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Designing a monochromatic spatially-structured light field that recovers the pre-specified profile of optical force (OF) exerted on a particle is an inverse problem. It usually requires high dimensional optimization and involves lengthy calculations, thus remaining little studied despite decades of research on OF. We report here the first attempt to attack this inverse design problem. The modus operandi relies on the back-propagation algorithm, which is facilitated by the currently available machine learning framework, and, in particular, by an exact and efficient expression of OF that shows only polynomial and trigonometric functional dependence on the engineered parameters governing the structured light field. Two illustrative examples are presented in which the inversely designed structured light fields reproduce, respectively, a predefined spatial pattern of OF and a negative longitudinal OF in a transversely trapping area.

Optical tractor beams capable of pulling particles backward have garnered significant and increasing interest. Traditional optical tractor beams are limited to free space beams with small forward wavevectors, enabling them to pull selected particles. Here, we present a comprehensive theory for the optical force exerted by a surface wave using analytical and numerical calculations, revealing the relationship between the canonical momentum and optical forces. Based on this theory, we demonstrate a general purpose optical surface tractor beam that can pull any passive particle, regardless of size, composition, or geometry. The tractor beam utilizes a surface wave with negative canonical momentum characterized by a single well-defined negative Bloch k vector. The tractor beam relies on a mechanism where the negative incident force always surpasses the recoil force. As such, the tractor beam, when excited on the surface of a double-negative index metamaterial, can pull particles with different morphologies. Authors demonstrate that Minkowski momentum is relevant for optical manipulation by surface wave. Thus, unconditional optical pulling irrespective of particle morphology can be achieved by a forward-propagating surface wave with a negative k-vector. [ABSTRACT FROM AUTHOR]

Background Limited data exist on the association between gut permeability, circulating bacterial fragment and volume overload in peritoneal dialysis (PD) patients. We measured circulating bacterial fragments, N-terminal pro B-type natriuretic peptide (NT-proBNP), calprotectin and zonulin levels, and evaluate their association with the clinical outcomes in PD patients. Methods This was a single-center prospective study on 108 consecutive incident PD patients. Plasma endotoxin and bacterial DNA, and serum NT-proBNP, calprotectin and zonulin levels were measured. Primary outcomes were technique and patient survival, secondary outcomes were hospitalization data. Results There was no significant correlation between plasma endotoxin and bacterial DNA, and serum NT-proBNP, calprotectin and zonulin levels. The Homeostatic Model Assessment for Insulin Resistance (HOMA)-2β index, which represents insulin resistance, positively correlated with plasma bacterial DNA (r = 0.421, P  < .001) and calprotectin levels (r = 0.362, P  = .003), while serum NT-proBNP level correlated with the severity of volume overload and residual renal function. Serum NT-proBNP level was associated with technique survival even after adjusting for confounding factors [adjusted hazard ratio (aHR) 1.030, 95% confidence interval 1.009–1.051]. NT-proBNP level was also associated with patient survival by univariate analysis, but the association became insignificant after adjusting for confounding factors (aHR 1.010, P  = .073). Similarly, NT-proBNP correlated with the number of hospitalizations and duration of hospitalization by univariate analysis, but the association became insignificant after adjusting for confounding factors. Conclusion There was no correlation between markers of gut permeability, circulating bacterial fragments and measures of congestion in PD patients. Bacterial fragments levels and gut permeability are both associated with insulin resistance. Serum NT-proBNP level is associated with the severity of volume overload and technique survival. Further studies are required to delineate the mechanism of high circulating bacterial fragment levels in PD patients. [ABSTRACT FROM AUTHOR]

The equipartition theorem is an elegant cornerstone theory of thermal and statistical physics. However, it fails to address some contemporary problems, such as those associated with optical and acoustic trapping, due to the non-Hermitian nature of the external wave-induced force. We use stochastic calculus to solve the Langevin equation and thereby analytically generalize the equipartition theorem to a theory that we denote the non-Hermitian non-equipartition theory. We use the non-Hermitian non-equipartition theory to calculate the relevant statistics, which reveal that the averaged kinetic and potential energies are no longer equal to kBT/2 and are not equipartitioned. As examples, we apply non-Hermitian non-equipartition theory to derive the connection between the non-Hermitian trapping force and particle statistics, whereby measurement of the latter can determine the former. Furthermore, we apply a non-Hermitian force to convert a saddle potential into a stable potential, leading to a different type of stable state. The authors propose a generalization of the equipartition theorem of thermal physics to account for non-Hermitian trapping forces, relevant for the problems in non-equilibrium open systems and advanced nanotechnology. [ABSTRACT FROM AUTHOR]

Background: Diabetic kidney diseases (DKD) is a the most common cause of end-stage kidney disease (ESKD) around the world. Previous studies suggest that urinary podocyte stress biomarker, e.g. podocin:nephrin mRNA ratio, is a surrogate marker of podocyte injury in non-diabetic kidney diseases. Method: We studied 118 patients with biopsy-proved DKD and 13 non-diabetic controls. Their urinary mRNA levels of nephrin, podocin, and aquaporin-2 (AQP2) were quantified. Renal events, defined as death, dialysis, or 40% reduction in glomerular filtration rate, were determined at 12 months. Results: Urinary podocin:nephrin mRNA ratio of DKD was significantly higher than the control group (p = 0.0019), while urinary nephrin:AQP2 or podocin:AQP2 ratios were not different between groups. In DKD, urinary podocin:nephrin mRNA ratio correlated with the severity of tubulointerstitial fibrosis (r = 0.254, p = 0.006). and was associated with the renal event-free survival in 12 months (unadjusted hazard ratio [HR], 1.523; 95% confidence interval [CI] 1.157–2.006; p = 0.003). After adjusting for clinical and pathological factors, urinary podocin:nephrin mRNA ratio have a trend to predict renal event-free survival (adjusted HR, 1.327; 95%CI 0.980–1.797; p = 0.067), but the result did not reach statistical significance. Conclusion: Urinary podocin:nephrin mRNA ratio has a marginal prognostic value in biopsy-proven DKD. Further validation is required for DKD patients without kidney biopsy. [ABSTRACT FROM AUTHOR]

Bioelectrical impedance analysis (BIA) has been extensively applied in nutritional assessments on the general population, and it is recommended in establishing the diagnosis of malnutrition and sarcopenia. The bioimpedance technique has become a promising modality through which to measure the whole-body composition in dialysis patients, where the presence of subclinical volume overload and sarcopenic obesity may be overlooked by assessing body weight alone. In the past two decades, bioimpedance devices have evolved from applying a single frequency to a range of frequencies (bioimpedance spectroscopy, BIS), in which the latter is incorporated with a three-compartment model that allows for the simultaneous measurement of the volume of overhydration, adipose tissue mass (ATM), and lean tissue mass (LTM). However, clinicians should be aware of common potential limitations, such as the adoption of population-specific prediction equations in some BIA devices. Inherent prediction error does exist in the bioimpedance technique, but the extent to which this error becomes clinically significant remains to be determined. Importantly, reduction in LTM has been associated with increased risk of frailty, hospitalization, and mortality in dialysis patients, whereas the prognostic value of ATM remains debatable. Further studies are needed to determine whether modifications of bioimpedance-derived body composition parameters through nutrition intervention can result in clinical benefits. [ABSTRACT FROM AUTHOR]

Purpose: The effect of residual astigmatism and its axis on distance and near visual acuities (VAs) with multifocal intraocular lenses (IOLs) has not been studied extensively. This study compared the tolerance to experimentally induced residual astigmatism among bifocal, trifocal, and extended depth-of-focus (EDOF) IOLs. Patients and Methods: This retrospective, comparative study included 70 eyes of 70 patients implanted with bifocal, trifocal, or EDOF IOLs. Distance and near VAs were assessed with experimentally induced astigmatism by placing positive cylindrical lenses in increments of 0.50 diopters to 2.00 diopters at 90° and 180° axes over the best distance correction. Results: Both distance and near VAs worsened with increasing magnitudes of experimentally induced astigmatism except in the EDOF group, in which the near VA remained within a clinically acceptable limit, ie, within one line from the best corrected VA under all ranges of experimentally induced astigmatism. Furthermore, the EDOF group showed the highest astigmatic threshold for losing VA lines following experimental astigmatic induction at both distance and near. The distance VA was generally better at with-the-rule (WTR) than against-the-rule (ATR) astigmatism for all three IOL groups. On the other hand, the near VA was generally better at WTR than ATR astigmatism in the bifocal group, comparable between WTR and ATR astigmatism in the trifocal group, and generally better at ATR than WTR astigmatism in the EDOF group. Conclusion: The EDOF IOL demonstrated the highest tolerance to experimentally induced astigmatism at both distance and near. VA was generally less affected by WTR astigmatism than ATR astigmatism, especially at distance. We proposed the residual astigmatism thresholds for clinically acceptable VA reduction in all three IOL groups. [ABSTRACT FROM AUTHOR]

Background: The relationship between dietary patterns and the malnutrition–inflammation–frailty complex in patients undergoing peritoneal dialysis (PD) is currently unknown. Our objective was to measure dietary nutrient intake and evaluate its association with malnutrition, inflammation, and frailty. Methods: We prospectively recruited adult PD patients. We assessed their dietary nutrient intake using a food frequency questionnaire. Frailty, malnutrition, and inflammation were evaluated by validated Frailty Score (FQ), Subjective Global Assessment (SGA), and Malnutrition-Inflammation Score (MIS). Results: A total of 209 patients were recruited for the study. Among them, 89 patients (42.6%) had an insufficient protein intake, and 104 patients (49.8%) had an insufficient energy intake. Additionally, 127 subjects were identified as frail, characterized by being older (61.9 ± 9.5 vs. 55.6 ± 12.8, p < 0.001), malnourished (SGA: 21.0 ± 2.7 vs. 22.7 ± 3.1, p < 0.001), and having a high inflammation burden (MIS: 10.55 ± 3.72 vs. 7.18 ± 3.61, p < 0.001). There was a significant correlation between dietary zinc intake and body mass index (r = 0.31, p < 0.001), SGA (r = 0.22, p = 0.01), and MIS (r = −0.22, p = 0.01). In the multivariate model, a higher dietary zinc intake predicted a higher SGA (beta 0.03, p = 0.003) and lower FQ (beta −0.38, p < 0.001) and MIS (beta −0.14, p < 0.001), indicating a better nutrition, less frail and inflamed state. A higher dietary zinc intake was also associated with a lower odds of being frail (adjusted odds ratio 0.96, p = 0.009). Conclusion: Dietary inadequacy and micronutrient deficiency are common among the PD population. Dietary zinc intake is independently associated with an improved nutrition, physical condition, and reduced inflammatory state. [ABSTRACT FROM AUTHOR]

Background: The result of published studies on the clinical outcome of peritoneal dialysis (PD) after kidney allograft failure is conflicting. There are also few published data on the outcome of patients who had PD before kidney transplant and then return to PD after allograft failure. Methods: We reviewed 100 patients who were started on PD after kidney allograft failure between 2001 and 2020 (failed transplant group); 50 of them received PD before transplant. We compared the clinical outcome to 200 new PD patients matched for age, sex, and diabetic status (control group). Results: The patients were followed for 45.8 ± 40.5 months. the 2-year patient survival rate was 83.3% and 87.8% for the failed transplant and control groups, respectively (log rank test, p = 0.2). The corresponding 2-year technique survival rate 66.5% and 71.7% (p = 0.5). The failed transplant and control groups also had similar hospitalization rate and peritonitis rate. In the failed transplant group, there was also no difference in patient survival, technique survival, hospitalization, or peritonitis rate between those with and without PD before transplant. In the failed transplant group, patients who had PD before transplant and then returned to PD after allograft failure had substantial increase in D/P4 (0.585 ± 0.130 to 0.659 ± 0.111, paired t-test, p = 0.032) and MTAC creatinine (7.74 ± 3.68 to 9.73 ± 3.00 ml/min/1.73m2, p = 0.047) from the time before the transplant to the time after PD was resumed after failed allograft. Conclusions: The clinical outcome of PD patients with a failed kidney allograft is similar to other PD patients. However, patients who have a history of PD before kidney transplant and then return to PD after allograft failure have increased peritoneal transport parameters. [ABSTRACT FROM AUTHOR]

Background: Emerging evidence suggests that long non-coding RNA (lncRNA) plays important roles in the regulation of gene expression. We determine the role of using urinary lncRNA as a non-invasive biomarker for lupus nephritis. Method: We studied three cohorts of lupus nephritis patients (31, 78, and 12 patients, respectively) and controls (6, 7, and 24 subjects, respectively). The urinary sediment levels of specific lncRNA targets were studied using real-time quantitative polymerase chain reactions. Results: The severity of proteinuria inversely correlated with urinary maternally expressed gene 3 (MEG3) (r = −0.423, p = 0.018) and ANRIL levels (r = −0.483, p = 0.008). Urinary MEG3 level also inversely correlated with the SLEDAI score (r = −0.383, p = 0.034). Urinary cancer susceptibility candidate 2 (CASC2) levels were significantly different between histological classes of nephritis (p = 0.026) and patients with pure class V nephritis probably had the highest levels, while urinary metastasis-associated lung carcinoma transcript 1 (MALAT1) level significantly correlated with the histological activity index (r = −0.321, p = 0.004). Urinary taurine-upregulated gene 1 (TUG1) level was significantly lower in pure class V lupus nephritis than primary membranous nephropathy (p = 0.003) and minimal change nephropathy (p = 0.04), and urinary TUG1 level correlated with eGFR in class V lupus nephritis (r = 0.706, p = 0.01). Conclusions: We identified certain urinary lncRNA targets that may help the identification of lupus nephritis and predict the histological class of nephritis. Our findings indicate that urinary lncRNA levels may be developed as biomarkers for lupus nephritis. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To evaluate the performance of a real-time continuous glucose monitor (CGM) in individuals with diabetes on peritoneal dialysis (PD). RESEARCH DESIGN AND METHODS: Thirty participants with type 2 diabetes on continuous ambulatory PD wore a Guardian Sensor 3 on the upper arm paired with Guardian Connect for 14 days. We compared CGM readings against Yellow Springs Instrument (YSI) venous glucose during an 8-h in-clinic session with glucose challenge. RESULTS: The mean absolute relative difference (MARD) was 10.4% (95% CI 9.6, 11.7) from 941 CGM-YSI matched pairs; 81.3% of readings were within %15/15 of YSI values in the full glycemic range. Consensus error grid analysis showed 99.9% of sensor values in zones A and B. There were no correlations between pH, uremia, hydration status, and MARD. CONCLUSIONS: We showed satisfactory performance of a real-time CGM sensor in PD patients with diabetes, supporting future use to facilitate treatment decisions. [ABSTRACT FROM AUTHOR]

Background: Dysnatraemias are commonly reported in COVID-19. However, the clinical epidemiology of hypernatraemia and its impact on clinical outcomes in relation to different variants of SARS-CoV-2, especially the prevailing Omicron variant, remain unclear. Methods: This was a territory-wide retrospective study to investigate the clinical epidemiology and outcomes of COVID-19 patients with hypernatraemia at presentation during the period from 1 January 2020 to 31 March 2022. The primary outcome was 30-day mortality. Key secondary outcomes included rates of hospitalization and ICU admission, and costs of hospitalization. Results: In this study, 53,415 adult COVID-19 patients were included for analysis. Hypernatraemia was observed in 2688 (5.0%) patients at presentation, of which most cases (99.2%) occurred during the local "5th wave" dominated by the Omicron BA.2 variant. Risk factors for hypernatraemia at presentation included age, institutionalization, congestive heart failure, dementia, higher SARS-CoV-2 Ct value, white cell count, C-reactive protein and lower eGFR and albumin levels (p < 0.001 for all). Patients with hypernatraemia showed significantly higher 30-day mortality (32.0% vs. 5.7%, p < 0.001) and longer lengths of stay (12.9 ± 10.9 vs. 11.5 ± 12.1 days, p < 0.001) compared with those with normonatraemia. Multivariate analysis revealed hypernatraemia at presentation as an independent predictor for 30-day mortality (aHR 1.32, 95% CI 1.14–1.53, p < 0.001) and prolonged hospital stays (OR 1.55, 95% CI 1.17–2.05, p = 0.002). Conclusions: Hypernatraemia is common among COVID-19 patients, especially among institutionalized older adults with cognitive impairment and other comorbidities during large-scale outbreaks during the Omicron era. Hypernatraemia is associated with unfavourable outcomes and increased healthcare utilization. [ABSTRACT FROM AUTHOR]

Introduction: It is believed that the excessive cardiovascular (CV) burden of patients on peritoneal dialysis (PD) is closely associated with chronic inflammation. Neutrophil-lymphocyte ratio (NLR) is an inflammatory marker that was shown to correlate with CV outcomes. However, little is known about the significance of serial monitoring of serum NLR. We aimed to determine the prognostic value of serial NLR on all-cause mortality and CV mortality in PD patients. Methods: Serial measurement of NLR was obtained from 225 incident PD patients in a single center, with each measurement 1 year apart. Patients were divided into two groups ("high" vs. "low") by the median value of NLR. The primary and secondary outcome measure was all-cause and CV mortality, respectively. Results: After a median of follow-up for 43.9 months, patients with lower baseline NLR demonstrated a higher survival rate (p = 0.01). Patients with persistently high NLR values on serial measurement had the lowest survival rate (p = 0.03). Multivariate Cox regression showed that this group of patients had significantly higher all-cause mortality (HR: 1.74, 95% CI: 1.09–2.79, p = 0.02). However, the NLR failed to demonstrate a statistically significant relationship with CV mortality. Conclusions: While baseline NLR was an independent predictor of all-cause mortality in PD patients, persistent elevation in NLR appeared to further amplify the risk. Regular monitoring of serial serum NLR may enable early identification of patients who are at risk of adverse outcome. [ABSTRACT FROM AUTHOR]

Background: Renal glycogen synthase kinase-3 beta (GSK3β) overactivity has been associated with a diverse range of kidney diseases. GSK3β activity in urinary exfoliated cells was reported to predict the progression of diabetic kidney disease (DKD). We compared the prognostic value of urinary and intrarenal GSK3β levels in DKD and nondiabetic chronic kidney disease (CKD). Methods: We recruited 118 consecutive biopsy-proved DKD patients and 115 nondiabetic CKD patients. Their urinary and intrarenal GSK3β levels were measured. They were then followed for dialysis-free survival and rate of renal function decline. Results: DKD group had higher intrarenal and urinary GSK3β levels than nondiabetic CKD (p < 0.0001 for both), but their urinary GSK3β mRNA levels were similar. Urinary p-GSK3β level is statistically significantly correlated with the baseline estimated glomerular filtration rate (eGFR), but urinary GSK3β level by ELISA, its mRNA level, the p-GSK3β level, or the p-GSK3β/GSK3β ratio had no association with dialysis-free survival or the slope of eGFR decline. In contrast, the intrarenal pY216-GSK3β/total GSK3β ratio significantly correlated with the slope of eGFR decline (r = −0.335, p = 0.006) and remained an independent predictor after adjusting for other clinical factors. Conclusion: Intrarenal and urinary GSK3β levels were increased in DKD. The intrarenal pY216-GSK3β/total GSK3β ratio was associated with the rate of progression of DKD. The pathophysiological roles of GSK3β in kidney diseases deserve further studies. [ABSTRACT FROM AUTHOR]

Background: Recombinant human erythropoietin (rHuEPO) is an effective treatment for renal anemia. Recently, there is evidence to suggest that rHuEPO may reduce podocyte injury in diabetic kidney disease (DKD). However, there is no published study on the change in podocyte injury marker levels before and after rHuEPO treatment in DKD. Methods: We measured serum nephrin and podocalyxin level, and their corresponding plasma mRNA levels, in 49 DKD patients before rHuEPO treatment, and then 12 and 36 weeks afterward. Results: There were reductions in serum nephrin (p = 0.002) and podocalyxin levels (p = 0.09), as well as their corresponding plasma mRNA levels (p < 0.0001 for both) after rHuEPO treatment. The change in serum nephrin and podocin level had significant inverse correlation with the concomitant change in hemoglobin level (r = -0.670 and -0.739 respectively, p < 0.0001 for both), but not with the change in kidney function or proteinuria. Conclusion: Serum nephrin and podocalyxin levels and their corresponding plasma mRNA levels were significant reduced after rHuEPO treatment in DKD patients, and the change in serum nephrin and podocalyxin levels correlated with the change in hemoglobin level. The effect of rHuEPO on podocyte injury deserves further study. [ABSTRACT FROM AUTHOR]

Background: The correlation between microRNA, obesity, and glycemic intolerance in patients on peritoneal dialysis (PD) is unknown. We aimed to measure the adipose and plasma miR-221 and -222 levels, and to evaluate their association with adiposity, glucose intolerance, and new onset diabetes mellitus (NODM) after the commencement of PD. Methods: We prospectively recruited incident adult PD patients. miR-221 and -222 were measured from adipose tissue and plasma obtained during PD catheter insertion. These patients were followed for 24 months, and the outcomes were changes in adiposity, insulin resistance, and NODM after PD. Results: One hundred and sixty-five patients were recruited. Patients with pre-existing DM had higher adipose miR-221 (1.1 ± 1.2 vs. 0.7 ± 0.9-fold, p = 0.02) and -222 (1.9 ± 2.0 vs. 1.2 ± 1.3-fold, p = 0.01). High adipose miR-221 and -222 levels were associated with a greater increase in waist circumference (miR-221: beta 1.82, 95% CI 0.57–3.07, p = 0.005; miR-222: beta 1.35, 95% CI 0.08–2.63, p = 0.038), Homeostatic Model Assessment for Insulin Resistance (HOMA) index (miR-221: beta 8.16, 95% CI 2.80–13.53, p = 0.003; miR-222: beta 6.59, 95% CI 1.13–12.05, p = 0.018), and insulin requirements (miR-221: beta 0.05, 95% CI 0.006–0.09, p = 0.02; miR-222: beta 0.06, 95% CI 0.02–0.11, p = 0.002) after PD. The plasma miR-222 level predicted the onset of NODM (OR 8.25, 95% CI 1.35–50.5, p = 0.02). Conclusion: miR-221 and -222 are associated with the progression of obesity, insulin resistance, and NODM after PD. [ABSTRACT FROM AUTHOR]

Background Peritoneal dialysis (PD) is a home-based renal replacement therapy. Since hospital staff are not often familiar with PD and its complications, PD patients may have an excess risk of developing PD-related peritonitis during hospital admission for unrelated reasons, and the outcome may be affected. Methods We reviewed 371 episodes of hospital-acquired PD peritonitis in our center from 2000 to 2019. Their clinical characteristics and outcomes were compared with 825 episodes that required hospital admission and 1964 episodes that were treated as outpatient. Results Hospitalized PD patients had a significantly higher risk of developing peritonitis than outpatients [incident rate ratio 4.41 (95% confidence interval 3.95–4.91]. Hospital-acquired peritonitis episodes were more commonly culture negative. Bacterial isolates from the hospital-acquired episodes were more likely resistant to ceftazidime (P < .0001) than the other groups. The primary response rate, complete cure rate and overall mortality of the hospital-acquired episodes were 66.6%, 62.0%, and 23.2%, respectively, all worse than episodes that developed outside the hospital (P < .0001 for all). Conclusion PD patients admitted to the hospital had a 4-fold increase in the risk of developing peritonitis. Hospital-acquired peritonitis episodes were more likely culture negative and resistant to antibiotics. They also had a lower primary response rate, a lower complete cure rate and higher mortality than episodes that developed outside the hospital. [ABSTRACT FROM AUTHOR]

Background There are limited data on the association of adipose microRNA expression with body composition and adverse clinical outcomes in patients with advanced chronic kidney disease (CKD). We aimed to evaluate the association of adipose miR-130b and miR-17-5p expressions with body composition, functional state, cardiovascular outcome and mortality in incident dialysis patients. Methods We performed a single-center prospective cohort study. Patients who were planned for peritoneal dialysis were recruited. miR-130b and miR-17-5p expressions were measured from subcutaneous and pre-peritoneal fat tissue obtained during peritoneal dialysis catheter insertion. Body composition and physical function were assessed by bioimpedance spectroscopy and Clinical Frailty Scale. Primary outcome was 2-year survival. Secondary outcomes were 2-year technique survival and major adverse cardiovascular event (MACE) rate. Results Adipose expression of miR-130b and miR-17-5p correlated with parameters of muscle mass including intracellular water (miR-130b: r = 0.191, P = 0.02; miR-17-5p: r = 0.211, P = 0.013) and lean tissue mass (miR-17-5p: r = 0.176, P = 0.04; miR-17-5p: r = 0.176, P = 0.004). miR-130b expression predicted frailty significantly (P = 0.017). Adipose miR-17-5p expression predicted 2-year all-cause survival (P = 0.020) and technique survival (P = 0.036), while miR-130b expression predicted incidence of MACE (P = 0.015). Conclusions Adipose miR-130b and miR-17-5p expressions correlated with body composition parameters, frailty, and predicted cardiovascular events and mortality in advanced CKD patients. [ABSTRACT FROM AUTHOR]

Patients treated with peritoneal dialysis (PD) experience complex body composition changes that are not adequately reflected by traditional anthropometric parameters. While lean and adipose tissue mass can be readily assessed by bioimpedance spectroscopy (BIS), there is concern about the potential confounding effect of volume overload on these measurements. This study aimed to assess the influence of fluid status (by echocardiography) on body composition parameters measured by BIS and to describe the longitudinal changes in adipose and lean tissue mass. We conducted a prospective observational study in a tertiary hospital. Incident Chinese PD patients underwent baseline echocardiography and repeated BIS measurements at baseline and 12 months later. Among 101 PD patients, lean tissue index (LTI) or fat tissue index (FTI) was not associated with echocardiographic parameters that reflected left ventricular filling pressure (surrogate of volume status). Sixty-eight patients with repeated BIS had a significant increase in body weight and FTI, while LTI remained similar. Gains in fat mass were significantly associated with muscle wasting (beta = −0.71, p < 0.0001). Moreover, progressive fluid accumulation independently predicted decrease in FTI (beta = −0.35, p < 0.0001) but not LTI. Body composition assessments by BIS were not affected by fluid status and should be considered as part of comprehensive nutrition assessment in PD patients. [ABSTRACT FROM AUTHOR]

The therapeutic modulation of the gut microbiome has been suggested to be one of the tools in the integrated management of chronic kidney disease (CKD) in recent years. Lactobacillus and Bifidobacterium genera are the two most commonly used probiotics strains. Most of the probiotics used in studies are mixed formulation. There is no consensus on the dose and duration of the probiotic administration for CKD patients Increasing evidence indicates that patients with early stage (1–2) CKD have an altered quantitative and qualitative microbiota profile. However, there was a dearth of prospective controlled studies on the use of probiotics in the early stage of the CKD population. The association between gut microbiota disturbance and advanced CKD was reported. Most randomized controlled trials on probiotic treatment used in CKD stage 3–5ND patients reported positive results. The metabolites of abnormal gut microbiota are directly involved in the pathogenetic mechanisms of cardiovascular disease and inflammation. We summarized 13 studies performed in the dialysis population, including 10 in hemodialysis (HD) patients and 3 in peritoneal dialysis (PD). Some controversial results were concluded on the decreasing plasma concentration of uremic toxin, symptoms, inflammation, and cardiovascular risk. Only three randomized controlled trials on PD were reported to show the potential beneficial effects of probiotics on inflammation, uremic toxins and gastrointestinal symptoms. There is still no standard in the dosage and duration of the use of probiotics in CKD patients. Overall, the probiotic administration may have potential benefit in improving symptoms and quality of life, reducing inflammation, and delaying the progression of kidney failure. Further research studies using a larger sample size with longer follow-up durations and a greater focus on clinical outcomes—including survival—are warranted to elucidate the significant clinical impact of the use of probiotics in CKD patients. [ABSTRACT FROM AUTHOR]

In developed countries, diabetes is the leading cause of chronic kidney disease (CKD) and accounts for 50% of incidence of end stage kidney disease. Despite declining prevalence of micro- and macrovascular complications, there are rising trends in renal replacement therapy in diabetes. Optimal glycemic control may reduce risk of progression of CKD and related death. However, assessing glycemic control in patients with advanced CKD and on dialysis (G4-5) can be challenging. Laboratory biomarkers, such as glycated haemoglobin (HbA1c), may be biased by abnormalities in blood haemoglobin, use of iron therapy and erythropoiesis-stimulating agents and chronic inflammation due to uraemia. Similarly, glycated albumin and fructosamine may be biased by abnormal protein turnover. Patients with advanced CKD exhibited heterogeneity in glycemic control ranging from severe insulin resistance to 'burnt-out' beta-cell function. They also had high risk of hypoglycaemia due to reduced renal gluconeogenesis, frequent use of insulin and dysregulation of counterregulatory hormones. Continuous glucose monitoring (CGM) systems measure glucose in interstitial fluid every few minutes and provide an alternative and more reliable method of glycemic assessment, including asymptomatic hypoglycaemia and hyperglycaemic excursions. Recent international guidelines recommended use of CGM-derived Glucose Management Index (GMI) in patients with advanced CKD although data are scarce in this population. Using CGM, patients with CKD were found to experience marked glycemic fluctuations with hypoglycemia due to loss of glucose and insulin during haemodialysis (HD) followed by hyperglycemia in the post-HD period. On the other hand, during peritoneal dialysis, patients may experience glycemic excursions with influx of glucose from dialysate solutions. These undesirable glucose exposure and variability may accelerate decline of residual renal function. Although CGM may improve the quality of glycemic monitoring and control in populations with CKD, further studies are needed to confirm the accuracy, optimal mode and frequency of CGM as well as their cost-effectiveness and user-acceptability in patients with advanced CKD and dialysis. [ABSTRACT FROM AUTHOR]

Background The global prevalence of both obesity and end-stage kidney diseases (ESKDs) has increased in recent decades. Given the complicated interaction between obesity and ESKD, we examined the change in the prevalence of obesity in incident Chinese peritoneal dialysis (PD) patients over the past 25 years. Methods We reviewed the anthropometric measures of incident PD patients in a single Hong Kong center from 1995 to 2019. The results are reported in five 5-year periods. Patients with and without diabetes were analyzed separately, and the incidence of new-onset diabetes after PD was explored. Results We reviewed 1681 patients. Their mean age was 58.4 ± 12.5 years; 931 patients (55.4%) had pre-existing diabetes. From 1995–99 to 2015–19, the prevalence of obesity or overweight at the initiation of PD increased progressively for every 5-year period (from 21.9% to 26.2, 37.9, 42.7 and 47.3%, P < 0.001 for linearity). The increase in the prevalence of obesity or overweight was more pronounced in diabetic patients (from 33.7% to 59.6%) than non-diabetic ones (from 13.2% to 32.3%). Among nondiabetics patients, the incidence of new-onset diabetes after started on PD showed an insignificant rising trend during that period (from 18.0, 19.7, 17.8 and 22.4% to 23.3%, P = 0.106). The incidence of new-onset impaired fasting glucose or diabetes was significantly higher in obese or overweight patients than the others (56.9% versus 51.4%, P < 0.001). Conclusions The prevalence of obesity has increased substantially in both diabetic and nondiabetic new PD patients in Hong Kong over the past 25 years. The incidence of new-onset diabetes was significantly higher in new PD patients with pre-existing obesity or overweight than those without obesity. The prognostic implication and impacts on the healthcare system deserve further studies. [ABSTRACT FROM AUTHOR]

Background: Basal metabolic rate is associated with cancer, but these observations are open to confounding. Limited evidence from Mendelian randomization studies exists, with inconclusive results. Moreover, whether basal metabolic rate has a similar role in cancer for men and women independent of insulin-like growth factor 1 increasing cancer risk has not been investigated. Methods: We conducted a two-sample Mendelian randomization study using summary data from the UK Biobank to estimate the causal effect of basal metabolic rate on cancer. Overall and sex-specific analysis and multiple sensitivity analyses were performed including multivariable Mendelian randomization to control for insulin-like growth factor 1. Results: We obtained 782 genetic variants strongly (p -value < 5 × 10–8) and independently (r 2 < 0.01) predicting basal metabolic rate. Genetically predicted higher basal metabolic rate was associated with an increase in cancer risk overall (odds ratio, 1.06; 95% confidence interval, 1.02–1.10) with similar estimates by sex (odds ratio for men, 1.07; 95% confidence interval, 1.002–1.14; odds ratio for women, 1.06; 95% confidence interval, 0.995–1.12). Sensitivity analyses including adjustment for insulin-like growth factor 1 showed directionally consistent results. Conclusion: Higher basal metabolic rate might increase cancer risk. Basal metabolic rate as a potential modifiable target of cancer prevention warrants further study. [ABSTRACT FROM AUTHOR]

Background: Physical frailty contributes to adverse clinical outcomes in peritoneal dialysis (PD) patients. Little has been reported about frailty transitions in this population. We aimed to describe the transitions of frailty in PD patients and identify factors that predicted changes in frailty state. Methods: In a prospective observational study, we recruited 267 PD patients. Frailty was assessed by a validated frailty score. Depression was graded by PHQ-9 score, and nutritional status was evaluated by serum albumin, Subjective Global Assessment (SGA), and comprehensive Malnutrition Inflammation Score (MIS). The primary outcome was the change in frailty score at follow-up compared to baseline. Results: At baseline, 194 (72.7%) patients were classified as frail. With time, their frailty scores significantly increased (p < 0.001), and 93 of the surviving subjects (78.2%) were classified as frail. There was a modest significant correlation between change in MIS (p < 0.001), change in SGA score (p < 0.001), and change in PHQ-9 score (p < 0.001) with change in frailty score. An increase in PHQ-9 score (p < 0.001) and MIS (p = 0.001), as well as longer duration of hospitalization (p = 0.001), was independently associated with a greater change in frailty score after adjustment for confounding factors. Frailty score was also improved in patients who were converted to hemodialysis (p = 0.048) and received renal transplantation (p = 0.005). Conclusion: Our findings suggested that frailty transitions were common in PD patients. Worsening in nutrition and depression, together with a longer duration of hospitalization, were associated with worsening in frailty. [ABSTRACT FROM AUTHOR]

Background Dialysate sodium (DNa) prescription policy differs between haemodialysis (HD) units, and the optimal DNa remains uncertain. We sought to summarize the evidence on the agreement between prescribed and delivered DNa, and whether the relationship varied according to prescribed DNa. Methods We searched MEDLINE and PubMed from inception to 26 February 2020 for studies reporting measured and prescribed DNa. We analysed results reported in aggregate with random-effects meta-analysis. We analysed results reported by individual sample, using mixed-effects Bland–Altman analysis and linear regression. Pre-specified subgroup analyses included method of sodium measurement, dialysis machine manufacturer and proportioning method. Results Seven studies, representing 908 dialysate samples from 10 HD facilities (range 16–133 samples), were identified. All but one were single-centre studies. Studies were of low to moderate quality. Overall, there was no statistically significant difference between measured and prescribed DNa {mean difference = 0.73 mmol/L [95% confidence interval (CI) −1.12 to 2.58; P = 0.44]} but variability across studies was substantial (I 2 = 99.3%). Among individually reported samples (n  = 295), measured DNa was higher than prescribed DNa by 1.96 mmol/L (95% CI 0.23–3.69) and the 95% limits of agreement ranged from −3.97 to 7.88 mmol/L. Regression analysis confirmed a strong relationship between prescribed and measured DNa, with a slope close to 1:1 (β  = 1.16, 95% CI 1.06–1.27; P < 0.0001). Conclusions A limited number of studies suggest that, on average, prescribed and measured DNa are similar. However, between- and within-study differences were large. Further consideration of the precision of delivered DNa is required to inform rational prescribing. [ABSTRACT FROM AUTHOR]

Background Relapsing and recurrent peritonitis episodes are major causes of technique failure in peritoneal dialysis (PD). We examined the efficacy of extended antibiotic therapy for the prevention of relapsing and recurrent peritonitis. Methods From February 2016 to November 2018 we recruited 254 PD patients who fulfilled the diagnostic criteria for PD peritonitis. They were randomized to a standard group, with the duration of intraperitoneal (IP) antibiotic treatment following the International Society for Peritoneal Dialysis (ISPD) guideline according to the causative microorganisms, and an extended group, with 1 extra week of IP antibiotics. The primary endpoint was relapsing, recurrent or repeat peritonitis episodes within 6 months. Results The primary endpoint developed in 36 and 29 patients of the extended and standard groups, respectively (28.3% versus 22.8%; P = 0.34). The rate of complete cure, without relapsing, recurrent or repeat peritonitis within 6 months, was 63.8 and 69.3% for the extended and standard groups, respectively (P = 0.35). Repeat peritonitis episodes were more common in the extended than the standard group (15.0% versus 5.5%; P = 0.013). Conclusions In patients with PD-related peritonitis, extending the antibiotic therapy for 1 extra week beyond the ISPD protocol should not be recommended. Extending the treatment does not reduce the risk of relapsing or recurrent peritonitis episodes but rather is associated with a higher risk of repeat peritonitis episodes. [ABSTRACT FROM AUTHOR]

Essential and nonessential element concentrations in human blood provide important information on the nutritional status of individuals and can assist in the screening or diagnosis of certain disorders and their association with other causative factors. A simple and sensitive method, suitable for use with small sample volumes, for quantification of multiple trace element concentrations in whole blood and plasma has been developed using inductively coupled plasma-mass spectrometry. Method validation was performed using standard reference materials of whole blood and serum using varying sample treatments with nitric acid, water and hydrogen peroxide. The method was applied to quantify the trace element concentrations in whole blood and plasma samples (0.1 mL) from 50 adult blood donors in Queensland. The whole blood sample (5 mL) was collected in Vacutainer tubes with K2EDTA as anticoagulant. The developed method was able to quantify, in blood and plasma samples over a wide range of concentrations, several essential elements: cobalt, copper, zinc, iron, manganese and selenium; the nutritionally probably essential elements vanadium and strontium; and nonessential elements including lead, cadmium, arsenic, caesium, barium, thallium and uranium. Significant differences (P  < 0.0001) were observed between whole blood and plasma concentrations for 13 elements; 5 of the measured elements, cobalt (0.49 vs. 0.36 μg/L), copper (1.0 vs. 0.75 mg/L), strontium (28 vs. 16 μg/L), barium (1.5 vs. 0.64 μg/L) and thallium (0.06 vs. 0.03 μg/L), had higher mean concentrations in plasma than in blood. Whole blood concentrations of nine trace elements were significantly correlated (P  < 0.0001) with plasma concentrations. The distribution of the trace elements between human blood and plasma varied considerably for the different elements. These results indicate that, using a small sample volume, this assay is suitable for the evaluation of nutritional status as well as in monitoring human toxic elemental exposures. [ABSTRACT FROM AUTHOR]