In a dialysis-dependent population, patients with gout showed a higher cardiovascular comorbidity burden and an increased risk of hospitalization and mortality, compared with patients without gout. In addition, older age, previous kidney transplant, and hypertension showed the most evident association with gout diagnosis among studied potential factors. Physician’s Weekly spoke with Anthony Bleyer, MD, Professor of nephrology at Wake Forest School of Medicine, who presented the results of a cohort study on the prevalence, risk factors and outcomes of gout in patients on dialysis at the Kidney Week of the American Society of Nephrology, held virtually from November 4-7.1
Dr. Bleyer and colleagues conducted a study to assess the prevalence and risk factors for gout in dialysis-dependent patients with end-stage renal disease. Data from 389,321 patients who were registered in The United States Renal Data system (USRDS) in 2017 were extracted. Baseline characteristics and comorbidities were examined at the first dialysis and 3 months after gout diagnosis.
Gout was diagnosed in 15% of assessed patients. Patients with gout were on average older than those without gout (mean 64.5 vs 56.8), showed higher rates of obesity (31.4 vs 30.2 kg/m2), and were more frequently of Asian origin (6.2% vs 3.7%) and of male sex (62%). Notably, patients with gout demonstrated higher comorbidity rates than those without the condition over a wide spectrum of cardiovascular diseases: heart failure (49% vs 30%), ischemic heart disease (49% vs. 30%), peripheral vascular disease (32% vs. 22%), stroke (12% vs. 8%), and acute myocardial infarction (7% vs. 3%). Adjusted regression analysis revealed that older age (≥ 65; OR, 4.23), hypertension (OR, 2.71), and previous kidney transplant (OR, 2.37) showed the strongest association with gout diagnosis. Following the year of diagnosis, risks for hospitalization and mortality were increased by 11% and 9%, respectively, in patients with and without gout.
Physician’s Weekly interviewed Prof. Bleyer to discuss the implications of the study results regarding the management and recognition of gout in dialysis-dependent patients.
Physician’s Weekly: Could you describe the general design and main results of the study?
Dr. Bleyer: We observed 389,321 patients included in the United States renal data system from 2017 who had at least one outpatient dialysis claim in that year. These data capture almost all dialysis patients in the United States. Approximately 15% of the included patients had at least one gout claim. We then compared demographic data and clinical characteristics, such as comorbidities and causes of kidney disease, between patients with and without gout. The results showed that gout occurred more often in men and patients of older age. In general, we observed a similar breakdown in terms of race. Interestingly, patients with gout had a higher comorbidity burden, especially regarding cardiovascular conditions, and a higher risk for hospitalization and mortality.
What can nephrologists, and practitioners in general, learn from these results?
The first thing we need to do is recognize that gout is highly prevalent in dialysis patients. That is the key point from this study, in my opinion. Next, gout is often mistakenly portrayed as a lifestyle disease. The stereotypical patient with gout is rich, lazy, eats liver pudding, and drinks beer. However, this is not the common presentation of the disease. If we approach gout predominantly as a lifestyle disease and prescribe lifestyle interventions to our patients as sole treatment, the results will be disappointing. In fact, gout is associated with chronic kidney disease. In 80% of cases, gout and decreased renal excretion of uric acid co-occur. If we treat gout with the available medical therapies, we can prevent a lot of associated morbidity.
What are the actionable items that can be addressed by physicians in clinical practice?
The 15% prevalence of gout we observed among dialysis patients demonstrated that gout is a real problem. Moreover, gout occurs more frequently in patients with an increased prevalence of comorbidities. Therefore, we need to consider the treatment of gout and the prevention of gout in this population. The available treatments are sufficient for this purpose. Almost no one should have to suffer from severe gout or recurrent intermittent gout. Allopurinol is an excellent initial treatment for the prevention and treatment of gout. Febuxostat is an effective second-line agent. Furthermore, pegloticase can be prescribed for patients with tophaceous or refractory gout. These therapies are highly effective for the prevention and treatment of gout, and we need to use them for our patients. Moreover, if we happen to encounter a patient with gout who we can’t treat well, we shouldn’t hesitate to refer this patient to a rheumatologist or other expert.
A research component needs to be addressed. Our study found that patients with gout have an increased adjusted death rate of approximately 10% compared with those without gout. We need to understand the mechanisms behind this increased mortality in patients with gout. In the current study, we observed elevated ferritin levels, a marker of inflammation, in patients with gout. I think this observation could be a starting point for future studies to unravel the physiology of increased mortality rates in dialysis patients with gout. Finally, we always need to consider the medications we can administer to patients who are on dialysis and be cognizant of our dosing.