There is a high prevalence of chronic kidney disease in the
United States, which has risen over
the past decade, according to a study led by researchers at the
Johns Hopkins Bloomberg School
of Public Health.
The study found that the overall prevalence of chronic
kidney disease increased from 10
percent of the population during a period from 1988 to 1994 to 13
percent from 1999 to 2004. The
researchers conclude that the increase is partly due to the rise
in the number of Americans with
diabetes and hypertension and the aging of the population. The
study is published in a recent edition
of JAMA.
Chronic kidney disease increases the risk for complications
from medications cleared by the
kidney, hypertension, anemia, bone disease, death from
cardiovascular disease and ultimately kidney
failure, which requires treatment with kidney transplantation or
dialysis.
"Our study demonstrates chronic kidney disease in the United
States is more common than
previously appreciated. However, less than one in 10 individuals
with kidney disease are aware they
have a problem," said Josef Coresh, lead author of the study and
a professor in the departments of
Epidemiology and Medicine at
Johns Hopkins. "The medical community is starting to realize that
chronic kidney disease is a serious concern, similar to the
increased awareness of hypertension in the
1970s and diabetes in the 1990s."
Analyzing data from more than 28,000 participants in the
National Health and Nutrition
Examination Surveys for 1988-94 and 1999-2004, the research team
measured the prevalence of
chronic kidney disease stages 1 to 4. According to the results,
the number of people with chronic
kidney disease stages 1 and 2, those with increased protein in
the urine but unimpaired kidney
filtration, increased slightly from 4.4 percent during 1988-94 to
5 percent during 1999-2004. Larger
increases were seen in the prevalence of stages 3 and 4 kidney
disease, which indicate impaired kidney
function called glomerular filtration rate; a GFR less than 60
equals approximately half the kidney
function of young adults. The proportion of adults with this
level of impaired kidney function rose
from 5.6 percent to 8 percent.
The increases in prevalence of chronic kidney disease were
largely due to the increases in the
prevalence of diabetes, hypertension and obesity, as well as to
the aging of the U.S. population. Some
of the increase was due to a shift in the mean serum creatinine
of the population, which is the blood
marker of impaired kidney function.
"Americans and their physicians should be aware that chronic
kidney disease is common, has
treatable components and [that] its progression can be slowed
substantially," said co-author Andrew
S. Levey, chief of nephrology at Tufts-New England Medical
Center. "Blood pressure control with
agents that protect the kidney, blood sugar control and avoiding
medications toxic to the kidneys are
the most important factors for patients with kidney disease to be
educated about."
The study was written by Coresh, Elizabeth Selvin, Lesley A.
Stevens, Jane Manzi, John W.
Kusek, Paul Eggers, Frederick Van Lente and Levey.
Funding for the research was provided by grants from the
National Institute of Diabetes and
Digestive and Kidney Diseases.