Upward-directed exit-site of the swan-neck catheter and "Easy-to-disinfect the backside area of exit-site" may prevent PD complications.

BACKGROUND: Upward-directed exit-site has been believed to be the worst for frequent ESI by an old retrospective study using straight catheters. No comparison study of 3 exit-site directions using swan-neck catheter has been performed regarding which direction is the best for our endpoints, Easy-to-see the backside area of exit-site: ESBE, Easy-to-disinfect the backside area of exit-site: EDBE, reduction of both exit-site infection (ESI), symptomatic catheter dislocation and peritonitis. METHODS: We assessed the relationship of exit-site direction with our endpoints in a quantitative cross-sectional, multicentered questionnaire survey. Patients who received either non-surgical catheter implantation or exit-site surgery were excluded. RESULTS: The numbers (percentage) of exit-site directions in included 291 patients were upward 79 (26.0), lateralward 108 (37.5) and downward 105 (36.5). Cochran-Armitage analysis showed a significant step-ladder increase in the prevalence of ESI as the direction changed from upward to lateralward to downward (0.15 ± 0.41, 0.25 ± 0.54, 0.38 ± 0.69 episodes/patient-year, p = 0.03). Multivariable regression analysis revealed the upward exit-site independently associates with both higher frequency of ESBE (OR 5.55, 95% CI 2.23-16.45, p < 0.01) and reduction of prevalence of ESI (OR 0.55, 95%CI 0.27-0.98, p = 0.04). Positive association between the prevalence of symptomatic catheter dislocation and ESI (OR 2.84, 95% CI 1.27-7.82, p = 0.01), and inverse association between EDBE and either prevalence of symptomatic catheter dislocation (OR 0.27, 95% CI 0.11-0.72) or peritonitis (OR 0.48, 95% CI 0.23-0.99) observed. CONCLUSION: Upward-directed swan-neck catheter exit-site may be the best for both ESBE and prevention of ESI. EDBE may reduce catheter dislocation and peritonitis. Symptomatic catheter dislocation may predict ESI.

The relation between proteinuria and the severity of COVID-19.

BACKGROUND: The association between proteinuria, which is also an indicator of chronic kidney disease (CKD), and coronavirus disease 2019 (COVID-19) severity is unclear. METHODS: We selected 342 hospitalized patients with COVID-19 diagnosed via polymerase chain reaction testing between February 2020 and October 2022 and who had at least one urinalysis 14-365 days before admission. RESULTS: Proteinuria before admission was associated neither with oxygen administration nor developing pneumonia in multivariate analysis (odds ratio [OR] 1.03; 95% confidence interval (CI) 0.44-2.40, p = 0.95 and OR 1.01; 95% CI 0.47-2.17, p = 0.98, respectively). Proteinuria on admission was associated both with oxygen administration and developing pneumonia in multivariate analysis (OR 3.29; 95% CI 1.37-7.88, p < 0.01 and OR 3.81; 95% CI 1.68-8.62, p < 0.01, respectively). The percentage of patients with proteinuria on admission was significantly higher than those before admission (37.4% vs. 17.8%; p < 0.01). In the subgroup analysis, proteinuria on admission among patients with eGFR ≥ 60 mL/min/1.73 m2 was associated with both oxygen administration and developing pneumonia (OR 4.86; 95% CI 1.22-19.38, p = 0.03, OR 3.65; 95% CI 1.06-12.58, p = 0.04, respectively). In contrast, proteinuria on admission among patients with eGFR < 60 mL/min/1.73 m2 was associated with developing pneumonia (OR 6.45; 95%CI 1.78-23.35, p = 0.01), not with oxygen administration (OR 3.28; 95% CI 0.92-11.72, p = 0.07). CONCLUSIONS: Although underlying proteinuria before admission was not associated with COVID-19 severity, proteinuria on admission was associated with oxygen demand and developing pneumonia.

Early diagnosis leading to improvement of critical illness polyneuropathy associated with severe Staphylococcus aureus infection in a patient on hemodialysis.

Critical illness polyneuropathy (CIP) is a very rare complication of sepsis and multi-organ failure. Herein, we report the first case of CIP reported in a patient on maintenance hemodialysis, who improved with rehabilitation. A 55-year-old male patient was emergently admitted with fever and altered consciousness and diagnosed with bacterial meningitis based on cerebral spinal fluid and cranial magnetic resonance imaging findings. Methicillin-susceptible Staphylococcus aureus was detected in blood and cerebral spinal fluid cultures. Despite treatment with appropriate antibiotics, blood cultures were positive for 9 days and serum C-reactive protein (CRP) levels were persistently elevated. Magnetic resonance imaging of hands and feet to determine infection origin revealed osteomyelitis in several fingers and toes, which required the amputation of 14 necrotic fingers and toes. Thereafter, blood cultures became negative and CRP levels declined. However, flaccid paralysis was noted in both upper and lower extremities during sepsis treatment. Nerve conduction studies showed peripheral axonal disorder in motor and sensory nerves, and CIP was determined as the cause of paralysis based on the fulfillment of all four CIP diagnostic criteria. The patient's muscle strength improved with early and appropriate medical treatment and physical therapy, and he was discharged home 147 days after admission. Prolonged high-level inflammation is a cause of CIP. Patients on hemodialysis, who are potentially immunosuppressed and vulnerable to infection, are at high risk for CIP. In patients on maintenance hemodialysis who develop flaccid paralysis during treatment for severe infection, CIP should be considered for early diagnosis and intervention.

Association between the serum zinc level and nutritional status represented by the geriatric nutritional Rrisk index.

BACKGROUND: Although it is widely known that patients with chronic kidney disease (CKD) can develop zinc deficiency, in our previous analysis, the estimated glomerular filtration rate (eGFR) was not independently associated with the serum zinc level. Thus, a post hoc analysis was conducted to investigate the involvement of nutritional status. METHODS: A total of 655 subjects not on dialysis (402 males; mean age, 57 ± 18 years) who underwent serum zinc level measurements at Jikei University Hospital between April 2018 and March 2019 were selected using the Standardized Structured Medical Information eXchange2 (SS-MIX2) system. In addition, anthropometric data and the Geriatric Nutritional Risk Index (GNRI) representing nutritional status were obtained, and the relationship between the serum zinc level and nutritional status was investigated by multiple regression analysis. RESULTS: The serum albumin level and the GNRI were lower in the zinc-deficiency group, and both were positively associated with the serum zinc level (rho = 0.44, P < 0.01 and rho = 0.44, P < 0.01, respectively). On multiple regression analysis, the GNRI (t = 3.09, P < 0.01) and serum albumin level (t = 4.75, P < 0.01) were independently associated with the serum zinc level. Although a higher eGFR was associated with a higher serum zinc level, this association disappeared on multivariate analysis. CONCLUSION: In this post hoc analysis, the GNRI, as well as the serum albumin level, were correlated with the serum zinc level, indicating that nutritional status is an important determinant of the zinc level. Further investigations are needed to clarify the effects of nutritional status and kidney function on zinc deficiency.

A Case of Hypokalemia Caused by Left Native Renal Artery Stenosis in a Kidney Transplant Recipient.

A 39-year-old woman with end-stage renal failure of unknown origin was on peritoneal dialysis for 10 years. One year ago, she underwent ABO-incompatible living-donor kidney transplantation from her husband. After the kidney transplantation, her serum creatinine level remained around 0.7 mg/dL, but her serum potassium level remained low at around 3.5 mEq/L despite potassium supplementation and spironolactone. The patient's plasma renin activity (PRA) and plasma aldosterone concentration (PAC) were markedly elevated (20 ng/mL/h and 868 pg/mL, respectively). A CT angiogram of the abdomen performed 1 year previously suggested stenosis of the left native renal artery, which was considered responsible for the hypokalemia. Renal venous sampling was done on both the native kidneys and the transplanted kidney. Since renin secretion from the left native kidney was significantly elevated, a laparoscopic left nephrectomy was performed. Postoperatively, the renin-angiotensin-aldosterone system was markedly improved (PRA: 6.4 ng/mL/h, PAC: 147.3 pg/mL), and the serum potassium levels also improved. Pathological examination of the removed kidney showed many atubular glomeruli and hyperplasia of the juxtaglomerular apparatus (JGA) in residual glomeruli. In addition, renin staining showed strong positivity in the JGA of these glomeruli. Here, we report a case of hypokalemia caused by left native renal artery stenosis in a kidney transplant recipient. This valuable case study provides histological confirmation of maintained renin secretion in an abandoned native kidney after kidney transplantation.

Changes in erythropoiesis-stimulating agent responsiveness after transfer to combined therapy with peritoneal dialysis and hemodialysis for patients on peritoneal dialysis: A prospective multicenter study in Japan.

INTRODUCTION: Inadequate dialysis and fluid overload are corrected after starting combined therapy with peritoneal dialysis (PD) and hemodialysis (HD). However, the effects on anemia management has not been elucidated. METHODS: We conducted a prospective, multicenter, observational cohort study of 40 PD patients (age, 60 ± 10 years; male, 88%; median PD duration, 28 months) starting combined therapy and investigated changes in several clinical parameters, including erythropoiesis-stimulating agent (ESA) resistance index (ERI). RESULTS: ERI decreased significantly during 6 months after switching to combined therapy (from 11.8 [IQR 8.0-20.4] units/week/kg/(g/dL) to 7.8 [IQR 3.9-18.6] units/week/kg/(g/dL), p = 0.047). Body weight, urinary volume, serum creatinine and the dialysate-to-plasma creatinine ratio (D/P Cr) decreased, whereas hemoglobin and serum albumin increased. In subgroup analysis, the changes in ERI were not affected by cause for starting combined therapy, PD holiday and D/P Cr. CONCLUSION: Although detailed mechanism was unclear, ESA responsiveness improved after switching from PD alone to combined therapy.

Interferon-gamma Release Assay-positive Granulomatous Interstitial Nephritis in a Patient with a History of Diffuse Large B Cell Lymphoma.

Tuberculosis is a common etiology of granulomatous interstitial nephritis (GIN). However, the absence of evidence of lung involvement and lack of mycobacterial isolation in cultures make the etiological diagnosis and treatment decision challenging. We herein report a 46-year-old man with severe renal failure, a persistent fever, and a history of lymphoma. A renal biopsy exhibited GIN. Despite no evidence of tuberculosis except for a positive interferon-gamma release assay (IGRA), the patient was successfully treated with anti-tuberculosis drugs. Our case suggests that anti-tuberculosis therapy should be considered for patients with IGRA-positive GIN after excluding other etiologies.

A Pregnant Woman with IgA Nephropathy Showing Histological Preeclampsia Findings without Hypertension Treated with Steroids: A Case Report and Literature Review.

A 35-year-old woman pregnant with twins developed nephrotic syndrome (NS) at 33 weeks' gestation, but her blood pressure remained within the normal range throughout gestation and puerperium. At 34 weeks' gestation, she delivered healthy twins via Caesarean section. After delivery, she developed massive proteinuria (21.1 g/day) and severe hypoalbuminemia (1.0 g/dL). A renal biopsy performed 19 days after delivery revealed IgA nephropathy (IgAN) and preeclampsia. She was treated with steroids, and the NS gradually resolved. This is a rare case of massive gestational proteinuria with IgAN and preeclampsia pathologically that did not meet the clinical criteria for preeclampsia.

Association between serum ß2-microglobulin and mortality in Japanese peritoneal dialysis patients: A cohort study.

BACKGROUND: Higher serum ß2-microglobulin (B2M) concentrations are associated with higher mortality in the general population, non-dialyzed chronic kidney disease patients and patients receiving hemodialysis (HD). However, this relationship among patients on peritoneal dialysis (PD) has not been validated. METHODS: We collected baseline data for 3,011 prevalent PD patients from a nationwide dialysis registry in Japan at the end of 2010. Clinical outcomes for 9 years were then evaluated using the registry at the end of 2011 to 2019. All-cause and cardiovascular (CV) mortality was assessed using Cox regression analysis and competing-risks regression analysis, respectively. We used multiple imputation to deal with missing covariate data. RESULTS: During a median follow-up of 87 months, 2,054 patients transferred to combined therapy with PD and HD or HD directly. A total of 3,011 patients, 1,235 (41.0%) died, including 437 patients (14.5%) from CV causes. Among them, 612 patients died after transfer to other dialysis modalities. Univariate analyses revealed no significant association between serum B2M and mortality, whereas higher serum B2M was independently associated with both all-cause and CV mortalities in adjusted models. However, the significant association between serum B2M and CV mortality disappeared in analysis treating serum B2M as a categorical variable. The effect of serum B2M on all-cause mortality was significantly higher among patients with higher urinary volume and a significant interaction was evident. CONCLUSIONS: Using a large-scale registry, we found that serum B2M contributes tenuously but significantly to worse outcome and residual kidney function significantly affects this relationship. On the contrary, serum B2M per se had no predictive value for patient outcome in prevalent PD patients.

Association between lipid profile and residual renal function in incident peritoneal dialysis patients.

INTRODUCTION: Residual renal function (RRF) is one of the most crucial factors in the management of peritoneal dialysis (PD). The aim of this study was to evaluate the association between lipid profile and preservation of RRF among incident PD patients. METHODS: This retrospective cohort study investigated 113 patients (male, 72%; age, 59 ± 14 years) who initiated PD between 2006 and 2017. We investigated the relationships between high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) at PD initiation and change in renal Kt/V during the first year after PD initiation. RESULTS: Alterations in renal Kt/V during the first year after PD initiation correlated negatively with HDL-C at PD initiation but not with LDL-C. On multivariate analysis, HDL-C at PD initiation was independently associated with a change in renal Kt/V during the first year after PD initiation. CONCLUSION: These results suggest the importance of lipid management among incident PD patients for the preservation of RRF.

Chronic Kidney Disease Patients Visiting Various Hospital Departments: An Analysis in a Hospital in Central Tokyo, Japan.

To further improve care for chronic kidney disease (CKD) patients, healthcare providers' awareness of CKD must be raised. Proteinuria testing is essential for CKD care, and collaboration with specialists is recommended for advanced cases. We reviewed data from the electronic medical records of outpatients at our hospital to analyze the clinical departments visited by CKD patients, and the frequency of proteinuria testing and referrals to nephrologists. We defined CKD as an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 or a urine protein concentration (U-pro) ≥ +1. We found that 31.1% of the CKD tests in September 2021 were performed in clinical departments other than internal medicine. Furthermore, within 1 year, 68.0% of CKD patients identified in September 2020 underwent a urine dipstick test, and 33.7% underwent a quantitative test for urinary protein or albumin. Additionally, 27.5% of individuals with an eGFR < 30 mL/min/1.73 m2 or U-pro ≥ +1 identified by non-nephrology departments in September 2020 visited the nephrology department within 1 year. Repeated assessments of these quality indicators may be useful for progress management in improving CKD care. Because CKD patients visited various departments in our hospital, campaigns to raise CKD awareness must reach a wide range of healthcare providers in hospitals.

Clinical feasibility of transfer to combined therapy with peritoneal dialysis and hemodialysis for patients on peritoneal dialysis: A prospective multicenter study in Japan.

INTRODUCTION: Although combined therapy with peritoneal dialysis (PD) and hemodialysis (HD) is widespread in Japan, its clinical utility has been reported only in retrospective or before-and-after test lacking a control group. METHODS: We conducted a prospective, multicenter, observational cohort study of 176 incident PD patients and compared patient survival and changes in clinical parameters between patients on different dialysis modalities. RESULTS: During a median follow-up of 41 months, 47 patients transferred to combined therapy and 35 patients transferred directly to HD. Patients transferred to combined therapy had a significantly better survival than those transferred directly to HD. However, we could not establish this difference in a multivariate analysis because only six patients died among these groups. The decreases in urea nitrogen and serum creatinine were more prominent among patients directly transferred to HD. CONCLUSION: This is the first report revealing clinical feasibility of transfer to combined therapy for PD patients.

Long-term changes in anemia-related parameters among Japanese dialyzed patients assessed by newly developed web-based system.

Anemia treatment is crucial in the management of dialyzed patients. Although Hb and serum ferritin levels are commonly used as indicators for treatment, these values change over time due to changes in policy, drugs for treating anemia, and target levels suggested by clinical guidelines. To clarify long-term changes in anemia-related parameters in Japan, we extracted annual patient data from a newly developed web-based system by the Japanese Society for Dialysis Therapy, the Web-based Analysis of Dialysis Data Archives system. Hb levels gradually increased from 2008 to 2019. Serum ferritin levels and transferrin saturation tended to increase between 2012 and 2019. Although these changes were found in all dialyzed patients, these were more pronounced in patients on peritoneal dialysis. We believe that our results can contribute to a better understanding of the results of clinical studies assessing the effects of treatment for anemia on clinical outcomes among dialyzed patients.

Acute tubulointerstitial nephritis associated with antineutrophil cytoplasmic antibody following cimetidine treatment: a case report.

BACKGROUND: Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis usually induces rapidly progressive glomerulonephritis, including pauci-immune necrotizing crescentic glomerulonephritis. Acute tubulointerstitial nephritis (ATIN), which is often drug-induced, is a frequent cause of kidney injury. However, ATIN associated with ANCA without any glomerular lesions has been rarely reported, and drug-induced ATIN associated with ANCA is not well recognized. Here we present a case of an older woman with ATIN associated with myeloperoxidase-ANCA (MPO-ANCA) following cimetidine treatment. CASE PRESENTATION: A 70-year-old woman was admitted to our hospital due to acute kidney injury and mild proteinuria. She had a one-year history of chronic thyroiditis and dyslipidemia, for which she was taking levothyroxine sodium and atorvastatin, respectively. Two weeks before admission she had started cimetidine, methylmethionine sulfonium chloride, and itopride hydrochloride for gastric discomfort persistent since a month. She had experienced fatigue for two weeks and later appetite loss. The patient demonstrated a positive titer for MPO-ANCA (192 IU/mL) and a positive drug-induced lymphocyte stimulation test for cimetidine. She underwent two kidney biopsies that revealed ATIN without any glomerular lesions. Despite discontinuation of cimetidine on admission, renal injury continued with the presence of high MPO-ANCA titer. Oral steroid treatment was closely related with the recovery of her renal function and disappearance of MPO-ANCA. CONCLUSIONS: In this case, ATIN presented as sustained renal insufficiency and high MPO-ANCA titer despite withdrawal of cimetidine. Therefore, we reason that the development of ANCA-associated ATIN was caused by cimetidine. Serologic follow-up with measurement of MPO-ANCA titers and renal biopsy are recommended when the clinical history is inconsistent with the relatively benign course of drug-induced ATIN.

Zinc deficiency: its prevalence and relationship to renal function in Japan.

BACKGROUND: Although zinc deficiency is common among dialyzed patients, its prevalence among non-dialyzed subjects and its relationship to renal function remain unclear. METHODS: We selected 816 non-dialyzed subjects (495 males; mean age, 56 ± 18 years) who underwent measurement of serum zinc at Jikei University Hospital between April 2018 and March 2019 using the Standardized Structured Medical Information eXchange2 (SS-MIX2) system, a global standard in Japan that enables collection of structured medical records with automatic data transfer to a registry database system. A serum zinc level of 60-80 µg/dL was defined as marginal zinc deficiency and a level of < 60 µg/dL as absolute zinc deficiency. We investigated factors associated with serum zinc using multiple regression analysis. RESULTS: Marginal and absolute zinc deficiency were present in 52.3% and 30.6% of subjects, respectively. Serum zinc levels tended to decrease with increasing stage of chronic kidney disease (CKD) (P = 0.051). Estimated glomerular filtration rate (eGFR) was not independently associated with serum zinc levels. Instead, serum albumin (t = 4.69, P < 0.01), hemoglobin (t = 2.54, P = 0.01) and mean corpuscular volume (MCV) (t = - 2.20, P = 0.03) were independently associated with serum zinc. In sensitivity analyses, serum zinc was not associated with either serum copper- or iron-related parameters. CONCLUSION: This large-scale study clarified the prevalence of zinc deficiency among non-dialyzed Japanese subjects. In addition, eGFR was not independently associated with serum zinc, probably due to confounding factors, such as nutritional status and degree of anemia. Further investigations are needed to clarify the epidemiology of zinc deficiency and its associations with CKD.

Association between anemia and mortality in hemodialysis patients is modified by the presence of diabetes.

BACKGROUND: The prevalence and severity of anemia differ between diabetic and non-diabetic patients. We investigated whether the effect of hemoglobin (Hb) on patient outcome was affected by the presence or absence of diabetes among Japanese patients receiving chronic hemodialysis (HD). METHODS: We enrolled 149,308 patients from a nationwide dialysis registry in Japan at the end of 2012 (mean age, 67.6 ± 12.3 years; male, 61.7%; diabetes, 43.5%; median dialysis duration, 65 months) who underwent three HD sessions weekly. One-year all-cause and cardiovascular (CV) mortality were assessed using Cox regression analysis and competing-risks regression analysis. We used multiple imputation to deal with missing covariate data. RESULTS: Baseline Hb and serum ferritin levels were independently associated with all-cause and CV mortality. In non-diabetic patients, a significantly higher risk for all-cause mortality compared to the reference group (10 to 11 g/dL) was observed in patients with Hb < 8 g/dL (hazard ratio (HR): 1.266; 95% confidence interval (CI) 1.097-1.460) and 8 to 9 g/dL(HR: 1.153; 95% CI 1.030-1.290). On the other hand, diabetic HD patients in the same Hb category group did not have increased risk of all-cause mortality. CONCLUSIONS: We found that non-diabetic HD patients had an increased risk of all-cause mortality if they had lower Hb levels, whereas the effect of Hb levels on mortality was attenuated in diabetic HD patients. These data suggest that the association between Hb levels and mortality rate could be different between diabetic and non-diabetic HD patients.

Comparisons of fatigue between dialysis modalities: A cross-sectional study.

BACKGROUND: Fatigue is one of the most frequent complications in dialyzed patients and is associated with poorer patient outcomes. Multiple factors are reported to be associated with fatigue development. Of them, the impacts of dialysis modalities remain unknown. METHODS: A total of 194 dialysis patients (mean age, 61±11 years; 134 males; modalities included hemodialysis (HD) in 26, online hemodiafiltration (HDF) in 74, peritoneal dialysis (PD) in 68, and combined therapy with PD and HD in 26 cases) were recruited for this cross-sectional study. Fatigue was assessed using the Profile of Mood States (POMS), a Visual Analogue Scale (VAS), and our original scale of fatigue, and depression was assessed by the Beck Depression Inventory-second edition (BDI-II). Our original scale of fatigue was administered both on dialysis and dialysis-free days to patients on HD and online HDF. RESULTS: The scores of the POMS, VAS, and our original scale were weakly but significantly inter-related (rho = 0.58, P<0.01; rho = 0.47, P<0.01, and rho = 0.42, P<0.01 between POMS and VAS, POMS and our original scale for fatigue, and VAS and our original scale for fatigue, respectively). The scores of these 3 tests showed no significant differences among the 4 modalities. On multivariate analysis, age, body mass index, creatinine, and employment status were associated with the presence or severity of fatigue, whereas dialysis modality was not. A similar result was obtained in 122 patients without depression. The prevalence of fatigue by our original scale was significantly lower on dialysis-free days than on dialysis days in patients on HD and online HDF. CONCLUSIONS: The results suggest that there is no significant association between different dialysis modalities including HD, online HDF, PD and combined therapy with PD and HD and the prevalence or severity of fatigue.

False-negative diagnosis of high anion gap in patients with end-stage kidney disease.

The traditional anion gap (AG) equation is widely used, but its misdiagnosis in end-stage kidney disease (ESKD) patients has not been investigated fully. Diagnostic accuracy to detect high AG was cross-sectionally evaluated using 3 AG equations in 1733 ESKD patients with an eGFR less than 15 mL/min/1.73 m2. The prevalence of high AG was 67.9%, 92.1% and 97.4% by the traditional, albumin-adjusted AG (aAG) and full AG equations, respectively. The sensitivity, specificity, accuracy and Kappa coefficient obtained with the traditional AG vs aAG equation were 0.70 vs 0.94, 0.98 vs 0.93, 0.7 vs 0.94, and 0.103 vs 0.44, respectively. Next, we created a subcohort comprising only patients with high full AG and investigated how the traditional AG equation leads to misdiagnoses. Multivariable-adjusted regression analysis in 1688 patients revealed that independent factors associated with a false-negative AG diagnosis were ARB use, eGFR, blood leukocyte count, serum chloride, bicarbonate, ionized calcium, potassium, albumin and phosphate. 93.2% of our subcohort prescribed any of RAAS inhibitors, Loop diuretics or Alkali which could increase either serum chloride or bicarbonate. Frequent use of these possible AG-reducing medications may conceal high AG state in patients with ESKD unless they have incidental inflammation which may increase AG value.

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.