Association of podocyte ultrastructural changes with proteinuria and pathological classification in type 2 diabetic nephropathy.

AIMS: Podocyte injury plays an essential role in the progression of diabetic nephropathy (DN). The associations between the ultrastructural changes of podocyte with proteinuria and the pathological classification of DN proposed by Renal Pathology Society (RPS) have not been clarified in patients with type 2 diabetic nephropathy (T2DN). METHODS: We collected 110 patients with kidney biopsy-confirmed T2DN at Peking University First Hospital from 2017 to 2022. The morphometric analysis on the podocyte foot process width (FPW) and podocyte detachment (PD) as markers of podocyte injury was performed, and the correlations between the ultrastructural changes of podocytes with severity of proteinuria and the RPS pathological classification of DN were analyzed. RESULTS: Mean FPW was significantly broader in the group of T2DN patients with nephrotic proteinuria (565.1 nm) than those with microalbuminuria (437.4 nm) or overt proteinuria (494.6 nm). The cut-off value of FPW (> 506 nm) could differentiate nephrotic proteinuria from non-nephrotic proteinuria with a sensitivity of 75.3% and a specificity of 75.8%. Percentage of PD was significantly higher in group of nephrotic proteinuria (3.2%) than that in microalbuminuria (0%) or overt proteinuria (0.2%). FPW and PD significantly correlated with proteinuria in T2DN (r = 0.473, p < 0.001 and r = 0.656, P < 0.001). FPW and PD correlated with RPS pathological classification of T2DN (r = 0.179, P = 0.014 and r = 0.250, P = 0.001). FPW value was increased significantly with more severe DN classification (P for trend =0.007). The percentage of PD tended to increase with more severe DN classification (P for trend = 0.017). CONCLUSIONS: Podocyte injury, characterized by FPW broadening and PD, was associated with the severity of proteinuria and the pathological classification of DN.

A modified renal risk score for Chinese patients with antineutrophil cytoplasmic antibody-associated vasculitis.

BACKGROUND: The renal risk score (RRS) is a useful tool to predict end-stage renal disease (ESRD) in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). The current study aimed to validate the predictive performance of RRS and to further modify this model in Chinese AAV patients. METHODS: Two hundred and seventy-two patients diagnosed with AAV confirmed by renal biopsies were retrospectively enrolled from a single center. The RRS was calculated based on 3 categorical variables, i.e., the proportion of normal glomeruli, the proportion of interstitial fibrosis and tubular atrophy (IF/TA), and eGFR at biopsy, classifying these patients into low-, medium-, and high-risk groups. In addition, a modified model was developed based on the RRS and was further validated in another independent cohort of 117 AAV patients. The predictive performance of each model was evaluated according to discrimination and calibration. RESULTS: Patients were classified by the RRS into low- (26.5%), medium- (46.7%), and high-risk (26.8%) groups, with 120-month renal survival rates of 93.3%, 57.2%, and 18.4%, respectively (P < 0.001). The RRS showed good discrimination but less satisfactory calibration. Therefore, a modified model with improved discrimination and calibration was developed in Chinese AAV patients, with eGFR, proportion of normal glomeruli (both as continuous variables), and IF/TA (< 25%, 25-50%, > 50%) included. Internal and external validation of the modified model were performed. Finally, an online risk prediction tool was developed based on the modified model. CONCLUSIONS: The RRS was an independent predictor of ESRD of AAV patients. The modified model could predict the probability of ESRD for AAV patients with improved performance in Chinese AAV patients.

The role of Kimmelstiel-Wilson nodule in the kidney outcome in patients with diabetic kidney disease: A two-center retrospective cohort study.

AIMS: In the current study, we aimed to investigate the predictive value of the Kimmelstiel-Wilson (K-W) nodule for the risk of ESKD in patients with type 2 diabetes mellitus (T2DM). METHODS: In the two-center retrospective study, clinical and pathological parameters were compared between DKD patients with and without K-W nodules. Furthermore, we used Cox regression analysis to explore the predictive value of the K-W nodule for the risk of ESKD. RESULTS: Compared with DKD patients without K-W nodules, patients with K-W nodules had a significantly higher level of proteinuria [5.1(3.1, 8.0) g/24 hr vs. 2.4(1.1, 4.4) g/24 hr, p < 0.001]. Patients with K-W nodules had significantly higher interstitial fibrosis and tubular atrophy (IFTA) and arteriosclerosis scores than those without (p = 0.001 and p = 0.006). Kaplan-Meier analysis showed that the probability of developing ESKD was significantly higher in patients with K-W nodules than in those without (log-rank test, p < 0.001). However, after adjusting closer variables, the K-W nodule was not an independent predictor for the risk of ESKD (p > 0.05). CONCLUSIONS: In T2DM patients with DKD, the K-W nodule was associated with a more severe phenotype, and to some extent, associated with poorer renal outcome, but might not be an independent risk factor for the progression of ESKD.

The therapeutic effects of human embryonic stem cells-derived immunity-and-matrix regulatory cells on membranous nephropathy.

BACKGROUND: Primary membranous nephropathy (MN) is a kidney-specific autoimmune disease. Human embryonic stem cells-derived immunity-and-matrix regulatory cells (hESC-IMRCs) have immunoregulatory functions. We hypothesized that hESC-IMRCs might have therapeutic effects on MN and be a potential treatment in clinical practice. METHODS: Rats of Heymann nephritis were injected with sheep anti-rat Fx1A serum. hESC-IMRCs were intravenously administrated upon the detection of proteinuria, with 6 × 106 cells (high-dose) or 3 × 106 cells (low-dose) in 1 ml every other day. Splenocytes and IMRCs were co-cultured at different times and ratios. Cell types and cytokines were detected by flow cytometry and enzyme-linked immunosorbent assay. RESULTS: The urinary protein of rats with Heymann nephritis was reduced remarkably to a level comparable to negative controls, in both low-dose (45.6 vs. 282.3 mg/d, P < 0.001) and high-dose (35.2 vs. 282.3 mg/d, P < 0.001) hESC-IMRC treatment groups. IgG and C3 deposit, glomerular basement membrane thickness and foot process effacement were alleviated and the reduced podocin was recovered in the kidneys. The proportions of CD4 + CD25 + T cells in circulation and spleen were increased, and the circulating level of IL-10 was increased, after IMRC interventions. IL-17 and TNF-α were reduced after IMRCs treatments. IL-10 increased remarkably in the co-culture supernatant of lymphocytes and IMRCs at 48 h with ratio 10:1. CONCLUSIONS: The intravenously delivered hESC-IMRCs alleviated proteinuria and kidney injuries of Heymann nephritis, by their immunosuppressive functions through regulatory T cells and IL-10. These pre-clinical results indicate that IMRCs worth careful consideration for human trials in the treatment of MN.

A 28-Year-Old Woman Presenting with a Clinical Flare of Systematic Lupus Erythematosus and Abdominal Pain Due to Rectus Sheath Hematoma.

BACKGROUND A flare, or flare-up, of systematic lupus erythematosus (SLE) is diagnosed by an increase in disease activity in one or more organs, new symptoms, or changes in laboratory measurements. A hematoma can occur in the sheath of the rectus abdominis following muscle trauma or rupture of an epigastric vessel, or it can occur spontaneously. This report is of a 28-year-old woman who presented with a clinical flare of SLE and abdominal pain due to rectus sheath hematoma. CASE REPORT A 28-year-old woman had been suspected of having SLE 9 years ago and had received glucocorticoid therapy combined with hydroxychloroquine. However, lupus flared after she discontinued glucocorticoids, and she was admitted with a 1-month history of marked generalized edema, abdominal distension, frothy urine, and massive ascites. During hospitalization, she abruptly developed a continuous, stabbing abdominal pain and a bulge over the right abdomen as a result of straining during a bowel movement. On examination, a well-demarcated round mass that measured 121 mm × 96 mm was detected in the right quadrant. Abdominal emergency computed tomography revealed a right rectus sheath hematoma (21.4×4.7 cm). After her condition improved, the patient underwent an ultrasound-guided renal biopsy and was diagnosed with class III (A/C) and class V lupus nephritis. CONCLUSIONS This case has shown that spontaneous rectus sheath hematoma can occur without a history of trauma in a patient with an exacerbation of SLE. This association appears to be rare, and the cause is unknown.

A non-invasive differential diagnostic model for light chain cast nephropathy in newly diagnosed multiple myeloma patients with renal involvement: a multicenter study.

OBJECTIVE: Light chain cast nephropathy is the most common form of renal lesion in multiple myeloma. Kidney impairment caused by light chain cast nephropathy can be reversed and survival can be improved if early diagnosis is available. It is thus of imperative importance to develop a non-invasive method to diagnose light chain cast nephropathy once the kidney biopsy is not always applicable. METHODS: We consecutively screened newly diagnosed multiple myeloma patients with kidney biopsies from 4 centers in China. Kidney pathologies were reviewed and clinical presentations were recorded. Then a diagnostic model was established by logistic regression and the predictive values were assessed. RESULTS: Between 1 June 1999 and 30 June 2019, a kidney biopsy was performed in 94 patients with newly diagnosed multiple myeloma, and light chain cast nephropathy was the most common pattern, seen in 52% of biopsied patients. The diagnostic model was established by multivariate logistic regression analysis as P(z) = 1/(1 + e-z) and z = - 0.093 Hemoglobin (g/L) + 0.421 Serum albumin (g/L) + 3.463 Acute kidney injury (0/1) - 9.207 High-density lipoprotein (mmol/L). If P(z) ≥ 0.55, the diagnosis pointed to light chain cast nephropathy; if P(z) < 0.55, the diagnosis favored non-light chain cast nephropathy. The area under the receiver operating characteristic curves was 0.981 (95% CI 0.959, 1.000). The model had a sensitivity of 93.9%, a specificity of 95.6%, a positive predictive value of 96.0%, a negative predictive value of 94.0%, and a total consistency of 95.0%. CONCLUSION: We built a novel, non-invasive diagnostic model through a multicenter study, which may be helpful in the diagnosis of light chain cast nephropathy in newly diagnosed multiple myeloma patients.

Association of acute kidney injury and clinical outcomes in patients with COVID-19 in Shenzhen, China: a retrospective cohort study.

BACKGROUND: Acute kidney injury (AKI) was found in some patients with COVID-19 pneumonia and accompanied with poor outcomes. The objective of this study was to investigate the association of AKI with clinical outcomes in COVID-19 patients. METHODS: In this cohort study, we reviewed electronic medical data from patients with COVID-19 in Shenzhen from January 11 to February 19, 2020. Clinical features and clinical outcomes in COVID-19 patients with and without AKI were analyzed. Further, we evaluated the association between AKI development and clinical outcomes. RESULTS: In this study, 9.6% patients developed AKI during hospitalization. Those with AKI presented older age, severer pneumonia, more comorbidity and lower lymphocyte count. Totally, more patients (77.5%) had primary composite outcomes (intensive care unit (ICU) admission, use of high-flow nasal cannula (HFNC) and mechanical ventilation) in AKI group compared to non-AKI group (2.9%) during the observation period. The median length of stay (LOS) and ICU stay were longer among those with AKI. After adjusted for related covariates, AKI development was independently correlated with LOS (ß (95% CI): 9.16 (3.87-14.46)), rather than primary outcomes (HR (95% CI): 1.34 (0.56-3.21)) in COVID-19 patients. CONCLUSIONS: The development of AKI was not one of the reasons for ICU admission, use of HFNC and mechanical ventilation, but a kind of manifestation of severe illness in COVID-19 hospitalized patients.

Pramipexole in peritoneal dialysis patients with restless legs syndrome (RLS): a protocol for a multicentre double-blind randomised controlled trial.

INTRODUCTION: Restless legs syndrome (RLS) is a common neurological sensorimotor disorder among patients with end stage renal disease. This clinical trial aimed to provide evidence on the efficacy and safety of pramipexole in patients with uremic RLS receiving peritoneal dialysis (PD). METHODS AND ANALYSIS: This is a 12-week, multicentre, randomised, double-blind, placebo-controlled clinical trial. In total, 104 patients with uremic RLS receiving PD will be enrolled from four hospitals and randomly assigned in a 1:1 ratio to either placebo or pramipexole. We will determine the efficacy of pramipexole in the improvement of International RLS Study Group Rating Scale as the primary outcome, while responder rates for other RLS scales at week 12, change from baseline to week 12 for psychological status, sleep disorder and quality of life and blood pressure represent the secondary outcomes. ETHICS AND DISSEMINATION: The study was approved by the ethics committees of Peking University First Hospital, Xinqiao hospital of Army Medical University, Cangzhou Center Hospital and Peking University Shenzhen Hospital. The results will be disseminated in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT03817554.

Depression at Baseline Is an Independent Risk Factor for Cognitive Decline in Patients on Peritoneal Dialysis: A Multicenter Prospective Cohort Study.

Background:Depression has been recognized as a risk factor for cognitive impairment (CI) from cross-sectional datasets. This multicenter prospective study investigated the association between depression and cognitive decline in peritoneal dialysis (PD) patients.Methods:This multicenter prospective cohort study included 458 PD patients who were followed up for 2 years. The Modified Mini-Mental State Examination (3MS) was used for assessment of global cognitive function, Trail-Making Tests A and B for executive function, subtests of the Battery for the Assessment of Neuropsychological Status for immediate and delayed memory, visuospatial skill, and language ability. Depression was assessed using Zung's Self-Rating Depression Scale.Results:During the 2-year follow-up, patients with moderate/severe depression at baseline showed a significant decline in global cognitive function (80.5 ± 15.2 vs 76.6 ± 15.5, p = 0.008), while patients without depression or with mild depression kept a stable global cognitive function. In the meantime, patients without depression showed significant improvements in immediate memory, visuospatial skill, and language ability. However, no significant improvement in these parameters was shown in depression groups. In multivariable linear regression analysis, depression at baseline was a significant predictor of worsening global cognitive function, whether depression was analyzed as a continuous variable (odds ratio [OR] = -0.14, 95% confidence interval [CI] -0.27, -0.01, p = 0.031) or a rank variable (OR = -1.88, 95% CI -3.30, -0.45, p = 0.010). Moreover, higher depression score or more severe depression degradation was significantly associated with decline of immediate memory, delayed memory, and language skill.Conclusion:Depression was a significant risk factor for worsening of CI in PD patients.

The Association of Cognitive Impairment with Peritoneal Dialysis-Related Peritonitis.

Background:Research on the association between cognitive impairment (CI) and peritoneal dialysis (PD)-related peritonitis is limited. Therefore, we investigated whether CI contributed to the risk of PD-related peritonitis.Methods:This prospective cohort study enrolled 458 patients from 5 PD centers between 1 March 2013, and 30 November 2013, and continued until 31 May 2016. We used the Modified Mini-Mental State Examination (3MS) to assess general cognition, the Trail-Making Test to assess executive function, and subtests of the Battery for the Assessment of Neuropsychological Status to assess immediate and delayed memory, visuospatial skills, and language ability. Patients were assigned to CI and non-CI groups based on their 3MS scores. The first episode of peritonitis was the primary endpoint event. Treatment failure of peritonitis was defined as peritonitis-associated death or transfer to hemodialysis. We used competing risk models to analyze the association between CI and the risk of peritonitis. The association of CI with treatment failure after peritonitis was analyzed using logistic regression models.Results:Ninety-four first episodes of peritonitis were recorded during a median follow-up of 31.4 months, 18.1% of which led to treatment failure. No significant group differences were observed for the occurrence, distribution of pathogenic bacteria, or outcomes of first-episode peritonitis. Immediate memory dysfunction was independently associated with a higher risk of PD-related peritonitis (hazard ratio [HR] 1.736, 95% confidence interval [CI] 1.064 - 2.834, p < 0.05), adjusting for confounders.Conclusions:Immediate memory dysfunction was a significant, independent predictor of PD-related peritonitis. Neither general nor specific domains of CI predicted treatment failure of peritonitis.

Cognitive Changes in Peritoneal Dialysis Patients: A Multicenter Prospective Cohort Study.

RATIONALE & OBJECTIVE: Cognitive impairment is an independent predictor of technique failure and mortality in patients on peritoneal dialysis (PD) therapy. We investigated changes in cognitive function and factors associated with it in this population. STUDY DESIGN: Multicenter prospective cohort study. SETTING & PARTICIPANTS: 458 PD patients were enrolled and followed up for 2 years. PREDICTORS: Global and specific domains of cognitive function were measured at baseline and after 2 years. The Modified Mini-Mental State Examination (3MS) was used for assessment of global cognitive function; Trail-Making Tests A and B, for executive function; and subtests of the Battery for the Assessment of Neuropsychological Status, for immediate and delayed memory, visuospatial skill, and language ability. OUTCOMES: The primary outcome was change in cognitive function. Secondary outcomes included all-cause mortality, cardiovascular mortality, hospitalization, and transition to hemodialysis therapy. ANALYTICAL APPROACH: Multivariable linear regression models. RESULTS: The prevalence of cognitive impairment increased from 19.8% to 23.9%. 3MS scores significantly decreased (84.8 to 83.1), although executive function, immediate memory, and visuospatial skill improved over time. Delayed memory capacity and language ability were unchanged. Lower serum albumin level was associated with deteriorated delayed memory, visuospatial skill, and language ability, as well as with the decline in general cognitive function (ß values of 0.64, 0.90, 0.80, and 0.44, respectively). Advanced age, lower education, and depression were also correlated with deterioration in general and specific cognitive function. After multivariable adjustment, both global and specific cognitive impairment at baseline were associated with a greater rate of hospitalization, and memory dysfunction was associated with a lower dialysis modality survival rate. LIMITATIONS: A relatively short observation period, small number of deaths, and potential selection bias due to patients unavailable for the second assessment. CONCLUSIONS: In a PD population, global cognitive function declined over 2 years, though some specific cognitive domains improved. Besides well-recognized factors, hypoalbuminemia and depression were also risk factors for cognitive impairment.

An association of cognitive impairment with diabetes and retinopathy in end stage renal disease patients under peritoneal dialysis.

BACKGROUND: Diabetes and retinopathy have been considered as risk factors of cognitive impairment (CI) in previous studies. We investigated both of these two factors and their relationship with global and specific cognitive functions in end stage renal disease patients under peritoneal dialysis (PD). METHODS: In this multicenter cross-sectional study, 424 clinically stable patients were enrolled from 5 PD units, who performed PD for at least three months and completed fundoscopy examination if they had diabetes. Global cognitive function was measured using the Modified Mini-Mental State Examination (3MS), Trail-Making Test forms A and B for executive function, and subtests of the Battery for the Assessment of Neuropsychological Status for immediate and delayed memory, visuospatial skills, and language ability. RESULTS: PD Patients with DM and Retinopathy had significantly higher prevalence of CI, executive dysfunction, impaired immediate memory and visuospatial skill, compared with patients in non-DM group. By multivariate logistic regression analyses, DM and retinopathy rather than DM only were significantly associated with increased risk for CI, executive dysfunction, impaired immediate memory and visuospatial skill, odds ratios(ORs) and 95% confidence intervals were 2.09[1.11,3.92], 2.89[1.55,5.37], 2.16 [1.15,4.06] and 2.37[1.32,4.22], respectively (all P < 0.05). CONCLUSIONS: Diabetic PD patients with retinopathy were at two times risk for overall cognitive impairment, executive dysfunction, impaired immediate memory and visuospatial skill as compared to non-diabetic PD patients.

Performance of the Modified Mini-Mental State Examination (3MS) in Assessing Specific Cognitive Function in Patients Undergoing Peritoneal Dialysis.

PURPOSE: While Cognitive impairment (CI) has been identified as an independent risk factors for mortality in patients undergoing peritoneal dialysis (PD), it is inadequately assessed. We evaluated the applicability of the Modified Mini-Mental State Examination (3MS) in assessing specific cognitive function and compared it to a detailed neuropsychological test battery as the reference standard. METHODS: In this multicentric cross-sectional study, we enrolled 445 clinically stable patients from five PD units, who were undergoing PD for at least 3 months. The 3MS was evaluated for general cognitive function. A detailed neuropsychological battery including domains of immediate memory, delayed memory, executive function, language, and visuospatial ability were evaluated as reference standards. Sensitivity and specificity of the 3MS was determined by using receiver operating characteristic (ROC) analysis. RESULTS: The CI prevalence evaluated by 3MS was 23.6%. PD patients with CI performed worse in all cognitive domains. The 3MS correlated well with specific cognitive domains. However, 18.5%, 57.4%, 12.6%, 8.8%, and 41.2% of patients whom were idendified as normal by 3MS still showed executive dysfunction, immediate memory impairment, delayed memory impairment, and language-ability and visuospatial-ability impairment, respectively. The 3MS identified patients having specific cognitive dysfunction with varied extent of diagnostic value, with 0.50, 0.42, 0.35, 0.34, and 0.26 of Youden index in executive function, delayed memory, language ability, immediate memory, and visuospatial ability, respectively. CONCLUSIONS: The 3MS is not a comprehensive instrument for major cognitive domains in PD patients. It could, however, be used for executive dysfunction and delayed memory impairment screening.

Depression and Cognitive Impairment in Peritoneal Dialysis: A Multicenter Cross-sectional Study.

BACKGROUND: Depression and cognitive impairment have been identified as independent risk factors for mortality in peritoneal dialysis (PD) patients. The relationship between depression and global and specific cognitive functions in PD patients was investigated in this study. STUDY DESIGN: Multicenter cross-sectional study. SETTING & PARTICIPANTS: 458 clinically stable patients, drawn from 5 PD units, who performed PD for at least 3 months were enrolled. PREDICTOR: Depression, defined as depression severity index score > 0.5 using the Zung Self-rating Depression Scale. OUTCOMES: Global and specific cognitive impairment. Global cognitive function was measured using the Modified Mini-Mental State Examination (3MS), Trail-Making Test forms A and B for executive function, and subtests of the Battery for the Assessment of Neuropsychological Status for immediate and delayed memory, visuospatial skills, and language ability. RESULTS: Prevalences of depression and cognitive impairment evaluated by the 3MS were 52% and 28.4%, respectively. Patients with mild or moderate/severe depression had higher prevalences of general cognitive impairment, executive dysfunction, and impaired immediate and delayed memory. After adjusting for demographics, comorbid conditions, and clinical parameters, depression scores were independently associated with lower 3MS scores, lower immediate and delayed memory and language ability scores, and longer completion times of Trails A and B. Even mild depression was independently associated with higher risk for cognitive impairment, executive dysfunction, and impaired immediate and delayed memory after multivariable adjustments. LIMITATIONS: The causal relationship between depression and cognitive impairment could not be determined, and the potential copathogenesis behind depression and cognitive impairment was not fully investigated. CONCLUSIONS: Even mild depression is closely associated with global and specific cognitive impairment in PD patients.

Anti-Glomerular Basement Membrane Disease Combined with IgA Nephropathy Complicated with Reversible Posterior Leukoencephalopathy Syndrome: An Unusual Case.

BACKGROUND: Anti-glomerular basement membrane disease (anti-GBM disease) is an autoimmune glomerulonephritis disease that is characterized by IgG linear deposition along the non-collagen domain of a3 chains of type IV collagen on the GBM. Although anti-GBM disease accompanied with IgA linear deposition along GBMs was discussed previously in some papers, anti-GBM disease combined with IgA granular deposition in the mesangial area, especially complicated with reversible posterior leukoencephalopathy syndrome (RPLS), was rarely reported. RPLS is usually caused by hypertensive encephalopathy, renal decompensation, fluid retention, and adverse effects of immunosuppressive drugs. CASE REPORT: A male patient with the chief complaints of headache, gross hematuria, and nocturia was referred to our hospital. Based on renal biopsy, the diagnosis was finally confirmed as anti-GBM disease combined with IgA nephropathy and, the patient received comprehensive treatment, including cyclophosphamide (CTX), which led to symptom improvement. Two days after the third impulse CTX was given, he suddenly experienced headache and dizziness, which eventually developed into a tonic-clonic seizure. RPLS was identified by cranial magnetic resonance imaging (MRI) with reversible neuroimaging. After diazepam and antihypertension management, seizures were controlled. RPLS, a neurological complication, was found in anti-GBM disease with IgA nephropathy during our immunosuppressants therapy for the first time. CONCLUSIONS: It is worth paying more attention to patients with rapidly progressive glomerulonephritis (RPGN), as they might be complicated with RPLS during intravenous administration of CTX and methylprednisolone. We suggest the neuroimaging be examined as soon as the seizure happens.

Hyponatremia and Cognitive Impairment in Patients Treated with Peritoneal Dialysis.

BACKGROUND AND OBJECTIVES: Hyponatremia has been identified as a relevant factor for cognitive impairment but has not been investigated in patients receiving peritoneal dialysis (PD). This study investigated the relationship between hyponatremia and cognitive functions in PD patients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A total of 476 clinically stable patients from five PD units who were older than 18 years of age and had undergone PD for at least 3 months between March 2013 and March 2014 were enrolled in this multicenter cross-sectional study. Global cognitive function was measured using the Modified Mini-Mental State Examination (3MS); executive function, by trail making tests A (trails A) and B (trails B); and immediate memory, delayed memory, and language ability, by subtests of Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Hyponatremia was defined as serum sodium level ≤135 mmol/L, which was calculated as the mean of measurements taken over the preceding 3 months. RESULTS: Fifty patients (10.5%) had hyponatremia; these patients tended to be older and less educated, to have less inflammation, and to have the higher prevalence of cognitive impairment. They also had lower scores on RBANS subtests. After adjustment for demographic and clinical confounders, hyponatremia was independently associated with lower 3MS score (coefficient, -5.28; 95% confidence interval [CI], -8.44 to -2.13) and longer completion time of trials A (coefficient, 22.68; 95% CI, 3.44 to 41.92) and B (coefficient, 45.56; 95% CI, 1.30 to 89.81). After additional adjustment for laboratory measures, hyponatremia was still associated with 3MS score and completion time of trails A. Hyponatremia was independently associated with CI (odds ratio, 2.17; 95% CI, 1.02 to 4.94) and executive dysfunction (odds ratio, 2.43; 95% CI, 1.01 to 5.87) using multivariate logistic regression analysis. Sensitivity analyses with multivariable models that included propensity score still supported the association between hyponatremia and cognitive impairment. CONCLUSIONS: Hyponatremia was associated with global and specific cognitive impairment in PD patients.