High serum uric acid level is a mortality risk factor in peritoneal dialysis patients: a retrospective cohort study

The relationship between serum uric acid level and carotid intima-media thickness in hemodialysis patients

INTRODUCTION

We aimed to evaluate the relationship between carotid intima-media thickness (CIMT), which is a known indicator of cardiovascular risk and atherosclerosis, and uric acid level, which may be an easy marker for cardiovascular diseases due to its antioxidant and pro-oxidant properties in hemodialysis patients.

METHODS

In this cross-sectional study, we evaluated 77 hemodialysis patients. The mean CIMT of these patients was measured and recorded by Doppler ultrasonography. Patients were divided into two groups according to their serum uric acid levels. Correlation analysis and linear regression analysis were used to define the relationship between study parameters.

FINDINGS

The mean CIMT levels in the normouricemic group and the hyperuricemic group were 0.95 ± 0.15 and 1.07 ± 0.15, respectively. There was a statistically significant difference between the two groups (p = 0.001). There was a statistically significant and moderate linear correlation between serum uric acid level and mean CIMT (r = 0.402; p = 0.002). Univariate and multivariate linear regression analyses were performed to identify variables that could independently affect the mean CIMT value. According to analysis, uric acid (p < 0.001), hypertension (p = 0.008), albumin (p = 0.029), and C-reactive protein (p = 0.042) were found independent risk factors for mean CIMT value.

DISCUSSION

We found a significant relationship between serum uric acid level and CIMT, which indicates carotid atherosclerosis. Serum uric acid level is a low-cost laboratory parameter that can be measured in almost all laboratories, and it may be valuable in the hemodialysis patient group to identify patients at high risk of carotid atherosclerosis.

Comparative analysis of hospitalizations among patients treated with hemodialysis and peritoneal dialysis in European pediatric nephrology centers: results from a prospective EPDWG/ESPN Dialysis Working Group study

Background and hypothesis

Hospital admissions in pediatric dialysis patients need to be better studied, and most existing studies are retrospective and based on registry data. This study aimed to analyse and compare hospital admission rates, causes, length of stay (LOS), and outcomes in children treated with peritoneal dialysis (PD) and hemodialysis (HD).

Methods

Data from 236 maintenance PD and 138 HD patients across 16 European dialysis centers were collected between 1 July 2017 and 30 June 2018. A total of 178 hospitalized patients (103 PD, 75 HD) were included for further analyses.

Results

There were 465 hospitalization events (268 PD, 197 HD) with a rate of 0.39 admissions per 100 patient-days at risk (PDAR) and 2.4 hospital days per 100 PDAR. The admission rates were not significantly different between HD and PD patients. The most common causes of hospitalization were access-related infections (ARI) (17%), non-infectious complications of access (NIAC) (14%), and infections unrelated to access (12%). ARI was the leading cause in PD patients (24%), while NIAC was more common in HD patients (19%). PD patients had more ARIs, diagnostic procedures, and treatment adjustments (P < .05), while HD patients had more NIACs, infections unrelated to access, access placement procedures, and interventional/surgical procedures (P < .001). LOS was longer with acute admissions than non-acute admissions (P < .001). Overall LOS and LOS in the intensive care unit were similar between HD and PD patients. High serum uric acid and low albumin levels were significant predictors of longer LOS (P = .022 and P = .045, respectively). Young age, more significant height deficit, and older age at the start of dialysis were predictors of longer cumulative hospital days (P = .002, P = .001, and P = .031, respectively).

Conclusion

Access-related complications are the main drivers of hospitalization in pediatric dialysis patients, and growth and nutrition parameters are significant predictors of more extended hospital stays.

Serum uric acid to creatinine ratio as a risk factor for mortality among patients on continuous ambulatory peritoneal dialysis: a multi-center retrospective study

BACKGROUND

Serum uric acid to serum creatinine ratio (SUA/Scr) has emerged as a new biomarker, which is significantly associated with several metabolic diseases. However, no study has investigated the association between SUA/Scr and mortality among patients on continuous ambulatory peritoneal dialysis (CAPD).

METHODS

In this multicenter retrospective cohort study, we enrolled CAPD patients in eight tertiary hospitals in China from 1 January 2005 to 31 May 2021. Cox proportional hazard models were used to determine the relationship between SUA/Scr and mortality.

RESULTS

A total of 2480 patients were included; the mean age was 48.9 ± 13.9 years and 56.2% were males. During 12648.0 person-years of follow-up, 527 (21.3%) patients died, of which 267 (50.7%) deaths were caused by cardiovascular disease. After multivariable adjustment for covariates, per unit increase in SUA/Scr was associated with a 62.9% (HR, 1.629 (95% confidence interval (CI) 1.420-1.867)) and 73.0% (HR, 1.730 (95% CI 1.467-2.041)) higher risk of all-cause and cardiovascular mortality. Results were similar when categorized individuals by SUA/Scr quartiles. Compared with the lowest quartile of SUA/Scr, the highest and the second highest quartile of SUA/Scr had a 2.361-fold (95% CI 1.810-3.080) and 1.325-fold (95% CI 1.003-1.749) higher risk of all-cause mortality, as well as a 3.701-fold (95% CI 2.496-5.489) and 2.074-fold (95% CI 1.387-3.100) higher risk of cardiovascular mortality. Multivariable-adjusted spline regression models showed nonlinear association of SUA/Scr with mortality in CAPD patients.

CONCLUSIONS

Higher levels of SUA/Scr were associated with higher risk of all-cause and cardiovascular mortality in CAPD patients.

The significance of follow-up serum uric acid levels in predicting all-cause mortality and cardiovascular mortality in peritoneal dialysis patients

BACKGROUND

This study aimed to analyze the change of serum uric acid (SUA) level post peritoneal dialysis (PD), and the correlation between follow-up SUA and prognosis in patients with PD.

METHODS

A total of 1402 patients with PD were evaluated. We graded SUA levels into four grades at baseline, 6 months, 12 months, 18 months, and 24 months post PD, and then compared all-cause mortality and cardiovascular mortality among patients with different SUA grades at each time point. Kaplan-Meier and Cox proportional-hazards regression models were used in the analysis.

RESULTS

The SUA levels were 7.97 ± 1.79, 7.12 ± 1.48, 7.05 ± 1.33, 7.01 ± 1.30, and 6.93 ± 1.26 mg/dl at baseline, 6, 12, 18, and 24 months, respectively. There was significant difference on all-cause mortality among patients with PD with different graded SUA levels at 6 months post PD (p = 0.010), and the all-cause mortality was lowest in patients with the grade of 5.65 mg/dl ≤ SUA <7.13 mg/dl.

CONCLUSION

SUA level decreased after PD during follow-up. At 6 months post PD, the grade of 5.65 mg/dl ≤ SUA <7.13 mg/dl was appropriate for better patients' survival.

Non-specific electrocardiographic ST-T abnormalities predict mortality in patients on peritoneal dialysis

Background

This study aimed to evaluate the predictive value of non-specific ST-segment and/or T-wave abnormalities in electrocardiography (ECG) for all-cause and cardiovascular mortality (CVM) in peritoneal dialysis (PD) patients.

Methods

All patients who started PD between November 1, 2005, and February 28, 2017, at the First Affiliated Hospital of Nanchang University were enrolled. The primary outcomes were all-cause mortality and CVM. The Kaplan-Meier method and a log-rank test were used for the survival analysis. Multivariate Cox proportional hazards models were used to investigate the risk factors for all-cause mortality and CVM.

Results

A total of 724 eligible PD patients were enrolled, including 401 (55.4%) men. In total, 153 (21.1%) patients died during a mean follow-up period of 27 (interquartile range, 13-41) months, and cardiovascular death was responsible for 84 of these deaths. The patients with non-specific ST-T abnormalities (NSSTTAs) had lower overall and cardiovascular survival rates compared to those free from any ECG abnormalities. According to the multivariate Cox proportional hazards models, (NSSTTAs) are independent risk factors for all-cause mortality and CVM, the hazard ratios are 1.81 (95% confidence interval, 1.11-2.95; p = 0.017) and 2.86 (95% confidence interval, 1.52-5.37; p = 0.001), respectively.

Conclusion

Non-specific ST-T abnormalities can serve as risk markers of all-cause and CVM in PD patients.

Serum uric acid level and all-cause and cardiovascular mortality in peritoneal dialysis patients: A systematic review and dose-response meta-analysis of cohort studies

BACKGROUND

The association between serum uric acid (SUA) and all-cause and cardiovascular disease (CVD) mortality in peritoneal dialysis (PD) patients is controversial. Therefore, we aimed to determine the relationship between SUA and all-cause and CVD mortality in PD patients.

METHOD

Web of Science, EMBASE, PubMed and the Cochrane Library databases were searched from their inception to 7 April 2021. Effect estimates were presented as hazard ratios (HRs) with 95% confidence intervals (95% CIs) and pooled using random effects model.

RESULT

Thirteen cohort studies with 22418 patients were included in this systematic review, of which 9 were included in the meta-analysis. Before switching the reference group, pooled result for the highest SUA category was significantly greater than the median for all-cause mortality (HR = 2.41, 95% CI: 1.37-4.26). After switching the reference group, the highest SUA category did not demonstrate an increased all-cause (HR = 1.40, 95% CI: 0.95-2.05) or CVD (HR = 1.30, 95% CI: 0.72-2.34) mortality compared with the lowest SUA category. Dose-response analysis suggested a nonlinear association between SUA and all-cause mortality risk (Pnonlinearity = 0.002).

CONCLUSION

This meta-analysis didn't find the relationship between SUA levels and all-cause and CVD mortality risk in PD patients. More rigorously designed studies are warranted in the future.

Increased risk of modality failure with higher serum uric acid level in continuous ambulatory peritoneal dialysis patients: a prospective cohort study

BACKGROUND

Peritoneal dialysis (PD) is one of the most important kidney replacement therapies for patients with end-stage kidney disease (ESKD). PD technique failure can lead to an escalated cost and increased infectious and cardiovascular risk, up and including to death. The accumulation of uric acid (UA) was associated with adverse outcomes in ESKD patients. However, the relationship between serum UA and technique failure is little explored.

METHODS

Here, a total of 266 continuous ambulatory peritoneal dialysis (CAPD) patients (age, 41.8 ± 12.6 years; 125 males) were enrolled and followed up for 31.7 months. Serum UA levels were examined at baseline and each visit. Subjects were divided into three groups according to their baseline serum UA concentrations. Multivariable Cox regression models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) of PD technique failure.

RESULTS

The level of serum UA increased gradually as time prolonged. During the follow-up period, 77 (28.9%) patients occurred PD technique failure, of which 56 (21.1%) transferred to hemodialysis (HD) and 21 (7.9%) died. Compared to the lowest UA tertile, after adjusting for potential confounders, HRs of technique failure in tertile 2 and tertile 3 were 1.82 (95% CI: 0.95-3.49) and 2.03 (95% CI: 1.05-3.92), respectively, and p for trend was 0.043. Adjusted HRs of all-cause technique failure, transferring to HD and mortality with each 1 mg/dL increase in serum UA were 1.20 (95% CI: 1.03-1.40, p = 0.019), 1.22 (95% CI: 1.01-1.48, p = 0.039), and 1.25 (95% CI: 0.94-1.67, p = 0.128), respectively.

CONCLUSION

Higher serum UA level predicted higher risk of technique failure in CAPD patients.

Causes and risk factors for peritoneal dialysis withdrawal

INTRODUCTION

This study intends to investigate the causes and risk factors for withdrawal from peritoneal dialysis (PD) in patients with ESRD.

METHODS

293 patients admitted to the peritoneal dialysis center in nephrology department for PD treatment were divided into 175 cases in group A (continuous treatment group) and 118 cases in group B (withdrawal group).

RESULTS

The proportion of patients in group B whose primary disease was glomerulonephritis was significantly lower than that in group A (P<0.05), whereas the proportion of patients with diabetic nephropathy was significantly higher in group B than in group A (P<0.05). Group A received better emotional support and care services from family members than group B. Family care was mostly severely impaired in patients who died and were lost to follow-up.

CONCLUSION

Diabetes mellitus, level of knowledge regarding PD, depression and family care are risk factors for withdrawal from PD. This article is protected by copyright. All rights reserved.

Serum Uric Acid and Cardiovascular or All-Cause Mortality in Peritoneal Dialysis Patients: A Systematic Review and Meta-Analysis

Background: Studies have shown inconsistent associations between serum uric acid (SUA) levels and mortality in peritoneal dialysis (PD) patients. We conducted this meta-analysis to determine whether SUA levels were associated with cardiovascular or all-cause mortality in PD patients.

Methods: PubMed, Embase, Web of Science, the Cochrane Library, CNKI, VIP, Wanfang Database, and trial registry databases were systematically searched up to April 11, 2021. Cohort studies of SUA levels and cardiovascular or all-cause mortality in PD patients were obtained. Random effect models were used to calculate the pooled adjusted hazard ratio (HR) and corresponding 95% confidence interval (CI). Sensitivity analyses were conducted to assess the robustness of the pooled results. Subgroup analyses and meta-regression analyses were performed to explore the sources of heterogeneity. Funnel plots, Begg's tests, and Egger's tests were conducted to evaluate potential publication bias. The GRADE approach was used to rate the certainty of evidence. This study was registered with PROSPERO, CRD42021268739.

Results: Seven studies covering 18,113 PD patients were included. Compared with the middle SUA levels, high SUA levels increased the risk of all-cause mortality (HR = 1.74, 95%CI: 1.26–2.40, I² = 34.8%, τ² = 0.03), low SUA levels were not statistically significant with the risk of all-cause or cardiovascular mortality (HR = 1.04, 95%CI: 0.84–1.29, I² = 43.8%, τ² = 0.03; HR = 0.89, 95%CI: 0.65–1.23, I² = 36.3%, τ² = 0.04; respectively). Compared with the low SUA levels, high SUA levels were not statistically associated with an increased risk of all-cause or cardiovascular mortality (HR = 1.19, 95%CI: 0.59–2.40, I² = 88.2%, τ² = 0.44; HR = 1.22, 95%CI: 0.39–3.85, I² = 89.3%, τ² = 0.92; respectively).

Conclusion: Compared with middle SUA levels, high SUA levels are associated with an increased risk of all-cause mortality in PD patients. SUA levels may not be associated with cardiovascular mortality. More high-level studies, especially randomized controlled trials, are needed to determine the association between SUA levels and cardiovascular or all-cause mortality in PD patients.

Systematic Review Registration:https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021268739, identifier: CRD42021268739.

Relationship between serum uric acid, all-cause mortality and cardiovascular mortality in peritoneal dialysis patients: systematic review and meta-analysis of cohort studies

OBJECTIVES

To analyse the relationship between serum uric acid (SUA), all-cause and cardiovascular (CV) mortality in peritoneal dialysis (PD) patients to inform clinical practice and future research.

DESIGN

A systematic review of observational studies.

DATA SOURCES

PubMed, Embase, Web of Science, the Cochrane Library, China National Knowledge Infrastructure (CNKI), SinoMed, Chinese Science and Technology Journal Database (VIP) and Wan Fang databases were searched from their inception to January 2021 for cohort and case-control studies reporting SUA and mortality in patients with PD.

METHODS

The Newcastle-Ottawa Quality Assessment Scale was used to appraise quality of cohort and case-control studies. Effect estimates were presented as HRs with 95% CIs in a meta-analysis using STATA V.16.0. Data not suitable for pooling were synthesised qualitatively.

RESULTS

Fourteen cohort studies with 24 022 patients were included. No case-control studies were identified. For prospective cohort studies, pooled results for the highest SUA category were significantly greater than the lowest for all-cause (one study; 1278participants; HR 1.79; 95% CI 1.17 to 2.75) and CV mortality (one study; 1278 participants; HR 2.63; 1.62-4.27). An increase of 1 mg/dL in SUA level was associated with a 16% increased risk of all-cause mortality (one study; 1278 participants; HR 1.16; 1.03-1.32) and 34% increased CV mortality risk (one study; 1278 participants; HR 1.34; 1.16-1.55). For retrospective cohort studies, the highest SUA category did not demonstrate an elevated all-cause (five studies; 4570 participants; HR 1.09; 0.70-1.70) or CV mortality (three studies; 3748 participants; HR 1.00; 0.44-2.31) compared with the lowest SUA category. Additionally, there was no increase in all-cause (eight studies; 11 541 participants; HR 0.94; 0.88-1.02) or CV mortality (three studies; 7427 participants; HR 0.90; 0.76-1.06) for every 1 mg/dL increase in SUA level.

CONCLUSIONS

Results of prospective and retrospective cohort studies were inconsistent. Consequently, prospective, multicentre, long-term follow-up studies are required to confirm the relationship between SUA and mortality in patients with PD.

High Serum Uric Acid and High-Sensitivity C Reactive Protein Concentrations Predict Three-Year Cardiovascular Mortality in Patients Treated With Continuous Ambulatory Peritoneal Dialysis

AIMS

This study aims to access the predicting value of serum uric acid (UA) and high-sensitivity C reactive protein (hs-CRP) concentration on three-year cardiovascular-related mortality in patients performing continuous ambulatory peritoneal dialysis (CAPD).

METHODS

A total of267 CAPD patients [150 male (56.2%); mean age 48.93 ± 13.58 years] were included in our study. All patients had measured serum UA and hs-CRP concentration. A high-sensitivity particle-enhanced immunoturbidimetric assay determined serum hs-CRP; serum UA levels were determined using an enzymatic colorimetric assay. All patients were followed for three years to detect cardiovascular-related mortality by cardiologists and stroke specialists.

RESULTS

Mean serum UA level was 415.16 ± 84.28 µmol/L, 58.4% of patients had increased serum UA level. Median serum hs-CRP level was 2 (1-4) mg/L, 12.4% of patients had increased serum hs-CRP level. During 36 months of follow-up, 41 patients (15.4%) had cardiovascular-related mortality. The results of Cox proportional hazards regression showed that hypertension, diabetes, high serum UA and hs-CRP were risk factors that related to cardiovascular-related mortality (p<0.05). The receiver operating characteristic (ROC) curve and Kaplan-Meier analysis results showed that UA and hs-CRP level had predictive value for three-year cardiovascular-related mortality in CAPD patients [uric acid: area under the curve (AUC)=0.822; hs-CRP: AUC=0.834, p < 0.001].

CONCLUSION

High serum UA and hs-CRP levels were predictive factors of cardiovascular-related mortality in CAPD patients.

Associations between Serum Vitamins and Serum Uric Acid in a Population of Shenyang, China

Previous studies have demonstrated that serum vitamins are associated with serum uric acid (SUA) level. However, no study has comprehensively investigated whether various serum vitamins are associated with SUA level in a general population. Thus, a cross-sectional study was designed to explore the associations between SUA level and serum vitamins. The data of this study for SUA levels were collected from participants aged ≥18 y. Serum vitamin and other baseline information, including age and body mass index, was determined. Moreover, associations between SUA level and serum vitamins were explored using analysis of covariance. Higher levels of SUA were significantly associated with a higher level of serum vitamins A, B9 and B5 (p<0.05). Higher level of SUA were associated with a lower level of serum vitamins C, and D2 (p<0.05). No significant associations were found between vitamins C, and D2 and SUA levels after adjustment. Study results suggested that serum vitamins A, B9 and B5 were positively associated, whereas serum vitamins C, and D2 were inversely associated with SUA levels.

Urate levels and clearance in renal patients under peritoneal dialysis

Hemodialysis adequately controls serum uric acid (UA) levels, making UA-lowering drugs unnecessary; scant data are available for peritoneal dialysis (PD). We analyzed blood, 24 h urine and dialysis fluid from twenty patients under PD, to assess UA levels and clearances, and factors associated with better performance and maintenance of target levels (<6mg/dL). Median serum UA was 5.4 mg/dL (p25-75 4.4-5.8), mainly achieved through peritoneal clearance (3.0 mL/min/1.73m2, 71.2% of total UA clearance); 75% of participants was on UA targets. Continuous cycling peritoneal dialysis showed highest UA clearance and target achievements. These findings may be of interest for end-stage renal patients with gout.

Risk factors for mortality in patients undergoing peritoneal dialysis: a systematic review and meta-analysis

Aim

Inconsistent investigations of the risk factors for all-cause mortality in patients undergoing peritoneal dialysis (PD) were reported. The present meta-analysis aimed to assess the impact of some clinical characteristics on the risk of mortality in PD patients.

Methods

PubMed and Embase were systematically searched for studies evaluating the risk factors for all-cause mortality in PD patients. Hazard ratio (HR) and 95% confidence interval (CI) were derived using a random-effect or fixed-effect model considering the heterogeneity across studies.

Result

A total of 26 studies were included in this meta-analysis in accordance with the inclusion and exclusion criteria. Age, primary cardiovascular diseases, diabetes mellitus, and high level of alkaline phosphatase showed significant positive associations with elevated risk of all-cause and cardiovascular mortality in PD patients, while hemoglobin acted as a benefit factor. Furthermore, early onset of peritonitis, high peritoneal transport status, elevated body mass index and high-sensitivity C-reactive protein could also considerably increase the risk of all-cause mortality. The absolute serum level of magnesium, potassium, and uric acid required to improve survival in PD patients should be verified further.

Conclusions

Multiple factors could affect the risk of mortality in PD patients.

Serum Uric Acid and Mortality in Patients with Chronic Kidney Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Existing studies suggested conflicting relationships between serum uric acid (SUA) and mortality in CKD patients. The present meta-analysis aimed to determine whether SUA can be a predictor for mortality in CKD cohorts.

METHOD

A systematical search was conducted on PubMed, EMBASE, and The Cochrane Library to identify studies reporting the relationship between SUA level and all-cause and cardiovascular mortality in CKD populations. In addition, random-effects models were adopted to calculate the hazard ratios (HRs) and corresponding 95% confidence intervals (CIs).

RESULTS

On the whole, 29 studies were involved. In the present meta-analysis, patients exhibiting the maximum SUA level showed an association with a significantly higher risk for all-cause mortality (HR, 1.30; 95% CI, 1.06-1.59) compared with patients exhibiting the minimum SUA level. As revealed from the meta-analysis of 8 studies, low level of SUA was another predictor for all-cause mortality in patients with CKD (HR, 1.36; 95% CI, 1.20-1.54). No significant relationship was identified between SUA and cardiovascular mortality.

CONCLUSIONS

Higher and lower SUA levels are both associated with significantly increased risk of all-cause mortality in patients with CKD. A appreciate dose of treatment of lowering SUA agents should be confirmed.

Uric acid to high-density lipoprotein cholesterol ratio predicts cardiovascular mortality in patients on peritoneal dialysis

BACKGROUND AND AIMS

Serum uric acid (UA) and high-density lipoprotein cholesterol (HDL-C) disorders are both considered as risk factors of cardiovascular mortality. The predictive value of UA to HDL-C ratio (UHR) has been validated in diabetes. However, association of UHR with cardiovascular (CV) mortality is undetermined in peritoneal dialysis (PD) patients.

METHODS AND RESULTS

In this retrospective cohort study, we enrolled 1953 eligible incident patients who commenced PD treatment on our hospital from January 1, 2006 to December 31, 2015, and followed up until December 31, 2019. Of the participants, 14.9% were older than 65 years (mean age 47.3 ± 15.2 years), 24.6% were diabetics, and 59.4% were male. Patients were categorized into quartiles according to baseline UHR level. Multivariate Cox Proportional Regression analysis was applied to explore the association of UHR with mortality. Overall, 567 patients died during a median follow-up period of 61.3 months, of which 274 (48.3%) were attributed to CV death. The mean baseline UHR was 16.4 ± 6.7%. Compared to quartile 2 UHR, hazard ratios (HRs) for the highest quartile UHR were 1.35 (95% confidence interval [CI] 1.06-1.78; P = 0.017) and 1.46 (95% CI 1.00-2.12; P = 0.047) for all-cause and CV mortality, respectively. Subgroup analysis showed that association of UHR with CV mortality was remarkable among PD patients with age ≥65 years, malnutrition (albumin <35 g/L), diabetes, and CVD history.

CONCLUSIONS

An elevated UHR predicted increased risk of all-cause and CV mortality in PD patients.

The Association between Serum Uric Acid and Appendicular Skeletal Muscle Mass and the Effect of Their Interaction on Mortality in Patients on Peritoneal Dialysis

BACKGROUND

Serum uric acid (SUA) has been revealed to be positively associated with the body composition parameters in hemodialysis patients, but few studies have investigated that in patients on peritoneal dialysis (PD). The aim of this study was to identify the relationship between SUA and appendicular skeletal muscle mass (ASM) and the effect of their interaction on mortality in PD patients.

METHODS

This was a single-center retrospective cohort study. Patients who underwent multifrequency bioelectrical impedance analysis between January 1, 2013, and December 31, 2016, and had data on SUA values were enrolled. All patients were followed up until December 31, 2019.

RESULTS

In total, 802 prevalent PD patients (57.9% male), with mean age of 46.2 ± 14.2 years were enrolled. The average SUA and ASM were 6.8 ± 1.3 mg/dL and 21.2 ± 4.9 kg. According to multiple linear regression models, SUA was positively associated with relative ASM in middle-aged and older PD patients (standardized coefficients [β] 0.117; 95% confidence interval [CI] 0.027, 0.200; p = 0.010). Further sex-stratified analysis showed that the association existed only in males (β 0.161; 95% CI 0.017, 0.227; p = 0.023). Moreover, the presence of hyperuricemia was found to predict lower risk of all-cause mortality (hazard ratio [HR] 0.514, 95% CI 0.272, 0.970; p = 0.040) only in patients with lower relative ASM. And, the adjusted HR of every 1 mg/dL elevated SUA level was 0.770 (95% CI 0.609, 0.972; p = 0.028) for all-cause mortality in the lower relative ASM subgroup.

CONCLUSIONS

There exists a positive association between the SUA and ASM, and the ASM significantly affected the association between SUA and all-cause PD mortality.

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

BACKGROUND

Several studies have reported that low serum uric acid (SUA) levels are related to increased risk of mortality in maintenance hemodialysis (MHD) patients. However, the possible detrimental effects of high SUA on the mortality risk have not been well examined. Moreover, the possible effect modifiers for the SUA-mortality association have not been fully investigated. To address the aforementioned gap, we aimed to explore the nonlinear relationship between SUA levels and all-cause and cardiovascular disease (CVD) mortality risk, and to examine any possible effect modifiers in MHD patients.

METHODS

We conducted a multicenter, prospective cohort study among 1,018 MHD patients from 8 hemodialysis centers. The primary outcome was all-cause mortality, and the secondary outcomes were CVD mortality and non-CVD mortality.

RESULTS

The mean value for SUA in the total population was 8.5 ± 1.9 mg/dL. The lowest and highest quintiles of SUA were <7.0 and >10.1 mg/dL, respectively. Over a median follow-up of 45.6 months, 343 deaths were recorded, of which 202 (58.9%) were due to CVD. When SUA was assessed as quintiles, a significantly higher risk of all-cause mortality was found in patients in quintile 1 (<7.0 mg/dL; hazard ratio [HR], 1.33; 95% confidence interval [CI]: 1.02-1.73) or quintile 5 (≥10.1 mg/dL; HR, 1.47; 95% CI: 1.09-2.00), compared to those in quintiles 2-4 (7-10.1 mg/dL). Moreover, the U-shaped SUA-mortality association was mainly found in those with lower C-reactive protein levels (<3 compared with ≥3 mg/L; p for interaction = 0.018). Similar trends were found for CVD mortality and non-CVD mortality.

CONCLUSION

There was a U-shaped relationship between SUA levels and the risk of all-cause mortality, CVD mortality, and non-CVD mortality in MHD patients.

Effect of uric acid levels on mortality in Japanese peritoneal dialysis patients

Background:

Unlike the situation in the general population, most studies of patients receiving hemodialysis have reported lower uric acid (UA) as associated with higher mortality. However, the relationship between UA level and mortality remains unclear among patients receiving peritoneal dialysis (PD).

Methods:

We collected baseline data for 4742 prevalent PD patients (age, 63 ± 14 years; male, 61.5%; diabetes, 29.1%; median dialysis duration, 28 months) from a nationwide dialysis registry in Japan at the end of 2012. One-year all-cause and cardiovascular (CV) mortality and mortality caused by infectious disease were assessed using Cox regression analysis and competing-risks regression analysis, respectively. We used multiple imputation to deal with missing covariate data.

Results:

Within 1 year, 379 patients (8.0%) died, including 129 patients (2.7%) from CV causes and 95 patients (2.0%) from infectious disease. In multivariate analysis, serum UA, treated as a continuous variable, was not associated with any outcome. Conversely, both lower (<297 µmol/L) and higher (≥476 µmol/L) UA levels were independently associated with higher all-cause mortality compared to the reference group (416 to <446 µmol/L) in analyses where serum UA was treated as a categorical variable. Body mass index (BMI) affected the association between serum UA and all-cause mortality (interaction p = 0.049).

Conclusions:

A U-shaped relationship appears to exist between UA levels and all-cause mortality among Japanese PD patients. Additionally, lower BMI significantly enhanced the effect of UA levels on mortality.