Triglyceride glucose-body mass index and cardiovascular mortality in patients undergoing peritoneal dialysis: a retrospective cohort study.

BACKGROUND: Recent studies have shown that triglyceride glucose-body mass index (TyG-BMI) is associated with the risk of ischemic stroke and coronary artery disease. However, little attention has been given to the association between TyG-BMI and cardiovascular disease (CVD) mortality in patients undergoing peritoneal dialysis (PD). Therefore, this study aimed to explore the relationship between TyG-BMI and CVD mortality in southern Chinese patients undergoing PD. METHODS: Incident patients receiving PD from January 1, 2006, to December 31, 2018, with baseline serum triglyceride, glucose, and body mass index (BMI) information, were recruited for this single-center retrospective cohort study. TyG-BMI was calculated based on fasting plasma glucose, triglyceride, and BMI values. The association between TyG-BMI, CVD and all-cause mortality was evaluated using a multivariate-adjusted Cox proportional hazard regression model. RESULTS: Of 2,335 patients, the mean age was 46.1 ± 14.8 years; 1,382 (59.2%) were male, and 564 (24.2%) had diabetes. The median TyG-BMI was 183.7 (165.5-209.2). Multivariate linear regression showed that advanced age, male sex, history of CVD, higher levels of albumin and low-density lipoprotein cholesterol, and higher urine output were correlated with a higher TyG-BMI (P < 0.05). During a median follow-up period of 46.6 (22.4-78.0) months, 615 patients died, of whom 297 (48.2%) died as a result of CVD. After adjusting for demographics and comorbidities, TyG-BMI was significantly associated with an increased risk of CVD mortality (hazard ratio [HR] 1.51, 95% confidence interval [CI] 1.05-2.17) and all-cause mortality (HR 1.36, 95% CI 1.05-1.75). After full adjustment, the 28% risk of CVD mortality (HR 1.28, 95% CI 1.13-1.45) and 19% risk of all-cause mortality were elevated (HR 1.19, 95% CI 1.09-1.31) when TyG-BMI increased by 1 stand deviation (SD) (34.2). CONCLUSIONS: A higher baseline TyG-BMI was independently associated with an increased risk of CVD and all-cause mortality in patients receiving PD.

Relationship Between Peritoneal Protein Clearance and Hemoglobin in Peritoneal Dialysis Patients: A Prospective Cohort Study.

OBJECTIVE: The relationship between higher peritoneal protein clearance (PPCl) and hemoglobin (Hb) levels in peritoneal dialysis (PD) patients is unknown. We explored this relationship and interaction on all-cause mortality in this prospective cohort study with a large number of PD patients. METHODS: We enrolled prevalent PD patients in a single PD center. Demographic characteristics and clinical and biochemical data were collected. The total amount of protein loss in the dialysate and PPCl corrected for serum albumin were calculated. The primary study endpoint was all-cause mortality. We examined the relationship between PPCl, Hb, and all-cause mortality in the Cox regression model. RESULTS: We included a total of 487 PD patients (58.3% males, mean age 49.5 ± 14.9 years). The median PD duration at enrollment was 30.1 (15.8-48.3) months. Mean Hb level was 11.1 ± 1.9 g/dL, and 221 (45.3%) patients had Hb levels <11 g/dL. Patients with Hb < 11 g/dL had lower serum albumin, lower residual renal creatinine clearance, and higher PPCl. In a multilinear regression model, PPCl (ß = -0.12, P = .015) had an independent negative linear association with Hb levels. In the logistic regression model, higher PPCl was independently associated with lower Hb (<11 g/dL) (odds ratio = 1.02; 95% confidence interval [CI]: 1.01-1.03). In the overall cohort, after adjusting for confounders in the Cox regression model, decrease in Hb level was independently associated with increased risk (hazard ratio: 0.86, 95% CI: 0.77-0.95) of all-cause mortality. Interaction-effect test showed that PPCl influenced the relationship between Hb level and all-cause mortality (P = .011). After adjusting for confounders, lower Hb level was independently associated with a higher risk (hazard ratio: 0.85, 95% CI: 0.74-0.97) of all-cause mortality only in patients with PPCl ≥59.5 mL/day and not in patients with lower PPCl. CONCLUSIONS: Higher PPCl was an independent predictive factor of lower Hb levels in PD patients. Therefore, PPCl influenced the relationship between Hb level and all-cause mortality in PD patients.

Patient-reported gastrointestinal symptoms in patients with peritoneal dialysis: the prevalence, influence factors and association with quality of life.

BACKGROUND: The aims of this study were to investigate the prevalence and the influence factors of gastrointestinal symptoms, and its association with the quality of life (QOL) in peritoneal dialysis (PD) patients. METHODS: Continuous ambulatory PD patients (CAPD) who followed up in our PD center between March 2016 and December 2017 were enrolled in this cross-sectional study. Gastrointestinal symptom rating scale (GSRS) was used to evaluate gastrointestinal symptoms. The related clinical data were also collected. Multiple linear regression analysis was test for the influence factors associated with score of GSRS and QOL. RESULTS: This study included 471 CAPD patients. The mean age was 48.5±13.9 years, 53.9% were male and 15.1% with diabetic nephropathy. The median duration of PD was 37.3 (17.5~66.5) months. The median score of GSRS was 1.2(1.1~1.3) scores. Totally 82.2% (n=387) CAPD patients had at least one gastrointestinal symptom. Higher glycosylated hemoglobin, higher score of depression, lower diastolic blood pressure, urine output, score of instrumental activities of daily living scale and more amount of pills per day were independently associated with higher score of GSRS (all P<0.05). Score of dyspepsia and eating dysfunction were independently associated with worse score of QOL and physical health (all P<0.05). CONCLUSIONS: Gastrointestinal symptoms were common but not serious in CAPD patients. Glycemic control, depression, blood pressure, urine output, activity of daily life and amount of pills were all associated with gastrointestinal symptoms. Moreover, gastrointestinal symptoms were correlated with QOL of PD patients.

Incidence and Risk Factors Associated with Technique Failure in the First Year of Peritoneal Dialysis: A Single Center Retrospective Cohort Study in Southern China.

BACKGROUND: Technique failure is more likely to occur during the first 12 months after peritoneal dialysis (PD) initiation, which is a great challenge encountered in PD patients. The aim of this study was to investigate the incidence and risk factors associated with technique failure within the first year of PD patients in Southern China. METHODS: Incident PD patients who were followed up for at least one year at The First Affiliated Hospital of Sun Yat-sen University from January 1, 2006 to December 31, 2015 were included. Technique failure was defined as transferring to hemodialysis (HD) for more than 30 days or death within the first year after start of PD. A competitive risk regression analysis was used to explore the incidence and risk factors of the technique failure. RESULTS: Overall, 2,290 incident PD patients were included in this study, with a mean age of 48.2 ± 15.7 years, 40.9% female and 25.2% with diabetes. A total of 173 patients (7.5%) had technique failure during the first year of PD. Among them, the patient death account for 62.4% (n = 108) and transferring to HD account for 37.6% (n = 65). The main reasons for death were cardiovascular diseases (n = 32, 29.6%), infection (n = 15, 13.8%) and for conversion to HD were mechanical cause (n = 28, 43.1%), infection cause (n = 22, 33.8%). The risk factors for the technique failure included advanced age (HR 2.78, 95%CI 1.82-4.30), low body mass index (BMI < 18.5 kg/m2: HR 1.77, 95%CI 1.17-2.67), history of congestive heart failure (HR 2.81, 95%CI 1.58-4.98), or time on HD before PD ≤ 3 months (HR 1.49, 95%CI 1.05-2.10), peritonitis (HR 2.02, 95%CI 1.36-3.01);while higher serum albumin (HR 0.93, 95%CI 0.89-0.96) and using employee medical insurance to pay expenses (HR 0.47, 95%CI 0.32-0.69) were associated with reduced risk. CONCLUSIONS: Advanced age, poor nutritional status, history of HD or congestive heart failure, and peritonitis are related factors that increase the risk of technique failure in the first year of PD, while patients' type of medical insurance may also have an influence on early technique failure.

The incidence of pain and its association with quality of life in patients with peritoneal dialysis.

BACKGROUND: The aims of this study were to investigate the incidence of pain in peritoneal dialysis (PD) patients and to analyze the correlation between pain and quality of life. METHODS: PD patients who followed up in our PD center from March 2016 to December 2017 were included. The Short-Form McGill Pain Questionnaire was used to assess pain status. Depression status, sleep quality, quality of life and clinical data were also collected. RESULTS: A total of 463 PD patients were included, of whom 153 patients (33.1%) with pain. The main cause of pain was calcium and phosphorus metabolism disorder (51.6%). About 101 patients (66.0%) had multiple sites of pain, and 28 patients (18.3%) with pain were treated with analgesic drugs. Binary Logistic regression analysis showed that older age (OR = 1.026; p = 0.032) and higher intact parathyroid hormone level (OR = 1.043; p = 0.040) were independent risk factors for pain in PD patients. Multivariate analysis showed that score of pain rating index was an independent risk factor for depressive symptoms (OR = 1.100; p = 0.015), the score of Pittsburgh sleep quality index (B = 0.005; p = 0.044) and the score of physical component scale (B= -0.727; p = 0.016) in PD patients. CONCLUSIONS: The incidence of pain in PD patients was 33.1%. Older age and higher intact parathyroid hormone level were independent risk factors for pain. Pain was independently associated with depressive symptoms, sleep quality and quality of life in PD patients.

Risk Factors and Clinical Outcomes of Cognitive Impairment in Diabetic Patients Undergoing Peritoneal Dialysis.

INTRODUCTION: Cognitive impairment (CI) is common in patients with CKD or diabetes mellitus (DM). However, the relevance between DM and CI in diabetic patients undergoing peritoneal dialysis (PD) has not been clearly established. This study aimed to explore the role of DM in CI, the association of glycemic control with CI, and clinical outcomes of CI in diabetic PD patients. METHODS: Continuous ambulatory PD (CAPD) patients followed up in our PD center between 2014 and 2016 were enrolled. The participants were followed until an endpoint was reached or December 2017. Demographic data and clinical characteristics were collected, and laboratory parameters were measured. The Montreal Cognitive Assessment (MoCA) was used to evaluate global cognitive function, and a score of <26 was considered to indicate CI. A propensity score matching according to age, gender, and mean arterial pressure was conducted between the DM and non-DM groups. RESULTS: A total of 913 CAPD patients were enrolled, of whom 186 (20.4%) had diabetes. After appropriate matching, 175 patients in the DM group and 270 patients in the non-DM group were included. Patients with diabetes had a higher prevalence of CI and lower scores for visuospatial/executive function, naming, language, delayed recall, and orientation. Higher HbA1c (odds ratio [OR], 1.547; 95% confidence interval [95% CI], 1.013-2.362) and cardiovascular disease (CVD; OR, 2.926; 95% CI, 1.139-7.516) significantly correlated with a risk of CI in diabetic patients. During a median of 26.0 (interquartile range 13.5-35.6) months of follow-up, diabetic patients with CI demonstrated a significantly lower survival rate than those without CI, and CI was an independent risk factor for mortality after adjustment (hazard ratio, 7.224; 95% CI, 1.694-30.806). However, they did not show worse technique survival or higher peritonitis rate than patients without CI. CONCLUSIONS: HbA1c and CVD are independent risk factors for CI in diabetic patients undergoing CAPD, and CI is independently associated with a higher risk of mortality.

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.

Elevated Serum Trimethylamine N-Oxide Levels Are Associated with Mortality in Male Patients on Peritoneal Dialysis.

BACKGROUND: Elevated levels of serum trimethylamine N-oxide (TMAO) have been previously linked to adverse cardiovascular (CV) and all-cause mortality in hemodialysis patients. However, the clinical significance of serum TMAO levels in patients treated with peritoneal dialysis (PD) is unclear. METHODS: A total of 1,032 PD patients with stored serum samples at baseline were enrolled in this prospective study. Serum concentrations of TMAO were quantified by ultra-performance liquid chromatography-tandem mass spectrometry. Cox proportional hazards and competing-risk regression models were performed to examine the association of TMAO levels with all-cause and CV mortality. RESULTS: The median level of serum TMAO in our study population was 34.5 (interquartile range (IQR), 19.8-61.0) µM. During a median follow-up of 63.7 months (IQR, 43.9-87.2), 245 (24%) patients died, with 129 (53%) deaths resulting from CV disease. In the entire cohort, we observed an association between elevated serum TMAO levels and all-cause mortality (adjusted subdistributional hazard ratio [SHR], 1.22; 95% confidence interval [95% CI], 1.01-1.48; p = 0.039) but not CV mortality. Further analysis revealed such association differed by sex; the elevation of serum TMAO levels was independently associated with increased risk of both all-cause (SHR, 1.37; 95% CI, 1.07-1.76; p = 0.013) and CV mortality (SHR, 1.41; 95% CI, 1.02-1.94; p = 0.038) in men but not in women. CONCLUSIONS: Higher serum TMAO levels were independently associated with all-cause and CV mortality in male patients treated with PD.

Fetal and maternal outcome in patients with active lupus nephritis: comparison between new-onset and pre-existing lupus nephritis.

BACKGROUND: This study aimed to investigate fetal and maternal outcomes in women with active lupus nephritis (LN). Specifically, we compared women who had new-onset LN and those with pre-existing LN during pregnancy. METHODS: Patients with active LN during pregnancy were divided into the new-onset group (LN first occurred during pregnancy) and the pre-existing group (a history of LN) on the basis of the onset time of LN. Data on clinical features, laboratory findings, and pregnancy outcome were collected and analyzed between the two groups. Multivariate logistic regression analysis was used to compare the effects of active LN on adverse pregnancy outcomes. RESULTS: We studied 73 pregnancies in 69 women between 2010 and 2019. Of these, 38 pregnancies were in the pre-existing LN group and 35 were in the new-onset group. Patients with pre-existing LN had a higher risk of composite adverse fetal outcomes than those with new-onset LN [adjusted odds ratio (ORs), 44.59; 95% confidence interval (CI), 1.21-1664.82; P = 0.039]. However, the two groups had similar adverse maternal outcomes (ORs, 1.24; 95% CI, 0.36-4.29). Serum albumin and proteinuria significantly improved after pregnancy (P < 0.001). Kaplan-Meier analysis showed that the long-term renal outcome was similar between the two groups. CONCLUSIONS: Pregnant patients with pre-existing LN were associated with a higher risk of composite adverse fetal outcomes than those with new-onset LN. However, these two groups of patients had similar adverse maternal outcomes. The long-term renal outcomes were not different after pregnancy between these two groups.

Prevalence, risk factors and impact on outcomes of 30-day unexpected rehospitalization in incident peritoneal dialysis patients.

BACKGROUND: Rehospitalization is a major problem for end stage renal disease (ESRD) populations. However, researches on 30-day unexpected rehospitalzation of incident peritoneal dialysis (PD) patients were limited. This study aimed to investigate the prevalence, risk factors and impact on outcomes of 30-day unexpected rehospitalization in incident PD patients. METHODS: This was a retrospective cohort study. Patients who accepted PD catheter implantation in our centre from Jan 1, 2006 to Dec 31, 2013 and regular follow-up were included. The demographic characteristics, laboratory parameters, and rehospitalization data were collected and analyzed. The primary outcome was all-cause mortality, and the secondary outcomes included cardiovascular disease (CVD) mortality and technical failure. RESULTS: Totally 1632 patients (46.9 ± 15.3 years old, 60.1% male, 25.6% with diabetes) were included. Among them, 149 (9.1%) had a 30-day unexpected rehospitalization after discharge. PD-related peritonitis (n = 48, 32.2%), catheter malfunction (n = 30, 20.1%) and severe fluid overload (n = 19, 12.8%) were the top three causes for the rehospitalization. Multivariate logistic regression analysis showed that length of index hospital stays [Odds ratio (OR) =1.02, 95% confidence interval (CI) 1.00-1.03, P = 0.036) and hyponatremia (OR = 1.85, 95% CI 1.06-3.24, P = 0.031) were independently associated with the rehospitalization. Multivariate Cox regression analysis indicated that 30-day rehospitalization was an independent risk factor for all-cause mortality [Hazard ratio (HR) =1.52, 95% CI 1.07-2.16, P = 0.019) and CVD mortality (HR = 1.73, 95% CI 1.03-2.90, P = 0.038). CONCLUSIONS: The prevalence of 30-day unexpected rehospitalization for incident PD patients in our centre was 9.1%. The top three causes for the rehospitalization were PD-related peritonitis, catheter malfunction and severe fluid overload. Thirty-day unexpected rehospitalization increased the risk of all-cause mortality and CVD mortality for PD patients.

Association of brachial-ankle pulse wave velocity with cognitive impairment in peritoneal dialysis patients.

BACKGROUND: The relationship between cognitive impairment (CI) and arterial stiffness in peritoneal dialysis (PD) patients has not been clearly clarified. The aim of this study was to examine the relationship between CI and arterial stiffness in PD patients. METHODS: This cross-sectional study enrolled PD patients who performed a vascular profiler test at a single PD center in China between January 2014 and June 2016. The cognitive function was evaluated using the Montreal cognitive assessment (MoCA). A noninvasive vascular screening device was used to assess arterial stiffness relevant indicators. RESULTS: A total of 643 PD patients with median age 45 (37-57.4) years and median duration of PD 27.8 (8.7-56.4) months were enrolled. The rate of CI was 49.9%. The mean brachial-ankle pulse wave velocity (baPWV) was 17.2 ± 5.6 m/s. Compared with normal cognitive function group, patients with CI had higher baPWV (18.6 ± 7.0 vs. 15.8 ± 3.2 m/s), systolic blood pressure (150.3 ± 21.5 vs. 144.2 ± 20.2 mmHg), and pulse pressure (59.7 ± 14.7 vs. 52.5 ± 11.6 mmHg), and lower ankle-brachial index (ABI, 1.12 ± 0.12 vs. 1.15 ± 0.09) (all p<.05). Compared with systolic blood pressure, pulse pressure, and ABI in receiver operating characteristic (ROC) analysis, baPWV had better performance in predicting CI (area under curve: 0.68, 95% confidence interval: 0.64-0.72). BaPWV was independently associated with MoCA score (B per SD, -0.42 [95% confidence interval, -0.71 to -0.12]; p = .006) and CI (OR per SD, 1.55 [95% confidence interval, 1.11-2.17]; p = .011) in PD patients after adjustment for confounders. CONCLUSIONS: Higher baPWV was independently associated with CI 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 [ß] 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 (ß 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.

Serum Sodium Modifies the Association of Systolic Blood Pressure with Mortality in Peritoneal Dialysis Patients.

INTRODUCTION: High serum sodium is associated with increased blood pressure (BP) in dialysis patients, which is a risk factor for cardiovascular (CV) disease. However, the interaction between serum sodium and BP and their association with clinical outcomes in peritoneal dialysis (PD) patients is uncertain. METHODS: We analyzed a retrospective cohort of 1,656 incident PD patients from January 2006 to December 2013, who were followed up until December 2018. Cox proportional hazards regression models were used to evaluate the association of serum sodium and BP with all-cause and CV mortality. A priori interaction between serum sodium and systolic BP (SBP) was explored, and a subgroup analysis was performed by stratifying SBP into the following 3 groups: <110, 110-130, and >130 mm Hg. RESULTS: Mean baseline serum sodium was 140.2 ± 3.6 mmol/L, mean SBP was 137 ± 20 mm Hg, and diastolic BP was 85 ± 14 mm Hg. During a median (range) follow-up time of 46.5 (2.6-154.3) months, 507 patients died, 252 of whom died due to CV disease. SBP did not predict all-cause and CV mortality when BP was assessed as a continuous variable. However, SBP >130 or <110 mm Hg was associated with higher risk of all-cause and CV mortality compared with SBP of 110-130 mm Hg. There was a significant interaction between baseline serum sodium and SBP for all-cause mortality (p for interaction = 0.016). In subgroup analysis, among those with SBP >130 mm Hg, the risk of all-cause mortality was elevated in those with serum sodium ≥140 mmol/L (adjusted hazard ratio [aHR] 1.45 [95% confidence interval (CI): 1.07-1.98]), but not for those with serum sodium <140 mmol/L (aHR 1.27 [95% CI: 0.89-1.82]). Conversely, among those with SBP <110 mm Hg, those with serum sodium <140 mmol/L had an elevated risk of mortality (aHR 1.99 [95% CI: 1.31-3.02]), but not those with serum sodium ≥140 mmol/L (aHR 1.15 [95% CI: 0.74-1.79]) (p for interaction = 0.028). CONCLUSION: The association of BP with mortality was modified by serum sodium levels in PD patients. Further studies are needed to evaluate whether individualized BP control based on serum sodium levels contributes to improve patient outcomes.

Age Difference in the Association between Hyponatremia and Infection-Related Mortality in Peritoneal Dialysis Patients.

OBJECTIVES: This study aimed to examine the association of serum sodium with infection-related mortality and its age difference among continuous ambulatory peritoneal dialysis (CAPD) patients. METHODS: A total of 1,656 CAPD patients from January 2006 to December 2013 were included in this study. All patients were followed up until December 2018. Hyponatremia was defined as serum sodium <135 mmol/L. Cox proportional hazards regression model was used to investigate the relationship between baseline serum sodium levels and infection-related mortality. RESULTS: Participants were aged 47.5 ± 15.3 years, 666 (40.2%) patients were female. Glomerulonephritis was the main cause of end-stage renal disease (61.1%). After a median of 46 months of follow-up, 507 patients died. Among the deaths, 252 (49.7%) died from cardiovascular diseases, 105 (20.7%) from infections, and 150 (29.6%) from other causes. The overall infection-related mortality was 14.8 events per 1,000 patients-year, which was higher in patients aged ≥50 years than those younger than 50 years (28.3 vs. 5.3 events per 1,000 patients-year). In the entire cohort, hyponatremia at was not associated with infection-related (hazards ratios [HR] 1.66, 95% CI 0.91-3.02) and all-cause mortality (HR 1.14, 95% CI 0.83-1.57) after adjusting for potential confounders. There was a significant interaction by age of association of serum sodium with infection-related (p = 0.002) and all-cause (p = 0.0002) death. Age-stratified analysis showed that compared with control group, hyponatremia was independently related to increased risks of infection-related death, but not all-cause mortality in patients aged ≥50 years, with HR of 2.32 (95% CI 1.25-4.32) and 1.33 (95% CI 0.95-1.87), respectively. CONCLUSIONS: Hyponatremia was associated with increased risk of infection-related mortality in CAPD patients aged ≥50 years.

Roles of peritoneal clearance and residual kidney removal in control of uric acid in patients on peritoneal dialysis.

BACKGROUND: There have been few systematic studies regarding clearance of uric acid (UA) in patients undergoing peritoneal dialysis (PD). This study investigated peritoneal UA removal and its influencing factors in patients undergoing PD. METHODS: This cross-sectional study enrolled patients who underwent peritoneal equilibration test and assessment of Kt/V from April 1, 2018 to August 31, 2019. Demographic data and clinical and laboratory parameters were collected, including UA levels in dialysate, blood, and urine. RESULTS: In total, 180 prevalent patients undergoing PD (52.8% men) were included. Compared with the normal serum UA (SUA) group, the hyperuricemia group showed significantly lower peritoneal UA clearance (39.1 ± 6.2 vs. 42.0 ± 8.0 L/week/1.73m2; P = 0.008). Furthermore, higher transporters (high or high-average) exhibited greater peritoneal UA clearance, compared with lower transporters (low or low-average) (42.0 ± 7.0 vs. 36.4 ± 5.6 L/week/1.73 m2; P < 0.001). Among widely used solute removal indicators, peritoneal creatinine clearance showed the best performance for prediction of higher peritoneal UA clearance in receiver operating characteristic curve analysis [area under curve (AUC) 0.96; 95% confidence interval [CI], 0.93-0.99]. Peritoneal UA clearance was independently associated with continuous SUA [standardized coefficient (ß), - 0.32; 95% CI, - 6.42 to - 0.75] and hyperuricemia [odds ratio (OR), 0.86; 95% CI, 0.76-0.98] status, only in patients with lower (≤2.74 mL/min/1.73 m2) measured glomerular filtration rate (mGFR). In those patients with lower mGFR, lower albumin level (ß - 0.24; 95%CI - 7.26 to - 0.99), lower body mass index (ß - 0.29; 95%CI - 0.98 to - 0.24), higher transporter status (ß 0.24; 95%CI 0.72-5.88) and greater dialysis dose (ß 0.24; 95%CI 0.26-3.12) were independently associated with continuous peritoneal UA clearance. Furthermore, each 1 kg/m2 decrease in body mass index (OR 0.79; 95% CI 0.63-0.99), each 1 g/dL decrease in albumin level (OR 0.08; 95%CI 0.01-0.47), and each 0.1% increase in average glucose concentration in dialysate (OR 1.56; 95%CI 1.11-2.19) were associated with greater peritoneal UA clearance (> 39.8 L/week/1.73m2). CONCLUSIONS: For patients undergoing PD who exhibited worse residual kidney function, peritoneal clearance dominated in SUA balance. Increasing dialysis dose or average glucose concentration may aid in controlling hyperuricemia in lower transporters.

Direct medical costs of end-stage kidney disease and renal replacement therapy: a cohort study in Guangzhou City, southern China.

BACKGROUND: Renal replacement therapy was a lifesaving yet high-cost treatment for people with end-stage kidney disease (ESKD). This study aimed to estimate the direct medical costs per capita of ESKD by different treatment strategies: haemodialysis (HD); peritoneal dialysis (PD); kidney transplantation (KT) (in the first year); KT (in the second year), and by two urban health insurance schemes. METHODS: This was a retrospective observational cohort study. Data were obtained from outpatient and inpatient claims database of two urban health insurance from Guangzhou City, Southern China. Adult patients with HD (n = 3765; mean age 58 years), PD (n = 1237; 51 years), KT (first year) (n = 117; 37 years) and KT (second year) (n = 41; 39 years) were identified between 2010 and 2012. The primary outcome was the annual per patient medical costs in 2013 Chinese Yuan (CNY) incurred in the outpatient and inpatient sectors. Secondary outcomes were annual outpatient visits and inpatient admissions, length of stay per admission. Generalized linear regression and bootstrapping statistical methods were used for analysis. RESULTS: The estimated average annual medical costs for patients on HD were CNY 94,760.5 (US$15,066.0), 95% Confidence Interval (CI): CNY85,166.6-106,972.2, which was higher than those for patients on PD [CNY80,762.9 (US$12,840.5), 95% CI: CNY 76,249.8-85,498.9]. The estimated annual cost ratio of HD versus PD was 1.17 (95% CI: 1.12-1.25). Among the transplanted patients, the estimated average annual medical costs in the first year were CNY132,253.0 (US$21,026.9), 95%CI: CNY114,009.9-153,858.6, and in the second year were CNY93,155.3 (US$14,810.8), 95%CI: CNY61,120.6-101,989.1. The mean annual medical costs for dialysis patients under Urban Employee-based Basic Medical Insurance scheme were significantly higher than those for patients under Urban Resident-based Basic Medical Insurance scheme (P < 0.001). CONCLUSIONS: The direct medical costs of ESKD patients were high and different by types of renal replacement therapy and insurance. The findings can be used to conduct cost-effectiveness research on different types of RRT for ESKD patients that provides economic evidence for health policy design in China.

Lower Phase Angle Measured by Bioelectrical Impedance Analysis Is a Marker for Increased Mortality in Incident Continuous Ambulatory Peritoneal Dialysis Patients.

OBJECTIVE: Phase angle (PA) determined by bioelectrical impedance analysis has been suggested to be a predictor of death in a variety of disease conditions, but its associations with outcomes have not yet been assessed in a large continuous ambulatory peritoneal dialysis (CAPD) patient cohort. The aim of the present study was to examine the association of PA with risks for all-cause and cardiovascular death in patients treated with CAPD. METHODS: Incident CAPD patients were enrolled from January 1, 2010 to December 31, 2015 and were followed until December 31, 2017. Multifrequency bioelectrical impedance analysis was conducted in the morning with patients in a fasting state. Multivariable linear regression analyses were performed to study the relationships between PA and other variables. Cox proportional hazard models were used to evaluate the association between PA and mortality. RESULTS: A total of 760 incident CAPD patients were enrolled in this study. Patients have a median PA value of 4.59° ranging from 2.30° to 7.22°. Aging, presence of diabetes mellitus, and fluid overload were independently associated with lower PA, whereas male sex, higher body mass index, higher serum levels of albumin and creatinine, and better residual renal function were independently associated with higher PA in a multivariable linear regression model. A total of 125 (16.4%) patients died during a median follow-up of 42 months. In the Cox model with adjustment for confounders, PA was significantly associated with all-cause and cardiovascular mortality in incident CAPD patients (hazard ratio, 0.584; 95% confidence interval, 0.403 to 0.844, P = .004; hazard ratio, 0.597; 95% confidence interval, 0.359 to 0.993, P = .047, respectively). CONCLUSIONS: PA reflected a combined dimension of the illness including deranged hydration status and nutritional status. Lower PA was associated with both all-cause and cardiovascular death in patients with CAPD.

Association of Lean Body Mass Index and Peritoneal Protein Clearance in Peritoneal Dialysis Patients.

BACKGROUND/AIMS: The relationship between peritoneal protein clearance (PPCl) and nutritional status in peritoneal dialysis (PD) population have not been clarified. This study aims to investigate the relationship between PPCl and nutritional status in PD population. METHODS: Prevalent PD patients were enrolled in the cross-sectional survey in a single center from April to November 2013. The total amount of protein loss in the dialysate was calculated. PPCl reflects the individual differences of peritoneal protein loss, and is calculated by the formula, that PPCl (ml/day)=24-h dialysate protein loss / (albumin/0.4783). Nutritional status measured by lean body mass index (LBMI) was assessed by multi-frequency bioelectrical impedance analysis (BIA). RESULTS: Totally 351 PD patients (55% male, 17.1% with diabetes, mean age 47.7±14.3 years) were included. The median PPC l was 58 ml/day. Patients were divided into four groups for comparison according to the PPC quartiles. Compared with lower PPCl quartiles, patients with higher PPCl had higher body mass index (BMI) (P< 0.001), body surface area (BSA) (P < 0 .001), LBMI (P<0.001), 4-hour D/P creatinine ratio (P< 0.001), and lower residual renal CCl (P<0.001). Compared with conventional body index (BMI and BSA) in ROC analysis, LBMI (area under curve: 0.71, 95% confidence interval [CI]: 0.66-0.77) had better performance in predicting higher PPCl. After adjustment in logistic regression models, each 1 kg/m2 increase of LBMI (odd ratio[OR] =1.37; 95% CI: 1.17-1.60), each 0.1 increase of 4-hour D/P creatinine ratio (OR =1.47; 95% CI: 1.11-1.93), and every 1 L/week/1.73m2 decrease of residual renal CCl (OR =0.98; 95% CI: 0.96-0.99) were independently associated with higher PPCl (> 58 ml/day). CONCLUSION: Higher LBMI was independently associated with higher , indicating that better nutritional status dominates peritoneal protein metabolism in PD patients.

Associations between serum mineral metabolism parameters and mortality in patients on peritoneal dialysis.

AIM: Disturbances in mineral metabolism markers are common in patients with chronic kidney disease but there is no consensus on the association between these markers and clinical outcomes. This study investigated associations between mineral metabolism parameters and mortality in Chinese peritoneal dialysis (PD) patients. METHODS: This was a single-centre retrospective cohort study. Incident PD patients between 1 January 2006 and 31 December 2013 with baseline phosphate, albumin-corrected calcium, and calcium-phosphate product data were enrolled. Associations between these parameters and all-cause and cardiovascular mortality were assessed using multivariable-adjusted Cox models. RESULTS: Of 1662 patients (mean age: 47.4 ± 15.3 years), 59.3% were male and 23.8% had diabetes. Over a median 38.1 month (interquartile range: 21.3-59.7 months) follow-up period, 382 (23.0%) patients died. After adjusting for confounders, the higher serum phosphate level (>1.78 mmol/L) and calcium-phosphate product level (≥4.4 mmol2 /L2 ) were significantly associated with an increased risk for all-cause mortality (hazards ratio (HR) = 1.818, 95% CI = 1.379-2.396 and HR = 1.735, 95% CI = 1.261-2.386) and cardiovascular mortality (HR = 2.069, 95% CI = 1.428-2.998 and HR = 2.175, 95% CI = 1.450-3.262), respectively. While each 1 mmol/L higher baseline albumin-corrected calcium level was associated with an 14.3% (95% CI = 0.749-0.981) lower risk for all-cause mortality after adjusting for potential confounders. CONCLUSION: Abnormalities in mineral metabolism markers, particularly higher serum phosphate and calcium-phosphate product levels, at the commencement of PD were independently associated with increased all-cause and cardiovascular mortality in this cohort of PD patients.

Urgent-start peritoneal dialysis for patients with end stage renal disease: a 10-year retrospective study.

BACKGROUND: Urgent-start peritoneal dialysis (PD) can help patients with end-stage renal diseases (ESRD) that are referred late to dialysis. However, catheter patency and related complications of urgent-start PD have not been thoroughly clarified. We investigated the clinical outcomes of urgent-start PD in a Chinese cohort. METHODS: We enrolled ESRD patients who received urgent-start PD (starting PD within 14 days after catheter insertion) in our center from January 1, 2006 to December 31, 2014, and followed them up for 10 years. The primary outcome was catheter failure. Secondary outcomes included short-term and long-term complications related to urgent-start PD. RESULTS: Totally 2059 patients (58.9% male, mean age 47.6 ± 15.9 years) were enrolled. Few perioperative complications were observed, including significant hemorrhage (n = 3, 0.1%) and bowel perforation (n = 0). Early peritonitis occurred in 24 (1.2%) patients (0.28 episodes per patient-year). Within the first month after catheter insertion, functional catheter malfunction occurred in 85 (4.1%) patients, and abdominal wall complications (including hernia, hydrothorax, hydrocele, and leakage) in 36 (1.7%) patients. During a median 36.5 (17.7-61.4) months of follow-up, 75 (3.6%) patients experienced catheter failure, and 291 (14.1%) had death-censoring technique failure. At the end of 1-month, 1 -year, 3-year, and 5-year, catheter patency rate was 97.6, 96.4, 96.2, 96.2%; and technique survival rate was 99.5, 97.0, 90.3, 82.7%, respectively. After adjusting for confounders, every 5-year increase in age was associated with 19% decrease of risk for catheter failure (hazard ratio [HR]: 0.81, 95% confidence interval [CI]: 0.73-0.89). Male sex (HR: 1.43, 95% CI: 1.00-2.04), diabetic nephropathy (HR: 1.56, 95% CI: 1.08-2.25) and low hemoglobin levels (HR: 0.89, 95% CI: 0.81-0.98) were independent risk factors for abdominal wall complications. CONCLUSIONS: Urgent-start PD is a safe and efficacious option for unplanned ESRD patients. A well-trained PD team, a standardized catheter insertion procedure by experienced nephrologists, and a carefully designed initial PD prescription as well as comprehensive follow-up care, might be essential for the successful urgent-start PD program.