Nutritional Status of Maintenance Dialysis Patients: Low Lean Body Mass Index and Obesity Are Common, Protein-Energy Wasting Is Uncommon

Whey Protein, Vitamins C and E Decrease Interleukin-10 in Chronic Hemodialysis Patients: A Pioneer, Randomized, Double-Blind Pilot Trial

OBJECTIVE

To evaluate the effects of supplementation with whey protein combined with vitamins C and E on inflammatory markers in hemodialysis (HD) patients.

DESIGN AND METHODS

This was a pioneer, randomized and double-blinded study. Patients were randomized into two groups and stratified by HD frequency. The supplementation group received 20 g of whey protein, 250 mg of vitamin C, and 600 IU of vitamin E; the placebo group, 20 g of rice flour, and microcrystalline cellulose capsules. The interventions were given after HD, 3 times a week, for 8 weeks. The inflammatory markers were assessed: interleukin (IL) IL-12p70, IL-10, IL-6, IL-8, and tumor necrosis factor alpha. For statistical analysis, the χ2 test, Student's t-test, Mann-Whitney test, analysis of variance for repeated two-way measurements, paired t test, and Wilcoxon test were performed. P < .05 was considered statistically significant.

RESULTS

Twenty-three patients completed the study. No significant differences were found in inflammatory markers when comparing the groups postintervention. In the intragroup was a decrease in IL-10 in the supplementation group after 8 weeks (P = .0382). IL-6 tended to decrease by 810.95% in the supplementation group and increased by 732.8% (nonsignificant) in the placebo group.

CONCLUSION

Whey protein combined with vitamins C and E significantly reduced IL-10 in the supplementation group and could be beneficial to reduce IL-6 in HD patients. Future studies are suggested with a larger sample size, different supplementation doses, and longer interventions.

Association Between Adipokine Profile, Systemic Inflammation, Muscle and Protein Energy Wasting in Children With Chronic Kidney Disease

OBJECTIVES

This cross-sectional study explores the association of adipokines and interleukin-6 (IL-6) with muscle and protein energy wasting (PEW) in children with chronic kidney disease (CKD).

METHODS

We measured serum adiponectin, leptin, resistin and IL-6 in 53 patients with CKD stage 3-5. Lean tissue (LTI) and fat tissue index (FTI) were estimated by bioimpedance analysis spectroscopy. PEW was defined as muscle wasting [LTI adjusted to height age (LTI HA) z-score < -1.65 SD) and at least 2 of the following: reduced body mass [body mass index adjusted to height age (BMI HA) z-score < -1.65 SD), poor growth [height z-score < -1.88 SD], questionnaire-based decreased appetite, and serum albumin ≤3.8 g/dL.

RESULTS

PEW, observed in 8 (15.1%) patients, was more prevalent in CKD stage 5 (P = .010). Among the adipokines, adiponectin, and resistin levels were significantly higher in CKD stage 5 (P < .001, P = .005). Adiponectin was correlated to LTI HA z-score (Rs = -0.417, P = .002), leptin to FTI z-score (Rs = 0.620, P < .001), while no correlation was observed between resistin and body composition parameters. Resistin was the only adipokine correlated to IL-6 (Rs = 0.513, P < .001). After adjustment for CKD stage and patient age, PEW was associated with adiponectin and IL-6 rise by 1 μg/mL and 10 pg/mL respectively (odds ratio (OR) 1.240, 95% confidence interval (CI) 1.040, 1.478 and OR 1.405, 95% CI 1.075-1.836) but not with leptin, while resistin association with PEW lost its significance.

CONCLUSIONS

In pediatric CKD, adiponectin is associated with muscle wasting, leptin with adiposity and resistin with systemic inflammation. Adiponectin and cytokine IL-6 may serve as PEW biomarkers.

Normal weight and waist obesity indicated by increased total body fat associated with all-cause mortality in stage 3–5 chronic kidney disease

Patients with chronic kidney disease (CKD) demonstrate a survival benefit with a high body mass index (BMI); this is the obesity paradox. Central obesity has a higher prognostic value than BMI, even in those with normal weight. Whether total body fat percentage (TBF%) provides more information than BMI and waist circumference (WC) remains unknown. We included 3,262 Asian patients with stage 3–5 CKD and divided these patients by TBF% and waist-to-height ratio (WHtR) quartiles (Q1–Q4). TBF% was associated with BMI, WC, nutritional markers, and C-reactive protein. In all patients, BMI but not TBF% or WHtR demonstrated a survival paradox. In patients with BMI &lt;25 kg/m2, but not in those with BMI ≥ 25 kg/m2, TBF% Q4 and WHtR Q4 were associated with all-cause mortality, with hazard ratios [HRs; 95% confidence intervals (CIs)] of 2.35 (1.31–4.22) and 1.38 (1.06–1.80), respectively. The HRs of TBF% Q4 for all-cause mortality were 2.90 (1.50–5.58) in patients with a normal WC and 3.81 (1.93–7.50) in patients with normal weight and normal WC (All P for interaction &lt; 0.05). In conclusion, TBF% can predict all-cause mortality in patients with advanced CKD and a normal weight, normal WC, or both.

Can Overnutrition Lead to Wasting?-The Paradox of Diabetes Mellitus in End-Stage Renal Disease Treated with Maintenance Hemodialysis

Background: The population of end-stage renal disease (ESRD) patients with diabetes mellitus (DM) may be at increased risk of protein energy wasting (PEW). The aim of the study was to investigate the impact of DM on selected indicators of PEW in the ESRD population that was undergoing maintenance hemodialysis (MHD). Methods: A total of 515 MHD patients were divided into two subgroups with and without DM. The evaluation of diet composition, Charlson Comorbidity Index (CCI), SGA, and laboratory and BIS analyses were performed. All-cause and cardiovascular mortality was recorded. Results: DM patients had lower albumin (3.93 (3.61–4.20) vs. 4.10 (3.80–4.30) g/dL, p < 0.01), total cholesterol (158 (133–196) vs. 180 (148–206) mg/dL, p < 0.01), and creatinine (6.34 (5.08–7.33) vs. 7.12 (5.70–8.51) mg/dL, p < 0.05). SGA score (12.0 (10.0–15.0) vs. 11.0 (9.0–13.0) points, p < 0.001), BMI (27.9 (24.4–31.8) vs. 25.6 (22.9–28.8) kg/m², p < 0.001), fat tissue index (15.0 (11.4–19.6) vs. 12.8 (9.6–16.0) %, p < 0.001), and overhydration (2.1 (1.2–4.1) vs. 1.8 (0.7, 2.7) L, p < 0.001) were higher in the DM group. Increased morbidity, reflected in the CCI and mortality—both all-cause and cardiovascular—were observed in DM patients. Conclusions: Hemodialysis recipients with DM experience overnutrition with a paradoxically higher predisposition to PEW, expressed by a higher SGA score and lower serum markers of nutrition. This population is also more comorbid and is at higher risk of death, including from cardiovascular causes.

Dialysis of the Obese Patient: Meeting Needs for a Growing Epidemic

Increasing population obesity and associated metabolic consequences has led to increased number of obese patients with chronic kidney disease and end-stage renal disease. While obesity is associated with increased cardiovascular morbidity and mortality, obese dialysis patients present a seeming paradox for survival benefit, given other acute intervening illnesses for those on dialysis with loss of lean body mass overtime. Challenges remain in providing adequate renal replacement options and therapy for this growing segment of obese patients on dialysis which are discussed in this article.

Sarcopenic Obesity in Chronic Kidney Disease: Challenges in Diagnosis Using Different Diagnostic Criteria

OBJECTIVES

Obesity, muscle impairment (low muscle mass or strength), and sarcopenic obesity are present in chronic kidney disease (CKD) and are associated with worse clinical prognosis. However, the various existing definitions for these conditions make the diagnosis variable. The aim of the present study was to evaluate the agreement between diagnostic criteria for sarcopenic obesity and its components in CKD.

SUBJECT AND METHODS

267 patients with CKD were included in the study. We assessed body composition by dual-energy X-ray absorptiometry and muscle function by handgrip strength (HGS) and adiposity by body mass index (BMI), waist circumference (WC), fat mass index (FMI), and percentage of FM. Diagnosis of muscle impairment was made by HGS, appendicular lean mass (ALM), and ALM index; obesity by BMI, WC, FMI, and %FM, and sarcopenic obesity was diagnosed by concomitant presence of muscle impairment and obesity.

RESULTS

Prevalence of muscle impairment varied from 11 to 50%, higher when low muscle mass criteria were used. Prevalence of obesity varied from 26 to 62%, higher when WC and %FM criteria were used. Prevalence of sarcopenic obesity varied from 2 to 23%. Women were more affected by sarcopenic obesity. Muscle impairment and sarcopenic obesity were more prevalent among patients on hemodialysis and obesity among nondialysis-dependent and kidney transplant patients. The agreement was poor between muscle mass and strength criteria; substantial between FMI, BMI, and %FM and fair between WC and the other measures; for sarcopenic obesity, it varied from poor to almost perfect.

CONCLUSION

Significant differences were found among the various diagnostic criteria that are used in the diagnosis of sarcopenic obesity. Our results highlight the need for standardization in the diagnosis of sarcopenic obesity.

Comparison between dual-energy x-ray absorptiometry and bioelectrical impedance for body composition measurements in adults with chronic kidney disease: A cross-sectional, longitudinal, multi-treatment analysis

OBJECTIVE

The aim of this study was to evaluate the agreement between bioelectrical impedance spectroscopy (BIS) and dual-energy x-ray absorptiometry (DXA) for assessment of body composition in patients with chronic kidney disease (CKD).

METHODS

We performed cross-sectional and prospective analyses by DXA and BIS in whole body (BISWB) and segmental (BISSEG) protocols in CKD non-dialysis-dependent (n = 81), hemodialysis (n = 83), peritoneal dialysis (n = 24), and renal transplantation (n = 80) patients. Intraclass correlation coefficient (ICC) and Bland-Altman plots were evaluated. Linear regression analysis was performed for bias assessment and development of equations. Receiver operating characteristics curve was constructed for diagnosis of inadequate error tolerance (DXA - BIS >±2kg).

RESULTS

The agreement with DXA was greater for BISWB than BISSEG; for fat mass (FM; ICC men = 0.894; women = 0.931) than fat-free mass (FFM; ICC men = 0.566; women = 0.525), with greater bias for FFM as muscle increases and for FM in body fat extremes. The agreement was lower for body change analysis (ICC FFM men = 0.196; women = 0.495; ICC FM men = 0.465; women = 0.582). The ratio of extra- to intracellular water (ECW/ICW), body mass index, fat mass index, waist circumference, resistance, and reactance interfered in bias between methods. An ECW/ICW cutoff point of ≥0.7250 for inadequate error tolerance was determined. New prediction equations for FFM (r² = 0.913) and FM (r² = 0.887) presented adequate error tolerance in 55% and 63% compared with 30% and 39% of the original equation, respectively.

CONCLUSION

For body composition evaluation in patients with CKD, BIS applied using the whole body protocol, in normal hydration patients with CKD is as reliable as DXA; BIS must be used with caution in overhydration patients with ECW/ICW ≥ 0.7250. The newly developed equations are indicated for greater precision.

The cut-off values of handgrip strength and lean mass index for sarcopenia among patients on peritoneal dialysis

Background

Sarcopenia is common and contributes to a high risk of mortality among general population. There is no consensus regarding the cut-off values for sarcopenia in terms of mortality among chronic kidney disease patients. This study aimed to explore and validate cut-off points of handgrip strength (HGS) and lean mass index (LMI) for estimating the risk of mortality in peritoneal dialysis (PD) patients.

Methods

This single-center prospective cohort study enrolled 1089 incident PD patients between October 2002 and July 2019. All patients were followed until death, transfer to hemodialysis, receiving renal transplantation or the end date of study (December 2019). All participants were randomly sampled to development cohort (70% participants) and validation cohort (30% participants), matched by gender and diabetes. Lean body mass was calculated by using the equation published by our center. Cubic spline regression analysis was used to examine the relationship between HGS or LMI values and mortality, and explore the cut-off points after adjusting for age, diabetes, cardiovascular disease and serum albumin in the development cohort. The derived cut-off values were verified by the agreement rate for predicting mortality and then compared with cut-off values from various clinical guidelines in the validation cohort.

Results

All 1089 patients were followed up with the median of 36.0 (18.0, 71.0) months. In the development cohort, cut-off points for predicting the higher mortality were derived as 24.5 kg and 14 kg of HGS for males and females, 16.7 kg/m² and 13.8 kg/m² of LMI for males and females respectively. In the validation cohort, these cut-off values significantly predicted worse outcomes, with HR 1.96 (1.35, 2.84) of HGS and HR 1.76 (1.26, 2.47) of LMI for all-cause mortality after multivariate adjustment. The newly derived cut-off points of HGS have numerically higher prognostic values in all-cause mortality compared with those from current clinical guidelines, and agreement rates of HGS were 65.2 versus 62.5–64.6 respectively.

Conclusions

The derived cut-off values of HGS and LMI have sufficient and better prognostic value in predicting all-cause mortality in PD patients compared with the cut-off values in the existing guidelines. These cut-off values are only validated in a single population, thus limiting the generalizability.

Markers of protein-energy wasting and physical performance in haemodialysis patients: A cross-sectional study

Background

Physical impairments are common in uraemia, as reflected by the high risk of falls of haemodialysis (HD) patients. Furthermore, these patients often suffer from malnutrition.

Objective

Up to now, it is unknown which aspects of physical performance are predominantly driven by malnutrition in HD patients. As this answer could steer different interventions, the aim of this study was to evaluate the cross-sectional relationship between nutritional status, muscle strength, exercise capacity and the risk of falls.

Methods

This study recruited HD patients between December 2016 and March 2018 from two hospital-based and five satellite dialysis units (registration number on clinicaltrial.gov: NCT03910426). The mini-nutritional assessment scale as well as objective measures of protein-energy wasting were obtained (total iron-binding capacity, total protein levels, and CRP). Physical assessment included muscle strength (quadriceps, handgrip force, and sit-to-stand test), exercise capacity (six-minute walking test) and the risk of falls (Tinetti, FICSIT, and dialysis fall index). Their interrelationship was analysed by ridge regression models.

Results

Out of 113 HD patients (mean age 67 years ± 16.1, 57.5% male) 36.3% were malnourished according to the mini-nutritional assessment scale and a majority had impaired quadriceps force (86.7%), six-minute walking test (92%), and an increased risk of falls (73.5%). Total protein and CRP levels were identified as relevant nutritional factors in the association with physical performance. Nutritional parameters explained 9.2% of the variance in the risk of falls and 7.6% of the variance in exercise capacity. No conclusive association was found between nutritional status and muscle strength.

Conclusion

Protein-energy wasting is a determinant of the risk of falls and exercise capacity in patients on HD. The association between malnutrition and muscle weakness remains inconclusive.

Evaluation of body composition monitoring for assessment of nutritional status in hemodialysis patients

Background: Body composition monitoring is the only clinically available method for distinguishing among the three body components. This study aimed to determine the relationship between body composition and all-cause mortality in Chinese hemodialysis patients and examine whether the lean tissue index (LTI) derived from body composition monitoring can accurately diagnose malnourished patients.

Methods: Hemodialysis patients (n = 123) with nutritional and body composition assessment records in 2015 were examined. Body composition was assessed using a body composition monitor machine.

Results: Fifty-seven patients (46.3%) had low LTI (LTI less than the 10th percentile of the respective normal distribution). Significant differences in the fat tissue index (FTI) were observed, with the low LTI group having a higher FTI (10.8 kg/m² vs. 9.0 kg/m², p= .007). The kappa coefficient of agreement between LTI and subjective global assessment (SGA) was 0.26 for the presence of malnutrition. During the mean observation period of 26.7 months, 20 of 123 (16.3%) patients died. Low LTI remained highly predictive of survival in the Cox regression analysis (hazard ratio: 3.24, 95% confidence interval 1.06–9.91, p= .04). Malnourishment defined by SGA predicted survival in the Kaplan–Meier analysis (log-rank χ²=4.05; p= .04) but not in the multivariate analysis.

Conclusions: LTI is a predictor of mortality, and its predictive power was not affected when FTI, SGA, and hydration status were included in the multivariate analysis. However, SGA may not be adequate to identify patients at a risk of death among Chinese hemodialysis patients.

Bioelectrical Impedance Analysis-Derived Phase Angle Predicts Protein-Energy Wasting in Maintenance Hemodialysis Patients

OBJECTIVE(S)

To explore the validity of using bioelectrical impedance analysis (BIA)-derived 50 kHz phase angle (PhA) in predicting protein-energy wasting (PEW) in Chinese maintenance hemodialysis (MHD) patients.

DESIGN AND METHODS

The design was a cross-sectional study. A total of 173 of MHD patients and 173 healthy adults were enrolled in the study. The prevalence of PEW in patients was performed by the International Society of Renal Nutrition and Metabolism criteria. The PhA, body cell mass, fat mass, body fat percentage, fat-free mass, and extracellular water/total body water were measured by InBody S10 body composition analyzer. The biochemical indices and anthropometric measurements were assessed using the way published elsewhere. The PhA, other values of BIA and its relationship with age, visceral protein, anthropometric measurements of the MHD patients were compared with the healthy group. The independent variables for predicting PEW and its cutoff values were explored using logistic regression model and receiver operating characteristic curve analysis, respectively.

RESULTS

The MHD patients' PhA value was significantly lower than the healthy group (4.89°± 1.19 vs. 6.32°± 2.23, P < .01). A total of 34.1% MHD patients with PEW had significantly lower PhA values compared with well-nourished patients (P < .05). The PhA decreased more significantly with age in MHD (r = -0.35, P < .001), compared with controls (r = -0.26, P < .001). The PhA values were positively associated with nutritional indices related to serum albumin, prealbumin, fat-free mass, and mid-arm muscle circumference. PhA values were not associated significantly with fat mass and body fat percentage (P > .05). Multivariate logistic regression analysis showed that PhA and body mass index were independent predictors of PEW, but the PhA was the stronger predictor (odds ratio = 4.48, P < .05). Receiver operating characteristic curve analysis suggested that the optimal PhA cutoff value to predict PEW was 4.6°.

CONCLUSIONS

BIA-derived PhA appears to be a useful bioelectrical marker for predicting PEW in Chinese hemodialysis patients with a cutoff value of 4.6°.

Evaluating haemodialysis patient's nutritional status: Body mass index or body cell mass index?

OBJECTIVE

Evaluate which of two combinations of parameters based on International Society of Renal Nutrition and Metabolism recommendations could better identify patients with protein-energy wasting (PEW) and to compare the relationship of these two combinations with other clinical and body composition parameters.

METHODS

This was a multicentre longitudinal study with 24 months of follow-up. The PEW patients were characterized by: Group A (G_A ) - normalized protein catabolic rate (nPCR) < 1.0 g/kg per day, albumin <3.8 g/dL and body cell mass index (BCMI) < 6.4 kg/m² (n = 203); Group B (G_B ) - nPCR <1.0 g/kg per day, albumin <3.8 g/dL and body mass index (BMI) <23 kg/m² (n = 109). All the patients who did not meet these requirements were considered "well-nourished" (G_A : n = 1818; G_B : n = 3292).

RESULTS

When compared to the well-nourished patients, PEW patients in the G_A presented higher age, Kt/V, C-reactive protein, relative overhydration, fat tissue index (FTI); lower creatinine, albumin, nPCR, PTH, haemoglobin, phosphorus, calcium X phosphorus product, potassium, dry weight, BMI, BCMI, lean tissue index, %IDWG . In the G_B , well-nourished patients FTI was significantly higher. In Cox analysis, the combination with BCMI was a strong independent predictor of mortality in these patients (hazard ratio: 1.48; confidence interval: 1.00-2.19; P = 0.048), even after adjustment. Although G_B combination seemed to be also a predictor of death (hazard ratio: 2.67; confidence interval: 1.92-3.71; P < 0.001), when adjusted, the association remained no longer significant.

CONCLUSION

A new combination of parameters including protein intake, albumin and BCMI demonstrated significant associations with other nutrition and inflammation parameters as well as with mortality.

Historical Study (1986-2014): Improvements in Nutritional Status of Dialysis Patients

OBJECTIVE

Malnutrition is common in dialysis patients and is associated with adverse clinical outcomes. Despite an increased focus on improved nutrition in dialysis patients, it is claimed that the prevalence of malnutrition in this group of patients has not changed during the last decades. Direct historical comparisons of the nutritional status of dialysis patients have never been published. To directly compare the nutritional status of past and current dialysis patients, we implemented the methodology of a study from 1986 on a population of dialysis patients in 2014.

DESIGN

Historical study comparing results of two cross-sectional studies performed in 1986 and 2014.

SETTING

We compared the nutritional status of hemodialysis (HD) and peritoneal dialysis (PD) patients attending the dialysis center at Roskilde Hospital, Denmark, in February to June 2014, with that of HD and PD patients treated at the dialysis center at Fredericia Hospital, Denmark, in April 1986.

SUBJECTS

Maintenance PD and HD patients (n = 64 in 2014 and n = 48 in 1986).

METHODS

We performed anthropometry (body weight, triceps skinfold, and midarm muscle circumferences [MAMCs]) and determined plasma transferrin.

MAIN OUTCOME MEASURE

Relative body weight, triceps skinfold, MAMC, body mass index, and prevalence of protein-caloric malnutrition as defined in the original study from 1986.

RESULTS

Average relative body weight, triceps skinfold, MAMC, and body mass index were significantly higher in 2014 compared with 1986. The prevalence of protein-caloric malnutrition was significantly lower in 2014 (18%) compared with 1986 (52%).

CONCLUSIONS

The nutritional status of maintenance dialysis patients has improved during the last 3 decades. The reason for this improvement could not be identified in the present study, but the most likely contributors are the higher prevalence of obesity in the general population, less predialytic malnutrition, and an improved focus on nutrition in maintenance dialysis patients.