By analyzing information from the National Health and Nutrition Examination Survey (NHANES) from 1988-1994 and 2007-2010, researchers have uncovered a 30% rate of gout prevalence among Americans with severe chronic kidney disease (CKD). They also found significantly higher rates of gout among individuals with lower average estimated glomerular filtration rates (eGFRs) or higher levels of albuminuria, even after adjusting for uric acid levels (Juraschek SP, et al. Semin Arthritis Rheum. 2013 Jan 8 [Epub ahead of print]).
“Health practitioners treating patients with CKD who have new-onset joint pain or swelling should be vigilant for undiagnosed gout,” noted Allan C. Gelber, MD, PhD, Associate Professor of Medicine at the Johns Hopkins Bloomberg School of Public Health, Baltimore, and his coauthors in their write-up of the study. “Moreover, practitioners treating patients with gout should be wary of CKD as an underlying factor contributing to both hyperuricemia and gout risk, because many urate-lowering medications require renal dosing or have associated nephrotoxicity.”
Dr Gelber and his colleagues looked at the signals produced by levels of albuminuria, serum uric acid, hyperuricemia, and eGFR among 15,132 adults in the 1988-1994 NHANES and 10,814 adults in the 2007-2010 NHANES.
The overall prevalence of gout among Americans was 2.7% in the 1988-1994 time frame and 3.7% during 2007-2010. In both periods, there was an inverse relationship between the proportion of patients with a reduced eGFR and gout or hyperuricemia, and a direct relationship between increased albuminuria and gout or hyperuricemia. The mean eGFR for patients with gout was 76 mL/min/1.73 m2 to 82 mL/min/1.73 m2, whereas for people without gout it was 97 mL/min/1.73 m2 to 102 mL/min/1.73 m2.
Similarly, in both NHANES timeframes, approximately 1% to 2% of people with eGFRs of ≥90 mL/min/1.73 m2 had gout compared with 30% among those with eGFRs of <30 mL/min/1.73 m2. The team observed a similar pattern for albuminuria, even after adjusting for factors such as age, sex, race/ethnicity, hypertension, body mass index, and diabetes.
“One of the more impressive aspects of our findings is the dose-response relationship. Incremental changes in eGFR, albuminuria, and CKD are associated with a higher prevalence of gout. And these findings were not merely relegated to persons with severe CKD,” Stephen Juraschek, an MD/PhD student in epidemiology at Johns Hopkins University, said. “Furthermore, we found that the relationship persisted even after accounting for multiple risk factors associated with both CKD and gout, including uric acid levels.”