An Inverse Relationship between Hyperuricemia and Mortality in Patients Undergoing Continuous Ambulatory Peritoneal Dialysis

Abstract

Background: The results have been inconsistent with regards to the impact of uric acid (UA) on clinical outcomes both in the general population and in patients with chronic kidney disease. The aim of this study was to study the influence of serum UA levels on mortality in patients undergoing continuous ambulatory peritoneal dialysis. Methods: Data on 492 patients from a single peritoneal dialysis unit were retrospectively analyzed. The mean age of the patients was 53.5 ± 15.3 years, with 52% being female (n = 255). The concomitant comorbidities at the start of continuous ambulatory peritoneal dialysis (CAPD) encompassed diabetes mellitus (n = 179, 34.6%), hypertension (n = 419, 85.2%), and cardiovascular disease (n = 186, 37.9%). The study cohort was divided into sex-specific tertiles according to baseline UA level. A Cox proportional hazard model was used to calculate hazard ratios (HRs) of all-cause, cardiovascular, and infection-associated mortality with adjustments for demographic and laboratory data, medications, and comorbidities. Results: Multivariate Cox regression analysis showed that, using UA tertile 1 as the reference, the adjusted HR of all-cause, cardiovascular, and infection-associated mortality for tertile 3 was 0.4 (95% confidence interval (CI) 0.24–0.68, p = 0.001), 0.4 (95% CI 0.2–0.81, p = 0.01), and 0.47 (95% CI 0.19–1.08, p = 0.1). In the fully adjusted model, the adjusted HRs of all-cause, cardiovascular, and infection-associated mortality for each 1-mg/dL increase in UA level were 0.84 (95% CI, 0.69–0.9, p = 0.07), 0.79 (95% CI, 0.61–1.01, p = 0.06), and 0.79 (95% CI, 0.48–1.21, p = 0.32) for men and 0.57 (95% CI, 0.44–0.73, p < 0.001), 0.6 (95% CI, 0.41–0.87, p = 0.006), and 0.41 (95% CI, 0.26–0.6, p < 0.001) for women, respectively. Conclusions: Higher UA levels are associated with lower risks of all-cause, cardiovascular and infection-associated mortality in women treated with continuous ambulatory peritoneal dialysis.

Extreme hyperuricemia is a risk factor for infection-related deaths in incident dialysis patients: a multicenter prospective cohort study

“…Model 1; adjusted for age and gender, Model 2; adjusted for Model 1 þ diabetes, coronary artery disease, stroke, vascular access, ACEI/ARB, allopurinol, loop diuretics, thiazide, hemoglobin, albumin, eGFR, and CRP, Model 3; stepwise regression adjusted for Model 2 þ BMI, primary kidney disease, cancer, dialysis modality, b-blockers, statin, ESA, BUN, creatinine, adjusted calcium, phosphate, total cholesterol, and HCO 3 À . HR: hazard ratio; CI: confidence interval; CV: cardiovascular; ACEI: angiotensin-converting enzyme inhibitor; ARB: angiotensin receptor blocker; eGFR: estimated glomerular filtration rate; CRP: C-reactive protein; BMI: body mass index; ESA: erythropoiesis-stimulating agent; BUN: blood urea nitrogen [24,26,39,40,41]. The results of previous studies were different from our results.…”

“…According to the results from several studies, it is possible that both hyperuricemia and hypouricemia are risk factors for mortality [21,22]. However, only a few previous reports have evaluated this relationship in dialysis patients [23][24][25][26]. Especially, the relationship between serum UA levels and infection-related mortality has not been reported in even if not dialysis patients though there are a report that suggested UA is one of biomarkers for evaluating severity of sepsis [27].…”

Relationship between Serum Uric Acid and Mortality Risk in Hemodialysis Patients: A Multicenter Prospective Cohort Study

“…In the general population, some studies [7-9], but not all [10-12], have indicated that an elevated SUA level is a risk factor for the CVD and all-cause mortality. In the peritoneal dialysis (PD) patients, studies have shown positive [13-15], negative [16] or U-shaped [17] associations between SUA and mortality. To date, only a handful of studies have detected the association between SUA levels and the risk of mortality in maintenance hemodialysis (MHD) patients and reached inconsistent conclusions.…”

Uric acid levels and clearance in chronic kidney disease patients

“…There are studies describing positive and negative relationship between uric acid level and cardiovascular mortality in HD and PD patients as an independent risk factor. [11][12][13][14][15][16][17] Since the patients in our study were ESRD and dialysis patients, elevated uric acid levels expected in our study because our patients were end stage renal failure and underwent HD or PD. Elevated uric acid levels in these patients were due to renal dysfunction.…”