Austin G. Stack
Gout is associated with a 29% increased risk for developing advanced chronic kidney disease and a 210% increased risk for end-stage renal disease, according to data published in BMJ Open.
“An emerging body of evidence has linked elevated uric acid levels with the risk of kidney disease,” Austin G. Stack, MD, MBBCh, MSc, FASN, FRCP, of the University of Limerick in Ireland, told Healio Rheumatology. “However, very few studies have examined the relationship between gout and the risk of advanced chronic kidney disease (CKD). The clinical community has always believed that high levels of uric acid might be bad for kidneys and that patients who suffered from gout were at greater risk of kidney failure than those without gout.”
To analyze the association between gout and the risk for advanced chronic kidney disease, Stack and colleagues conducted a retrospective matched cohort study of data from the U.K. Clinical Practice Research Datalink. The researchers then linked this data with admissions information from the Hospital Episode Statistics, and death certificate data from the Office for National Statistics. The study included data on 68,897 adult patients with gout, as well as 554,964 matched patients without the disease. All included patients had been registered at U.K. practices and had at least 12 months of clinical data available.
Those with a history of advanced chronic kidney disease, juvenile gout, cancer, HIV, tumor lysis syndrome, Lesch-Nyhan syndrome or familial Mediterranean fever were excluded. The researchers defined advanced chronic kidney disease as the first occurrence of dialysis, kidney transplant, diagnosis of end-stage kidney disease or stage 5 chronic kidney disease; an estimated glomerular filtration rate less than 10 mL/min/1.73 m²; the doubling of serum creatinine from baseline; and death associated with chronic kidney disease.
Gout is associated with a 29% increased risk for developing advanced chronic kidney disease and a 210% increased risk for end-stage renal disease, according to data.
According to the researchers, the incidence of advanced chronic kidney disease was higher among patients with gout, with a rate of 8.54 per 1,000 patient-years (95% CI, 8.26-8.83), compared with a rate of 4.08 for those without gout (95%CI, 4-4.16). In addition, gout was associated with a greater risk for advanced chronic kidney disease in both unadjusted (HR = 2; 95%CI, 1.92-2.07) and adjusted (HR = 1.29; 95%CI, 1.23-1.35) analyses.
“Our analysis has shown that gout more than doubled the risk of kidney failure,” Stack said in an interview. “These findings suggest that gout is an independent risk factor for the development of advanced kidney disease and kidney failure. This new research suggests that gout may also play an important role in the progression of kidney disease.”
The association was strongest for end-stage kidney disease (HR = 2.13; 95%CI, 1.73-2.61), according to Stack and colleagues. The association was also present for estimated glomerular filtration rate less than 10 mL/min/1.73 m² (HR = 1.45; 95%CI, 1.3-1.61) and serum creatinine doubling (HR = 1.13; 95%CI, 1.08-1.19), but not death related to chronic kidney disease (HR = 1.14; 95%CI, 0.99-1.31). This link between gout and advanced chronic kidney disease was also seen in propensity-score matched analysis (HR = 1.23; 95%CI, 1.17-1.29) and an analysis limited to patients with incident gout (HR = 1.28; 95%CI, 1.22-1.35).
“The identification of gout as a potential risk factor opens up new opportunities for the prevention of kidney disease and its consequences,” Stack said. “First, patients with a diagnosis of gout should be viewed as a high-risk group for kidney disease and should be screened for kidney disease with blood test and urine sample. Second, every effort should be made to get good control of gout as per international guidelines, although it is not yet proven whether optimal control — achieving target uric acid levels less than 360 µmol/L — can reduce the risk of kidney failure.”
“Third, many patients with gout have other conditions, such as diabetes or hypertension, and these should be treated effectively in order to reduce overall risk,” he said. “Finally, we encourage the conduct of new clinical trials need to test whether better control of gout leads to less kidney failure.” – by Jason Laday
Disclosure: Stack reports funding from AstraZeneca. Please see the full study for additional authors’ disclosures.