Effects of volume status on body composition in incident peritoneal dialysis patients

BACKGROUND

Inadequate fluid removal or high water intake leads to overhydration, which results in malnutrition. The aim of the present study was to evaluate the effects of volume status on body composition in incident peritoneal dialysis (PD) patients.

METHODS

All incident PD patients who survived ≥1 year after PD initiation were considered eligible. A total of 366 incident PD patients were finally included and divided into three tertiles according to the time-averaged-edema index (TA-EI). The body composition parameters measured using bioimpedance analysis included the EI, fat mass index (FMI, kg/m²), and appendicular muscle mass index (AMMI, kg/m²). dFMI and dAMMI were defined as delta values for each variable. The cutoff value for sarcopenia (SP) was defined as previously reported. Patients with AMMI below the cutoff values were defined as having SP.

RESULTS

The number of participants in the low, middle, and high tertiles was 126, 100, and 140, respectively. A high volume status was associated with high solute clearance, albumin loss, and glucose absorption through the peritoneal membrane, which led to high dialysate glucose. In addition, volume status was inversely associated with increases in AMMI, but was not associated with changes in FMI. SP as a categorical variable was positively associated with a high volume status. On subgroup analyses, TA-EI had the greatest negative correlation coefficients for dAMMI.

CONCLUSION

Overhydration in PD patients was associated with decrease in muscle mass indices and the development of SP.

Actual diet and nutritional deficiencies status in children on peritoneal dialysis at the Vietnam National Hospital of Pediatrics

Nutrition is essential for children with end-stage renal disease, especially for those suffering from peritoneal dialysis (PD). Although the number of PD children has increased annually at the Vietnam National Hospital of Pediatrics, studies about the diet and nutritional deficiencies status of PD children is still limited. The aim of this study was to describe the actual diet and status of nutritional deficiencies of PD patients. This cross-sectional study was conducted on 31 PD children aged 2-15 years old using the 24-h dietary recall and biochemical parameters in blood (albumin, hemoglobin, calcium, sodium, potassium, and chloride). The energy intake was lowest in children over 13-year-old with only 32.9% of dietary reference intakes (DRIs). Carbohydrate intake among 10-15-year-old children was 38.1% of DRIs. Daily consumption of sodium was 65.6% and 33%-35% of DRIs for children under and over three-year-old, respectively. In comparison with DRIs, daily consumption of magnesium, iron, and calcium of over 10-year-old children was lower than that of younger children. In terms of vitamins, B-group vitamins, Vitamin C achieved the recommended levels except Vitamin A (63.0%) and Vitamin D (20.0%). The prevalence of children with serum albumin concentration lower than the normal range was 45.2% and prevalence of anemia was 51.6%. The proportion of children with decreased plasma calcium, sodium, and potassium levels was 83.8%, 77.4%, and 12.9%, respectively. PD children's diet lacks energy, protein, lipid, carbohydrate, as well as micronutrients. The prevalence of nutritional deficiencies is remarkably high in PD children.

Persistent overhydration is associated with a significant risk of peritoneal infection by enteric pathogens in patients treated with peritoneal dialysis

BACKGROUND

Overhydration (OH) complicates frequently the clinical course of Peritoneal Dialysis (PD) patients, and keeps a controversial association with the risk of peritoneal infection. The main objective of this study was to disclose an association between persistent OH and the risk of enteric peritonitis in a relatively large sample of patients undergoing PD.

METHOD

Following a prospective design, we monitorized systematically body composition of patients treated with PD in our unit (2011-2016), searching for a correlation with the ensuing risk of peritonitis, with an emphasis on the association between persistent OH (main study variable) and the risk of infection by enteric pathogens (main outcome). Essential demographic, clinical and laboratory variables with a potential influence on the risk of peritonitis were recorded. We used multivariate survival analysis to clarify the specific effect of different body composition parameters on the main outcome.

MAIN RESULTS

We included 139 patients for analysis (mean follow-up 24 months). Sixty-three patients suffered at least one peritonitis, and 17 had at least one diagnosis of enteric peritonitis. Univariate analysis disclosed a general trend to an increased risk of enteric peritonitis in overhydrated patients, as evidenced by associations of this outcome with mean extracellular water/intracellular water (ECW/ICW) (p=.007), OH/ECW (p=.033) and ECW/total body water (ECW/TBW) (p=.004) ratios, but not with absolute OH values. Multivariate analysis confirmed similar associations or trends (RR: 3.48, 95% CI: 1.03-14.59; p=.046, highest versus lowest tertile of ECW/ICW, RR: 2.31, 95% CI: 0.98-6.56; p=.061, highest versus lowest tertile of OH/ECW, and RR: 6.33, 95% CI: 1.37-19.37; p=.011, highest versus lowest tertile of ECW/TBW). On the contrary, no apparent association was detected between OH and the overall risk of peritoneal infection.

CONCLUSION

Persistent overhydration portends a significant risk of peritoneal infection by enteric pathogens, among patients undergoing chronic PD.

Evaluation of Nutritional Status in Children during Predialysis, or Treated By Peritoneal Dialysis or Hemodialysis

OBJECTIVE

Malnutrition is one of the major causes of morbidity and mortality in children with chronic kidney disease (CKD). The objective of this study was to evaluate nutritional status of children with stage 3-4 CKD and treated by peritoneal dialysis or hemodialysis using anthropometric measurements, biochemical parameters and bioelectrical impedance analysis.

PATIENTS AND METHODS

The study included a total of 52 patients and 46 healthy children.

RESULTS

In anthropometric evaluation, the children with CKD had lower values for standard deviation score for weight, height, body mass index, skinfold thickness and mid-arm circumference than those of healthy children (p < 0.05). The fat mass (%) and the body cell mass (%) measurements performed by bioelectrical impedance analysis were lower compared with the control group (p < 0.05).

CONCLUSION

It is considered that bioelectrical impedance analysis measurement should be used with anthropometric measurements, which are easy to perform, to achieve more accurate nutritional evaluation in children.

Pilot validation of objective malnutrition-inflammation scores in pediatric and adolescent cohort on chronic maintenance dialysis

Background:

In recognition of the challenges inherent with the use of single-item indices for the diagnosis of malnutrition–inflammation morbidity in pediatric dialysis patients, to enhance accuracy, we validated a composite scoring system in a pilot study. The objective malnutrition—inflammation score seeks to validate the use of a composite scoring system as a tool for assessing malnutrition—inflammation burden in a pediatric dialysis population.

Methods:

We enrolled 20 patients on hemodialysis (n = 14) and peritoneal dialysis (n = 6) over a period of 12 months. We derived composite scores from selected indices of renal pathology, nutrition, dialysis adequacy, protein catabolism, and dialysis modality. We assessed reliability by a test–retest method and measured validity by defining the relationship of the indices with serum C-reactive protein in a multiple regression analysis. We calculated sensitivity, specificity, accuracy, and precision for the malnutrition—inflammation score.

Results:

The mean age was 12.8 years (standard deviation = 6.1), and male–female ratio was 12:8. Patients (n = 8) with elevated serum C-reactive protein (>0.3 mg/dL) had higher composite score for malnutrition—inflammation morbidity. Similarly, the pediatric cohort on hemodialysis had higher score than those on peritoneal dialysis. Upon reliability testing, a low value of typical error (0.07) and high correlation coefficient (r = 0.95) supported validity of the instrument. Moreover, multiple regression analysis showed a strong predictive relationship (R² = 0.9, p = 0.03) between the indices and serum C-reactive protein. Sensitivity of malnutrition—inflammation score was 62.5%, specificity was 83%, accuracy was 75%, and precision was 71%.

Conclusion:

Using criterion-validation method, we established the potential use of multi-diagnostic approach to quantify malnutrition—inflammation morbidity in a pediatric dialysis cohort. Given the small sample size, large-scale population-specific studies are needed to ratify these findings and to demonstrate its clinical effectiveness.

Assessment of nutritional status in children with chronic kidney disease and on dialysis

Protein-energy wasting (PEW) is defined as a state of decreased body protein mass and fuel reserves (body protein and fat mass) and is a common complication of chronic kidney disease (CKD). It is multifactorial: the main causative factors are hormonal imbalances and a low nutrient intake, but low residual renal function, inadequate dialysis dose, chronic inflammation and metabolic acidosis are other important contributory factors. Adult PEW has been defined, but there is no accepted definition of pediatric PEW and consequently no precise diagnostic criteria. Assessing nutritional status in children is also complicated by the absence of a gold standard, specific abnormalities in body composition, and the slowly progressive course of the disease. The evaluation of PEW should take into account all of its pathogenetic aspects, which include dietary assessment, clinical and anthropometric assessment (based on weight, height, and body mass index), a panel of biochemical parameters, and a normalized protein catabolic rate (in the case of adolescents on hemodialysis). Bioimpedance indices can be used in individual patients on a regular basis in centers with expertise. The longitudinal follow-up data relating to the above parameters are valuable for comparing patient and normative data. Given the complex nature of PEW, only a multidisciplinary approach can provide an accurate assessment of nutritional status and its derangements in children with CKD and on dialysis.

Malnutrition and its association with inflammation and vascular disease in children on maintenance dialysis

BACKGROUND

Malnutrition is associated with both inflammation and atherosclerotic cardiovascular disease in adults with chronic kidney disease. We studied the prevalence of malnutrition and its possible associations with inflammation and vascular disease in children on chronic dialysis.

METHODS

Thirty-three patients on maintenance dialysis (18 peritoneal dialysis, 15 hemodialysis) and 19 age- and gender- matched healthy controls were studied. Nutritional status was assessed by anthropometric measurements including body mass index (BMI), upper arm measurements, multifrequency bioimpedance analysis (BIA) and serum levels of albumin, prealbumin, and cholesterol. Inflammation was assessed by serum levels of C-reactive protein (CRP), interleukin (IL)-6, and tumor necrosis factor (TNF)-alpha. The carotid artery intima thickness (cIMT) was measured to assess vascular disease.

RESULTS

Compared with healthy children, patients had lower anthropometric measurements (P < 0.05) and serum albumin level (P < 0.001), and higher CRP and TNF-alpha (P = 0.030 and P = 0.007, respectively), and higher cIMT-SDS (P < 0.001). Malnutrition was present in 8 (24%) and lower BIA-based fat mass was independently associated with higher IL-6 levels (P = 0.035). An increased cIMT was present in 16 (48.5%); however, there was no difference in cIMT-SDS between patients with and without malnutrition. Carotid IMT did not show any association with nutritional indices; but positively correlated with serum IL-6 (P = 0.037), CRP (P = 0.012), and iPTH (P = 0.009), and independently associated with only iPTH (P = 0.018).

CONCLUSIONS

Children on dialysis are at an increased risk of malnutrition, inflammation, and vascular disease. Although each of these three conditions exists, there is no interaction among them all. We postulate that the malnutrition-inflammation-atherosclerosis (MIA) complex might not exist in pediatric dialysis patients.

Solutions for peritoneal dialysis in children: recommendations by the European Pediatric Dialysis Working Group

The purpose of this article is to provide recommendations on the choice of peritoneal dialysis (PD) fluids in children by the European Pediatric Dialysis Working Group. The literature on experimental and clinical studies with PD solutions in children and adults was analyzed together with consensus discussions within the group. A grading was performed based on the international KDIGO nomenclature and methods. The lowest glucose concentration possible should be used. Icodextrin may be applied once daily during the long dwell, in particular in children with insufficient ultrafiltration. Infants on PD are at risk of ultrafiltration-associated sodium depletion, while anuric adolescents may have water and salt overload. Hence, the sodium chloride balance needs to be closely monitored. In growing children, the calcium balance should be positive and dialysate calcium adapted according to individual needs. Limited clinical experience with amino acid-based PD fluids in children suggests good tolerability. The anabolic effect, however, is small; adequate enteral nutrition is preferred. CPD fluids with reduced glucose degradation products (GDP) content reduce local and systemic toxicity and should be preferred whenever possible. Correction of metabolic acidosis is superior with pH neutral bicarbonate-based fluids compared with single-chamber, acidic, lactate-based solutions. Prospective comparisons of low GDP solutions with different buffer compositions are still few, and firm recommendations cannot yet be given, except when hepatic lactate metabolism is severely compromised.

Precision and within- and between-day variation of bioimpedance parameters in children aged 2-14 years

BACKGROUND & AIMS

Bioimpedance spectroscopy (BIS) offers the possibility to perform rapid estimates of fluid distribution and body composition. Few studies, however, have addressed the precision and biological variation in a pediatric population. Our objectives were to evaluate precision, variation within- and between-days for the BIS-determined parameters total body fluid, extra-cellular fluid, intra-cellular fluid, body cell mass, fat-free mass, extra-cellular resistance, intra-cellular resistance and percentage body fat using a Xitron 4200.

METHODS

All 133 children (81 boys, 52 girls; 2.4-14.9 years) had one series measured on day one (precision population). Forty-four children had a second series on day one (within-day sub-population). Thirty-two children had a series measured on the next day (between-day sub-population). Each measurement series consisted of three repeated measurements. A linear mixed model was used for statistical analysis.

RESULTS

The precision was 0.3-0.8% in children ≥6 years and 0.5-2.4% in children <6 years with a statistically significant difference between the two age-groups (p<0.001). Within-day variation was 1.1-2.8% and between-day variation 2.4-5.7%. Total variation and reference change values are reported.

CONCLUSION

The Xitron 4200 has a very good but age-dependent precision. The median value of three repeated measurements is recommended in order to avoid incorrect measurements.

Linkage of some trace elements, peripheral blood lymphocytes, inflammation, and oxidative stress in patients undergoing either hemodialysis or peritoneal dialysis

BACKGROUND

Changes in essential trace elements may affect the inflammatory and immunological state of patients on hemodialysis (HD) or peritoneal dialysis (PD). Therefore, we aimed to determine trace element content and markers of oxidative stress, inflammation, and immune status in HD and PD patients and to assess the relationships among these parameters.

METHODS

Patients on either HD (n = 20) or PD (n = 20) and age-, sex-, body mass index-matched healthy individuals (n = 20) were enrolled in the study. The trace elements zinc, copper, selenium, and iron; markers of oxidative stress thiobarbituric acid reactive substances (TBARS) and protein carbonyl levels; activities of antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase; percentages of CD3 T lymphocytes and the subsets CD4 and CD8; the CD4/CD8 ratio; and C-reactive protein (CRP) were measured.

RESULTS

All dialysis patients had low levels of albumin and hemoglobin. Significantly decreased percentages of CD3 and CD4 T lymphocytes and increased levels of CRP, TBARS, and carbonyl compounds were observed in HD patients. HD patients also had elevated erythrocyte SOD, lower GPx and catalase activities, and decreased levels of Se, Zn, and Fe in comparison to PD patients and healthy subjects. In addition, CRP was positively associated with TBARS and carbonyl levels, but was significantly inversely associated with Zn and Se levels. Positive correlations were found between T lymphocyte CD3 and CD4 percentages and Zn, Se, and Fe levels.

CONCLUSIONS

There were significant decreases in T lymphocyte-related immunological regulation and increased inflammation and oxidative stress in dialysis patients. Essential trace element status was independently related to immune status, inflammation, and oxidative damage.

Pediatric renal supportive therapies: the changing face of pediatric renal replacement approaches

PURPOSE OF REVIEW

The term 'renal replacement therapy' has been employed for describing dialytic interventions for acute and chronic patients. The implications of this terminology do not correctly reflect the extent that we are able to address native renal function. Provision of correct terminology to describe dialytic therapies may provide insight and investigation into the 'nonreplaceable' aspects of renal function in the acute and chronic settings.

RECENT FINDINGS

The terms 'chronic kidney disease' and 'acute kidney injury' have replaced the terms chronic renal failure and acute renal failure, respectively. Changing terminology has improved definitions and clinical care in these patient groups. Improvements in dialytic therapies have not been paralleled by changes in our understanding of the native renal function components that are not replaced during dialysis.

SUMMARY

A paradigm shift in our understanding of replacement of renal function is necessary. The terminology of 'renal replacement therapy' should be supplanted by more appropriate terminology, 'renal supportive therapy'. The benefits of employing terminology that adequately reflects the extent to which we can offer supportive dialytic treatment to our acute and chronic patients may be realized as a significant stimulus for scientific investigation and clinical care improvements.