Chronic Kidney Disease in Gout in a Managed Care Setting

Serum uric acid control in gout was poor among patients without chronic kidney disease (CKD) and even worse among those with CKD.

Serum uric acid control in gout was poor among patients without chronic kidney disease (CKD) and even worse among those with CKD, according to the results of a recent study.

The retrospective study, which was headed by Mahesh J. Fuldeore at Takeda Pharmaceuticals International Inc., used data from a large US health plan. Claims and laboratory data were analyzed for enrollees from the health plan database from January 2002 through December 2005. Patients with gout were identified from pharmacy and medical claims data based on the presence of codes for gout medication or gout diagnosis.

“Severity of CKD was determined using the estimated glomerular filtration rate (eGFR). Allopurinol titration was defined as a change in average daily dose from first prescription to last prescription of 50 mg or more,” the authors wrote in the study, which appeared in BMC Nephrology.

A total of 3,929 patients were identified for inclusion in this study, 39% of whom had CKD (based on having an eGFR < 90 mL/min/1.73 m2). Subjects with CKD were older (P<0.01) and more likely to be women (P<0.01), had a greater number of comorbid conditions (P<0.01), and were more likely to be prescribed allopurinol (P<0.01) compared to those with no CKD.

“The average starting dose of allopurinol was lower among those with CKD, and it decreased with worsening kidney function. Among the 3,122 gout patients who used allopurinol, only 25.6% without CKD and 22.2% with CKD achieved a serum uric acid concentration of <6.0 mg/dL (p=0.0409). Also, only 15% of allopurinol users had an upward dose titration (by 50 mg or more), but the average increase in dose did not differ significantly between those with and without CKD,” the authors concluded.