Associations between different insulin resistance indices and the risk of all-cause mortality in peritoneal dialysis patients.

BACKGROUND: Insulin resistance (IR) is prevalent in individuals undergoing peritoneal dialysis (PD) and is related to increased susceptibility to coronary artery disease and initial peritonitis. In recent investigations, correlations have been found between indices of IR and the incidence of all-cause mortality in various populations. However, such correlations have not been detected among individuals undergoing PD. Hence, the present study's aim was to explore the connections between IR indices and the incidence of all-cause mortality in PD patients. METHODS: Peritoneal dialysis patients (n = 1736) were recruited from multiple PD centres between January 2010 and December 2021. Cox proportional hazards and restricted cubic spline regression models were used to evaluate the connections between the triglyceride-glucose (TyG) index, triglyceride-glucose/body mass index (TyG-BMI), and triglyceride/high-density lipoprotein cholesterol (TG/HDL-C) ratio and the occurrence of all-cause mortality. All three IR indices were integrated into the same model to assess the predictive stability. Furthermore, a forest plot was employed to display the findings of the subgroup analysis of PD patients. RESULTS: Overall, 378 mortality events were recorded during a median follow-up time of 2098 days. Among PD patients, a higher TyG index, TyG-BMI, and TG/HDL-C ratio were identified as independent risk factors for all-cause mortality according to Cox proportional hazards analyses (hazard ratio (HR) 1.588, 95% confidence interval (CI) 1.261-2.000; HR 1.428, 95% CI 1.067-1.910; HR 1.431, 95% CI 1.105-1.853, respectively). In a model integrating the three IR indices, the TyG index showed the highest predictive stability. According to the forest plot for the TyG index, no significant interactions were observed among the subgroups. CONCLUSION: Significant associations were found between the TyG index, TyG-BMI, and TG/HDL-C ratio and the incidence of all-cause mortality among PD patients. The TyG index may be the most stable of the three surrogate IR markers. Finally, a correlation was identified between IR and the risk of all-cause mortality in patients undergoing PD.

Association between systemic immune inflammation Index and all-cause mortality in incident peritoneal dialysis-treated CKD patients: a multi-center retrospective cohort study.

BACKGROUND: Chronic inflammatory disorders in peritoneal dialysis (PD) contribute to the adverse clinical outcome. Systemic immune inflammation index (SII) is the novel and convenient measurement that is positively associated with various diseases. However, scarce is known regarding the association between SII with all-cause mortality among PD patients. METHODS: In this multi-center retrospective cohort study, 1,677 incident patients with PD were enrolled. Eligible patients were stratified into groups based on SII level: tertile 1(< 456.76), tertile 2(456.76 to 819.03), and tertile 3(> 819.03). The primary endpoint was the all-cause mortality. Both Cox regression analysis and competing risk models were used to examine the association between SII and all-cause mortality. Subgroup analysis was performed to assess the influence of the SII tertiles on all-cause mortality in different subgroups. RESULTS: During the follow-up period of 30.5 ± 20.0 months, 26.0% (437/1,677) patients died, of whom the SII tertile 3 group accounted for 39.1% (171/437) of the deaths. Patients in the SII tertile 3 group had a higher all-cause mortality rate than patients in the SII tertile 1 and 2 groups (log-rank = 13.037, P < 0.001). The SII tertile 3 group was significantly associated with 80% greater risk (95% confidence interval:1.13 to 2.85; P = 0.013) compared with the SII tertile 1 group in multivariable Cox regression analysis. The competing risk model also indicated that the relationship between SII tertiles and all-cause mortality remains (subdistribution hazard ratio: 1.86; 95% confidence interval: 1.15 to 2.02, P = 0.011). Furthermore, the relationship between the log-transformed SII and all-cause mortality in patients with PD was nearly linear (P = 0.124). CONCLUSION: A close relationship was observed between the SII and all-cause mortality in patients undergoing PD, suggesting that more attention should be paid to the SII, which is a convenient and effective measurement in clinical practice.

Platelet-to-albumin ratio: a potential biomarker for predicting all-cause and cardiovascular mortality in patients undergoing peritoneal dialysis.

BACKGROUND: Although peritoneal dialysis (PD) is an efficient therapy for renal replacement, the long-term survival rate of patients undergoing PD remains low. The platelet-to-albumin ratio (PAR), recently identified as a parameter of inflammatory and nutritional status, is associated with an adverse prognosis for various diseases. However, the association between the serum PAR and prognosis of patients undergoing PD is poorly understood. This study aimed to evaluate whether the PAR is a reliable predictor of cardiovascular disease (CVD) and all-cause mortality in patients undergoing PD. METHODS: This multicenter cohort study enrolled patients undergoing PD from January 1, 2009, to September 30, 2018. The patients were divided into four groups according to the quartiles of their baseline PAR. The primary endpoint was all-cause and CVD-related mortality. Cox proportional hazard models were used to determine the association between the PAR and all-cause or CVD-related mortality. The receiver operating characteristic (ROC) curve was utilized to compare the performance among PAR and other inflammatory indicators. C-statistic, net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were applied to examine the incremental prognostic value of PAR compared with baseline model for predicting all-cause and CVD mortality. RESULTS: A total of 2825 patients were included. During the follow-up period of 47.5 ± 28.3 months, 747 (26.4%) mortality cases were observed, of which 415 (55.6%) were CVD-related. Compared with the Q1 (PAR < 4.43), placement in Q4 (PAR > 7.27) was associated with an increased risk of all-cause mortality and CVD mortality (p < 0.001). The adjusted restricted cubic spline analysis indicated that the relationship of the PAR with all-cause and cardiovascular mortality was linear (p for nonlinearity = 0.289 and 0.422, respectively). No positive correlations were shown in the interaction tests. PAR exhibited superior predictive value for mortality compared to other inflammatory indicators, with a respective AUC value of 0.611 (P < 0.001) for all-cause mortality and 0.609 (P < 0.001) for cardiovascular mortality. According to the C-statistic, continuous NRI and IDI, the addition of PAR to the baseline model yielded a moderate but significant improvement in outcome prediction. CONCLUSIONS: The PAR is an independent prognostic factor associated with all-cause and cardiovascular mortality in patients undergoing PD.

The relationship between serum uric acid and gastrointestinal bleeding in peritoneal dialysis patients: a propensity score analysis.

PURPOSE: Gastrointestinal bleeding is an important gastrointestinal complication among peritoneal dialysis patients and correlated with a higher risk of mortality. Increased uric acid levels are a significant complication for peritoneal dialysis patients and have been associated with an increased risk of hemorrhagic stroke. The objective of the present study was to investigate the relationship between serum uric acid levels and gastrointestinal bleeding in peritoneal dialysis patients. METHODS: A total of 2498 peritoneal dialysis patients were recruited. Based on the optimal uric acid cutoff value, two groups of patients were divided. We constructed a propensity-score-matched population of 1762 patients by matching sex, age, and body mass index. Survival outcomes between the two groups were compared using adjusted Kaplan-Meier curves. We constructed the restricted cubic splines regression to assess the correlation between levels of uric acid and gastrointestinal bleeding. A multivariate Cox proportional hazards regression was performed to test whether higher levels of uric acid are an independent risk factor for gastrointestinal bleeding. We performed a forest plot to show interaction effects in different subgroups. RESULTS: According to restricted cubic splines regression, uric acid levels were positively correlated with the risk of gastrointestinal bleeding events. After adjusted different confounding factors, patients with high levels of uric acid were prone to experience gastrointestinal bleeding (HR 1.868, 95%CI 1.001-3.486). In subgroups, the interaction between higher levels of uric acid and utilizing proton pump inhibitors was significant (P for interaction = 0.034). Further research found that taking proton pump inhibitors could decrease the risk of gastrointestinal bleeding in peritoneal dialysis patients accompanied high levels of uric acid. CONCLUSION: The baseline high levels of uric acid are an independent risk factor for gastrointestinal bleeding in patients undergoing peritoneal dialysis.

Association of albumin to non-high-density lipoprotein cholesterol ratio with mortality in peritoneal dialysis patients.

OBJECTIVE: Malnutrition and inflammation are associated with mortality in peritoneal dialysis (PD) patients. Serum albumin and non-high-density lipoprotein cholesterol (non-HDL-C) are independently associated with mortality in PD patients. Combining albumin and non-HDL-C with mortality may be more plausible in clinical practice. METHODS: This retrospective cohort study included 1954 Chinese PD patients from 1 January 2009 to 31 December 2016. Kaplan-Meier curve was used to determine the relationship between albumin to non-HDL-C ratio and all-cause mortality. Cox regression analysis was applied to assess the independent predictive value while adjusting for confounding factors. Competitive risk analysis was used to examine the effects of other outcomes on all-cause mortality prognosis. RESULTS: In the 33-month follow-up period, there were 538 all-cause deaths. Kaplan-Meier analysis presented significant differences in all-cause mortality. Multivariate Cox regression showed that the risk of all-cause mortality was lower in the moderate group (9.36-12.79) (HR, 0.731; 95% CI, 0.593-0.902, p = 0.004) and the highest group (>12.79) (HR, 0.705; 95% CI, 0.565-0.879, p = 0.002) compared to the lowest group (≤9.36). Competitive risk analysis revealed significant differences for all-cause mortality (p < 0.001), while there was no statistical significance for other competing events. CONCLUSIONS: Low albumin to non-HDL-C ratio was associated with a high risk of all-cause mortality in PD patients. It may serve as a potential prognostic biomarker in PD patients.

Remnant cholesterol as a risk factor for all-cause and cardiovascular mortality in incident peritoneal dialysis patients.

BACKGROUND AND AIMS: Remnant cholesterol (RC) adversely contributes to cardiovascular disease (CVD) and overall survival in various diseases. However, its role in CVD outcomes and all-cause mortality in patients undergoing peritoneal dialysis (PD) is limited. Therefore, we aimed to investigate the association between RC and all-cause and CVD mortality in patients undergoing PD. METHODS AND RESULTS: Based on lipid profiles recorded using standard laboratory procedures, fasting RC levels were calculated in 2710 incident patients undergoing PD who were enrolled between January 2006 and December 2017 and followed up until December 2018. Patients were divided into four groups according to the quartile distribution of baseline RC levels (Q1: <0.40 mmol/L, Q2: 0.40 to <0.64 mmol/L, Q3: 0.64 to <1.03 mmol/L, and Q4: ≥1.03 mmol/L). Associations between RC and CVD and all-cause mortality were evaluated using multivariable Cox models. During the median follow-up period of 35.4 months (interquartile range, 20.9-57.2 months), 820 deaths were recorded, of which 438 were CVD-related. Smoothing plots showed non-linear relationships between RC and adverse outcomes. The risks of all-cause and CVD mortality increased progressively through the quartiles (log-rank, p < 0.001). Using adjusted proportional hazard models, a comparison of the highest (Q4) to lowest (Q1) quartiles revealed significant increases in the hazard ratio (HR) for all-cause mortality (HR 1.95 [95% confidence interval (CI), 1.51-2.51]) and CVD mortality risk (HR 2.60 [95% CI, 1.80-3.75]). CONCLUSION: An increased RC level was independently associated with all-cause and CVD mortality in patients undergoing PD, suggesting that RC was important clinically and required further research.

Combined influence of depression and low-grade inflammation on mortality in peritoneal dialysis patients.

BACKGROUND: The relationship between depression and systemic inflammation as risk factors for mortality is not well understood and requires further investigation. METHODS: Patients undergoing continuous ambulatory peritoneal dialysis (CAPD) between July 01, 2015 to December 31, 2019, were analyzed and followed up until December 31, 2020. According to their status of depression (PHQ-9 score ≥ 5) and low-grade inflammation (hs-CRP level ≥ 3 mg/L), patients were divided into four groups (G1, without depression, nor inflammation; G2, with depression, without inflammation; G3, with inflammation, without depression; G4, with both depression and inflammation). We performed Kaplan-Meier and multivariable Cox proportional analyses of mortality for the combined influence of depression and systemic inflammation in this cohort. RESULTS: During the mean follow-up of 36.3 ± 14.8 months, 73 deaths were recorded in 358 participants. Compared with patients in group G1, patients in group G2 and G3 carried 137% {hazard ratio (HR): 2.37, 95% confidence interval (CI): 1.06-5.23, p = 0.035} and 140% (HR: 2.40, 95% CI: 1.01-5.69, p = 0.048) higher risk of mortality. Patients in group G4 (with both depression and inflammation) showed the highest risks of all-cause mortality with 276% higher mortality risk (HR: 3.76, 95% CI: 1.73-8.15, p = 0.001), respectively. CONCLUSION: The combined of depression and inflammation is associated with all-cause mortality in peritoneal dialysis patients, suggesting a need for further study of depression and low-grade inflammation in PD patients and potential relationship between them.

Association of a low ankle brachial index with progression to end-stage kidney disease in patients with advanced-stage diabetic kidney disease.

INTRODUCTIONS: The effect of a low ankle-brachial index (ABI) in patients with advanced-stage diabetic kidney disease is not fully understood. This study investigates the prevalence of a low ABI in patients with advanced-stage diabetic kidney disease, which was defined as a urinary albumin-to-creatinine ratio (UACR) ≥300 mg/g and an estimated glomerular filtration rate (eGFR) between 15-60 mL/min/1.73 m2. Furthermore, the association between a low ABI and end-stage kidney disease (ESKD) was determined. METHODS: This single-center, retrospective, cohort study included 529 patients with advanced-stage diabetic kidney disease who were stratified into groups according to the ABI: high (>1.3), normal (0.9-1.3), and low (<0.9). The Kaplan-Meier method and Cox proportional analysis were used to examine the association between the ABI and ESKD. RESULTS: A total of 42.5% of patients with a low ABI progressed to ESKD. A low ABI was associated with a greater risk of ESKD (hazard ratio (HR): 1.073). After adjusting for traditional chronic kidney disease risk factors, a low ABI remained associated with a greater risk of ESKD (HR: 1.758; 95% confidence interval: 1.243-2.487; p = 0.001). CONCLUSIONS: These results indicate that patients with a low ABI should be monitored carefully. Furthermore, preventive therapy should be considered to improve the long-term kidney survival of patients with residual kidney function.

Clinical significance of serum glucose to lymphocyte ratio as a prognostic marker in peritoneal dialysis patients.

BACKGROUND: The glucose-to-lymphocyte ratio (GLR), a glucose metabolism and systemic inflammatory response parameter, is associated with an adverse prognosis for various diseases. However, the association between serum GLR and prognosis in patients undergoing peritoneal dialysis (PD) is poorly understood. METHODS: In this multi-center cohort study, 3236 PD patients were consecutively enrolled between 1 January 2009 and 31 December 2018. Patients were divided into four groups according to the quartiles of baseline GLR levels (Q1: GLR ≤ 2.91, Q2:2.91 < GLR ≤ 3.91, Q3:3.91 < GLR < 5.59 and Q4: GLR ≥ 5.59). The primary endpoint was all-cause and cardiovascular disease (CVD) related mortality. The correlation between GLR and mortality was examined using Kaplan-Meier and multivariable Cox proportional analyses. RESULTS: During the follow-up period of 45.93 ± 29.01 months, 25.53% (826/3236) patients died, of whom 31% (254/826) were in Q4 (GLR ≥ 5.59). Multivariable analysis revealed that GLR was significantly associated with all-cause mortality (adjusted HR 1.02; CI 1.00 ∼ 1.04, p = .019) and CVD mortality (adjusted HR 1.02; CI 1.00 ∼ 1.04, p = .04). Compared with the Q1 (GLR ≤ 2.91), placement in Q4 was associated with an increased risk of all-cause mortality (adjusted HR: 1.26, 95% CI: 1.02 ∼ 1.56, p = .03) and CVD mortality (adjusted HR 1.76; CI 1.31 ∼ 2.38, p < .001). A nonlinear relationship was found between GLR and all-cause or CVD mortality in patients undergoing PD (p = .032). CONCLUSION: A higher serum GLR level is an independent prognostic factor for all-cause and CVD mortality in patients undergoing PD, suggesting that more attention should be paid to GLR.

Biosynthesis of Cosmosporasides Reveals the Assembly Line for Fungal Hybrid Terpenoid Saccharides.

Fungal hybrid terpenoid saccharides constitute a new and growing family of natural products with significant biomedical and agricultural activities. One representative family is the cosmosporasides, which feature oxidized terpenoid units and saccharide moieties; however, the assembly line of these building blocks has been elusive. Herein, a cos cluster from Fusarium orthoceras was discovered for the synthesis of cosmosporaside C (1) by genome mining. A UbiA family intramembrane prenyltransferase (UbiA-type PT), a multifunctional cytochrome P450, an α,ß-hydrolase, an acetyltransferase, a dimethylallyl transferase (DMAT-type PT) and a glycosyltransferase function cooperatively in the assembly of the scaffold of 1 using primary central metabolites. The absolute configuration at C4, C6 and C7 of 1 was also established. Our work clarifies the unexpected functions of UbiA-type and DMAT-type PTs and provides an example for understanding the synthetic logic of hybrid terpenoid saccharides in fungi.

Association of left ventricular systolic dysfunction with mortality in incident peritoneal dialysis patients.

AIM: Cardiovascular disease is associated with morbidity and mortality in peritoneal dialysis patients but the relationship between left ventricular ejection fraction (LVEF) and outcomes is unclear. This study aimed to explore the association between LVEF and mortality in incident continuous ambulatory peritoneal dialysis (CAPD) patients. METHODS: The patients were divided into three groups according to LVEF levels (>0.6, 0.5 to 0.6, and <0.5). Kaplan-Meier analysis and the Cox proportional hazards models were used to evaluate association of LVEF with mortality. RESULTS: Among the 594 patients, LVEF levels of >0.6, 0.5 to 0.6, and <0.5 were detected in 428 (72.0%), 127 (21.4%) and 39 (6.6%) patients, respectively. During a median follow-up of 39.6 months, 127 (21.4%) patients died, of the deaths, 57.5% were attributable to cardiovascular causes. Patients with LVEF <0.5 had worst overall rates of survival and cardiovascular death-free survival among groups. Compared with LVEF >0.6, adjusted all-cause mortality hazard ratio (HR) and 95% confidence interval (CI) for patients with LVEF 0.5 to 0.6 and <0.5 were 1.62 (1.09-2.43) and 1.93 (1.06-3.52), respectively. The corresponding adjusted cardiovascular mortality HR were 1.60 (0.94-2.47) and 2.16 (1.04-4.74), respectively. CONCLUSION: Reduced LVEF is significantly associated with increased all-cause and cardiovascular mortality in incident CAPD patients.

Faster Transport Status and Mortality in Anuric Patients Undergoing Continuous Ambulatory Peritoneal Dialysis.

BACKGROUND: There are limited data regarding the relationship between transport status and mortality in anuric continuous ambulatory peritoneal dialysis (CAPD) patients. METHODS: According to the dialysate to plasma creatinine ratio (D/P Cr), 292 anuric CAPD patients were stratified to faster (D/P Cr ≥0.65) and slower transport groups (D/P Cr <0.65). The Cox proportional hazards models were used to evaluate the association of transport status with mortality. RESULTS: During a median follow-up of 22.1 months, 24% patients died, 61.4% of them due to cardiovascular disease (CVD). Anuric patients with faster transport were associated with an increased risk of all-cause mortality (HR (95% CI) = 2.16 (1.09-4.26)), but not cardiovascular mortality, after adjustment for confounders. Faster transporters with pre-existing CVD had a greater risk for death compared to those without any history of CVD. CONCLUSION: Faster transporters were independently associated with high all-cause mortality in anuric CAPD patients. This association was strengthened in patients with pre-existing CVD.

The association between blood nickel level and handgrip strength in patients undergoing maintenance hemodialysis.

BACKGROUND: Progressive loss of peripheral muscle strength is highly pronounced in patients receiving maintenance hemodialysis (MHD), of which the pathological mechanism tends to be multifactorial. Plasma nickel was reportedly correlated with muscular strength in non-dialysis patients. However, scarce is known regarding the association between blood nickel level and handgrip strength among the patients undergoing MHD. METHODS: This cross-sectional study included patients undergoing MHD at our center in October 2021. Blood samples were collected before the hemodialysis sessions. Nickel level was measured using inductively coupled plasma mass spectrometry. Eligible patients were stratified into three groups by the blood nickel level: tertile 1 (≥ 5.2 ug/L); tertile 2 (< 5.2 ug/L and ≥ 4.5 ug/L); and tertile 3 (< 4.5 ug/L). Handgrip strength measurement was used to evaluate the muscle status. Spearman's analyses and multivariable linear regression analyses were performed to study the relationship between blood nickel level and handgrip strength. RESULTS: A total of 236 patients were enrolled, with an average age of 55.51 ± 14.27 years and a median dialysis vintage of 83 (IQR: 48-125) months. Patients in group with a higher blood nickel level (tertile 1) tended to be female, had longer dialysis vintage and higher Kt/V, but lower BMI, serum creatinine, hemoglobin, and handgrip strength level (all p < 0.05). After adjustment for confounding factors in multivariable models, for every 1ug/L increase in nickel level, the patient's handgrip strength decreases by 2.81 kg (ß: - 2.810, 95% confidence interval: - 5.036 to - 0.584, p = 0.014). Restricted cubic spline confirmed the relationship was nearly linear. CONCLUSIONS: Our study highlighted that blood nickel level was related to handgrip strength in patients undergoing MHD. Prospective studies with larger sample sizes are still needed to confirm the result.

The non-linear associations between blood manganese level and sarcopenia in patients undergoing maintenance hemodialysis: A multicenter cross-sectional study.

BACKGROUND AND AIMS: Manganese (Mn), a vital element in energy metabolism, is predominantly stored in skeletal muscles and plays a crucial role in muscle function and strength. Patients on maintenance hemodialysis (MHD) often experience muscle wasting due to metabolic disruption and inflammation. This study aimed to explore the relationship between blood Mn levels and sarcopenia in a patient population. METHODS: In this multicenter cross-sectional study, conducted from March 2021 to March 2022, 386 patients on MHD from three medical centers were included. Blood Mn levels were measured using inductively coupled plasma mass spectrometry, and body composition was assessed post-dialysis using bioelectrical impedance analysis. Grip strength was measured using a digital dynamometer. The patients were categorized into groups with and without sarcopenia. Using a generalized additive model to fit a smooth curve, we employed a generalized linear model to identify the optimal inflection point and explore the threshold effect after discovering a segmented relationship. Subsequently, a binary logistic regression analysis was conducted to investigate the relationship between blood manganese levels and the risk of sarcopenia, with adjustments made for potential confounding factors. RESULTS: A negative correlation was observed between blood Mn levels and sarcopenia-related parameters (Appendicular Skeletal Muscle Mass Index and grip strength) in Spearman's correlation analysis (both P < 0.05). After adjusting for confounding factors, a nonlinear association was identified. When blood Mn was ≤ 10.6 µg/L, the increase in sarcopenia was not statistically significant (P > 0.05). Conversely, when blood Mn exceeded 10.6 µg/L, each 1 µg/L increase raised the risk of sarcopenia by 0.1 times. Considering confounders, multivariate binary logistic regression confirmed an independent association between elevated blood Mn levels and sarcopenia. CONCLUSION: This study revealed an independent association between elevated blood Mn levels (> 10.6 µg/L) and sarcopenia in patients undergoing MHD. These findings emphasize the importance of understanding the Mn metabolism in the context of muscle health in this patient population. Further research is warranted to explore the underlying mechanisms and potential interventions for mitigating sarcopenia in patients with elevated blood Mn levels undergoing MHD.

Associations between insulin-like growth factor-1 standard deviation score and overall nutritional parameters in patients with maintenance hemodialysis: a cross-sectional study.

BACKGROUND: This study investigated the association between insulin-like growth factor-1 and nutritional status indicators in patients undergoing maintenance hemodialysis (MHD). METHODS: Patients undergoing MHD for > 3 months were included in this single-center cross-sectional study in March 2021. Clinical, demographic, and body mass data and blood samples were collected before the hemodialysis sessions. Serum insulin-like growth factor-1 (IGF-1) levels were measured using a radioimmunoassay, and serum IGF-1 standard deviation score (SDS) was calculated for MHD patients according to age and sex. The nutritional status of patients was assessed using serum albumin, serum prealbumin, handgrip strength, pinching strength, upper arm muscle circumference, lean body mass, phase angle, seven-point subjective global assessment (SGA) score, and geriatric nutritional risk index (GNRI). The patients were divided into groups according to tertiles of serum IGF-1 SDS levels. Spearman correlation analyses and univariate and multivariate binary logistic regression analyses were used to determine the association between serum IGF-1 SDS and nutritional status parameters. RESULTS: A total of 155 MHD patients (male: female = 90:65) were enrolled in the study, with a median dialysis vintage of 28.0 (11.0, 55.0) months, and an average age of 66 (65.5 ± 13.0) years. The median of IGF-1 SDS was - 0.1 (- 0.6 to 0.6). Compared to patients with higher IGF-1 SDSs, patients with lower IGF-1 SDSs had lower levels of serum ceruloplasmin (341.0 [287.5, 416.0] vs 395.0 [327.0, 451.0] vs 409.0 [349.5, 507.5], p = 0.002), serum albumin (34.7 ± 3.0 vs 37.0 ± 3.1 vs 37.8 ± 2.6, p < 0.001), serum prealbumin (270.3 [233.7, 327.8] vs 326.0 [279.3, 355.6] vs 363.0 [324.2, 398.2], p < 0.001), handgrip strength (13.8 [10.0, 20.7] vs 17.7 [10.7, 22.5] vs 23.3 [16.6, 27.8], p < 0.001), pinch strength (4.6 [3.9, 6.0] vs 4.9 (3.9, 6.9) vs 6.5 [4.7, 8.7], p = 0.002), phase angle (3.3 [3.0, 3.8] vs 3.9 [3.4, 4.7] vs 4.3 [3.6, 5.2, p < 0.001), modified Creatinine Index (83.1 ± 19.7 vs 93.1 ± 23.4 vs 113.9 ± 24.3, p < 0.001), intracellular water (14.5 ± 4.4 vs 16.1 ± 4.9 vs 16.9 ± 4.4, p = 0.031), higher extracellular water (26.9 ± 5.8 vs 25.7 ± 5.5 vs 25.1 ± 3.1, p = 0.042), and higher malnutrition risk as defined by GNRI (49.0% vs 15.7% vs 11.5%, p < 0.001) and SGA (53.9% vs 23.5% vs 7.7%, p < 0.001). CONCLUSIONS: Lower IGF-1 SDSs are independently associated with higher malnutrition risk in patients with MHD.

Atherogenic index predicts all-cause and cardiovascular mortality in incident peritoneal dialysis patients.

BACKGROUND AND AIMS: Atherosclerosis, the main cause of cardiovascular disease (CVD), is prevalent in patients undergoing peritoneal dialysis (PD). Atherogenic index (AI) is a strong predictor of atherosclerosis. However, its prognostic value in CVD outcomes and all-cause mortality among patients undergoing PD remains uncertain. Therefore, we aimed to evaluate the association between AI and all-cause and CVD mortality in PD patients. METHODS: Calculated based on lipid profiles obtained through standard laboratory procedures, AI was evaluated in 2682 patients who underwent PD therapy between January 2006 and December 2017 and were followed up until December 2018. The study population was divided into four groups according to the quartile distribution of AI (Q1: <2.20, Q2: 2.20 to <2.97, Q3: 2.97 to <4.04, and Q4: ≥4.04). Multivariable Cox models were employed to explore the associations between AI and CVD and all-cause mortality was evaluated. RESULTS: During a median follow-up of 35.5 months (interquartile range, 20.9-57.2 months), 800 patients died, including 416 deaths from CVD. Restricted cubic splines showed non-linear relationship between AI and adverse clinical outcomes. The risks of all-cause and CVD mortality gradually increased across quartiles (log-rank, p < 0.001). After adjusting for potential confounders, the highest quartile (Q4) showed significantly elevated hazard ratio (HR) for both all-cause mortality (HR 1.54 [95% confidence interval (CI), 1.21-1.96]) and CVD mortality risk (HR 1.78 [95% CI, 1.26-2.52]), compared to the lowest quartile (Q1). CONCLUSIONS: AI was independently associated with all-cause and CVD mortality in patients undergoing PD, suggesting that AI might be a useful prognostic marker.

Experimental and Simulation Investigation of Nd Additions on As-Cast Microstructure and Precipitate Development in Mg-Nd System Alloys.

The microstructure and precipitate evolution of as-cast Mg-Nd alloys with different contents of Nd was investigated via experimental and simulation methods. The research showed that the as-cast microstructure of Mg-Nd alloy consisted of α-Mg dendrites and the intermetallic phases. A metastable ß phase precipitated, followed by α-Mg dendrites that could be confirmed as Mg12Nd by X-ray diffraction (XRD) analysis. The amount of ß-Mg12Nd presented a rising trend with increasing Nd additions. In addition, the tertiary phase was also observed in as-cast Mg-Nd alloy when Nd content was greater than 3 wt.%, which precipitated from the oversaturated α-Mg matrix. The tertiary phase should be ß1-Mg3Nd, which is also a metastable phase with a face-centered cubic lattice. However, it is a pity that the tertiary phase was not detected by the XRD technique. Moreover, an effective cellular automaton (CA) model was explored and applied to simulate the time-dependent α-Mg/ß1-Mg3Nd eutectic growth. The simulated results of α-Mg/ß1-Mg3Nd eutectic growth in Mg-3Nd presented that the growth of α-Mg dendrites was accompanied by the nucleation and growth of ß1-Mg3Nd precipitates and eventually formed a eutectic structure. The eutectic morphologies for Mg-Nd system alloys with different Nd contents were also simulated using the proposed model, and the results revealed that α-Mg dendrite was a refinement, and the amount of α-Mg/ß1-Mg3Nd eutectic was promoted, with increasing Nd content.

High Blood Cu/Zn Ratio is Associated with Nutritional Risk in Patients Undergoing Maintenance Hemodialysis.

Patients undergoing maintenance hemodialysis (MHD) are at risk of an imbalance of copper and zinc homeostasis. We hypothesized that there is an association between the blood copper-zinc (Cu/Zn) ratio and nutritional status in these patients. For this cross-sectional study, blood samples were collected from patients undergoing MHD at Guangzhou Red Cross Hospital in September 2019. Zinc and copper levels were measured using inductively coupled plasma mass spectrometry. The seven-point subjective global assessment (SGA), nutritional risk screening 2002 (NRS2002), and geriatric nutritional risk index (GNRI) were used to evaluate the overall nutritional status. We enrolled 144 MHD patients (men:women = 78:66), with an average age of 64.33 ± 13.39 years and a median dialysis vintage of 33.50 (16.25-57.50) months. Patients with a higher blood Cu/Zn ratio had lower levels of hemoglobin, blood zinc, serum prealbumin, albumin, and creatinine as well as low SGA and GNRI scores, but higher modified Charlson comorbidity index score, serum C-reactive protein level, interleukin-6 level, blood copper level, and NRS2002 score (all p < 0.05). After adjustment for confounding factors in multivariable models, a high blood Cu/Zn ratio was independently associated with nutritional risk defined by all nutritional parameters (SGA, NRS2002, and GNRI). Prospective studies with larger sample sizes are warranted to confirm these results.

Current apparent treatment-resistant hypertension in patients undergoing peritoneal dialysis: A multi-center cross-sectional study.

Apparent treatment-resistant hypertension (aTRH) is the most commonly used term to report resistant hypertension (RH) and is considered as a common problem in dialysis population. However, few reports have focused on peritoneal dialysis (PD) hypertensive patients. The authors conducted a multi-center cross-sectional study involving 1789 PD patients from nine centers in Guangdong, China. The prevalence of aTRH was estimated by home blood pressure (BP) monitoring. Evaluating drug adherence through Eight-item Morisky Medication Adherence Scale (MMAS-8) and pill counting was performed to assess RH in one PD center. Related factors of aTRH were analyzed using logistic regression analysis. The prevalence of aTRH in PD patients was estimated at 42.2% (755 out of 1789 hypertensive patients) based on home BP. Of those, 91.4% patients were classified as uncontrolled RH, 2.0% as controlled RH, and 6.6% as refractory hypertension. The prevalence of RH was 40.6% and 41.9% among those with medium/high adherence based on the MMAS-8 scores and the pill counting rate, respectively. PD patients who were younger, with higher body mass index, with lower serum albumin and poorer dialysis adequacy were significantly associated with higher aTRH incident. In conclusion, the present study demonstrates a high prevalence of aTRH in PD population, which occurs in about two in five treated hypertensive patients. Nutritional status and dialysis adequacy might tightly associate with aTRH.

The Interface Microstructures and Mechanical Properties of Laser Additive Repaired Inconel 625 Alloy.

The microstructure and micro-mechanics around the repaired interface, and the tensile properties of laser additive repaired (LARed) Inconel 625 alloy were investigated. The results showed that the microstructure around the repaired interface was divided into three zones: the substrate zone (SZ), the heat-affected zone (HAZ), and the repaired zone (RZ). The microstructure of the SZ had a typical equiaxed crystal structure, displaying simultaneously precipitated block-shaped MC-type carbides (NbC, TiC), with bimodal sizes of approximately 10 µm and 0.5 µm and an irregularly shaped flocculent Laves phase. Recrystallization occurred in the HAZ, and led to significant grain growth; a portion of the second phase dissolved in the original grain boundaries. In the RZ, there was a columnar crystal structure, and the size increased with increasing deposition thickness. Moreover, the microstructure between the layer interface and layer interior was quite different, presenting an overlapping transition zone (OTZ), in which the dendritic structure coarsened and more Laves phase were precipitated, compared to in the layer interior. The hardness and tensile properties of the LARed samples were equivalent to those of the wrought substrate, which indicates that laser additive repairing (LAR) is a reliable repair solution for damaged and mis-machined components comprising Inconel 625 alloy.