Uncontrolled gout more likely to lead to chronic kidney disease, diabetes
ORLANDO — Patients with uncontrolled gout are more likely to develop chronic kidney disease, diabetes and heart disease compared with those with controlled disease, according to a poster presentation at the 2019 Rheumatology Nurses Society Annual Conference.
“When you look at your typical gout patient, they don’t just have gout,” Jacqueline A. LaPerriere, PharmD, regional medical director at Horizon Therapeutics plc, told Healio Rheumatology. “They have a bunch of comorbidities. Number one is usually hypertension, but there is also cardiovascular disease, diabetes and so on. We also decided to go ahead and specifically look at the presence of chronic kidney disease.”
“Most clinicians would say you wouldn’t develop gout unless you had some degree of renal insufficiency, because uric acid is handled by the kidneys and as we age our kidneys don’t work as well,” she added. “So, you are going to see patients with chronic kidney disease having sort of a risk factor for gout.”
To analyze and compare comorbidities and hospitalizations among patients with controlled and uncontrolled gout, Megan Francis-Sedlak, PhD, and colleagues conducted a retrospective review of Humana Inc. claims data from 2007 to 2016. Data included both private insurance and Medicare claims for at least one ICD-9 or -10 gout code, with the researchers focusing specifically on patients who had completed at least 90 days of continuous urate-lowering therapy within 1 year of diagnosis. In addition, patients had to have been enrolled in Humana for at least 6 months prior to their first gout diagnosis, and at least 6 months after the index date, to be included in the study.
For their study, the researchers defined controlled gout as a serum uric acid level of less than 6 mg/dL after at least 90 days of urate-lowering therapy, with uncontrolled disease status defined as 8 mg/dL or more during the same time period. Patients were required to have more than one test measuring serum uric acid to be included in the study. The researchers analyzed 5,473 patients with controlled gout and 1,358 with uncontrolled gout. The two groups were comparable in demographic characteristics, other than the controlled group was slightly older, with a mean age of 72.5 years compared with 69.1 years in the uncontrolled group.
According to the researchers, the top five ICD codes among patients in both groups included hypertension, hyperlipidemia and diabetes. However, after grouping multiple ICD codes together, the researchers found that diabetes — particularly diabetes with renal manifestations — chronic kidney disease and heart disease, including heart failure and atrial fibrillation, were more common among patients with uncontrolled gout. For example, 49.9% of patients with uncontrolled gout demonstrated chronic kidney disease, compared with 32.4% in the uncontrolled group (OR = 2.04; 95% CI, 1.808-2.301).
In addition, 20% of patients with uncontrolled patients had gone to the hospital for congestive heart failure, compared with 7% of those with controlled disease (OR = 3.16; 95% CI, 2.674-3.739). Similarly, 20% of patients in the uncontrolled group reported to the hospital with acute kidney failure, compared with 8% in the controlled group (OR = 2.95; 95% CI, 2.497-3.48).
“It begs the point of ‘What came first?’” LaPerriere said. “Do patients have poor renal function and then develop hyperuricemia, or does hyperuricemia contribute to toxicity in the kidney and poor renal function? ... The conclusion is that gout patients in particular suffer from cardiovascular and renal disease, but what we saw specifically, when we started to stratify patients, was that patients with uncontrolled gout were more likely to suffer from chronic kidney disease, diabetes and heart disease.” – by Jason Laday
Francis-Sedlak. Comorbidities in an early diagnosed cohort of uncontrolled versus controlled gout: Analysis of a large U.S. payer database. Presented at: Rheumatology Nurses Society Annual Conference; Aug. 7-10, 2019; Orlando, Florida.
Disclosure: Francis-Sedlak reports employment and owning stock, and stock options, in Horizon.