicated the logic behind the guideline development to a broader group of experts and brought about an even wider consensus.
The National Kidney Foundation is dedicated to preventing kidney and urinary tract diseases, improving the health and well being of individuals and families affected by these diseases and increasing the availability of all organs for transplantation.