AB1050 CHARACTERISTICS OF PATIENTS WITH COINCIDENT GOUT AND ADVANCED CHRONIC KIDNEY DISEASE

Abstract

BackgroundPatients with chronic kidney disease (CKD) are at increased risk for developing gout1 and vice versa.2 Those with both gout and CKD present distinct challenges for patients and physicians because of the high prevalence of other comorbidities and restrictions on gout medication use, including non-steroidal anti-inflammatories3,4 and some oral urate-lowering therapies (ULTs).5 This unique patient population has not been well characterized using real-world data.ObjectivesThis retrospective chart review study of patients with coincident gout and CKD was conducted to better understand patient characteristics and treatment patterns of this population. This study is unique in that patient data were obtained from nephrologists, allowing a glimpse of how they view gout and its management.Methods111 nephrologists provided de-identified medical record data of their most-recently seen advanced (stage 3─5) CKD patients. Patients met study criteria for gout if any of the following were true: gout listed as a comorbidity, ULT use, or visible tophi or gout flares documented. A patient’s gout was determined to be uncontrolled if they had serum uric acid >6 mg/dL in addition to ≥1 visible tophus, ≥2 gout flares in the past year, or gouty arthritis (≥1 tender or swollen joint). Characteristics of this unique population were examined, along with gout management patterns. Differences between patients with controlled and uncontrolled gout were also investigated using data from patients’ most recent evaluation.Results173 patients with stages 3-5 CKD and who met study criteria for gout were included. Mean age was 58.3±18.1 years and BMI averaged 32.0 ± 11.8 kg/m2. A higher than expected proportion of patients were female (47%). The most common comorbidities were hypertension (85%), diabetes mellitus (47%), anemia of CKD (42%), CKD-mineral bone disorder (41%), ischemic heart disease (23%), and congestive heart failure (21%). Mean CKD duration was 4.1 ± 5.5 years, mean estimated glomerular filtration rate (eGFR) at most recent visit was 32.3 ± 13.9 ml/min/1.73 m2, and 62% were using a ULT. 23 patients (13%) had uncontrolled gout (48% female, 63.1 ± 16.4 years, mean eGFR 32.0 ± 14.6 ml/min/1.73 m2), all of whom had been prescribed a ULT. Compared with controlled gout patients, uncontrolled patients had higher rates of pulmonary hypertension (14% vs. 4%), gout-related chronic pain in the 12-months prior to data collection (63% vs. 42%), and joint involvement (joint swelling, tenderness, flexibility loss, and/or damage/lesions on x-ray; 26% vs. 9%). Colchicine was also used more frequently in uncontrolled gout patients (26% vs. 7%).ConclusionThe coincident gout with advanced CKD population described here shows unique differences from the general gout population, including a high proportion of females (47%). Given that women have a lower likelihood of developing gout at the same serum uric acid level,6 this finding was particularly surprising (general gout population: 67% male7). Importantly, nearly 40% of included patients were not utilizing a ULT, leaving them susceptible to developing the painful and debilitating sequalae of uncontrolled gout. Additionally, 41% of the study population had a CKD-related mineral bone disorder, indicating that patients with coincident gout and CKD may have bones that are more vulnerable to gout-related bone damage. Our study confirms a high prevalence of gout and its associated comorbidities in patients with advanced CKD and suggests another nephrology education opportunity to highlight the potential benefits of gout monitoring, earlier intervention, and management.