Effect of the interaction between estimated glomerular filtration rate and serum uric acid on all-cause and cardiovascular mortality in patients on peritoneal dialysis

Objective To explore the effect of the interaction between estimated glomerular filtration rate (eGFR) and serum uric acid (SUA) on all-cause and cardiovascular mortality in patients on peritoneal dialysis (PD). Methods Patients who performed PD catheterization at the PD center of the First Affiliated Hospital of Sun Yat-sen University and had initiated PD therapy for over 3 months from January 2006 to December 2016 were enrolled and followed up until December 2018. Demographic data, baseline clinical and laboratory examination results of the patients were collected. Kaplan-Meier survival curve and Cox regression analysis were used to explore the correlation between SUA and all-cause mortality, cardiovascular mortality in different eGFR groups of PD patients. Results A total of 2 124 PD patients were enrolled with age of (47.0±15.2) years, among whom 1 269 patients were male and 536 patients had diabetes. The SUA level was (429±96) μmol/L and the median level of eGFR was 6.69(5.17, 8.61) ml?min-1?(1.73 m2)-1. After a median follow-up time of 42 months, 554 patients died, among whom 275 patients were cardiovascular death. The Cox regression analysis revealed that there was a significant interaction between eGFR and SUA on all-cause mortality (P=0.043). The Kaplan-Meier curve showed that the tertile 1 (SUA＜384 μmol/L) and tertile 3 (SUA＞460 μmol/L) group had significantly higher all-cause mortality (P=0.009) than the reference group of tertile 2 (SUA 384-460 μmol/L) in the higher eGFR group [eGFR＞6.69 ml?min-1?(1.73 m2)-1]but not in the lower eGFR. After adjusting for relevant demographic data, complications, biochemical results and other variables, in patients with higher eGFR, the risk of all-cause mortality increased by 0.2% (HR=1.002, 95%CI 1.000-1.003, P=0.019) for every 1 μmol/L increase in SUA. In addition, compared with the tertile 2 reference group, the tertile 3 group was independently correlated with higher risk of all-cause mortality (HR=1.670, 95%CI 1.242-2.245, P=0.001). Conclusions The eGFR and SUA level significantly interacts with all-cause mortality, and the higher SUA level in higher eGFR group is an independent risk factor for all-cause mortality in PD patients.     

Effect of serum uric acid level on prognosis in maintenance hemodialysis patients

Objective To analyze the relationship between serum uric acid (SUA) level and clinical indicators in maintenance hemodialysis (MHD) patients, and explore its influence on all-cause mortality and cardiovascular mortality. Methods This study was a retrospective cohort study. Patients who received MHD from the blood purification center of the Third Affiliated Hospital of Sun Yat-sen University from January 1, 2011 to December 30, 2015 were enrolled in the queue. They were divided into 3 groups according to the first and third quantile of the SUA level quartiles, and the baseline data of clinical and laboratory examinations were compared. The correlation between SUA level and clinical indicators was analyzed by Pearson correlation coefficient. Kaplan-Meier method and Cox proportional hazard regression model were used to examine the association between SUA and all-cause mortality and cardiovascular mortality in MHD patients. Results A total of 201 patients were enrolled in the study. The age of the patients was (56.9±16.7) years and the baseline SUA level was (531.1±137.9) μmol/L. Patients were divided into 3 groups with the first quantile (442 μmol/L) and the third quantile (620 μmol/L) of the SUA quartiles as the boundary points: group 1 (SUA＜442 μmol/L, n=52), group 2 (SUA 442-620 μmol/L, n=101) and group 3 (SUA＞620 μmol/L, n=48). The results showed that the patients in group 1 were older and had more proportion of patients with diabetes mellitus and cardiovascular diseases than those in group 3 (all P＜0.05). Compared to group 3, the serum albumin, serum phosphorus and serum creatinine were lower in group 1, while the hypersensitive C-reactive protein was higher (all P＜0.05). Pearson correlation analysis showed that SUA level was positively correlated with albumin (r=0.135, P=0.047), blood phosphorus (r=0.269, P＜0.001) and serum creatinine (r=0.333, P＜0.001), and negatively correlated with hypersensitive C-reactive protein (r=-0.216, P=0.002). After a median follow-up of 49.8 months, 66(32.8%) all-cause deaths and 32(15.9%) cardiovascular deaths were recorded. Kaplan-Meier method showed that with the decrease of SUA, all-cause mortality (Log-rank χ2=18.27, P＜0.001) and cardiovascular mortality (Log-rank χ2=15.04, P=0.001) increased. After adjusting for age, gender, comorbidity and other factors using the Cox proportional hazards model, the all-cause mortality and cardiovascular mortality decreased by 20.1% (HR=0.799, 95% CI 0.651-0.980, P=0.031) and 29.6% (HR=0.704, 95% CI 0.524-0.946, P=0.020) for each 100 μmol/L increase in baseline SUA. Compared to group 1, all-cause mortality (HR=0.332, 95%CI 0.142-0.774, P=0.011) and cardiovascular mortality (HR=0.140, 95%CI 0.030-0.657, P=0.013) were lower in the group 3. Conclusion Low SUA level increases the risk of all-cause mortality and cardiovascular mortality in MHD patients.     

Associations of low serum total bilirubin level with all-cause mortality and cardiovascular mortality in peritoneal dialysis patients

Objective To investigate the association of low serum total bilirubin (TBIL) level with all-cause mortality and cardiovascular mortality in peritoneal dialysis patients. Methods As a single-center, retrospective, cohort study, all the patients who underwent peritoneal dialysis catheterization in the Department of Nephrology, the First Affiliated Hospital of Sun Yat-sen University and started peritoneal dialysis for more than 3 months from January 1, 2006 to December 31, 2010 were included. Demographics, baseline clinical and laboratory test results were collected. All patients were followed up until December 31, 2012. Patients were divided into 4 groups according to their baseline serum TBIL levels (interquartile range). Kaplan-Meier method was used to compare the survival rate of each group. Cox regression model was used to analyze the association of TBIL with all-cause mortality and cardiovascular mortality. Logistic regression was used to analyze the influencing factors of low TBIL level. Results A total of 880 peritoneal dialysis patients with baseline TBIL data were enrolled in this study, with age of (48.0±15.4) years old, among whom 59.0% were male. Median TBIL was 4.5 μmol/L and interquartile range was 3.4-5.8 μmol/L. The comparison between TBIL quartile groups showed that the difference in proportion of diabetics, Charlson comorbidity index, hemoglobin, serum albumin, serum calcium, intact parathyroid hormone, urea nitrogen, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) was statistically significant (all P＜0.05), while the difference in body mass index (BMI), estimated glomerular filtration rate, serum creatinine, urea nitrogen, uric acid and phosphorus was not statistically significant. After a median follow-up of 31 months, 194 patients died, 104 of which were cardiovascular deaths. Kaplan-Meier curves showed higher all-cause mortality in patients with TBIL≤3.4 μmol/L (Q1 group) (P=0.032) and there was no statistical difference in the cardiovascular mortality among different groups. After adjusting for biochemical indicators such as demographics, comorbidities, and liver function, taking baseline TBIL Q2 level (3.4＜TBIL≤4.5 μmol/L) as a reference, the hazard ratio for all-cause death in patients with TBIL≤3.4 μmol/L was 1.702 (95%CI 1.093-2.650, P=0.019), and the hazard ratio for cardiovascular death was 1.760 (95%CI 0.960-3.227, P=0.068). Multiple logistic regression analysis results showed that diabetes (OR=1.065, 95%CI 1.010-1.122, P=0.019) and high BMI (OR=1.838, 95%CI 1.056-3.197, P=0.031) were risk factors for baseline serum TBIL≤3.4 μmol/L. However, high hemoglobin (OR=0.990, 95%CI 0.982-0.998, P=0.011), high serum albumin (OR=0.950, 95%CI 0.916-0.985, P=0.006) and high ALT (OR=0.998, 95%CI 0.976-0.999, P=0.036) were the protective factors for patients with baseline serum TBIL≤3.4 μmol/L. Conclusion Baseline serum TBIL≤3.4 μmol/L in peritoneal dialysis patients is independently associated with all-cause mortality, and is not significantly associated with cardiovascular mortality; and baseline serum TBIL≤3.4 μmol/L occurred is associated with diabetes, high body mass index, low levels of hemoglobin, serum albumin and ALT.     

Associations between home blood pressure and mortality in peritoneal dialysis

Objective To investigate the association between the home blood pressure (BP) and morality in peritoneal dialysis (PD). Methods PD patients from the First Affiliated Hospital of Zhejiang University from January 1, 2008 to June 30, 2016 were studied. Over the first 6 months PD therapy, systolic SB (SBP) and diastolic BP (DBP) averaged as 5 (＜120 to≥150 mmHg in 10 mmHg increments) and 4 (＜70 to≥90 mmHg in 10 mmHg increments) categories, respectively, as well as continuous measures. All-cause and cardiovascular mortality were assessed by using Cox regression models adjusted for demographics, laboratory measurements, comorbid conditions and antihypertensive medications. The relationships between home BP and all-cause and cardiovascular mortality were assessed by restricted cubic spline regression model. Results A total of 1663 PD patients were included with a median follow-up of 29.9 months, in which 737 patients (44.3%) were female. The SBP and DBP were (135.2±15.8) mmHg and (83.1±10.5) mmHg, respectively. Two hundred and twenty-one PD patients died during the study period, of which 102 patients (46.2%) died of cardiac-cerebral vascular events. With 130≤SBP＜140 mmHg as a refernece, SBP≥150 mmHg (HR=1.83, 95%CI 1.19-2.82, P=0.005) and SBP＜120 mmHg (HR=2.05, 95%CI 1.29-3.27, P＜0.001) were associated with significantly higher risks of all-cause morality, but not cardiovascular morality. With 80≤DBP＜90 mmHg as a refernece, patients with DBP≥90 mmHg exhibited significantly higher risks of all-cause mortality (HR=1.80, 95%CI 1.21-2.68, P=0.009). SBP presented a U-shaped association with all-cause mortality. DBP presented a J-shaped association with all-cause mortality. Conclusions Higher SBP, lower SBP and higher DBP are associated with higher risks of all-cause mortality in PD patients. However, neither SBP nor DBP is observed statistically significant relationship with the risk of cardiovascular mortality. Further prospective and randomized clinical trials are needed to determine the optimal BP targets and improve the management of hypertension in PD patients.     

Relationship between coronary artery calcification and outcomes in maintenance hemodialysis patients

Objective To evaluate the relationship between coronary artery calcification (CAC) and outcomes in maintenance hemodialysis (MHD) patients. Methods Eighty-six patients who were on MHD between October 2014 and May 2015 in the blood purification center of our hospital were enrolled prospectively. CAC was measured and scored by multiple slice computed tomography (MSCT). According to the CAC score (CACs), the patients were divided into mild CAC (CACs＜100) group and severe CAC (CACs≥100) group. Kaplan-Meier analysis was performed to analyze the survival rates of the two groups, and a COX proportional hazards regression model was used to estimate the risk factors of all-cause mortality and cardiovascular disease mortality in MHD patients. Results Severe CAC (CACs≥100) was present in 62.8% (54/86) patients. The median of follow-up duration was 28.9(23.8, 29.4) months. During the follow up, 2(6.3%) patients in CACs＜100 group and 18 (33.3%) patients in CACs≥100 group died. Kaplan-Meier survival analysis demonstrated that patients in CACs≥100 group had higher all-cause mortality and cardiovascular mortality as compared with patients in CACs＜100 group (P=0.007, P=0.030). Multivariate COX regression analysis demonstrated that CACs≥100 (HR=7.687, 95%CI 1.697-34.819, P=0.008) and low single-pool Kt/V (HR=0.092, 95%CI 0.020-0.421, P=0.002) were independent risk factors for all-cause mortality. Old age (HR=1.192, 95%CI 1.100-1.291, P＜0.001), short duration of dialysis (HR=0.598, 95%CI 0.445-0.804, P=0.001), low 25-hydroxy vitamin D3 (HR=0.461, 95%CI 0.326-0.630, P＜0.001), and low total cholesterol (HR=0.405, 95%CI 0.213-0.772, P=0.006) were independent risk factors for cardiovascular disease mortality. Conclusions The CACs is significantly related with overall survival in MHD patients. Large multicenter prospective studies are to be evaluated the association between CACs and long-term survival in MHD patients.     

Serum phosphorus variation is associated with mortality in maintenance hemodialysis patients

Objective To investigate the relationship between serum phosphorus variability and mortality in maintenance hemodialysis (MHD) patients. Methods A total of 502 MHD cases from Renji hospital hemodialysis center were registered in Shanghai Registry Network from January 2007 to April 2015. They were recruited with general information, laboratory results and outcomes. According to their median of coefficient of variation (CV) of blood phosphorus, the patients were divided into high variation group (CV≥0.226 mmol/L) and low variation group (CV＜0.226 mmol/L). The relationship of serum phosphorus CV with all-cause mortality and cardiovascular disease mortality was assessed respectively. Results The average age was (63.9±14.6) years, the median dialysis age was 82.0 (43.0, 139.0) months, 118 patients (23.5%) died for all cause and 64 patients (12.7%) died for cardiovascular disease. Compared with patients in low phosphorus variation group, patients had a higher all-cause mortality in high phosphorus variation group (27.7% vs 19.3%, P=0.028). Higher cardiovascular disease mortality was observed in high variation group as well, but this difference was no statistical significant (15.4% vs 10.0%, P=0.082). COX regression analysis showed that ＞60 years of age (HR=2.762, 95%CI 1.707-4.468, P＜0.001), low hemoglobin (HR=0.466, 95%CI 0.317-0.686, P＜0.001), low albumin (HR=0.555, 95%CI 0.366-0.840, P=0.005), high CV of phosphorus (HR=1.479, 95%CI 1.023-2.139, P=0.037) were independent risk factors for all-cause mortality. Moreover, ＞60 years of age (HR=2.666, 95%CI 1.469-4.837, P=0.001), low hemoglobin (HR=0.480, 95%CI 0.238-0.801, P=0.005), and high CV of phosphorus (HR=1.655, 95%CI 1.003-2.729, P=0.049) were independent risk factors for cardiovascular disease mortality. There was no significant statistical difference between patients phosphorus on target and patients phosphorus below target in all-cause disease mortality (P=0.065) and cardiovascular disease mortality (P=0.425). High variation group whose phosphorus on target had higher all-cause mortality and cardiovascular disease mortality than those in low variation group (29.2% vs 16.9%, P=0.047; 15.0% vs 6.0%, P=0.033). Kaplan-Meier method showed that patients with high phosphorus variation had higher all-cause (P=0.023) and cardiovascular disease mortality (P=0.047) than patients with low phosphorus variation. Conclusions The high CV of phosphorus is independently correlated with all-cause and cardiovascular disease mortality. Patients with standard-reaching phosphorus in the low variation group have a lower mortality. A serum phosphorus level sustainably reaching the standard may improve the survival in MHD patients.     

Effects of serum magnesium level on mortality in maintenance hemodialysis patients

Objective To investigate the effects of serum magnesium level on all-cause mortality and cardiovascular and cerebrovascular diseases mortality in maintenance hemodialysis (MHD) patients. Methods Clinical data of MHD patients in Shaoxing People's Hospital from June 1, 2016 to June 30, 2018 were collected retrospectively. The patients were divided into low magnesium group (serum magnesium≤0.96 mmol/L), medium magnesium group (serum magnesium 0.97-1.07 mmol/L) and high magnesium group (serum magnesium≥1.08 mmol/L) according to the tertile of mean serum magnesium level. The differences of clinical data and laboratory results were compared among the three groups. Kaplan-Meier method was used to draw the survival curves, and log-rank test was used to compare the survival rate differences. Multivariate Cox regression was used to analyze the relationship between serum magnesium and all-cause mortality and cardiovascular and cerebrovascular diseases mortality in MHD patients. Results A total of 332 patients [194 males (58.4%)] were included in this study, with a median age of 63(51, 72) years and a median follow-up time of 36(20, 45) months. Kaplan-Meier survival analysis showed that the all-cause survival rate and cardiovascular and cerebrovascular diseases survival rate in the low magnesium group were lower than those in the medium magnesium group and the high magnesium group (Log-rank χ2=36.286, P＜0.001; Log-rank χ2=20.145, P＜0.001; respectively). After adjusting for multiple confounding factors, the results of multivariate Cox regression analysis suggested that low serum magnesium was an independent risk factor for all-cause death and cardiovascular and cerebrovascular diseases death in MHD patients. The risk of all-cause death and cardiovascular and cerebrovascular diseases death in the low magnesium group were significantly higher than those in the high magnesium group (HR=2.925, 95%CI 1.352-6.330, P=0.006; HR=3.821, 95% CI 1.394-10.473, P=0.009; respectively). Conclusions Hypomagnesemia may be an independent risk factor for all-cause death and cardiovascular and cerebrovascular diseases death in MHD patients. Low serum magnesium level increases the risk of all-cause death and cardiovascular and cerebrovascular diseases in MHD patients.     

Correlation analysis of low-level serum uric acid and cardiovascular events in patients on peritoneal dialysis

Background

The impact of serum uric acid (SUA) on development of cardiovascular disease (CVD) in patients undergoing peritoneal dialysis (PD) remains controversial, especially the impact of hypouricemia (HUA) on CVD. The aim of our study was to investigate the influence of low-level SUA on cardiovascular (CV) events in PD patients.

Methods

A retrospective cohort study was conducted.728 PD patients from February 1, 2010 to May 31, 2019 were enrolled. All demographic and laboratory data were collected at baseline and 6 months after PD treatment. The study cohort was divided into four groups according to SUA level (μmol/L) after 6 months of PD: Group1 (<?360), Group2 (360–420), Group3 (420–480), Group4 (≥?480). The clinical characteristics of each group were analyzed. With Group2 as reference, logistic regression analysis was performed to investigate the correlation between SUA levels and risk of CV events in patients undergoing PD. Use Kaplan–Meier method to generate CV events risk graph.

Results

728 patients were enrolled in this study, including 403 (55.4%) males and 325 (44.6%) females, with an average age of 48.66?±?13.98 years; of which 158 (21.7%) patients developed CV events. Multivariate COX regression showed that after adjusting for multiple clinical factors, Group1 (HR?=?1.92, 95% CI 1.17–3.15, P?=?0.01), Group3 (HR?=?1.89, 95% CI 1.13–3.15, P?=?0.015), and Group4 (HR?=?2.38, 95% CI 1.35–4.19, P?=?0.003) are all independent risk factors for developing CV events. The Kaplan–Meier risk curve of CV events showed that the risk of CV events in the Group1, Group3 and Group4 were significantly higher (Log-Rank?=?12.67; P?=?0.005). Restricted cubic spline (RCS) showed that SUA level is non-linearly associated with the risk of CV events, showing an U-shaped curve (\(\chi_{4}^{2}\)=13.3 P?=?0.01).

Conclusions

Our study suggested that patients with SUA level less than 360 μmol/L also exhibited the higher risk for developing CV events, an U-shaped association between SUA level and risk of CV events in patients undergoing PD. Both SUA levels below 360 μmol/L and above 420 μmol/L were found to be significant risk factors for developing CV events in patients undergoing long-term PD.

     

Prognostic analysis of aged end-stage renal disease patients receiving hemodialysis and peritoneal dialysis

Objective To compare the survival rates of elderly hemodialysis (HD) and peritoneal dialysis (PD) patients and identify their independent prognostic predictors. Methods Patients aging ＞60 years old who initiated dialysis between January 1, 2008 and December 31, 2014 were included. Propensity score method (PSM) was applied to adjust for selection bias. Kaplan-Meier method was used to obtain survival curves and a Cox regression model was used to evaluate risk factors for mortality. Results 447 eligible patients with maintenance dialysis were identified, 236 with hemodialysis and 211 with peritoneal dialysis. 174 pairs of patients were matched, with the baseline data [age, gender, Charlson comorbidity index (CCI) and the primary disease] between two groups showing no significant difference (P＞0.05). Cardiovascular events, cerebrovascular events and infection were major causes of death in both groups and there was no significant difference in the causes of death between two groups (P＞0.05). The overall survival rates at 1 and 5 year were 93.6% and 63.4% respectively in HD group, 91.9% and 61.5% in PD group. The differences of total survival rates between HD and PD patients were not significant (P＞0.05). Cox regression analysis showed age(≥80 year) (P＜0.001, HR=1.058, 95%CI 1.028-1.088), diabetic nephropathy (P=0.001, HR=2.161, 95%CI 1.384-3.373), CCI≥5 (P=0.007, HR=1.935, 95%CI 1.201-3.117) were independent prognostic risk predictors in HD patients; age(≥80 year) (P=0.022, HR=1.043, 95%CI 1.006-1.081), serum albumin level ＜ 35 g/L (P=0.025, HR=1.776, 95%CI 1.075-2.934), and prealbumin (P=0.012, HR=0.968, 95%CI 0.944-0.993) were independent prognostic predictors in PD patients. Conclusions The differences of total survival rates between aged HD and PD patients are not significant. Age, diabetic nephropathy, CCI≥5 and age, serum albumin＜35 g/L, prealbumin＞30 g/L respectively influence the survival of elderly HD and PD patients.     

Risk factors for mortality in diabetic peritoneal dialysis patients

Objective To investigate the risk factors of all-cause mortality in diabetic patients on peritoneal dialysis (PD). Methods As a single-center retrospective cohort study, all incident PD patients who were catheterized at the First Affiliated Hospital of Nanchang University between November 1, 2005 and February 28, 2017 were included. Patients were divided into diabetes mellitus group (DM group) and non-diabetes mellitus group (NDM group). Outcomes were analyzed by Kaplan-Meier method. Multivariate Cox proportional hazards models were utilized to assess the risk factors of all-cause mortality. Results A total of 977 patients were enrolled. Compared with NDM group, patients in DM group were older (47.5±14.4 vs 59.3±11.3, P＜0.01), had more cardiovascular disease (CVD) (7.5% vs 20.3%, P＜0.01), higher levels of serum hemoglobin (78.2±17.2 vs 82.3±14.6 g/L, P＜0.01) , and lower levels of serum albumin (36.1±5.0 vs 32.7±5.6 g/L, P＜0.01). The one-, three- and five-year patient survival rates of DM and NDM group were 89.7%, 56.0%, 31.9% and 94.7%, 81.3%, 67.4%, respectively.Survival rate was significantly lower in DM group than in NDM group ( χ2=63.51, P＜0.01). Stratified analysis showed that DM group had significant lower survival rate than NDM group in patients younger than 70 years old ( χ2= 73.35, P＜0.01), while survival rate was similar between the two groups patients older than 70 years old ( χ2= 0.003, P=0.96). Multivariate Cox proportional hazards model analysis showed that DM (HR: 1.74, 95%CI: 1.27-2.38, P＜0.01), age (HR: 1.05, 95%CI: 1.04-1.06, P＜0.01), leukocyte (HR: 1.06, 95%CI: 1.00-1.12, P=0.04) and triglyceride (HR: 1.19, 95%CI: 1.07-1.32, P＜0.01) were all independent risk factors for all-cause mortality of PD patients. However, age (HR: 1.05, 95%CI: 1.04-1.07, P＜0.01) and alkaline phosphatase (HR: 1.01, 95%CI: 1.00-1.01, P=0.02) were independent risk factors for all-cause mortality of diabetic patients. Conclusions Long-term survival rate was lower in diabetic PD patients than in non-diabetic PD patients. DM, age, leukocyte and triglyceride were independent risk factors of mortality in PD patients. Age and alkaline phosphatase were independent risk factors of mortality in diabetic patients.     

透析开始残余肾功能与维持性透析患者预后的关系

目的 评估终末期肾病患者透析开始残余肾功能与维持性透析预后的关系.方法 收集2005年1月1日至2009年9年30日新进入血透或腹透治疗的终末期肾病成年患者资料,随访至2010年3月31日.根据透析开始时估算肾小球滤过率(eGFR)分为≥10.5、8～＜10.5、6～＜8、＜6 ml· min-1·(1.73 m2)-1 4组.eGFR评估采用MDRD简化公式.终点事件为全因死亡和心脑血管死亡.结果 (1)共562例患者入选,透析开始中位eGFR为5.60(2.26～12.62) ml· min-1·(1.73 m2)-1;中位随访时间为17(0～58)个月 ;死亡141例,中位生存期为45.48(43.05 ～47.90)个月.随着透析开始eGFR下降,4组患者Scr、BUN、血尿酸(SUA)、血前白蛋白、血磷、血钙磷乘积、整段甲状旁腺激素(iPTH)、平均动脉压(MAP)逐渐升高 ;血红蛋白(Hb)、男性患者比例、并发糖尿病比例、Charison并发症指数≥5比例逐渐下降,差异均有统计学意义(均P＜ 0.05).随着透析开始eGFR下降,并发左室肥大比例有逐渐升高趋势,但差异无统计学意义.(2)Kaplan-Meier生存曲线显示4组患者总体生存率差异无统计学意义.Cox回归分析显示透析开始eGFR与透析预后无显著关系.对透析非早期(＞3个月)死亡患者进行Kaplan-Meier生存曲线分析,4组患者1年生存率差异无统计学意义.多因素Cox回归分析显示透析开始eGFR是透析1年生存预后的保护因素(HR =0.791,95％CI 0.669～0.935,P＜0.01).(3)以心脑血管死亡为终点事件,多因素Cox回归分析显示,透析开始eGFR是心脑血管生存预后(HR =0.868,95％CI 0.777～0.971,P＜0.05)和1年心脑血管生存预后(HR=0.937,95％CI 0.851～0.992,P＜0.05)的保护因素.(4)多因素Cox回归分析显示,透析开始eGFR增高1 ml·min-1·(1.73 m2)-1,腹膜透析患者死亡风险下降10％(HR=0.90,95％CI 0.81～0.99,P＜ 0.05).血液透析方式4组患者Kaplan-Meier生存率分析显示,差异有统计学意义(Log-rank检验,P=0.047),8～＜10.5组生存率最低,与6～＜8组、＜6组差异有统计学意义(Log-rank检验,P=0.033,P=0.005).多因素Cox回归分析并未显示透析开始eGFR与预后相关.多因素Cox回归分析提示透析开始eGFR增高1 ml·min-1·(1.73 m2)-1,慢性肾小球肾炎患者和慢性肾小球肾炎腹膜透析患者死亡风险分别降低16.6％(HR=0.834,95％CI 0.736～0.946,P＜0.01)和32.1％(HR=0.679,95％CI 0.535～0.862,P＜0.01).以心脑血管死亡为终点,多因素Cox回归分析显示透析开始eGFR增高1 ml·min-1·(1.73 m2)-1,慢性肾小球肾炎患者心脑血管死亡风险下降18.2％(HR=0.818,95％CI 0.669～0.999,P＜0.05).结论 本组患者透析时机明显晚于国际透析指南的标准.随着透析开始eGFR降低,并发症增多及程度加重.早期透析可能无法提高透析患者的总体生存率,但可能有助于改善患者心脑血管及1年总体生存预后和腹膜透析、慢性肾小球肾炎患者的预后.     

Association of serum magnesium with cardiovascular mortality and all-cause mortality in peritoneal dialysis patients

Objective To investigate the association of serum magnesium with cardiovascular disease (CVD) and all-cause mortality in peritoneal dialysis patients. Methods A retrospective study was performed in patients who initiated peritoneal dialysis from January 1, 2013 to July 31, 2019 in the Shaoxing People's Hospital. According to the standard of serum magnesium, the patients were divided into control group (Mg≥0.7 mmol/L) and low-magnesium group (Mg﹤0.7 mmol/L). The differences in baseline biochemical variables, comorbidities, medications, and clinical outcomes between the two groups were compared. Logistic regression was used to analyze the related factors of hypomagnesemia. Kaplan-Meier survival analysis and Fine-Gray model were used to compare the difference in cumulative survival rate between the two groups. Cox regression model and competitive risk model were used to analyze the risk factors of all-cause mortality and CVD mortality. Results A total of 381 peritoneal dialysis patients were enrolled in this study. Among them, 321 patients were in control group and 60 patients in low-magnesium group. The total median follow-up time was 27(15, 43) months. There were significant differences in serum albumin, magnesium, phosphorus, intact parathyroid hormone, low-density lipoprotein chloesterol, high sensitivity C-reactive protein and 4-hour dialysate-to-plasma creatinine (4 h D/Pcr) between the two groups. CVD was the main cause of death in patients on peritoneal dialysis. Multivariate logistic regression analysis showed that hypoalbuminemia (OR=0.901, 95%CI 0.831-0.976, P=0.011), hypophosphatemia (OR=0.217, 95%CI 0.080-0.591, P=0.003), higher hsCRP (OR=1.276, 95%CI 1.066-1.528, P=0.008), and higher 4 h D/Pcr (OR=1.395, 95%CI 1.014-1.919, P=0.041) were independent risk factors for patients with hypomagnesemia. Kaplan-Meier survival curve analysis showed the cumulative survival rate of patients in low-magnesium group was significantly lower than that of control group (Log-rank χ2=5.388, P=0.020). Fine-Gray model analysis showed the cumulative CVD survival rate of low-magnesium group was significantly lower than that of control group (Gray=6.915, P=0.009). Multivariate-corrected Cox regression model and competitive risk model analysis showed that higher serum magnesium level was a protective factor for all-cause mortality and CVD mortality when serum magnesium was used as a continuous variable (HR=0.137, 95%CI 0.020-0.946, P=0.044; SHR=0.037, 95%CI 0.002-0.636, P=0.023, respectively). Hypomagnesemia was an independent risk factor for all-cause mortality and CVD mortality when serum magnesium was used as categorical variable (HR=1.864, 95%CI 1.044-3.328, P=0.035; SHR=2.117, 95%CI 1.147-3.679, P=0.029, respectively). Conclusions Hypomagnesemia is susceptible to peritoneal dialysis patients with hypoalbuminemia, hypophosphatemia, higher hsCRP and higher peritoneal transport characteristics. Hypomagnesemia is an independent risk factor for CVD mortality and all-cause mortality in peritoneal dialysis patients.     

Relationship between abdominal aortic calcification and outcomes in maintenance hemodialysis patients

Objective To investigate the relationship between abdominal aortic calcification (AAC) and outcomes in maintenance hemodialysis (MHD) patients. Methods One hundred and seventy MHD patients in the dialysis center of the Second Hospital of Tianjin Medical University from June 2014 and October 2014 were enrolled prospectively. Abdominal aortic calcification (AAC) was measured using AAC score (AACS) by abdominal lateral plain radiography. According to the AACS, the patients were divided into mild AAC (AACS＜5) group and severe AAC (AACS≥5) group for comparison, and Kaplan-Meier analysis was used to compare their survival rates. Multivariable COX regression models were used to determine the risk factors of all - cause mortality and cardiovascular disease mortality in MHD patients. Results Severe AAC (AACS≥5) was present in 28.2% (48/170) patients. The median follow-up duration was 25.6 (22.0, 26.0) months. During the follow-up, 6 patients (4.9%) in AACS＜5 group and 14 patients (29.2%) in AACS≥5 group died. Kaplan-Meier analysis showed that patients in AACS≥5 group had higher all-cause mortality rate and cardiovascular disease mortality rate as compared with patients in AACS＜5 group (χ2=9.746,P=0.002; χ2=9.697,P=0.002). Multivariate COX regression analysis demonstrated that high AACS (HR=4.373, 95%CI 1.562-7.246, P=0.005) and hypoproteinemia (HR=0.886, 95% CI 0.797 - 0.985, P=0.025) were independent risk factors for all-cause mortality, while hypoproteinemia (HR=0.829, 95%CI 0.718-0.956, P=0.010) and low 1,25(OH)D3 (HR=0.769, 95% CI 0.627 - 0.944, P=0.012) were independent risk factors for cardiovascular disease mortality. Conclusions AAC is significantly associated with overall survival in MHD patients. To further evaluate the relationship between AAC and outcomes in MHD patients, multi-center and long term follow up studies of large sample size are necessary.     

Long-term survival analysis of the elderly peritoneal dialysis patients

Objective To analyze the clinical data of the elderly peritoneal dialysis (PD) patients in Peking Union Medical College Hospital (PUMCH), and to find the risk factors for the long-term survival. Methods Baseline data and the outcome of maintenance PD patients from 1996-03 to 2015-09-30 were collected for a retrospective cohort study. Patients were divided into the non-elderly group (＜65 years old), the 65-79 years old group and the ≥80 years old group, and were follow to 2016-09-30. The survival rate was calculated by Kaplan-Meier method and the risk factors of outcome were analyzed by the Cox's regression model. Results Among 577 PD patients, about 243(42.1%) were elderly patients, including 207 patients aged between 65 and 79 years (35.9%) and 36 patients aged 80 or more (6.2%). The most common primary disease causing PD was diabetic nephropathy (DN) for both elderly and non-elderly patients. The 1-year, 3-year, 5-year survival rate of patients aged between 65 and 79 years were 87.0%, 61.9%, 32.4% respectively, and 72.5%, 48.5%, 27.3% for the ≥80 years old group. The dominating reasons of death were cardiovascular events and infection. There was no difference of technical survival rates among three groups, and the most common reason for technical failure was peritonitis. For elderly patients, diabetes (HR=2.193, 95%CI 1.445-3.328, P＜0.001) and lower baseline serum albumin (HR=0.968, 95%CI 0.940-0.996, P=0.026) were independent risk factors for death. However, for non-elderly patients, diabetes (HR=3.746, 95%CI 2.149-6.529, P＜0.001) was the only independent risk factor for death. Conclusions Cardiovascular diseases and infection are the main reasons for death among the elderly PD patients in PUMCH. Diabetes and lower baseline serum albumin may predict the mortality of elderly PD patients independently. Better management of nutrition might improve survival in elderly PD patients.     

Effects of abdominal aortic calcification progression on outcomes in maintenance hemodialysis patients

Objective To investigate the effects of abdominal aortic calcification (AAC) progression on outcomes in maintenance hemodialysis (MHD) patients. Methods Patients who were on MHD between Jun. 2014 and Oct. 2014 in the dialysis center of the Second Hospital of Tianjin Medical University and finished the AAC examination at baseline and two years later were included prospectively. The progression of AAC by AAC score (AACs) at baseline and two years later was evaluated. According to the change of AACs, the patients were divided into rapid AAC progression group and non-rapid AAC progression group. The effect of AAC progression on outcomes in MHD patients in the follow-up period was investigated. Kaplan-Meier analysis was used to compare their survival rates. Multivariable Cox regression model was used to determine the risk factors of all-cause mortality, cardiovascular mortality and cardiovascular events. Results A total of 111 MHD patients were included, including 51 males and 60 females, aged (52.24±12.69) years. Baseline AAC prevalence was 45.9% (51/111), and median AACs was 0 (0, 5); After 2 years, the prevalence of AAC was 78.4% (87/111), and the median AACs was 6 (2, 11). There were 54 cases in the AAC rapid progression group (AACs change value＞2) and 57 cases in the non-rapid AAC progression group (AACs change value≤2). The median follow-up duration was 27.9(27.1, 28.0) months. Kaplan-Meier analysis showed that patients in rapid AAC progression group had a higher risk of mortality as compared to patients in non-rapid AAC progression group (Log-rank χ2=5.695, P=0.017). Multivariate Cox regression analysis demonstrated that high baseline AACs (HR=1.135, 95%CI 1.001-1.286, P=0.048), hypoalbuminemia (HR=0.789, 95%CI 0.640-0.972, P=0.026) were independent risk factors for all-cause mortality in MHD patients. High baseline AACs (HR=1.187, 95%CI 1.038-1.356, P=0.012), low spKt/V (HR=0.103, 95%CI 0.013-0.801, P=0.030) were independent risk factors for cardiovascular mortality in MHD patients. Low spKt/V (HR=0.018, 95%CI 0.003-0.115, P＜0.001), hypoalbuminemia (HR=0.736, 95%CI 0.608-0.890, P=0.002) were independent risk factors for cardiovascular events in MHD patients. Conclusions Abdominal aortic calcification progression may increase the risk of cardiovascular events and death in MHD patients. Severity of AAC, adequacy of dialysis, and nutritional status are predictors of outcomes in MHD patients.     

Effects of timing of dialysis initiation on the prognosis of peritoneal dialysis patients: a retrospective cohort study

Objective To analyze the effects of dialysis therapy initiation on the prognosis of peritoneal dialysis (PD) patients. Methods PD patients who were newly catheterization and long-term followed-up in Peking University Shenzhen Hospital from January 1, 2012 to March 25, 2019 were retrospectively analyzed. According to the estimate glomerular filtration rate (eGFR) at the time of patients catheterization, the patients were divided into early-dialysis group [eGFR＞5.5 ml?min-1?(1.73 m2)-1] and late-dialysis group [eGFR≤5.5 ml?min-1?(1.73 m2)-1]. The endpoint events were transferred to other renal replacement therapy (such as hemodialysis, kidney transplantation) or death. Kaplan-Meier method was used to draw survival curve, and log-rank test was used to compare the difference of survival rate between the two groups. Cox proportional hazard model was used to analyze the influencing factors of all-cause death and technical death in PD patients. Results A total of 342 PD patients were enrolled in this study, and there were 165 cases and 177 cases in the early-dialysis and the late-dialysis group respectively. Compared with the early-dialysis group, the proportion of patients with diabetes and men, and the level of hemoglobin, serum calcium and CO2 binding capacity in the late-dialysis group were lower, while the incidence of hypertension, serum phosphorus, blood uric acid and blood urea nitrogen level were higher in the late-dialysis group (all P＜0.05). The median follow-up time was 33(16, 57) months. Kaplan-Meier survival analysis showed that the cumulative survival rate of late-dialysis group was significantly higher than that of early-dialysis group (Log-rank χ2=12.004, P＜0.001). After adjusting for gender, age of catheterization, body mass index (BMI), diabetes mellitus and hypertension, the risk ratio of all-cause death in the early-dialysis group was 1.950 times higher than that in the late-dialysis group (HR=1.950, 95%CI 1.019-3.730, P=0.044). Subgroup analysis showed that the timing of dialysis and the risk of end-point events were not affected by BMI, diabetes stratification and other factors (interactive P＞0.05), but there was interaction between dialysis time and catheter age (interactive P＜0.05). According to the age of catheterization, the risk of all-cause death were higher in the early dialysis group at a young age (≤48 years old) (HR=21.287, 95%CI 2.609-173.665, P=0.004). Conclusions The mortality rate of PD patients is higher in early-dialysis group, which is independent of gender, age, BMI, diabetes and hypertension. The difference is more distinct in low age group.     

Clinical features and treatment outcomes of early-onset peritoneal dialysis-associated peritonitis: a multi-center retrospective study

Objective To explore the clinical characteristics and treatment outcomes of early-onset peritoneal dialysis-associated peritonitis (EOP). Methods Clinical data of patients with peritoneal dialysis-associated peritonitis (PDAP) from 2013 to 2018 in four tertiary hospitals of Jilin province were collected retrospectively. According to whether the dialysis time of the first PDAP was ≤12 months or not, the subjects were divided into EOP group (≤12 months) and late-onset PDAP (LOP) group (＞12 months) , and clinical data, pathogenic bacteria, treatment outcomes of PDAP and prognosis of two groups were compared. Results A total of 575 patients were included, including 314 patients in the EOP group, with age of (56.53±15.57) years and 152 females (48.4%), and 261 patients in the LOP group, with age of (56.61±14.42) years old and 144 females (55.2%). Compared with LOP group, the proportion of pathogenic bacteria culture-negative in EOP group was higher and the proportion of streptococcal infection was lower (both P＜0.05). The initial treatment efficiency and cure rate of EOP group were higher than that of LOP group, while the extubation rate was lower than that of LOP group (all P＜0.05). Multivariate logistic analysis indicated that the cure rate of EOP was 79% higher than that of LOP (OR=1.79, 95%CI 1.13-2.82, P=0.012), and the extubation rate of EOP was 68% lower than that of LOP (OR=0.32, 95%CI 0.15-0.66, P=0.002). Kaplan-Meier survival curve showed that the cumulative rates of multiple PDAP, technical failure, all-cause death, and composite end points (technical failure or all-cause death) in EOP group were higher than those in LOP group (P≤0.001). After correcting for confounding factors by multivariate Cox proportional hazard regression, the risk of multiple PDAP, technical failure, all-cause death, and composite endpoint (technical failure or all-cause death) in EOP group was 2.02 times (HR=2.02, 95%CI 1.26-3.24, P=0.004), 2.53 times (HR=2.53, 95%CI 1.58-4.05, P＜0.001), 2.66 times (HR=2.66, 95%CI 1.70-4.16, P＜0.001) and 2.48 times (HR=2.48, 95%CI 1.78-3.43, P＜0.001) of LOP group respectively. Conclusion The treatment outcome of the first PDAP of EOP patients is good, but the long-term prognosis is poor.     

Prognostic analysis of end-stage renal disease patients without diabetes mellitus receiving hemodialysis and peritoneal dialysis

Objective To compare the prognosis of hemodialysis (HD) and peritoneal dialysis (PD) in end-stage renal disease (ESRD) patients without diabetes mellitus and identify related influencing factors. Methods Patients who started hemodialysis with an arteriovenous graft or fistula or PD in the First Affiliated Hospital of Zhengzhou University from January 1, 2013 to February 1, 2019 were included. They were followed up until May 1, 2019. The patients were divided into HD group and PD group according to the initial dialysis modality. Kaplan-Meier method was used to obtain survival curves, the Cox regression model was used to evaluate influence factors for survival rates, and the inverse probability of treatment weighting (IPTW) was used to eliminate influence of the confounders in the groups. Results There were 371 patients with maintenance dialysis enrolled in this study, including 113 cases (30.5%) in HD group and 258 cases (69.5%) in PD group. At baseline, the scores of standard mean difference (SMD) in age, body mass index (BMI), combined with cerebrovascular disease, Charlson comorbidity index (CCI), blood potassium, plasma albumin and hemoglobin between the two groups were greater than 0.1. The score of SMD decreased after IPTW, and the most data were less than 0.1, which meant that the balance had been reached between the two groups. The Kaplan-Meier survival curve showed that the cumulative survival rates had no significant difference for all-cause death before using IPTW between the two groups (Log-rank χ2=0.094, P=0.759). After adjusting for confounders with IPTW, the Kaplan-Meier survival curve showed that the cumulative survival rates still had no significant difference for all-cause death between the two groups (Log-rank χ2=2.090, P=0.150). Univariate Cox regression analysis showed that there was no significant difference between HD and PD on survival rates in ESRD patients without diabetes mellitus for all-cause death (PD/HD, HR=1.171, 95%CI 0.426-3.223, P=0.760). Multivariate Cox regression analysis showed that there was no significant difference between HD and PD on survival rates in ESRD patients without diabetes mellitus (PD/HD, HR=1.460, 95%CI 0.515-4.144, P=0.477), and high plasma albumin (HR=0.893, 95%CI 0.813-0.981, P=0.019) was an independent protective factor for survival in ESRD patients without diabetes mellitus. There was still no significant difference between HD and PD on survival rates in ESRD patients without diabetes mellitus after using IPTW (PD/HD, HR=1.842, 95%CI 0.514-6.604, P=0.348). Conclusion The difference of cumulative survival rates between HD and PD is not significant in ESRD patients without diabetes mellitus.     

Elevated serum uric acid is an independent risk factor for the loss of renal function

Objective To investigate the relationship between serum uric acid level and renal function decline by retrospective cohort study. Methods Through the physical examination system of the First People's Hospital of Foshan, the physical examination data from 2015 to 2018 of a public institution in Foshan city were obtained. The gender, age, blood cell analysis, liver function, serum creatinine, uric acid, fasting blood glucose were obtained. The change of eGFR (ΔeGFR=eGFR2018-eGFR2015) was analyzed. Results A total of 2505 subjects were followed up for four years. The subjects were divided into ΔeGFR ≥0 group and ΔeGFR＜0 group. There were 845 subjects in ΔeGFR ≥0 group, and 1660 subjects in ΔeGFR＜0 group. Compared with that in ΔeGFR＜0 group, the base-level of uric acid in ΔeGFR ≥ 0 group was higher [(349.48±87.62) μmol/L vs (325.72±82.58) μmol/L, t=6.669, P＜0.001], but the rate of uric acid decline was greater [-15.00(-53.50, 17.00) μmol/L vs 15.50(-18.00, 49.00) μmol/L, Z=-13.470, P＜0.001]. According to the levels of uric acid in 2015 and 2018, then the subjects were divided into four groups, normal to normal group (N-N, 1551 cases), normal change into high uric acid group (N-H, 299 cases), high uric acid drop to normal group (H-N, 238 cases), and high to high uric acid group (H-H, 417 cases). The ΔeGFR was -1.58(-4.17, 1.01) ml?min-1?(1.73 m2)-1 in N-N group, and -3.60(-7.24, -0.98）ml?min-1?(1.73 m2)-1 in N-H group, -0.20(-3.14, 3.27) ml?min-1?(1.73 m2)-1 in H-N group, -0.96(-4.07, 1.93) ml?min-1?(1.73 m2)-1 in H-H group, respectively. The ΔeGFR decreased most significantly in N-H group than the other three groups (χ2=103.130, P＜0.001). Multivariate logistic regression analysis showed that elevated uric acid was an independent risk factor for eGFR decline (OR=1.739, 95%CI 1.587-1.906, P＜0.001), while elevated indirect bilirubin (OR=0.968, 95%CI 0.943-0.993, P=0.013), elevated red blood cells (OR=0.815, 95%CI 0.680-0.976, P=0.026) were independent protective factors for eGFR decline. Conclusion Elevated uric acid is an independent risk factor for the decline of renal function. Good control of hyperuricemia is beneficial to the protection of renal function.     

Association between body-mass index and survival in peritoneal dialysis patients

Objective To evaluate the association between body-mass index and prognosis in peritoneal dialysis (PD) patients. Methods In this observational study of a single nephrology unit in Shanghai East Hospital, 81 incident continuous ambulatory peritoneal dialysis(CAPD) patients were included from Jan 2008 to Dec 2013, whom were followed-up by 36 months or until death. The patients were classified as underweight (BMI＜18.5kg/m2); normal weight (18.5～23.9kg/m2); overweight (24～27.9kg/m2) and obese (BMI≥28kg/m2). The patients and technique survival rates were estimated by Kaplan-Meier analysis. Cox proportional hazards analyses were used to elucidate relationship between BMI and all-cause mortality and technique failure in PD patients. Results The overall survival rate was similar between normal and overweight groups (P=0.96), but significantly lower in underweight group and obese group (P＜0.01 respectively). The overall technical survival rate of obese group was lower compare with normal group (P＜0.01). The main cause of technical failure was peritonitis (81.3%). BMI was positively correlated with albumin (r=0.24, P＜0.05), hemoglobin (r=0.56, P＜0.01), glucose(r=0.23, P＜0.05) and cholesterol (r=0.41, P＜0.01), but negatively correlated with Kt/V (r=-0.36, P＜0.01) and Ccr(r=-0.34, P＜0.01). In adjusted Cox proportional hazard mode 3, obese was independently associated with all-cause mortality (HR: 5.93, 95%CI: 1.10～31.79). Obese and peritonitis were independently associated with technical failure (HR: 10.33, 95%CI: 1.04～78.02 and HR: 2.74, 95%CI: 1.17～6.40 respectively). Conclusions Underweight and obese CAPD patients have poorer outcome. Obese CAPD patients also have lower technical survival rate. Obesity was an independent risk factor for all-cause mortality in CAPD patients.