Strong association between malnutrition, inflammation, and atherosclerosis in chronic renal failure

Late Renal Transplant Failure: An Adverse Prognostic Factor at Initiation of Peritoneal Dialysis

Background

Early renal transplant failure necessitating a return to dialysis has been shown to be a poor prognostic factor for survival. Little is known about the outcome of patients with late transplant failure returning to dialysis. It was our clinical impression that late transplant failure (>2 months) carries an increased morbidity and mortality risk in patients returning to dialysis.

Objective

To determine whether patients with a failed renal transplant have an outcome different to those on dialysis who have never received a kidney transplant.

Setting

Peritoneal dialysis (PD) unit in a teaching hospital.

Patients and Design

All failed renal transplant patients (fTx) in the Toronto Hospital Peritoneal Dialysis program between 1989 and 1996 were identified. This cohort of 42 fTx patients was compared with a cohort of randomly selected never-transplanted PD patients (non-Tx). The PD program was selected because of the availability of well-documented patient archival material. The non-Tx group was matched for age and presence of diabetes. Data were collected until retransplantation, change of dialysis modality or center, death, or until June 1998.

Results

There was no difference at initiation of PD between groups in serum albumin, residual renal function, or mean serum parathyroid hormone level. The mean low-density lipoprotein level was significantly higher in the fTx cohort. The duration of dialysis before Tx in fTx patients accounted for the increased total length of dialysis in fTx (mean 15 months). However, post-Tx the duration of PD was similar for both groups (30.7 months for fTx vs 31.6 months for non-Tx). The fTx group had a considerably worse outcome than the non-Tx group. The time to first peritonitis, subsequent episodes of peritonitis, catheter change, or transfer to hemodialysis occurred at a much faster rate in fTx patients. The most dramatic difference was in survival. There were 3 deaths in the non-Tx group and 12 in the fTx group ( p < 0.01). The mean age at time of death in the fTx group was 47.5 years. Deaths were due mainly to gram-negative peritonitis and cardiovascular disease.

Conclusions

W e conclude that late failed renal transplant patients starting dialysis are at increased risk of complications and have strikingly higher mortality rates than non-Tx patients. A previously failed kidney transplant can be considered an adverse prognostic factor for patients commencing PD; these patients need to be closely monitored. Although this study was limited to PD patients, the same principles likely apply to fTx patients returning to any form of renal replacement therapy.

Biocompatibility of New Peritoneal Dialysis Solutions: What Can We Hope to Achieve?

Despite the bioincompatibility of the “old”, standard, high glucose, lactate-buffered peritoneal dialysis (PD) solutions, PD is itself a highly successful dialysis modality with patient survival equivalent to that of hemodialysis (HD) during the initial 3 – 5 years of dialysis therapy. Nevertheless, PD technique survival is often limited by infectious complications and alterations in the structure and function of the peritoneal membrane. These local changes also have a negative impact on patient survival owing to systemic effects such as those often seen in patients with high peritoneal transport rate and loss of ultrafiltration (UF) capacity.

Patient mortality remains unacceptably high in both HD and PD patients, with most premature deaths being associated with signs of malnutrition, inflammation, and atherosclerotic cardiovascular disease (MIA syndrome). These systemic signs are likely to be influenced by PD solutions both directly and indirectly (via changes in the peritoneal membrane). New, biocompatible PD solutions may have favorable local effects (viability and function of the peritoneal membrane) and systemic effects (for example, on MIA syndrome). Amino acid–based solution [Nutrineal (N): Baxter Healthcare Corporation, Deerfield, IL, U.S.A.] may improve nutritional status as well as peritoneal membrane viability. Bicarbonate/lactate–buffered solution [Physioneal (P): Baxter Healthcare Corporation] may ameliorate local and systemic effects of low pH, high lactate, and high glucose degradation products. Icodextrin-based solution [Extraneal (E): Baxter Healthcare SA, Castlebar, Ireland] may improve hypertension and cardiovascular problems associated with fluid overload and may extend time on therapy in patients with loss of UF capacity.

The positive effects of each of these new, biocompatible solutions have been demonstrated in several studies. It is likely that the combined use of N, P, and E solutions will produce favorable synergies in regard to both local effects (peritoneal viability) and systemic effects (less malnutrition, inflammation, and fluid overload). Solution combination is an exciting area for clinical study in the coming years. Furthermore, dialysis fluid additives such as hyaluronan, which protects and improves the function of the peritoneal membrane, may further improve PD solutions. The new, biocompatible PD solutions represent an entirely new era in the evolution of the PD therapy; they are likely to have markedly positive effects on both PD technique and PD patient survival in coming years.

Peritoneal Transport Characteristics, Comorbid Diseases and Survival in CAPD Patients

Objective

To evaluate the influence of initial peritoneal transport rate, serum albumin concentration, and comorbid diseases on continuous ambulatory peritoneal dialysis (CAPD) patient survival.

Design

A prospective single-center study with a long-term follow-up.

Patients

A total of 213 consecutive CAPD patients, who underwent a peritoneal equilibration test (PET) at a mean of 7 days (range 3 – 30 days) after beginning CAPD, were included in this study. One hundred twenty patients were male, 116 patients had comorbid diseases, and mean age was 49.5 years (range 18 – 76 years).

Methods

A modified PET was performed using 4.25% glucose dialysis solution. Based on the dialysate-to-plasma creatinine concentration ratio at 4 hours’ dwell (D4/P4Cr, 0.62 ± 0.14), patients were divided into high (H), high-average (HA), low-average (LA), or low (L) transporters.

Results

Of 213 patients, 16.9% were classified as H transporters, 30.5% as HA, 36.6% as LA, and 16.0% as L transporters. The H transporter group had a higher proportion of men, higher proportion of patients with comorbid diseases, lower initial serum albumin concentration, lower D4/D0glucose, and lower drained volume. The initial D4/P4Cr correlated with initial serum albumin ( r = –0.35, p < 0.001). The patients with comorbid diseases had lower initial serum albumin and higher initial D4/P4Cr. On Kaplan–Meier analysis, 2-year patient survival of group H was significantly lower compared to the other groups combined (57.1% vs 79.5%, p = 0.009). On Cox proportional hazards analysis, age, comorbid diseases, initial serum albumin concentration, and initial D4/P4Cr were found to be independent risk factors for mortality. However, in the patients without comorbid diseases, patient survival was not different between group H and the other transport groups combined ( p > 0.05), and only age was found to be an independent risk factor for mortality.

Conclusion

These data suggest that a high peritoneal transport rate at initial PET is associated with high mortality, and that this is in part due to an increased prevalence of comorbid disease in H transporters. These H transporters with comorbid diseases represent a subset of patients with an especially poor prognosis. In patients without comorbid diseases, high transport status or low serum albumin concentration was not an independent risk factor for mortality.

Influence of Peritoneal Transport Rate, Inflammation, and Fluid Removal on Nutritional Status and Clinical Outcome in Prevalent Peritoneal Dialysis Patients

Objective

To evaluate the possible associations between peritoneal transport rate (PTR), fluid removal, inflammation, and nutritional status in patients treated with peritoneal dialysis (PD) for more than 6 months, and the impact of these factors on subsequent patient survival.

Design and Patients

A prospective study of 82 PD patients (48 males) that had been treated with PD more than 6 months. Based on the dialysate-to-plasma creatinine ratio at 4 hours of dwell (D/PCr; mean ± 1 SD), the patients were classified as having a high (H), high-average (HA), low-average (LA), or low (L) PTR.

Setting

Single PD unit in a university hospital.

Main Outcome Measures

The PTR, evaluation of adequacy of dialysis and nutritional status, and biochemical analyses were assessed at 10.8 ± 2.8 months after the start of PD.

Results

Compared to L and LA (L/LA) transporters, H and HA (H/HA) transporters had increased dialysate protein loss, glucose absorption from dialysate, and peritoneal creatinine clearance (CCr), and decreased night ultrafiltration volume and total Kt/V urea. However, nutritional variables, 24-hour total fluid removal (TFR), total CCr, and residual renal function were not significantly different between the two groups. The 24-hour TFR correlated significantly with D/PCr (rho = –0.25), mean arterial pressure (rho = –0.23), serum albumin (rho = 0.25), normalized protein equivalent of total nitrogen appearance (rho = 0.34), lean body mass (LBM) calculated from creatinine kinetics (rho = 0.41), total Kt/V urea (rho = 0.42), and total CCr (rho = 0.30). The group with serum C-reactive protein (sCRP) ⊕ 10 mg/L had a higher proportion of patients with reduced (< 1000 mL) TFR compared to the group with sCRP < 10 mg/(38% vs 16%, p = 0.04). Two-year patient survival rates from the time of the assessment were not different between the different transport groups (78% vs 73% for H/HA and L/LA, p = 0.99). Upon Cox proportional hazards multivariate analysis, age and high sCRP were independent predictors of mortality.

Conclusions

This study shows that, in a selected group of prevalent PD patients assessed after more than 6 months of PD therapy, ( 1 ) inflammation was an independent predictor for mortality; ( 2 ) reduced TFR was associated with impaired nutritional status, decreased small solute clearance, and inflammation; and ( 3 ) peritoneal transport status was not significantly associated with nutritional status and was not associated with subsequent patient survival. These results indicate that a high peritoneal solute transport rate, as such, should not be regarded as a relative contraindication for PD. Instead, the results suggest that more attention should be given to inflammation and inadequate fluid removal as predictors of mortality in PD patients.

Comparison between DOQI and Canadian Guidelines for Peritoneal Dialysis

The recently published Canadian Society of Nephrology (CSN) Guidelines for Peritoneal Dialysis Adequacy differ in a number of ways from the United States National Kidney Foundation Dialysis Outcomes Quality Initiative (DOQI) guidelines on the same topic. The three main differences are ( 1 ) the CSN targets are the same for continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD), whereas the DOQI targets are higher for APD; ( 2 ) the CSN guidelines have a lower creatinine clearance (CCr) target of 50 L/wk for low and low-average transporters compared to 60 L/wk for high and high-average transporters, but no such distinction is made by DOQI; and ( 3 ) the CSN has set lower limit targets as well as preferred targets for Kt/V and CCr.

Other differences are that the CSN recommendations do not give Kt/V the same primacy over CCr that DOQI does. Also, the CSN recommendations give greater emphasis to the risks associated with high transport status.

This review looks at the reasons for these differences and demonstrates that some are due to information that has become available since the publication of the DOQI guidelines. However, it is emphasized that, when recommendations are predominantly opinion- rather than evidence-based, geographic and economic factors may also account for differences.

Chronic Inflammation in Peritoneal Dialysis: The Search for the Holy Grail?

Mortality and morbidity in chronic kidney disease (CKD) patients are unacceptably high. The annual mortality rate due to cardiovascular disease (CVD) is approximately 9%, which, for the middle-aged person, is at least 10- to 20-fold higher than for the general population. Classic risk factors for CVD are highly prevalent in CKD patients, but they cannot fully account for the excessive rate of CVD in this population. Instead, it has become increasingly clear that nontraditional risk factors, such as systemic inflammation, may play a key role in the development of atherosclerosis. It is well established that inflammatory markers are very powerful predictors of high CVD morbidity and mortality not only in the general population, but particularly in CKD patients. Signs of a sustained low-grade inflammation, such as increased levels of C-reactive protein (CRP), are present in the majority of stage 5 CKD patients, even in patients in clinically stable condition, and they are also commonly observed after the initiation of dialysis therapy. Dialysis therapy — hemodialysis as well as peritoneal dialysis (PD) — may itself contribute to systemic inflammation. Local intraperitoneal inflammation can also occur in patients treated with PD. These local effects may result in a low-grade inflammation, caused by the bioincompatibility of conventional glucose-based dialysis fluids, to intense inflammation associated with peritonitis. Given these circumstances, it is reasonable to hypothesize that strategies aiming to reduce inflammation are potentially important and novel, and could serve to reduce CVD, thereby lowering morbidity and mortality in patients with CKD. In this review we provide information supporting the hypothesis that systemic inflammation is tightly linked to the most common complications of CKD patients, in particular those on PD, and that local inflammation in PD may contribute to various related complications. The aims of this review are to discuss the reasons that make inflammation an attractive target for intervention in CKD, the particular aspects of the inflammation–CVD axis during PD treatment that are likely involved, and possible means for the detection and management of chronic inflammation in PD patients.

Peritoneal Albumin Excretion is a Strong Predictor of Cardiovascular Events in Peritoneal Dialysis Patients: A Prospective Cohort Study

Background

Microalbuminuria is a marker of systemic endothelial dysfunction. We hypothesize that peritoneal albumin excretion in peritoneal dialysis (PD) patients, which is conceptually analogous to microalbuminuria in nonuremic patients, can predict cardiovascular disease in new PD patients.

Method

We studied peritoneal albumin excretion in 43 new PD patients. They were then followed prospectively for the development of cardiovascular events. All-cause mortality and duration of hospitalization for cardiovascular diseases were also recorded.

Result

The average duration of follow-up was 26.5 ± 17.6 months. During the follow-up period, 15 patients developed cardiovascular events. Event-free survival at 36 months was 81.4% and 53.6% for low (<300 mg/L) and high (≥300 mg/L) peritoneal albumin excretion groups respectively (log rank test, p = 0.042). By Cox regression analysis, the only independent factors for event-free survival were diabetic status and peritoneal albumin excretion rate. For every 100 mg/L increase in peritoneal albumin excretion, the adjusted hazard ratio of developing a cardiovascular event was 1.83 [95% confidence interval (CI) 1.11 – 3.02, p = 0.018]. Actuarial patient survival at 36 months was 85.7% and 59.1% for low and high peritoneal albumin excretion groups respectively (log rank test, p = 0.10). After adjusting for the duration of follow-up for individual patients, the average duration of hospitalization was 9.1 ± 16.2 and 21.7 ± 25.7 days per year of follow-up for low and high peritoneal albumin excretion groups respectively (Mann–Whitney U test, p = 0.012).

Conclusion

Although the sample size of our present study is small and does not have adequate statistical power, we conclude that peritoneal albumin excretion may be an important predictor of cardiovascular disease. Further studies are needed to examine the role of dialysate albumin excretion as a means of cardiovascular risk stratification in PD patients.

The Time Course of Serum C-Reactive Protein is More Predictive of Mortality than its Baseline Level in Peritoneal Dialysis Patients

Background

Several recent studies reported that a high baseline serum C-reactive protein (CRP) is a powerful predictor of mortality in dialysis patients. However, the acute-phase response is intermittent and not a continuous feature in an individual patient. The aim of this prospective study was to determine whether serial analysis of serum CRP during follow-up allows better prediction of mortality and echocardiographic cardiac disease than a single baseline measurement in peritoneal dialysis (PD) patients.

Methods

97 PD patients were monitored for 3 years from the beginning of the treatment. We evaluated the effect of demographic features, comorbidity, blood pressure, blood biochemistry, including CRP, residual renal function, and indices of dialysis adequacy, on mortality and left ventricular hypertrophy (LVH). Cox regression analysis using both the baseline and the averaged values of the study parameters was carried out to determine factors predicting mortality. Logistic regression analysis was performed to determine which factors were independently predictive for LVH and the type of time course of serum CRP.

Results

Baseline serum CRP was elevated in 29 patients (29.9%). While serum CRP exhibited a stable course (normal or high) in 55 patients (56.7%), it varied considerably over time in 42 patients (43.2%). In the Cox models, both the averaged serum CRP and the type of variability of CRP were predictors of mortality. On the contrary, baseline CRP did not affect adjusted survival. The averaged CRP was also an independent factor affecting LVH, but baseline CRP was not. Age, comorbidity index, instilled dialysate glucose concentration, and Kt/V urea were independently associated with the type of time course of serum CRP.

Conclusion

The averaged value of serum CRP is more predictive of prognosis compared to the baseline value in PD patients. Determining serum CRP on a regular basis may be helpful to detect early signs of tissue damage or asymptomatic inflammation.

Peritoneal Membrane Transport and Hypoalbuminemia: Cause or Effect?

Objective

Peritoneal membrane transport has been associated with serum albumin and clinical outcome. We examined the relationship between serum albumin and peritoneal membrane transport status before and after the initiation of peritoneal dialysis.

Setting

Patients were followed at a tertiary-care regional nephrology program at St. Joseph's Hospital, McMaster University, Hamilton, Ontario, Canada.

Methods

Incident peritoneal dialysis patients between 1 January 1995 and 31 May 1998 were eligible if there was a peritoneal equilibration test within 180 days of starting dialysis, and a serum albumin value measured within 90 days prior to, and 20 to 70 days after initiating dialysis.

Main Outcome Measures

Serum albumin, before and after the initiation of dialysis, and the presence of proteinuric renal disease were compared with the peritoneal equilibration test results.

Results

Among 67 identified patients, there were 7 high, 27 high-average, 26 low-average, and 7 low transporters and the mean serum albumin values before dialysis were 35.1, 37.4, 37.8, and 40.4 g/L, respectively ( p < 0.001). Serum albumin values prior to the initiation of dialysis correlated significantly with the 4-hour D/P creatinine ratio ( r = –0.251, p = 0.040). After initiation of dialysis, the correlation was stronger ( r = –0.447, p < 0.001). Serum albumin prior to initiation of dialysis was lower for those with proteinuric than nonproteinuric renal disease (36.4 g/L vs 38.8 g/L, p = 0.04). The trend to lower serum albumin in high transporters was seen in patients with both proteinuric and nonproteinuric renal disease.

Conclusion

The association between higher peritoneal membrane transport and lower serum albumin is present before initiation of dialysis in both proteinuric and nonproteinuric renal disease. The poor outcomes associated with low serum albumin and higher peritoneal membrane transport might be explained by other underlying factors. The contribution of inflammation, malnutrition, and fluid overload requires further study.

Aortic Valve Calcium Associates with All-Cause Mortality Independent of Coronary Artery Calcium and Inflammation in Patients with End-Stage Renal Disease

BACKGROUND

Aortic valve calcium (AVC) and coronary artery calcium (CAC) are common complications in end-stage renal disease (ESRD). We investigated the prognostic significance of overlapping presence of AVC and CAC, and whether AVC was associated with all-cause mortality independent of the presence of CAC in ESRD.

METHODS

259 ESRD patients (median age 55 years, 67% males) undergoing cardiac computed tomography were included. Framingham risk score (FRS), presence of cardiovascular disease (CVD), statin use, nutritional status and other relevant laboratory data were determined at baseline. During follow-up for median 36 months, 44 patients died, and 68 patients underwent renal transplantation.

RESULTS

The baseline overlap presence of AVC and CAC was 37%. Multivariate regression analysis showed that FRS (odds ratio (OR) 2.25; 95% confidence interval (95% CI), 1.43-3.55) and CAC score (OR (95% CI), 2.18 (1.34-3.59)) were independent determinants of AVC. In competing-risk regression models adjusted for presence of CAC, inflammation, nutritional status, CVD, FRS and statin use, AVC remained independently associated with all-cause mortality (sub-hazard ratio (95% CI), 2.57 (1.20-5.51)).

CONCLUSIONS

The overlap of AVC and CAC was 37% in this ESRD cohort. AVC was associated with increased all-cause mortality independent of presence of CAC, traditional risk factors and inflammation.

What is the Link between Poor Ultrafiltration and Increased Mortality in Anuric Patients on Automated Peritoneal Dialysis? Analysis of Data from Eapos

Background

Primary analysis of the European Automated Peritoneal Dialysis Outcomes Study (EAPOS) found that patients with daily ultrafiltration (UF) below a predefined target of 750 mL at baseline experienced increased mortality and continuing low UF over 2 years.

Setting

Multicenter, prospective observational study of prevalent, functionally anuric patients on automated peritoneal dialysis (APD) treated to predefined standards.

Methods

Secondary data analysis to determine clinical covariates that might support a link between poor UF and outcome, including pattern of comorbidity, prescription, nutrition as determined by Subjective Global Assessment (SGA), membrane function, and blood pressure (BP). Ultrafiltration was treated as a categorical (comparing patients above and below target at baseline) and continuous dependent variable in univariate and multivariate regression. The relationship between BP and survival was also explored.

Results

Of 177 patients recruited from 28 centers across Europe, 43 were below the UF target at baseline. Compared to those above target, there were no differences in the spread of comorbidity, type of APD prescription, SGA, BP, hemoglobin, HCO3, or parathyroid hormone, at baseline or at any later time. At baseline, plasma calcium and, at 12 months, plasma phosphate were lower in the low UF group. There was a weak positive correlation between baseline systolic or diastolic BP and UF, which remained on multivariate analysis but accounted for just 9% of the variability in BP. There was no clear relationship between baseline BP and survival, although, if anything, low BP was associated with earlier death. Poor UF was associated with lower mean dialysate glucose concentration during the first 4 months and with consistently worse membrane function.

Conclusions

The increased mortality associated with poor UF is likely multifactorial and not easily explained by clear differences in comorbidity, nutritional state, or other indices of treatment at baseline. The lower plasma phosphate suggests a subsequent fall in appetite. Poor BP control is unlikely to be the explanation, and a link between lower BP, reduced UF, and earlier death is suggested. Failure to achieve adequate UF due to worse membrane function remains an important and potentially reversible or preventable cause.

Determinants of Peritoneal Solute Transport Rates in Newly Started Nondiabetic Peritoneal Dialysis Patients

Objective

An overrepresentation of a fast peritoneal transport status in new peritoneal dialysis (PD) patients with extensive comorbidity has been reported in some studies. High mass transfer area coefficients (MTACs) of low MW solutes suggest the presence of a large effective peritoneal surface area. The mechanism is unknown. It might include comorbidity, chronic inflammation, or an effect of mesothelial cell mass on peritoneal transport by the production of vasoactive substances. To investigate their relative importance in early PD, peritoneal permeability characteristics in incident PD patients were analyzed for relationships with comorbidity, serum concentrations of inflammatory markers, and products of the mesothelial cells that can be detected in dialysate.

Design

A cross-sectional study.

Setting

A university hospital.

Methods

46 patients who fulfilled the following inclusion criteria were analyzed: a standard peritoneal permeability analysis (SPA) within 6 months after the start of PD, no peritonitis prior to the SPA, older than 18 years, and without diabetes mellitus as a primary renal disease. The patients were divided into tertiles based on the MTAC creatinine: slow, medium, and fast transport groups. The Davies comorbidity score was used to assess comorbidity. Serum and dialysate samples obtained during the SPA were used to determine hyaluronan, interleukin (IL)-6, vascular endothelial growth factor (VEGF), and cancer antigen 125 (CA125). The dialysate concentrations of these substances were expressed as their dialysate appearance rates.

Results

No significant differences were present in the three transport groups for comorbidity, serum concentrations of inflammatory markers, or serum VEGF. Interleukin-6 and VEGF concentration attributed to local VEGF production were not different between the tertiles. Levels of VEGF were higher in the medium transport group compared to the slow transport group ( p = 0.02); CA125 was higher in the fast transport group compared to the medium transport group ( p = 0.01). When analyzed as continuous variables, MTAC creatinine was related to VEGF ( r = 0.33, p < 0.05) and CA125 ( r = 0.41, p = 0.03). In linear regression analysis, VEGF influenced the association between CA125 and MTAC creatinine; IL-6 weakened this association only marginally.

Conclusion

A fast peritoneal transport status in incident nondiabetic PD patients was not related to comorbidity. The relationships found between VEGF, CA125, and MTAC creatinine may suggest a role of VEGF in the regulation of the vascular peritoneal surface area, possibly already before structural abnormalities have developed. Our analyses are consistent with the hypothesis that mesothelial cell mass is an important determinant of the peritoneal transport status in incident nondiabetic PD patients without previous peritonitis. Of the many potential mediators produced by mesothelial cells, VEGF was more important than the inflammation marker IL-6.

High-normal albuminuria is strongly associated with incident chronic kidney disease in a nondiabetic population with normal range of albuminuria and normal kidney function

BACKGROUND

Albuminuria and estimated glomerular filtration rate (eGFR) are clinically measured to evaluate the severity of chronic kidney disease (CKD). The aim of our study was to clarify the association between clinical parameters, including albuminuria and eGFR, and the risk of incident CKD in a nondiabetic population with normal range of albuminuria and eGFR.

METHODS

A 10-year follow-up, retrospective cohort study involving 317 Japanese men (mean age, 42 years) with eGFR ≥ 90 mL/min/1.73 m² and urine albumin-to-creatinine ratio (UACR) < 30 mg/gCr was performed. Participants were free of diabetes mellitus. Multivariate logistic regression approaches were used to assess independent predictors of the incidence of CKD.

RESULTS

Twenty-nine (9%) participants developed CKD (eGFR < 60 mL/min/1.73 m² and/or UACR ≥ 30 mg/gCr) through 10 years of follow-up. At the baseline examination, age, blood pressure, UACR, and eGFR were higher in participants who developed CKD than in those without CKD. After adjustment for confounders, high-normal albuminuria (P < 0.001) and hypertension (P = 0.045) were associated with an increased incidence of CKD. From receiver-operating characteristic curves, UACR ≥ 7.0 mg/gCr was defined as high-normal albuminuria. Logistic regression analysis also showed that, in addition to presence of hypertension, UACR ≥ 7.0 mg/gCr was identified as an independent risk of incident CKD within 10 years after adjustment for age, body mass index, smoking status, and dyslipidemia [UACR: odds ratio (OR) 17.36 (95% CI 6.16-48.93, P < 0.001)].

CONCLUSION

High-normal albuminuria and hypertension are associated with incident CKD in a nondiabetic population with normal-range UACR and eGFR.

Myocardial perfusion reserve of kidney transplant patients is well preserved

Background

Chronic kidney disease (CKD) is associated with endothelial dysfunction and increased cardiovascular mortality. Endothelial dysfunction can be studied measuring myocardial perfusion reserve (MPR). MPR is the ratio of stress and rest myocardial perfusion (MP) and reflects the capacity of vascular bed to increase perfusion and microvascular responsiveness. In this pilot study, our aim was to assess MPR of 19 patients with kidney transplant (CKD stages 2–3) and of ten healthy controls with quantitative [¹⁵O]H₂O positron emission tomography (PET) method.

Results

Basal MP was statistically significantly higher at rest in the kidney transplant patients than in the healthy controls [1.3 (0.4) ml/min/g and 1.0 (0.2) ml/min/g, respectively, p = 0.0015]. After correction of basal MP by cardiac workload [MP_corr = basal MP/individual rate pressure product (RPP) × average RPP of the healthy controls], the difference between the groups disappeared [0.9 (0.2)  ml/min/g and 1.0 (0.3) ml/min/g, respectively, p = 0.55)]. There was no difference in stress MP between the kidney transplant patients and the healthy subjects [3.8 (1.0) ml/min/g and 4.0 (0.9) ml/min/g, respectively, p = 0.53]. Although MPR was reduced, MPR_corr (stress MP/basal MP_corr) did not differ between the kidney transplant patients and the healthy controls [4.1 (1.1) and 4.3 (1.6), respectively, p = 0.8].

Conclusions

MP during stress is preserved in kidney transplant patients with CKD stage 2–3. The reduced MPR appears to be explained by increased resting MP. This is likely linked with increased cardiac workload due to sympathetic overactivation in kidney transplant patients.

Predictive value of the geriatric nutritional risk index in percutaneous coronary intervention with rotational atherectomy

The prognostic value of the geriatric nutritional risk index (GNRI) in patients undergoing percutaneous coronary intervention (PCI) with rotational atherectomy (RA) remains unknown. Therefore, we aimed to clarify whether the GNRI could predict major adverse cardiac events (MACE) in patients undergoing PCI with RA. A total of 206 patients who underwent PCI with RA from January 2009 to December 2017 were retrospectively tracked. The patients were divided into 2 groups based on the GNRI value on admission. MACE comprised all-cause death, target lesion revascularization (TLR), target vessel revascularization (TVR), and myocardial infarction. One year of follow up was completed in 95.6% of patients. During this period, 50 cases of MACE were observed (all-cause death, 32 cases; TLR, 21 cases; and TVR, 2 cases). Patients with a low GNRI (< 98) had a significantly higher incidence of MACE than did patients with a high GNRI (≥ 98) (37.9% vs. 15.5%, log-rank p < 0.05). The GNRI was an independent predictor of MACE (hazard ratio, 0.94; 95% confidence interval [CI], 0.92-0.97). Furthermore, the GNRI had better predictive power than did its components alone (i.e. body mass index and serum albumin level) (net-reclassification improvement, 0.39; 95% CI, 0.07-0.71; p = 0.01; integrated discrimination improvement, 0.02; 95% CI, - 0.01-0.04; p = 0.07). The GNRI on admission is a predictor of MACE after PCI with RA. Further studies are required to determine whether intensive medical therapy could improve clinical events, particularly cardiovascular death and revascularization, in this population.

Selected cardiovascular risk factors in early stages of chronic kidney disease

Cardiovascular diseases, including hypertension, congestive heart failure, myocardial infarction, stroke and atherosclerosis, are common in patients with chronic kidney disease. Aside from the standard biomarkers, measured to determine cardiovascular risk, new ones have emerged: markers of oxidative stress, apoptosis, inflammation, vascular endothelium dysfunction, atherosclerosis, organ calcification and fibrosis. Unfortunately, their utility for routine clinical application remains to be elucidated. A causal relationship between new markers and cardiovascular diseases in patients with chronic kidney disease remains to be established. First of all, there is a lack of large, randomized trials. Moreover, most studies focus on patients with end-stage renal disease as well as on dialysed patients. In such patients, cardiovascular diseases are already present and advanced while early detection of cardiovascular disease risk factor in patients with early-stages of chronic kidney disease would allow more precise prognosis and, as a result, changes in treatment algorithm. In this article, we conduct a comprehensive review of literature for publications relating to cardiovascular risk factors in patients with early-stages of chronic kidney disease. Overall, there are many encouraging advances in detection of cardiovascular risk factors that are making the future more promising for patients suffering from chronic kidney disease.

Bone mineral density at different sites and 5 years mortality in end-stage renal disease patients: A cohort study

BACKGROUND

Bone disease with osteoporosis and renal osteodystrophy is common in end stage renal disease (ESRD) patients and associates with cardiovascular disease (CVD) and increased morbimortality. We investigated associations of low bone mineral density (BMD) at various bone sites with five year all-cause and CVD mortality in ESRD patients.

METHODS

In a post hoc analysis of 426 ESRD patients (median age 56 years, 62% men) starting dialysis, BMD (whole-body dual-energy X-ray absorptiometry, DXA), body composition, nutritional status (subjective global assessment, SGA), handgrip strength (%HGS), Framingham CVD risk score (FRS) and biochemical biomarkers of nutrition and inflammation were assessed. We used the Fine and Gray competing risk regression analysis to assess survival analysis.

RESULTS

In multivariate logistic regression analysis, %HGS and intact parathyroid hormone associated with low tertile of: BMD_total, BMD_head and BMD_pelvis, after adjusting for FRS, SGA, %HGS, s-albumin, hsCRP, lean body mass index and year of recruitment. Patients with high FRS had low BMD_head (p<0.001). Low tertile of BMD_total (sHR, 1.53), BMD_head (sHR 1.54) and BMD_pelvis (sHR 1.60) associated with increased all-cause mortality whereas no such associations were found for the trabecular bone rich sites BMD arm, leg, trunk, rib or spine. Low tertile of BMD_total (sHR 1.94), BMD_head (sHR 1.68), BMD_leg (sHR 2.25) and BMD_pelvis (sHR 2.45) associated with increased CVD mortality whereas BMD at other sites did not associate with CVD mortality.

CONCLUSION

Low head and pelvis BMD, and low total BMD, as assessed by whole-body DXA, were independent predictors of increased risk of all-cause and CVD mortality. Cortical BMD appeared to have stronger association to survival in ESRD than trabecular BMD.

Effect of Dialysis on Aryl Hydrocarbon Receptor Transactivating Activity in Patients with Chronic Kidney Disease

PURPOSE

Elevated aryl hydrocarbon receptor (AhR) transactivating (AHRT) activity and uremia in chronic kidney disease (CKD) may interact with each other, further complicating the disease course. In this study, we prospectively estimated serum AHRT activity using a highly sensitive cell-based AhR-dependent luciferase activity assay in CKD patients and compared differences therein according to treatment modality.

MATERIALS AND METHODS

Patients undergoing peritoneal dialysis (PD) (n=22) and hemodialysis (HD) (n=38) and patients with pre-dialysis CKD stage IV or V (n=28) were included. AHRT activity and intracellular adenosine triphosphate (ATP) levels were measured. We performed a correlation analysis for AHRT activity, ATP levels, and various clinical parameters.

RESULTS

AHRT activity and intracellular ATP levels were inversely correlated and differed according to treatment modalities. AHRT activity was higher in non-dialysis CKD patients than in patients undergoing dialysis and was higher in patients undergoing HD, compared to PD. AHRT activity decreased after HD treatment in HD patients. ATP levels were higher in healthy controls than in patients with pre-dialysis CKD and PD and were further decreased in patients with HD. We noted significant correlations between multiple clinical parameters associated with cardiovascular risk factors and AHRT activity.

CONCLUSION

AHRT activity was elevated in CKD patients, while dialysis treatment reduced AHRT activity. Further studies are warranted to specify AHRT activity and to evaluate the precise roles thereof in patients with CKD.

Inflammation and Oxidative Stress in Chronic Kidney Disease-Potential Therapeutic Role of Minerals, Vitamins and Plant-Derived Metabolites

Chronic kidney disease (CKD) is a debilitating pathology with various causal factors, culminating in end stage renal disease (ESRD) requiring dialysis or kidney transplantation. The progression of CKD is closely associated with systemic inflammation and oxidative stress, which are responsible for the manifestation of numerous complications such as malnutrition, atherosclerosis, coronary artery calcification, heart failure, anemia and mineral and bone disorders, as well as enhanced cardiovascular mortality. In addition to conventional therapy with anti-inflammatory and antioxidative agents, growing evidence has indicated that certain minerals, vitamins and plant-derived metabolites exhibit beneficial effects in these disturbances. In the current work, we review the anti-inflammatory and antioxidant properties of various agents which could be of potential benefit in CKD/ESRD. However, the related studies were limited due to small sample sizes and short-term follow-up in many trials. Therefore, studies of several anti-inflammatory and antioxidant agents with long-term follow-ups are necessary.

Skin autofluorescence, arterial stiffness and Framingham risk score as predictors of clinical outcome in chronic kidney disease patients: a cohort study

BACKGROUND

The risk of cardiovascular disease (CVD) is predicted by Framingham's CVD risk scores (FRS) but the high CVD-related mortality in patients with chronic kidney disease (CKD) is only partially explained by traditional CVD risk markers. Therefore, there is a need to explore whether other CVD risk markers may improve risk prediction. Although arterial stiffness measured by augmentation index (AIx) and tissue content of advanced glycation end-products (AGEs) measured by skin autofluorescence (SAF) are two biomarkers that associate with CVD and mortality in CKD, it is not known how they compare with FRS. We evaluated associations between SAF, AIx and FRS, and their associations with CVD and mortality in CKD patients.

METHODS

SAF (AGE Reader) and AIx (SphygmoCor; adjusted for 75 heart beats per minute) were measured in 261 clinically stable and extensively phenotyped patients with CKD Stage 5 (median age 56 years, 66% male, 20% diabetes; 130 non-dialysed, 93 patients on peritoneal dialysis and 38 patients on haemodialysis). Multivariate receiver operator characteristics (ROC) curve analysis and multivariate Cox models followed by C-statistics were used to evaluate CVD-related and all-cause mortality risk associated with SAF, AIx and FRS during follow-up for median 25 months with 46 deaths.

RESULTS

In multivariate regression analysis, SAF associated with FRS, haemoglobin, fat body mass index and CVD, and inversely with per cent handgrip strength (HGS). AIx associated with FRS, and inversely with per cent HGS. Associations of SAF and AIx with high-sensitivity C-reactive protein (hsCRP), serum albumin, statin therapy and renal replacement therapy were not statistically significant. In ROC analysis, area under the curve (AUC) for CVD mortality ranged from AUC = 0.72 (AIx and FRS, respectively) to AUC = 0.78 (FRS + AIx), and for all-cause mortality from AUC = 0.70 (AIx) to AUC = 0.79 (FRS + AIx). In multivariate Cox analysis, after adjusting for 1-standard deviation (1-SD) of FRS, 1-SD increase of SAF associated with all-cause mortality and 1-SD increase of AIx associated with CVD mortality and all-cause mortality. After further adjustments for hsCRP, albumin and presence of CVD, AIx (but not SAF) remained independently associated with CVD mortality, hazard ratio (HR) 2.14 [95% confidence interval (95% CI) 1.18-3.89] and all-cause mortality, HR 1.74 (95% CI 1.16-2.60).

CONCLUSIONS

In patients with CKD Stage 5, SAF and aortic stiffness associated with mortality, independently of FRS. After adjusting for additional confounders including inflammation, aortic stiffness remained as an independent predictor of outcome. Since the contribution of SAF and aortic stiffness compared with FRS in ROC curve analysis was relatively modest, this underlines the importance of traditional CVD risk factors in CKD.

Malnutrition impairs mitochondrial function and leukocyte activation

BACKGROUND

The aim of this study was to evaluate markers of inflammation, oxidative stress and endothelial function in a disease-related malnutrition (DRM) outpatient population.

METHODS

For this cross-sectional study, a total of 83 subjects were included and clustered in 3 groups: 34 with normonutrition (NN), 21 with DRM without inflammation (DRM-I) and 28 with DRM and inflammation (DRM + I). Nutritional diagnosis was conducted for all subjects according to ASPEN. Biochemical parameters, proinflammatory cytokines, reactive oxygen species production, glutathione, mitochondrial membrane potential, oxygen consumption, adhesion molecules and leukocyte-endothelium interactions were evaluated.

RESULTS

DRM + I patients showed lower albumin, prealbumin, transferrin, and retinol-binding protein levels with respect to the NN group (p < 0.05), differences that were less noticeable in the DRM-I group. DRM + I was associated with a significant increase in hsCRP and IL6 vs the NN and DRM-I groups, and TNFα was increased in both DRM vs NN. DRM was characterised by increased oxidative stress, which was marked by a significant increase in ROS levels and a decrease in mitochondrial membrane potential in the DRM + I group. An evident reduction in mitochondrial oxygen consumption and glutathione concentration was observed in both DRM groups, and was accompanied by increased leukocyte adhesion and adhesion molecules and decreased rolling velocity in the DRM + I group. Furthermore, percentage of weight loss was negatively correlated with albumin, prealbumin, transferrin, O₂ consumption, glutathione and leukocyte rolling velocity, and positively correlated with hsCRP, IL6, TNFα, ROS, leukocyte adhesion, and VCAM-1.

CONCLUSIONS

Our results show that DRM is associated with oxidative stress and an inflammatory state, with a deterioration of endothelial dysfunction in the DRM + I population.

Predictive Model for Mortality Risk Including the Wound, Ischemia, Foot Infection Classification in Patients Undergoing Revascularization for Critical Limb Ischemia

Background:

The aim of this study was to develop a predictive model for mortality risk based on preoperative risk factors, including the Wound, Ischemia, Foot Infection (WIfI) classification, in patients undergoing revascularization for critical limb ischemia.

Methods:

We analyzed a database of the Surgical reconstruction versus Peripheral Intervention in Patients With Critical Limb Ischemia registry, a multicenter, prospective, observational study that included 520 critical limb ischemia patients (192 surgical and 328 endovascular patients).

Results:

Multivariate Cox regression analysis identified old age, impaired mobility, low body mass index, renal failure, heart failure, and high WIfI grade as independent risk factors for all-cause mortality (all P <0.05). The risk score comprising these risk factors discriminated the mortality risk well; the 2-year survival rate was >90% in the first quantile of the risk score and ≈20% in the fifth quantile. The area under the time-dependent receiver operating characteristics curve was 0.829 for thirty-day mortality and 0.811 for 2-year mortality. Adding more detailed preoperative information to the predictive model revealed that cystatin C-based estimated glomerular filtration rate, left ventricular ejection fraction, and cholinesterase levels were additional independent risk factors, but the predictive accuracy of the model was not significantly improved, according to the time-dependent receiver operating characteristics curve and net reclassification improvement.

Conclusions:

The current study developed a risk score for mortality using preoperative risk factors, including the WIfI classification, in critical limb ischemia patients undergoing revascularization.

Geriatric nutrition risk index is associated with renal progression, cardiovascular events and all-cause mortality in chronic kidney disease

BACKGROUND

Malnutrition is common and associated with poor outcomes in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). Recently, the geriatric nutritional risk index (GNRI) was reported as a novel tool for evaluating nutritional status. However, the association between GNRI and renal outcome, cardiovascular (CVD) events, and mortality in patients with CKD remains unclear.

METHODS

A prospective cohort study with adult patients with CKD stages 1-4 was conducted at 39 centers around China starting in 2011. Patients were divided into quartiles (Q1, Q2, Q3, and Q4) according to their GNRI category.

RESULTS

A total of 2791 CKD patients within a median follow-up of 4.38 years were included. A low GNRI quartile was independently associated with progression to ESRD, CVD events, and overall mortality. Compared to that in the Q1 group (the reference group), belonging to a higher GNRI quartile significantly reduced the risk of progression to ESRD in the crude and multivariate-adjusted models. Moreover, a significant inverse association was found between those in the high GNRI quartiles and overall mortality among patients with CKD (HR 0.25; 95% CI 0.15-0.43; p = 0.0007, Q4 vs. Q1) after multivariate adjustment. In addition, there was also a significant association between GNRI and CVD events (HR 0.57; 95% CI 0.39-0.84; p = 0.005, Q4 vs. Q1). Moreover, after adjusting for other confounders, only the Q3 group remained significantly fewer CVD events (HR 0.44; 95% CI 0.19-0.98; p = 0.04).

CONCLUSIONS

These findings suggest that GNRI might be a useful prognostic tool for patients with CKD.

Geriatric Nutritional Risk Index Is Associated with Unique Health Conditions and Clinical Outcomes in Chronic Kidney Disease Patients

Malnutrition is prevalent in patients with chronic kidney disease (CKD). However, current nutrition screening tools are not specific to the CKD population. In the present study, we aimed to investigate whether the geriatric nutritional risk index (GNRI), a simple tool designed for assessing nutrition-related risks in the elderly population, is associated with unique aspects of CKD such as fluid status, residual renal function, proteinuria, and inflammation, and whether it predicts clinical outcomes. The GNRI was calculated by incorporating serum albumin and anthropometric measurements in 326 patients with nondialysis stage 3–5 CKD who were followed up from September 2011 to March 2017 for end-stage renal disease (ESRD) and the composite outcome of all-cause death and cardiovascular events. Patients were stratified into tertiles according to baseline GNRI levels. Patients in the lowest GNRI tertile were more likely to have significantly higher levels of overhydration, proteinuria, and serum inflammatory markers and tended to have lower lean body mass and estimated glomerular filtration rate when compared with patients in the middle and upper GNRI tertiles. In multivariate linear regression analyses, the GNRI was independently associated with overhydration, proteinuria, and interleukin-6. During a median follow-up of 4.9 years, 101 patients developed ESRD; 40 deaths, and 68 cardiovascular events occurred. Patients in the lowest GNRI tertile had significantly increased risks of ESRD (hazard ratio (HR): 3.15, 95% confidence interval (CI): 1.95–5.07, p < 0.001) and the composite outcome (HR: 1.79, 95% CI: 1.10–2.92, p = 0.019) in fully adjusted models (reference: middle and upper GNRI tertiles). The GNRI takes CKD-specific health conditions into account. In addition, CKD patients with lower GNRI scores had a significantly higher risk of adverse clinical outcomes. Our findings suggest that the GNRI is an appropriate tool for nutrition screening and a prognostic predictor among patients with nondialysis stage 3–5 CKD.

Blood pressure modifies outcomes in patients with stage 3 to 5 chronic kidney disease

Observational studies have demonstrated that low blood pressure is related to poor clinical outcomes in patients with chronic kidney disease (CKD). Subgroup analyses from the SPRINT trial showed that targeting systolic blood pressure under 120 mmHg is less beneficial for patients with CKD. Although malnutrition and inflammation are common in patients with advanced CKD, such patients are usually excluded from clinical trials. Therefore, we hypothesized that malnutrition-inflammation-cachexia syndrome could explain this J-shaped relationship. To test this, we studied 2441 patients with CKD stages 3-5 who received anti-hypertensive treatment for at least one year. Averaged blood pressures of the first year were used in the analyses. Fine-Gray competing risks regression showed a J-shaped relationship between continuous systolic blood pressure and end-stage kidney disease (ESKD) with a nadir risk at a systolic blood pressure of 120 mmHg. Adjusted sub-distribution hazard ratios of categorical systolic blood pressure 100-109 and 110-119 mmHg were 2.17 (95% confidence interval: 1.21-3.89) and 1.37 (0.94-1.99) for ESKD, respectively, compared with systolic blood pressures of 120-129 mmHg. Cox regression also showed J-shaped relationships between continuous systolic or diastolic blood pressures, and the composite outcomes of cardiovascular events and all-cause mortality. Logistic regression demonstrated the odds ratios of blood pressure components for Malnutrition-Inflammation Scores over 4 were J-shaped. Sub-distribution hazard ratios of systolic blood pressure 100-119 mmHg for ESKD was higher in those with a Malnutrition-Inflammation Score over 4, compared to 0.93 (0.53-1.63) in those with a score of 4 or under with significant interaction. Thus, malnutrition-inflammation-cachexia syndrome is associated with low blood pressure and modifies the J-shaped relationship in patients with advanced CKD.

Disturbances in Insulin-Glucose Metabolism in Patients With Advanced Renal Disease With and Without Diabetes

CONTEXT

Use of insulin in patients with diabetes and advanced chronic kidney disease (CKD; stages 4 to 5) is challenging and shows great variability among individuals. We explored the mechanisms underlying this variability.

EVIDENCE ACQUISITION

PubMed was searched for articles in English from 1960 to 2018 for advanced CKD and diabetes, glucose and insulin metabolism, insulin clearance, secretion and resistance, plasma insulin concentration, glycemic control, hypoglycemia, insulin dosage, and continuous glucose monitoring (CGM) in CKD.

EVIDENCE SYNTHESIS

The evidence shows that in most patients the daily dose of insulin needs to be significantly reduced with a high degree of variability; in some the dose remains unchanged, and rarely it is increased. The premise that the marked reduction in insulin requirement is essentially attributable to decreased insulin clearance by kidneys leading to prolongation of its plasma half-life, elevated blood insulin concentration, and hypoglycemia is not entirely correct. Other factors including decreases in food intake, insulin secretion, insulin clearance by peripheral tissues, and renal gluconeogenesis play important roles. There is also heightened resistance to insulin due to metabolic acidosis, uremic toxins, inflammatory state, and vitamin D deficiency. Importantly, the magnitude of changes in each of these factors varies between individuals with the same degree of CKD.

CONCLUSIONS

In the presence of diabetes with advanced CKD, the insulin regimen should be individualized based on knowledge of the daily glucose patterns. The use of CGM is promising for safer glycemic control in patients with advanced CKD and diabetes and helps prevent extremes of hypoglycemia and hyperglycemia.

Albumin losses during hemodiafiltration: all dialyzers are not created equal - a case report

Background

Online hemodiafiltration (OL-HDF) is associated with better removal of both small and middle molecules and might improve survival compared to conventional hemodialysis (HD). Nevertheless, hemodiafiltration (HDF) can lead to an increase in albumin loss across the dialyzer, especially with high permeability membrane and high convective volume (CV). We present the case of a patient treated by OL-HDF who developed severe hypoalbuminemia resulting from massive albumin loss into dialysate.

Case presentation

A 71-year-old woman with ESRD started renal replacement therapy in December 2016. She was treated by high volume post-dilution OL-HDF, 4 h, 3 times per week. The dialyzer was the Phylther HF20SD (a 2.0m² heat sterilized high flux (HF) polyphenylene membrane from Bellco). At the initiation of dialysis, the serum albumin was 4.0 g/dl. During the following months, the patient developed severe hypoalbuminemia. The lowest value observed was 2.26 g/dl in July 2017. Diagnostic workup excluded nephrotic syndrome, hepatic failure and malabsorption. The patient was shifted from OL-HDF to standard HF HD, keeping the same dialyzer and dialysis schedule. During the following months, we observed a progressive correction of the hypoalbuminemia (3.82 g/dl at last follow-up). To precise the impact of the epuration technique on the albumin losses in this patient, we measured the amount of albumin in dialysate during one session with the Phylther HF20SD on OL-HDF and one session with the same filter but on standard HD. The CV was 29.0 l for the HDF session. The total albumin losses were 23.6 g on OL-HDF and 4.6 g on HD.

Conclusion

OL-HDF can lead to significant albumin loss into the dialysate, especially with high permeability membrane and high CV. When prescribing post-dilutional OL-HDF, the choice of the dialyzer membrane should be made with caution. Users of the steam sterilized polyphenylene membrane, the Phylther SD, should be informed of the risk of large albumin loss with this membrane during post-dilution OL-HDF.

Chronic inflammation in end-stage renal disease and dialysis

Under normal conditions, inflammation is a protective and physiological response to various harmful stimuli. However, in several chronic debilitating disorders, such as chronic kidney disease, inflammation becomes maladaptive, uncontrolled and persistent. Systemic persistent inflammation has, for almost 20 years, been recognized as a major contributor to the uraemic phenotype (such as cardiovascular disease, protein energy wasting, depression, osteoporosis and frailty), and a predictor of cardiovascular and total mortality. Since inflammation is mechanistically related to several ageing processes (inflammageing), it may be a major driver of a progeric phenotype in the uraemic milieu. Inflammation is likely the consequence of a multifactorial aetiology and interacts with a number of factors that emerge when uraemic toxins accumulate. Beside interventions aiming to decrease the production of inflammatory molecules in the uraemic milieu, novel strategies to increase the removal of large middle molecules, such as expanded haemodialysis, may be an opportunity to decrease the inflammatory allostatic load associated with retention of middle molecular weight uraemic toxins.

Elevated serum procalcitonin level in patients with chronic kidney disease without infection: A case-control study

Background

Inflammation is a necessary component of chronic kidney disease (CKD) that can be attributed to an accumulation of toxins and a reduced clearance of proinflammatory cytokines. Procalcitonin (PCT) is a widely applied biomarker in the diagnosis of infection, and considering the presence of pre‐existing inflammation in CKD patients, the PCT level could be high in such a population; however, no reference value for PCT in CKD patients has been available to date.

Methods

During the present study period, 361 CKD patients and 119 healthy controls were included. The PCT level and other biochemistry parameters were assayed by using a COBAS system. Statistical analysis was conducted to compare the differences in PCT levels and other biochemistry parameters between the two groups, and linear regression was used to assess the correlation between two variables. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the performance of PCT and the optimal cutoff value to differentiate between CKD patients and healthy controls.

Results

The PCT level in CKD patients was significantly higher than that in healthy controls, and among the CKD patients, the PCT level was increased with advanced clinical stage. Moreover, PCT was moderately correlated with CysC. The optimal off‐value was 0.075 with a sensitivity of 94.7% and specificity of 90.8%.

Conclusion

The PCT level was significantly higher in CKD patients than in healthy controls, and the reference value for CKD patients should be adjusted to avoid unnecessary antibiotic treatments which may pose a negative impact on residual renal function.

Restitution volumes at the end of dialysis sessions: A potential influencing factor on patients' haemoglobin levels?

AIM

To evaluate whether haemoglobin (Hb) levels are influenced by the restitution volume (RestVol) at the end of the dialysis session, independently of erythropoiesis-stimulating agents (ESA) and iron doses.

DESIGN

Over 12 months, 4,386 haemodialysis patients from 34 centres were enrolled in this observational descriptive study according to the checklist STrengthening the Reporting of Observational Studies in Epidemiology (STROBE).

METHOD

RestVol, Hb levels, ESA and iron doses of every patient were assessed on a monthly basis. To determine the ideal RestVol, the clinics were classified into three groups according to the restitution volumes at the end of the dialysis sessions.

RESULTS

Mean age was 69 ± 14 years, and 58.9% were men. The evaluation of 665,712 treatments revealed that RestVol of 380 ml seems to be the most efficient, since the clinics in this group managed to reduce ESA consumption with a negligible reduction in Hb levels.

Macrophage polarization in chronic kidney disease: a balancing act between renal recovery and decline?

Macrophages are heterogenous cells of the innate immune system that can fluidly modulate their phenotype to respond to their local microenvironment. They are found throughout the renal compartments, where they contribute to homeostasis and function. However, renal injury activates molecular pathways that initially stimulate differentiation of macrophages into a proinflammatory M1 phenotype. Later in the course of healing, abundant apoptotic debris and anti-inflammatory cytokines induce the production of anti-inflammatory M2 macrophages, which contribute to tissue regeneration and repair. Thus, the dynamic balance of M1 and M2 populations may outline the burden of inflammation and process of tissue repair that define renal outcomes, which has been the impetus for therapeutic efforts targeting macrophages. This review will discuss the role of these phenotypes in the progression of chronic renal injury, potential pathogenic mechanisms, and the promise of macrophage-based therapeutic applications for chronic kidney disease.

The Impact of Prognostic Nutritional Index on Coronary Flow Reserve in Patients with Inflammatory Bowel Disease

Objective

The recurring inflammation of mucosal layer of intestines is known as inflammatory bowel disease (IBD), which can be accompanied by nutritional deficiencies. The association between inflammation and coronary artery disease has been established. Coronary flow reserve (CFR), which is an established method to evaluate combined microvascular and epicardial flow of coronary arteries, can be assessed by using transthoracic echocardiography. The aim of this study was to evaluate the association of Prognostic Nutritional Index (PNI) with CFR in IBD patients.

Method

This prospective study included 101 patients with IBD. These patients were compared to control group (n=32). PNI was calculated by using serum albumin level and lymphocyte count. CFR was assessed by using Doppler echocardiography.

Results

Multivariate regression analysis indicated that the presence of IBD, age (>40 years) and decreased PNI (<53.8) independently predict impairment of CFR. The area under the curve (AUC) was 75.1% (95% CI:0.664-0.838), and PNI levels were significant predictor of low CFR (p<0.001).

Conclusion

This study showed that PNI, which is calculated using the serum level of albumin and lymphocyte count, is a strong predictor of decreased CFR in IBD patients in remission. Our findings support previous studies showing the relationship between PNI and coronary artery disease. This immunonutritional index has only two components and is easy to calculate, and inexpensive.

Targeted VEGF (Vascular Endothelial Growth Factor) Therapy Induces Long-Term Renal Recovery in Chronic Kidney Disease via Macrophage Polarization

Chronic kidney disease (CKD) universally associates with renal microvascular rarefaction and inflammation, but whether a link exists between these 2 processes is unclear. We designed a therapeutic construct of VEGF (vascular endothelial growth factor) fused to an ELP (elastin-like polypeptide) carrier and show that it improves renal function in experimental renovascular disease. We test the hypothesis that ELP-VEGF therapy will improve CKD, and that recovery will be driven by decreasing microvascular rarefaction partly via modulation of macrophage phenotype and inflammation. CKD was induced in 14 pigs, which were observed for 14 weeks. At 6 weeks, renal blood flow and filtration were quantified using multidetector computed tomography, and then pigs received single intrarenal ELP-VEGF or placebo (n=7 each). Renal function was quantified again 4 and 8 weeks later. Pigs were euthanized and renal microvascular density, angiogenic and inflammatory markers, fibrosis, macrophage infiltration, and phenotype were quantified. Loss of renal hemodynamics in CKD was progressively recovered by ELP-VEGF therapy, accompanied by improved renal microvascular density, fibrosis, and expression of inflammatory mediators. Although renal macrophage infiltration was similar in both CKD groups, ELP-VEGF therapy distinctly shifted their phenotype from proinflammatory M1 to VEGF-expressing M2. Our study unravels potential mechanisms and feasibility of a new strategy to offset progression of CKD using drug-delivery technologies. The results indicate that renal recovery after ELP-VEGF therapy was largely driven by modulation of renal macrophages toward VEGF-expressing M2 phenotype, restoring VEGF signaling and sustaining improvement of renal function and microvascular integrity in CKD.

Predictive factors for ambulatory state in critical limb ischemia patients at discharge

[Purpose] In patients with critical limb ischemia, the ambulatory state often has a lasting impact on recovery and wound healing. The aim of this study was to examine the predictive factors connected with the ambulatory state in wounds with critical limb ischemia. [Participants and Methods] This study included 125 inpatients with critical limb ischemia, who underwent physical therapy between January 2015 and December 2018. We retrospectively studied factors from the participant’s medical records and comparisons were made between the ambulatory and non-ambulatory groups. Next, we analyzed the differences between factors using multiple logistic regression analysis. [Results] The factors associated with the ambulatory state in patients with critical limb ischemia, as determined by multiple logistic regression analysis, were knee extension muscle strength, off-loading the foot duration, and the presence or absence of heart disease. [Conclusion] Shortening off-loading the foot period and intensive rehabilitation at an early stage after amputation need to be prioritized to maintain the quality of life and ambulatory status of patients with wounds in critical limb ischemia.

Inflammatory Dietary Pattern Predicts Dyslipidemia and Anemia in Middle-Aged and Older Taiwanese Adults with Declined Kidney Function: A Cross-Sectional Population Study from 2008 to 2010

Dyslipidemia, anemia, and inflammation are associated with declined kidney function. This study investigated the association of inflammatory dietary pattern with dyslipidemia, anemia, and kidney function biomarkers among middle-aged and older Taiwanese adults with declined kidney function. Biochemical data and food frequency questionnaire were obtained from 41,128 participants with estimated glomerular filtration rate (eGFR) <90 mL/min/1.73 m² and positive urinary protein. Inflammatory dietary pattern was identified by reduced rank regression with C-reactive protein (CRP) and neutrophil-to-lymphocyte ratio (N/L) as response variables. Males had higher prevalence of dyslipidemia and higher inflammatory markers, but lower prevalence of anemia and lower eGFR levels compared to females. Inflammatory dietary pattern characterized with low intakes of seafood, grains, vegetables, and fruits but high intakes of meat, eggs, preserved/processed foods, and sugary drinks was associated with an increased risk of dyslipidemia by 21% in males and an increased risk of anemia by 28–47% in both genders. Furthermore, high consumption of inflammatory dietary pattern was associated with reduced eGFR (males β = −0.85, 95% CI −1.26 to −0.43, females β = −0.53, 95% CI −0.98 to −0.08) and increased N/L and/or CRP in both genders. In conclusion, inflammatory dietary pattern is positively associated with dyslipidemia, anemia, and decreased kidney function in middle-aged and older adults with declined kidney function.

Outcomes of Infrainguinal Lower Extremity Bypass Are Superior in Kidney Transplant Recipients Than Patients with Dialysis

Patients with end-stage renal disease (ESRD) whether on dialysis therapy (DT) or who received a kidney transplant (KT) have previously shown unfavorable surgical outcomes. Little is known about the comparative efficacy and durability of lower extremity bypass (LEB) in those patients. The Vascular Quality Initiative database was explored to identify DT or KT recipients (2003-2016) who had LEB. We included 1,714 bypass procedures; DT: 1,512 (88.2%). Primary patency (PP) at 2 year was comparable between KT and DT groups (PP [95% confidence interval {CI}]: 77.0% [69.7%-82.8%] vs. 80.5% [77.8%-82.9%]; P = 0.212), and the risk-adjusted hazard was similar (adjusted hazard ratio [aHR] [95% CI]: 0.89 [0.61-1.30]; P = 0.540). Amputation-free survival (AFS) at 2 year was more favorable in KT group (AFS [95% CI]: 73.1% [66.3%-78.8%] vs. 48.0% [45.4%-50.6%]; P < 0.001), (aHR [95% CI]: 2.29 [1.62-3.23]; P < 0.001). Patients on DT exhibited a higher risk of mortality than KT recipients (aHR [95% CI]: 2.94 [2.07-4.17]; P < 0.001). This study demonstrated superior limb outcomes in KT recipients than patients on DT after LEB. Despite the comparable PP, the risk of amputation or death was doubled in patients on DT compared with KT recipients. Because both groups were similar in several baseline characteristics, the difference in outcome is likely driven by the positive effect of KT on the physiological milieu of these patients.

High Cardiovascular Risk Profile in Young Patients on the Kidney Transplant Waiting List

BACKGROUND

Cardiovascular complications are the leading causes of morbidity and mortality in patients with end-stage renal disease. The risk profile very often contributes to their death while on the waiting list. Most studies have been carried out in older patients with end-stage renal disease, reflecting the general dialysis population. The aim of this study was to analyze the risk profile in young patients with advanced chronic kidney disease on the kidney transplant waiting list.

METHODS

This was a retrospective, single-center study of 748 patients on the kidney transplant waiting list at the University Hospital Essen, Germany. Clinical and laboratory parameters were collected between 2015 and 2016.

RESULTS

Of 748 patients (62% male), the median age was 48 years. Hypertension, coronary heart disease, and diabetes mellitus were the leading comorbidities, and their frequency rose significantly with age. Their median laboratory values did not differ significantly depending on age except for albumin. Hyperuricemia was quite common in our population with a prevalence of about 75% in women and 50% in men throughout all age groups. A total of 26.6% of the patients between 18 and 35 years of age had advanced anemia (hemoglobin < 10 g/dL), and thus they were affected most frequently. Elevated C-reactive protein serum levels were observed in 37.2% of the patients. Regarding the lipid profile, we observed that HDL cholesterol was within the normal range in only among 51.9% of men and 44.3% of women.

CONCLUSIONS

Cardiovascular risk factors are quite common in our cohort and affect young patients similarly.

Clinical Significance of Postoperative Nutritional Status as a Prognostic Factor in Kidney Transplant Recipients

BACKGROUND

Despite advancements in the management of kidney transplantation (KT), kidney transplant recipients (KTRs) have a higher risk of mortality than the age-matched general population. Improvement of long-term graft and patient survival is a significant issue. Therefore we investigated the effects of postoperative nutritional status on graft and patient survival and explored the predictive factors involved in nutritional status.

METHODS

Our retrospective study included 118 KTRs who underwent KT at our hospital. Clinical and laboratory data were obtained from medical charts. The prognostic nutritional index (PNI) was used to assess nutritional status. Changes in nutritional status after KT were monitored and the effect of nutritional status on graft and patient survival was investigated. The variables involved in nutritional status were also explored.

RESULTS

The KTRs in this cohort comprised 66 men and 52 women with a median age of 47 years at KT. There were 16, 32, and 22 cases of cadaveric, preemptive, and ABO-incompatible KTs, respectively. Postoperative PNI gradually improved and was stable from 6 months after KT. Although graft survival was regulated by ABO-compatibility, independent predictors for patient survival were history of dialysis, PNI, and serum-corrected calcium levels. Preemptive KT and inflammatory status contributed to PNI.

CONCLUSIONS

Nutritional status of KTRs improved over time after KT and could contribute to patient survival. Optimal nutritional educational programs and interventions can lead to better outcomes in KTRs. Further studies are needed to validate our results and develop appropriate nutritional educational programs, interventions, and exercise programs.

Kidney cachexia or protein-energy wasting in chronic kidney disease: facts and numbers

BACKGROUND

Weight loss and homeostatic disturbances of both energy and protein balances are characteristics of several illnesses including cancer, heart failure, and chronic kidney disease (CKD). Different definitions have been used to describe this deleterious process. The term protein-energy wasting (PEW) has been proposed for CKD patients by the International Society of Renal Nutrition and Metabolism.

METHODS

We searched the publication in Medline from February 2008 to September 2018 using PEW or cachexia in their title.

RESULTS

Since its inception, the term PEW has been exceptionally successful, highlighted by 327 original publications referenced in PubMed over 10 years. Using this classification, several studies have confirmed that PEW is among the strongest predictors of mortality in CKD patients [hazard ratio of 3.03; confidence interval of 1.69-5.26 in 1068 haemodialysis patients and 1.40 (1.04-1.89) in 1487 non-dialysed patients across PEW stages 0 to 4]. Based on this classification, prevalence of PEW is 28% to 54% among 16 434 adults undergoing maintenance dialysis. PEW prevalence increases when renal function declines, that is, from <2% in CKD stages 1-2 to 11-54% in CKD stages 3-5. A more general definition of cachexia for all chronic diseases proposed by the Society on Sarcopenia, Cachexia and Wasting Disorders was also published concurrently. In the CKD area, we found 180 publications using 'cachexia' underlining that some confusion or overlap may exist. The definitions of PEW and cachexia are somewhat similar, and the main difference is that a loss of body weight >5% is a mandatory criterion for cachexia but supportive for PEW.

CONCLUSIONS

The recent understanding of cachexia physiopathology during CKD progression suggests that PEW and cachexia are closely related and that PEW corresponds the initial state of a continuous process that leads to cachexia, implicating the same metabolic pathways as in other chronic diseases. Despite the success of the definition of PEW, using a more uniform term such as 'kidney disease cachexia' could be more helpful to design future research through collaborative groups of researchers with focus on cachexia.

Impact of sarcopenia on long-term mortality and cardiovascular events in patients undergoing hemodialysis

BACKGROUND/AIMS

A high body mass index (BMI) is known to correlate with better survival in patients on hemodialysis (HD). However, the impacts of body composition and sarcopenia on survival have not been well studied in this population.

METHODS

One hundred and forty-two prevalent HD patients were recruited and followed prospectively for up to 4.5 years. Low muscle mass (measured using a portable, whole-body, bioimpedance spectroscopic device) was defined as a lean tissue index (LTI) two standard deviations (SD) or more below the normal gender-specific mean for young people. Low muscle strength was a handgrip strength (HGS) of less than 30 kg in males and less than 20 kg in females. Sarcopenia was considered present when both LTI and HGS were reduced.

RESULTS

The mean age was 59.8 ± 13.1 years; 57.0% were male and 47.2% had diabetes. Forty-seven patients (33.1%) had sarcopenia. During follow-up, 28 patients (19.7%) died, and low LTI (adjusted hazard ratio [HR], 2.77; 95% confidence interval [CI], 1.10 to 6.97) and low HGS (HR 5.65; 95% CI, 1.99 to 16.04) were independently associated with mortality. Sarcopenia was a significant predictor for death (HR, 6.99; 95% CI, 1.84 to 26.58; p = 0.004) and cardiovascular events (HR, 4.33; 95% CI, 1.51 to 12.43; p = 0.006).

CONCLUSION

Sarcopenia was strongly associated with long-term mortality and cardiovascular events in HD patients. Assessment of muscle strength and muscle mass may provide additional prognostic information to survival in patients with end-stage renal disease.

The impact of antihypertensive pharmacotherapy on interplay between protein-bound uremic toxin (indoxyl sulfate) and markers of inflammation in patients with chronic kidney disease

PURPOSE

Indoxyl sulfate (IS) is one of the most potent uremic toxins involved in chronic kidney disease (CKD) progression, induction of inflammation, oxidative stress, and cardiovascular diseases occurrence. It is proved that hypertension is a common CVD complication and a major death risk factor as well as contributes for decline in a renal function. The aim of our study was to investigate how implementing of antihypertensive therapy impact IS concentrations and the associations between IS and markers of renal function, inflammation and oxidative stress.

METHODS

Study was conducted on 50 patients diagnosed with CKD and hypertension, divided into three groups: without hypotensive therapy (CKD-NONE), hypotensive monotherapy (CKD-MONO), and hypotensive polypharmacotherapy (CKD-POLI), and 18 healthy volunteers. The markers of inflammation [interleukin-6, tumor necrosis factor-alpha (TNF-α), high-sensitive C-reactive protein (hs-CRP), neopterin, ferritin], oxidative status [superoxide dismutase (Cu/Zn-SOD), antibodies against oxidized low-density lipoprotein (oxLDL-abs)], and selectins were determinate using immunoenzymatic methods. IS levels were assayed using high-performance liquid chromatography and other parameters were analysed using routine laboratory techniques. Then cross-sectional analysis was performed.

RESULTS

Elevated levels of IS, indicators of kidney function, markers of inflammation and blood pressure values were observed in each CKD subgroups. There was no effect of antihypertensive therapy on IS levels between studied groups, as well as there was no clear relationship between IS and blood pressure values in each studied group. The positive associations between IS and Cu/Zn SOD, neopterin, hs-CRP, creatinine and neutrophils/lymphocytes ratio were observed in CKD-NONE and CKD-POLI subgroups. Additionally, in CKD-POLI group IS positively correlated with TNF-α, ferritin and neutrophils. In CKD-MONO group, IS was positively related to oxLDL-abs, neopterin, E-selectin and creatinine, whereas it was inversely associated with hs-CRP.

CONCLUSIONS

Our study showed for the first time that the antihypertensive therapy has no impact on IS levels in CKD patients with hypertension. However, the introduction of the antihypertensive therapy modified the dependencies between IS and the studied markers of kidney function, inflammation, oxidative stress and hematological parameters that are crucial for mortality and morbidity amongst the CKD patients with hypertension.