Chronic kidney disease (CKD) is a gradual loss of kidney function that can lead to fluid,
electrolyte and waste build-up in its advanced stages. Gout, a condition
marked by high levels of uric acid that can crystallize through the
body, can lead to CKD in some patients.
Could patients with chronic kidney disease benefit from therapies
that lower their serum uric acid levels to reach a target goal
associated with better organ function? A group of researchers set out to
examine whether this therapy, widely used for gout treatment, help CKD
patients who achieve the ACR target serum urate level of <6mg/dl.
‘Chronic kidney disease patients who take urate-lowering therapy and achieve target urate levels show improvement in kidney function.’
That minimum target is associated with improvement in the signs and
symptoms of gout, according to the 2012 ACR Guidelines for Management of
Gout. They also wanted to find out if patients' CKD stage at the
beginning of treatment would influence the benefits of urate-lowering
therapy (ULT). First-line therapies for lowering urate levels are
allopurinol and febuxostat.
Chronic kidney disease patients who take urate-lowering therapy and
achieve target urate levels show improvement in kidney function, revealed a new research findings presented this week at the 2016
ACR/ARHP Annual Meeting in Washington.
"Progressive kidney disease leading to dialysis impacts patients on a
daily basis and represents a major cost to the health care system,"
said Gerald Levy, MD, MBA, a rheumatologist at Kaiser Permanente in
Downey, California, and a lead author of the study. "Controlling
diabetes and hypertension are the primary tools to prevent end stage
kidney disease. Normalizing serum uric acid level potentially is another
tool to help prevent worsening kidney disease."
In this retrospective cohort study conducted from 2008 to 2014, the
researchers identified 12,751 patients with serum urate levels of
>7mg/dl. Patients' index date for the study was the first time they
achieved this test result. In addition, patients included in the study
had an estimated glomerular filtration rate (eGFR), a test used to
measure kidney function and how well the kidneys are filtering blood, in
the six months prior to that index date.
They also had to be ULT-naïve,
18 years of age or older, and have either CKD Stages 2, 3 or 4 at the
index date. The researchers also only included patients who had
continuous health coverage with drug benefits during the entire study
period. They defined outcomes in the study as either 30% decrease
or 30% improvement in the patients' eGFR test results from
baseline to the last available result.
During the study's span, 2,690 patients received ULT and 10,061
patients did not. Serum urate level goals were met in 42% of the
patients who were on ULT. Of those achieving this goal, 17.1% also showed a 30% improvement in their eGRF, compared to only
10.4% of those patients who did not meet the serum urate goal.
As for the influence of CKD stage at the onset of ULT, 7.1 of Stage 2
patients, 19.9% of Stage 3 patients, and 30% of Stage 4
patients all met the goal of 30% improvement in eGRF. Stage 3
patients had the most pronounced effect from ULT on their kidney
The study's findings suggest that CKD patients who achieve the ACR
serum urate goal of <6mg/dl have higher rates of eGFR improvement, a
key measure for kidney function and prevention of life-threatening
"This study suggests that patients with CKD should be tested for
uric acid independent of whether they have gout or not. In patients with
significantly elevated serum uric acid and moderate kidney failure, the
addition of urate lowering therapy may help stabilize or improve kidney
function," said Dr. Levy.