Assessment of body composition in peritoneal dialysis patients using bioelectrical impedance and dual-energy x-ray absorptiometry

Nutritional Assessments by Bioimpedance Technique in Dialysis Patients

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

Higher visceral adipose tissue is associated with decreased memory suppression ability on food-related thoughts: A 1-year prospective ERP study

Memory about food and eating is crucial in regulating appetite and eating behaviors. Successfully stopping vivid imagination of delicious food could help reduce food craving and thus reduce the possibility of further intake. Memory inhibition is a cognitive process that involves intentional suppression of certain memories coming to consciousness. Successful memory suppression derives from inhibitory control. Although considerable work has consistently observed the impairment in motor or response inhibitory control among individuals with obesity, there has been a lack of investigation into the influence of bodyweight status on memory inhibitory control. To fill this gap, current study investigated behavioral and neurophysiological correlates of memory suppression in young women. Using Think/No-Think task and event-related potentials among 47 females, we found that participants with higher visceral adipose tissue (VAT) showed a tendency towards decreased suppression ability for memories related to food but not memories related to nonfood items. In depth analysis showed that decrease in the differences in P2 amplitudes between suppression vs. retrieval of food-related memories mediated the impairment of suppression ability by high VAT. We then tested whether individual differences in memory suppression ability as well as ERP correlates predicted future BMI or VAT change over 1-year follow-up. Results showed that P2 amplitudes when retrieving food-related memory could predict VAT change at 1-year follow-up among participants with healthy BMI. These observations suggest a hypersensitivity inference hypothesis underlying memory control impairments. To be specific, deficits in memory suppression may be in part resulted from elevated sensitivity to the cues coupling with food-related memory. It extends previous studies of memory suppression with food rewards and provides the first evidence to help understand the relationship between inhibitory control on food-related memory and obesity.

Application of Bioelectrical Impedance Analysis in Nutritional Management of Patients with Chronic Kidney Disease

Body composition measurement plays an important role in the nutritional diagnosis and treatment of diseases. In the past 30 years, the detection of body composition based on bioelectrical impedance analysis (BIA) has been widely used and explored in a variety of diseases. With the development of technology, bioelectrical impedance analysis has gradually developed from single-frequency BIA (SF-BIA) to multi-frequency BIA (multi-frequency BIA, MF-BIA) and over a range of frequencies (bioimpedance spectroscopy, BIS). As the clinical significance of nutrition management in chronic kidney disease has gradually become prominent, body composition measurement by BIA has been favored by nephrologists and nutritionists. In the past 20 years, there have been many studies on the application of BIA in patients with CKD. This review describes and summarizes the latest research results of BIA in nutritional management of patients with CKD including pre-dialysis, hemodialysis, peritoneal dialysis and kidney transplantation, in order to provide reference for the application and research of BIA in nutritional management of chronic kidney disease in the future.

Calcium balance in peritoneal dialysis patients treated by continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD) cyclers

INTRODUCTION

Although vascular calcification is a recognised complication for haemodialysis patients, peritoneal dialysis (PD) patients are also at risk. As such we wished to review peritoneal and urinary calcium balance and the effect of calcium containing phosphate binders (CCPBs).

METHODS

Twenty-four-hour peritoneal calcium balance and urinary calcium were reviewed in PD patients undergoing their first assessment of peritoneal membrane function.

RESULTS

Results from 183 patients, 56.3% male, 30.1% diabetic, mean age 59.4 ± 16.4 years, median 2.0 (2-6) months of PD, 29% treated by automated PD (APD), 26.8% continuous ambulatory (CAPD) and 44.2% APD with a day-time exchange (CCPD) were reviewed. Peritoneal calcium balance was positive in 42.6%, and remained positive in 21.3% after including urinary calcium losses. PD calcium balance was negatively associated with ultrafiltration (odds ratio 0.99 (95% confidence limits 0.98-0.99), p = 0.005. PD calcium balance was lowest with APD (APD - 0.45 (- 0.78 to 0.05) vs CAPD - 0.14 (- 1.18 to 0.59) vs CCPD - 0.03) - 0.48 to 0.5) mmol/day), p < 0.05, with 82.1% of patients with a positive balance prescribed icodextrin, when combining peritoneal and urinary losses. When considering CCPB prescription, then 97.8% of subjects prescribed CCPD had an over-all positive calcium balance.

DISCUSSION

Over 40% of PD patients had a positive peritoneal calcium balance. Elemental calcium intake from CCPB had a major effect on calcium balance, as median combined peritoneal and urinary calcium losses were < 0.7 mmol/day (26 mg), so caution is required to prevent excessive CCPB prescribing, increasing the exchangeable calcium pool and thus potentially increasing vascular calcification, particularly for anuric patients.

Assessment of body composition in pediatric intestinal failure: A comparison study

BACKGROUND

The objective of the study was to compare bioelectrical impedance analysis (BIA) and skinfolds with dual energy x-ray absorptiometry (DXA) in the assessment of body composition of children with intestinal failure. DXA is the reference method for body composition assessment in clinical settings.

METHODS

Children aged 1-18 years with intestinal failure whohave DXA as part of routine clinical monitoring were eligible. BIA measured total body water on the same day as DXA. Skinfold measurements were taken at four sites: triceps, biceps, subscapular, and suprailiac. Percentage of fat mass (%FM) and fat-free mass (%FFM) were derived from resistance and reactance measured by BIA by using age-specific equations. Percentage of FM was calculated from skinfold measures by using age-specific equations. Data on patient characteristics, intestinal failure-related factors, and feeding method were collected. Paired t test examined differences in %FM and %FFM and Bland-Altman analysis determined the agreement between BIA, skinfolds, and DXA. Marginal linear model assessed the effect of age, sex, and feeding method on the difference in body composition obtained between DXA and BIA and between DXA and skinfolds.

RESULTS

Sixty-eight children with intestinal failure, mean age 8.9 ± 4.2 years, were studied. There was no difference between %FFM and %FM obtained by DXA and BIA (P = 0.26), with a mean bias (95% CI) of -0.69 (-1.9 to 0.5) for %FFM. Sex and age were individually and jointly associated with the bias observed between DXA and BIA (P < 0.05). Skinfold and DXA measurements were significantly different (P < 0.05).

CONCLUSIONS

BIA is an acceptable clinical tool for assessing body composition in pediatric intestinal failure.

Prevalence and determinants of low plasma zinc levels in adult peritoneal dialysis patients

OBJECTIVE

Zinc is an essential trace element, being a cofactor for almost 300 enzymes. As zinc is widely available in the diet, the European Best Practice Guidelines do not recommend routine supplementation in dialysis patients. However, some medicines prescribed to dialysis patients may potentially reduce absorption, and there may be increased losses with dialysis. As older and co-morbid patients are now treated by peritoneal dialysis (PD) we wished to determine the prevalence of patients with low plasma zinc levels.

DESIGN AND METHODS

We prospectively measured plasma zinc in 550 PD patients attending for their first peritoneal membrane assessment using atomic absorption spectroscopy. Body composition was determined by bioimpedance.

RESULTS

Plasma zinc was measured in 550 patients, mean age 58.7 years, 60.6% male, mean value 10.8 ± 2.2 umol/L, with 66.5% having low zinc levels (<11.5 umol/L). Normal plasma zinc was associated with haemoglobin (odds ratio (OR) 1.41 (95% confidence limits (95%CL) 1.22-1.63), serum albumin (OR 1.04 (95%CL 1.002-1.087), higher glucose dialysates L/day (OR 1.06 (1.001-1.129), and negatively with 24-hour urinary protein losses (OR 0.786 (95%CL 0.673-0.918) and age (OR 0.985 (95%CL 0.972-1.0). There was no association with dialysis adequacy, original renal disease or dietary protein estimation. Prescription of phosphate binders had no effect on zinc levels (10.7 ± 2.2 vs 10.8 ± 2.3 umol/L).

CONCLUSIONS

Most PD patients had low plasma zinc levels, associated with older age, probably reflecting reduced intake, urinary protein losses, and lower albumin and haemoglobin most likely linked to greater co-morbidity, low grade inflammation and volume expansion requiring higher glucose dialysates.

Weight loss and weight gains in patients starting peritoneal dialysis; the effect of peritonitis

AIM

Earlier studies reported that peritoneal dialysis (PD) patients gained fat mass after initiating dialysis. Clinical practice and demographics have changed over time with earlier initiation of dialysis and increasing numbers of elderly, co-morbid patients. As such, we wished to review changes in body composition with dialysis.

METHODS

Changes in body composition were compared by dual x-ray absorptiometry (DXA) in 151 adult PD patients, 81 males (54.6%), 50 diabetic (30.1%), mean age 60.5 ± 16.7 years, shortly after starting PD and then a median of 24 months later, to allow for the initial impact of dialysis.

RESULTS

Overall, weight appeared stable (71.7 ± 15.4 vs. 71.9 ± 15.3 kg). On follow-up, total weekly urea clearance fell from 2.29 (1.85-3.0) to 1.93 (1.63-2.4) whereas peritoneal glucose absorption increased from 119 (46-217) to 321 (187-805) mmol/day, p < .001, and estimated dietary protein (nPNA) fell from 0.92 ± 0.23 to 0.86 ± 0.23 g/kg/day, p = .006. However, 69 (45.7%) patients gained weight, with greater change in both lean and fat mass index versus those with weight loss (0.8 [-0.5 to 2.0] vs. -0.7 [-2.1 to 0.2] and 0.9 [-0.1 to 2.3] vs. 0 [-2.6 to 0.8] kg/m² , p < .001), respectively. Although there were no differences in hospital admissions, patients who gained weight experienced fewer episodes of PD peritonitis (0 [0-1] vs. 1[0-2], p = .019).

CONCLUSION

Dietary protein intake declined over time, and more PD patients lost weight. The major difference between those who gained and lost weight was episodes of peritonitis. Greater attention to nutritional support may potentially reduce loss of lean body mass.

Earlier anti-TNF therapy reduces the risk of malnutrition associated with alterations in body composition in patients with Crohn's disease

Background

Anti-TNF therapy has been found to exert an influence on long-term nutritional status and even reverse malnutrition in patients with Crohn's disease.

Aims

to observe the effect of anti-TNF therapy on nutritional status in patients with Crohn's disease, investigate the correlation between the timing of anti-TNF therapy and the human body composition and examine independent body composition factors for predicting malnutrition in these patients.

Methods

This was a retrospective study of 115 patients with Crohn's disease. Body composition parameters were assessed by bioelectrical impedance analysis. The nutritional status of the patients was determined by NRS2002 and MNA.

Results

The BMI, BFMI, FFMI, BCMI, SMI, BMC, intracellular water, protein and BMR were significantly lower in patients without any biologic agents (p < 0.05). Negative correlations were found between BMC, intracellular water, extracellular water, protein and BMR and the interval between the first symptom and first dose by Spearman's correlation analysis (r < 0, p < 0.05). Low BMI (OR 0.602, 95% CI 0.434-0.836, p = 0.002), low FFMI (OR 0.678, 95% CI 0.507-0.906, p = 0.009), and low BCMI (OR 0.564, 95% CI 0.367-0.868, p = 0.009) were independent risk factors for malnutrition in Crohn's disease patients. Anti-TNF therapy tended to reduce the malnutrition probability as assessed by Cox regression analysis (OR: 0.217, 95% CI 0.057-0.821, p = 0.024).

Conclusion

Body composition analysis is predictive of malnutrition in patients with Crohn's disease. Early application of anti-TNF therapy significantly affected skeletal muscle mass, fat mass and bone mineral content, supporting their long-term nutritional status and reducing their probability of malnutrition.

The influence of the China GLIM standards on the diagnosis of malnutrition in patients with hematopoietic stem cell transplant

Background

The muscle-related indicator is removed from Global Leadership Initiative on Malnutrition (GLIM) criteria implemented in China for many reasons. Patients with hematopoietic stem cell transplants are at nutrition risk and can enter into the second step of GLIM; thus, they are suitable for learning the diagnosing malnutrition significance between primary GLIM and GLIM-China criteria. This article aims to explore the role of muscle mass in the diagnostic criteria of malnutrition and the effects of GLIM-China for diagnosing malnutrition.

Methods

A total of 98 inpatients with hematopoietic stem cell transplants (HSCT) were recruited. Nutrition risk was assessed by using the Nutritional Risk Screening 2002 (NRS-2002). Appendicular skeletal muscle mass (ASMI) and fat-free mass index (FFMI) were determined using the bioelectrical impedance analysis (BIA) method. Malnutrition is defined by GLIM-China, GLIM, and PG-SGA. We use erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) to assess inflammation in GLIM and GLIM-China. The correlation or consistency among ASMI, FFMI, ESR, CRP, GLIM-China, GLIM, and PG-SGA was evaluated, respectively.

Results

One hundred percent instead of the patients had nutritional risk. The magnitude of malnutrition using PG-SGA, GLIM, and GLIM-China was 75.5, 80.6, and 64.3%, respectively. GLIM-China and PG-SGA showed the same performance (p = 0.052 vs. 1.00) and agreement (kappa = 0.404 vs. 0.433, p < 0.0001) with the FFMI. Consistency was noted between ASMI and PG-SGA in the assessment of malnutrition (p = 0.664) with a good agreement (kappa = 0.562, p = 0.084). ASMI and FFMI could determine muscle mass reduction, which could not be determined by BMI, albumin (ALB), and pre-albumin (pre-ALB); 34% of GLIM-China (-) patients were with low ASMI, and 40% with low FFMI; 30.0% of patients with PG-SGA (<4) still have low ASMI, and 38.2% have low FFMI.

Conclusion

If only the PG-SGA scale is used as a diagnostic criterion for evaluating malnutrition, a large proportion of patients with reduced muscle mass will be missed, but more patients with muscle loss will be missed via GLIM-China. Muscle-related indicators will help diagnose malnutrition.

Differences in prevalence of reduced and low bone mineral density between lumbar spine and femoral neck in peritoneal dialysis patients using dual-energy X-ray absorptiometry (DXA)

The pattern of chronic kidney disease-mineral bone disease has changed following the increase in elderly patients receiving dialysis, with escalating likelihood of osteoporosis, with associated increased fracture risk and mortality. Thus, we wished to determine the prevalence of osteoporosis in our peritoneal dialysis (PD) cohort. Lumbar spine (LS) and femoral neck (FN) bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA), and low BMD (osteoporosis) and reduced BMD (osteopenia) defined according to the World Health Organisation T scores. DXA scans from 734 patients, 57.2% male, mean age 61.0 ±16.0 years, 34.6% diabetic, with a median 8.0 (2-24) months of treatment with PD were reviewed. Fewer patients had normal BMD at the FN vs. LS (24.1 vs. 55%), and more classified as reduced (FN 55.9 vs. 34% LS) and low BMD (FN 17 vs. 11% LS), χ ² 112.2, p < 0.001. Agreement between FN and LS T scores was r = 0.36 with Spearman rank correlation, and 0.34 by Kendall's tau b, Cohen's kappa score 0.17, and Bland-Altman bias -0.37 (95% limits of agreement -1.8 to 1.08). The prevalence of reduced and low BMD was much greater when using FN T scores compared to LS, with LS T scores a mean of 0.34 higher than FN. DXA scanning at the LS can be affected by overlying vascular calcification and electron densities in the bowel, and as such we suggest that FN T scores are used to report BMD in PD patients.

Frailty, appendicular lean mass, osteoporosis and osteosarcopenia in peritoneal dialysis patients

INTRODUCTION

The pattern of chronic kidney disease mineral bone disorder (CKD-MBD) is changing with increasing numbers of elderly patients now treated by dialysis. The risk of falls and bone fractures increases with frailty and sarcopenia. As such we wished to review the association between osteoporosis and frailty and loss of appendicular lean mass (ALM).

METHODS

Dual-energy X-ray absorptiometry (DXA) was used to measure lumbar spine and femoral neck bone mineral density (BMD) and body composition. Osteoporosis and osteopenia were defined according to T scores. ALM was indexed to height (ALMI). Frailty was classified using the clinical frailty scale (CFS).

RESULTS

DXA scans from 573 patients, 57.8% male, 36.8% diabetic, mean age 61.0 ± 15.8 years, with a median 6.0 (2-20) months of treatment with PD were reviewed. Forty-two (7.3%) were classified as clinically frail, 115 (20%) osteoporotic, and 198 (34.6%) ALMI meeting sarcopenic criteria, with 43% of osteoporotic patients being osteosarcopenic. In a multivariable model, femoral neck BMD was associated with weight, standardised β (St β) 0.29, p = 0.004, ALM St β 0.11, p = 0.03 and Black vs other ethnicities St β 0.19, p = 0.02, and negatively with age St β -0.24, p < 0.001, and frailty St β -2.1, p = 0.04. Z scores (adjusted for gender and age) were associated with ALMI (r = 0.18, p < 0.001).

DISCUSSION

Osteoporosis is increasing with the numbers of elderly dialysis patients. As frailty and sarcopenia increase with age, then the risk of falls and bone fractures increases with osteosarcopenia. Whether interventions with exercise and nutrition can improve bone heath remains to be determined.

Established risk prediction models for the incidence of a low lean tissue index in patients with peritoneal dialysis

Objective

The objective of this study is to investigate the incidence of low lean tissue index (LTI) and the risk factors for low LTI in peritoneal dialysis (PD) patients, including to establish risk prediction models.

Methods

A total of 104 PD patients were enrolled from October 2019 to 2021. LTI was measured by bioimpedance spectroscopy. Multivariate logistic regression and machine learning were used to analyze the risk factors for low LTI in PD patients. Kaplan–Meier analysis was used to analyze the survival rate of patients with low LTI.

Results

The interleukin-6 (IL-6) level, red cell distribution width (RDW), overhydration, body mass index (BMI), and the subjective global assessment (SGA) rating significantly differed between the low LTI and normal LTI groups (all p < 0.05). Multivariate logistic regression showed that IL-6 (1.10 [95% CI: 1.02–1.18]), RDW (1.87 [95% CI: 1.18–2.97]), BMI (0.97 [95% CI: 0.68–0.91]), and the SGA rating (6.33 [95% CI: 1.59–25.30]) were independent risk factors for LTI. Cox regression analysis showed that low LTI (HR 3.14, [95% CI: 1.12–8.80]) was the only significant risk factor for all-cause death in peritoneal dialysis patients. The decision process to predict the incidence of low LTI in PD patients was established by machine learning, and the area under the curve of internal validation was 0.6349.

Conclusions

Low LTI is closely related to mortality in PD patients. Microinflammatory status, high RDW, low BMI and low SGA rating are risk factors for low LTI in PD patients. The developed prediction model may serve as a useful tool for assessing low LTI in PD patients.

Associations among body composition parameters and quality of life in peritoneal dialysis patients

Health-related quality of life (HRQOL) is an important issue among patients undergoing dialysis treatment. Peritoneal dialysis (PD) is associated with a number of adverse body composition changes. However, whether body composition is associated with HRQOL is uncertain. The purpose of this study was to analyze the effects of body composition on HRQOL in PD patients. We performed a cross-sectional observational study on the association between body composition and HRQOL in PD patients at a single center. Body composition was determined by multifrequency bioimpedance spectroscopy. HRQOL is summarized to three composite scores: kidney disease component summary (KDCS), physical component summary (PCS), and mental component summary (MCS). The relationships between HRQOL and the hydration index, lean tissue index (LTI), and fat tissue index (FTI) were analyzed by regression analysis. One hundred and ninety-seven PD patients were included in the present study. Patients with severe fluid overload showed a lower PCS. The hydration index and FTI showed statistically significant negative associations with PCS. In subgroup analysis, the associations between the hydration index and PCS remained robust after stratifying according to sex, age, and residual urine. Our results indicated that both the hydration index and FTI were negatively associated with HRQOL, especially PCS.

Characteristics of Frailty in Haemodialysis Patients

Background: Both frailty and cachexia increase mortality in haemodialysis (HD) patients. The clinical frailty score (CFS) is a seven-point scale and less complex than other cachexia and frailty assessments. We wished to determine the characteristics of frail HD patients using the CFS. Methods: Single centre cross-sectional study of HD patients completing physical activity questionnaires with bioimpedance measurements of body composition and hand grip strength (HGS). Results: We studied 172 HD patients. The CFS classified 54 (31.4%) as frail, who were older (70.4±12.2 vs 56.2 ± 16.1 years, p < 0.001), greater modified Charlson co-morbidity (3 (2–3) versus 1.5 (0–3), p < 0.001), and body fat (33 (25.4–40.2) versus 26.2 (15.8–34) %, p < 0.01), but lower total energy expenditure (1720 (1574–1818) versus 1870 (1670–2194) kcal/day, p < 0.01), lean muscle mass index (9.1 (7.7–10.1) versus 9.9 (8.9–10.8) kg/m2), and HGS (15.3 (10.3–21.9) versus 23.6 (16.7–34.4) kg), both p < 0.001. On multivariable logistic analysis, frailty was independently associated with lower active energy expenditure (odds ratio (OR) 0.98, 95% confidence limits (CL) 0.98–0.99, p = 0.001), diabetes (OR 5.09, CL 1.06–16.66) and HGS (OR 0.92, CL 0.86–0.98). Discussion: Frail HD patients reported less active energy expenditure, associated with reduced muscle mass and strength. Frail patients were more likely to have greater co-morbidity, particularly diabetes. Whether physical activity programmes can improve frailty remains to be determined.

Bioimpedance spectroscopy: Is a picture worth a thousand words?

Volume status can be difficult to assess in dialysis patients. Peripheral edema, elevated venous pressure, lung crackles, and hypertension are taught as signs of fluid overload, but sensitivity and specificity are poor. Bioimpedance technology has evolved from early single frequency to multifrequency machines which apply spectroscopic analysis (BIS), modeling data to physics-based mixture theory. Bioimpedance plots can aid the evaluation of hydration status and body composition. The challenge remains how to use this information to manage dialysis populations, particularly as interventions to improve over hydration, sarcopenia, and adiposity are not without side effects. It is therefore of no surprise that validation studies for BIS use in peritoneal dialysis patients are limited, and results from clinical trials are inconsistent and conflicting. Despite these limitations, BIS has clinical utility with potential to accurately evaluate small changes in body tissue components. This article explains the information a BIS plot ("picture") can provide and how it can contribute to the overall clinical assessment of a patient. However, it remains the role of the clinician to integrate information and devise treatment strategies to optimize competing patient risks, fluid and nutrition status, effects of high glucose PD fluids on membrane function, and quality of life issues.

Consistency of the estimated target weights and ECW/TBW using BIA after hemodialysis in patients between standing and lying-down positions

Background

As hemodialysis is administered with the patient lying down, the distribution of body fluid is stable in the lying position, which is why this position is recommended for bioimpedance analysis (BIA). Although the InBody S10 is widely used for hemodialysis patients in the lying position, clinicians must make the measurements in person. In contrast, patients can use the InBody 770 to obtain measurements by themselves in the standing position, which may be more convenient. Therefore, this study compared the measurements of hemodialysis patients’ estimated target weight and ECW/TBW obtained lying down using the S10 to those obtained in the standing position using the 770.

Methods

This study was conducted among maintenance hemodialysis patients at Chuncheon Sacred Heart Hospital in October 2020. Measurements from 56 patients before and after hemodialysis were obtained using the 2 machines. Each (S10 or 770) estimated target weight, both pre- and post-hemodialysis, was considered ideal when the ECW/TBW ratio was 0.380. R² was calculated and the Bland-Altman test was performed.

Results

The patients’ median age was 64 years old, and 51% were men. The actual ultrafiltration was 2 kg, and the mean TBW change measured using the InBody devices was 1.5 L (R² = 0.718) for the S10 and 1.7 L (R² = 0.616) for the 770. The estimated target weight at pre- and post-hemodialysis showed a remarkably high correlation with the patients’ actual pre- and post-hemodialysis weight (R² > 0.095). The correlation between these measurements (lying vs. standing) before and after hemodialysis was also very close (R² = 1.0000). In addition, ECW/TBW had a good correlation (R2 ≥ 0.970) The Bland-Altman test of dry weight and ECW/TBW yielded similar results.

Conclusions

This study showed that patients’ estimated target weights in the lying position using the InBody S10 device and in the standing position using the InBody 770 device were consistent in both pre- and post-hemodialysis states.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02737-3.

Comparison of frailty, sarcopenia and protein energy wasting in a contemporary peritoneal dialysis cohort

BACKGROUND

More elderly frail patients are now treated by peritoneal dialysis (PD). Frailty, sarcopenia and protein energy wasting (PEW) are all associated with increased mortality. Simple screening tools are required to identify patients to allow for interventions. As such, we wished to review the prevalence of frailty and compare frailty with sarcopenia and PEW in a contemporary PD population.

PATIENTS AND METHODS

We used the Clinical Frailty Score (CFS) to determine frailty, bio-impedance body composition and hand grip strength (HGS) to determine sarcopenia and combining laboratory, body composition and protein nitrogen appearance rate (PNA) to assess PEW.

RESULTS

Records of 368 PD patients, 61% male, mean age 60.9 ± 16.1 years, body mass index (BMI) 26.2 ± 5.1 kg/m² were reviewed, with 71 classified as frail (19.3%; CFS > 4), and frailty associated with age (odds ratio (OR) 1.047, 95% confidence interval (CL) 1.01-1.085, p = 0.012), Stoke-Davies co-morbidity (OR 1.808, 95%CL 1.129-2.895, p = 0.014) and negatively with HGS (OR 0.906, 95% CL 0.897-0.992, p = 0.033); 17.7% met muscle loss and HGS criteria for sarcopenia, with fair agreement with frailty (kappa 0.24 (CL 0.09-0.38)). Only two patients (0.5%) met all four criteria for PEW, 26.1% met the reduced BMI criteria, 4.6% the serum albumin, 32.9% the PNA and 39.4% the reduced muscle mass. HGS correlated with lean muscle mass (r ² = 0.42, p < 0.001).

CONCLUSION

Using the CFS, 19.3% of patients were classified as frail, compared to 17.7% with sarcopenia and <1% with PEW. The CFS requires no special equipment or laboratory tests and was associated with age, co-morbidity and HGS weakness.

Peri-dialytic hypoglycaemia with haemodialysis and on-line post-dilutional haemodiafiltration

INTRODUCTION

We wished to determine whether peri-dialytic hypoglycaemia is a clinical risk in contemporary dialysis patients using glucose containing dialysate.

METHODS

We measured blood glucose pre- and post-haemodialysis or haemodiafiltration, using 5.5 mmol/L glucose dialysate, and body composition by bioimpedance.

RESULTS

239 patients were studied, mean age 65±15.4 years, 59.4% male, 46.4% diabetes, 81.6% treated by haemodiafiltration, Five haemodiafiltration patients (2.1%) had hypoglycaemia, with 82 (33%) a blood glucose <5.5 mmol/L, with fewer diabetics (19.8 vs 74.7%, p=0.001, and %body fat 27.7(20.6-32.6) vs 34.7(26.6-42.8)%, p=0.001. Low post-dialysis blood glucose was negatively associated with glycated haemoglobin (OR 0.94 (0.84-0.97), p=0.004), weight (OR 0.94 (0.89-0.98), p=0.009), and % body fat (OR 0.92 (0.86-0.98), p=0.013).

CONCLUSIONS

Although hypoglycaemia occurred in 2%, 33% had a blood glucose below dialysate glucose. Low post-dialysis glucose was associated with lower glycated haemoglobin and body fat, suggesting nutritional status is important in determining the risk of peri-dialytic hypoglycaemia.

Assessment of uremic sarcopenia in dialysis patients: An update

Uremic sarcopenia, which is highly prevalent in dialysis patients, leads to an increased risk of adverse outcomes, such as poor quality of life, falls, fracture, hospitalization, and even mortality. Therefore, early detection of uremic sarcopenia is crucial for administering quick and adequate multidisciplinary therapy to improve clinical outcomes. This review updates the current information about uremic sarcopenia assessment in chronic dialysis patients. We discuss the methods of assessing skeletal muscle mass, strength, and physical performance. We also discuss surrogate markers derived from serum and dialysate creatinine, in addition to emerging screening tools. The prevalence, clinical relevance, and impact of uremic sarcopenia on survival are reviewed and we discuss the limitations and challenges in applying the current working definition of sarcopenia based on the senior population to dialysis patients. The review shows that dialysis patients with skeletal muscle weakness or poor physical performance, either with or without low skeletal muscle mass, should undergo multidisciplinary therapy, included nutritional counseling, lifestyle modification, and exercise intervention, to mitigate the detrimental effects of uremic sarcopenia.

Prevalence and correlates of low plasma selenium concentrations in peritoneal dialysis patients

OBJECTIVE

Selenium is a key component in multiple enzyme systems, and dialysis patients with lower levels have been reported to have increased mortality. Low selenium levels were commonly reported in historic hemodialysis patients, but not in recent studies. There have been very few studies in peritoneal dialysis (PD) patients, and with the increasing age and frailty of our PD population we wished to review factors associated with lower selenium in PD patients.

DESIGN & METHODS

We retrospectively reviewed plasma selenium, normal laboratory >0.8 umol/L, measurements from a cohort of PD patients, attending for routine peritoneal membrane assessments, along with measurement of dialysis adequacy (Kt/Vurea), and normalized nitrogen appearance rate (nPNA) and bioimpedance measured extracellular water (ECW)/total body water (TBW), and skeletal muscle mass indexed for height (SMMI).

RESULTS

The median plasma selenium was 0.84 (IQR-0.72-1.01) umol/L in 406 PD patients, 61.1 % male, mean age 59.0 ± 15.5 years, 44.9 % diabetic with 15.8 % designated as clinically frail (CFS). 41.4 % had selenium deficiency (<0.8 umol/L), and was more common with increasing CFS (χ2-6.8, p < 0.009), comorbidity grade(χ2-26.74, p < 0.001).Plasma selenium correlated with serum total protein (TP) (r = 0.352), albumin (r = 0.358), nPNA (r = 0.263), and negatively with ECW/TBW (r= -0.321) all p < 0.001, and positively with SMMI (rho = 0.109, p = 0.03). On multivariable analysis selenium was independently associated with TP (β 0.799 ± 0.15,95 % confidence limits (95CL) (0.505-1.093), p=<0.001), and negatively with C reactive protein (CRP) (β -0.02 ± 0.01, (95CL -0.047 to -0.005) p = 0.01), and ECW/TBW (β -1.499 ± 0.42 (95CL -2.33 to -0.666) p=<0.001).

CONCLUSIONS

Compared to recent studies in hemodialysis patients, we report a 41 % prevalence for low selenium levels. Plasma selenium was positively associated with total serum protein, and negatively with CRP and ECW/TBW. Thus, lower selenium concentrations were linked to reduced dietary protein intake, and increasing frailty, inflammation and ECW/TBW ratios.

The importance of body composition assessment in the rehabilitation process

Introduction. This personal study provides several aspects of the importance of body composition assessment in rehabilitation process in order to manage fat mass (FM), fat-free mas imbalances (FFM), pre-sarcopenia status, sarcopenia and risks association and to improve global functionality. Health outcomes and risk estimations regarding fat mass and skeletal muscle mass (SMM) plays a major role and should be integrated into the rehabilitation process routine in order to avoid functional impairment and physical disability by applying specific kinetic programs. Material and method. A number of 14 subjects classified as outpatients who have received physical therapy at home- kinesiotherapy for post-fracture / dislocation status of the lower limbs in accordance with the medical recommendations and legislation in force. At the end of the rehabilitation phase, the body composition was measured using bio impedance in order to adjust the next step of the active rehabilitation. The measurements were obtained with a completely bioelectrical impedance analyzer (BIA). Single frequency BIA (SF-BIA) was used. For each subject major body compartments determined as FFM (including bone mineral tissue, total body water-TBW and visceral protein), SMM and FM were measured as a tissue-system by means of linear empirical equations stored in the system memory together with personal physical data. IBM SPSS software version 25 was used for statistical analysis. Results and discussions. Four age groups determined as follows: 21.43% for 18-39 years, 50-69 years, >70 years each and 35.71% for 40-49 years, based on the rate of muscle loss, because its integrity is essential for rehabilitation program. From the 14 subjects there are 57.14 % men and 42.86% women, from urban environment 78.57% and rural 21.43%. Mean Age is 48.79 years ± 18.792 Std. Deviation. Fat mass from BIA recorded 21.43% cases low and normal each, and high/very high 57.14% of total cases. Consequently, of BMI (body mass index) association, 57.14% are at normal weight, 35.71% overweight and with obesity and 7.14% underweight. One Sample Chi-Square test applied to BMI Type Associate with FM reveals the statistical significance, < .05(.014). Fat-free mass index (FFMI), fat mass index (FMI), skeletal mass index (SMI) were computed by adjusted with height square. FMI somatotype components results are 64.3% adipose cases, 21.4% intermediate and 14.3% lean. One Sample Chi-Square test applied to FMI Types reveals the statistical significance < .05(.046). Regression equation of standard BMI and FMI with scatter plots for 77.8% of cases was computed in the present study. FFMI somatotype components recorded 57.1% intermediate cases, 21.4% slender and solid each. Regression equation of standard BMI and FFMI with scatter plots for 57.4% of cases was computed. Three patients exceeded 15 seconds at the chair stand test so probable sarcopenia was identified. From BIA were extracted the value for the skeletal mass and SMI was calculated by height adjusted: 13 (92.86%) cases have normal values and one (7.14%) case have optimal value. Regression equation of standard BMI and SMI with scatter plots for 66.4% of cases was computed. Pearson correlation (CI =99%) denotes strong statistical relationship between BMI and FMI (r=0.882), FFMI (r=0.815), Age (r=0.659), Water (r=-0.693). FMI also correlates strongly with Age (r= 0.707), Water (r=-0.925) and Proteins values (r=-0.819). FFMI also correlates strongly with SMI (r=0.984). Water correlates with Protein (r=0.848, CI = 99%). Beta regression analysis strongly correlates SMI prediction with FFMI (ß=0.731), Water (ß=0.138) and Protein (ß=-0.370) for p<0.05. Anova significance of .000 (CI=99%) with applicability of 99.8% of the cases (R2 =0.998) proved that constant predictors: Water (%), FFMI, Proteins (%), FMI, BMI interact to influence SMM variability. 64.25% of subjects recorded an insufficient water level and 71.43% of subjects recorded an insufficient proteins level. Body composition evaluation should be integrated into routine clinical practice for the initial assessment and sequential follow-up and the strongest point of BIA is the possibility to replace invasive laboratory analysis with a quick, noninvasive test that can be carried out in a medical office. Body composition evaluation should be performed at the different stages of the disease, during the course of treatments and the rehabilitation phase. Conclusions. For each patient specific kinetic program will be developed. FMI increase (64.3% adipose cases) denotes the risk of metabolic syndrome and insulin resistance. Consequently, resistive and concentric exercises will be applied. For FFMI loss (57.1% intermediate cases, 21.4% slender) and SMI increasing (92.86% cases have normal values but not optimal ones, 21.43% pre-sarcopenia detected by positive chair test) resistance, eccentric/concentric exercises should be applied. All kinetic programs will be preceded by warm-up and followed by stretching taking into account cardiac reserve for each patient. Maximal/sub-maximal force exercises will be used age-related. Additional water (64.25% of subjects recorded an insufficient water level) and proteins levels (71.43% of subjects recorded an insufficient proteins level) must be balanced by nutritional support in accordance with rehabilitation consult and current physician approval in the interdisciplinary team. BIA may be an important supporting tool for health professionals in order to customize the rehabilitation programs for each patient. Keywords: body composition, rehabilitation, bioelectrical impedance, fat-free mass index, fat mass index, skeletal muscle index,

Impact of frailty and its inter-relationship with lean tissue wasting and malnutrition on kidney transplant waitlist candidacy and delisting

BACKGROUND & AIMS

Frailty and body composition contribute to adverse pre-transplant outcomes including hospitalization and waitlist mortality, but the interaction between frailty and body composition remains uncertain.

METHODS

Frailty was diagnosed by Clinical Frailty Scale (CFS) and a standard Frailty Questionnaire (FQ). Nutrition was evaluated by serum albumin level, subjective global assessment (SGA) and comprehensive malnutrition-inflammation score (MIS). Body composition was assessed by bioimpedance spectroscopy. All patients were followed up for three years. Primary outcome measure was a composite of death and permanent removal from waitlist. Secondary outcomes were emergency room attendance and hospitalization.

RESULTS

432 prevalent peritoneal dialysis (PD) patients were recruited. 148 (34.3%) were listed on transplant waitlist. Frailty, age and comorbidity load predicted waitlisting. With time, 47 patients were delisted. Frailty by FQ (p = 0.028), serum albumin level (p = 0.005) and waist circumference (p = 0.010) predicted delisting after adjustment for confounders. Frailty significantly interacted with lean tissue wasting (FQ: p = 0.002, CFS: p = 0.048), and MIS (FQ: p = 0.004; CFS: p = 0.014) on delisting. Lean tissue wasting caused 2.56 times risk of delisting among frail individuals identified by FQ (p = 0.016), while serum albumin and the presence of diabetes mellitus predicted the risk of delisting among non-frail individuals. Lean tissue wasted and frail subjects had a higher all-cause and infection-related hospitalization.

CONCLUSION

Frailty predicted both kidney transplant waitlisting and subsequent delisting. Frailty interacted with body composition on transplant waitlist delisting. Lean tissue wasting and malnutrition independently predicted delisting in frail and non-frail listed subjects respectively.

Adipose expression of miR-130b and miR-17-5p with wasting, cardiovascular event and mortality in advanced chronic kidney disease patients

BACKGROUND

There were limited data on the association of adipose microRNA expression with body composition and adverse clinical outcomes in patients with advanced chronic kidney disease (CKD). We aimed to evaluate the association of adipose miR-130b and miR-17-5p expressions with body composition, functional state, cardiovascular outcome and mortality in incident dialysis patients.

METHODS

We performed a single-centre prospective cohort study. Patients who were planned for peritoneal dialysis were recruited. MiR-130b and miR-17-5p expressions were measured from subcutaneous and pre-peritoneal fat tissue obtained during peritoneal dialysis catheter insertion. Body composition and physical function were assessed by bioimpedance spectroscopy and Clinical Frailty Scale. Primary outcome was 2-year survival. Secondary outcomes were 2-year technique survival and major adverse cardiovascular event (MACE) rate.

RESULTS

Adipose expression of miR-130b and miR-17-5p correlated with parameters of muscle mass including intracellular water (miR-130b: r = 0.191, P = 0.02; miR-17-5p: r = 0.211, P = 0.013) and lean tissue mass (miR-130b: r = 0.180, P = 0.03; miR-17-5p: r = 0.176, P = 0.004). miR-130b expression predicted frailty significantly (P = 0.016). Adipose miR-17-5p expression predicted 2-year all-cause survival (P = 0.020) and technique survival (P = 0.036), while miR-130b expression predicted incidence of major adverse cardiovascular events (P = 0.015).

CONCLUSIONS

Adipose miR-130b and miR-17-5p expressions correlated with body composition parameters, frailty, and predicted cardiovascular events and mortality in advanced CKD patients.

Assessing lean tissue by bioelectrical impedance analysis pre hemodialysis underestimates the prevalence of sarcopenia in maintenance hemodialysis patients

BACKGROUND/OBJECTIVES

Patients undergoing maintenance hemodialysis dialysis (MHD) are at high risk of sarcopenia. Diagnosing sarcopenia requires measurement of both muscle mass and muscle function. However, few studies have rigorously evaluated the best timing for assessment. This study aimed to evaluate the changes in body composition following hemodialysis in an Asian population.

SUBJECTS/METHODS

Overall, 87 MHD patients were included. Body composition was estimated using bioelectrical impedance analysis. Handgrip strength was measured using a quantitative handgrip dynamometer, and physical performance was assessed using the 6-m usual gait speed. All measurements were performed pre and post dialysis. Blood samples were collected before and after the same dialysis session.

RESULTS

The prevalence of sarcopenia ranged from 6.9% to 18.8% pre dialysis (40-59-year group, 6.9%; 60-80-year group, 16.7%; >80-year group, 18.8%) and from 13.8% to 62.5% post dialysis. The body weight decreased from 59.32 ± 11.20 kg pre dialysis to 57.71 ± 11.05 kg post dialysis. Both the extracellular and intracellular water levels decreased post dialysis (from 14.70 ± 3.81 to 13.6 ± 2.82 L, P < 0.001, and from 21.30 ± 4.20 to 20.8 ± 4.13 L, P < 0.001, respectively). Albumin and creatinine levels were significantly lower in patients with sarcopenia. Elevated high-sensitivity C-reactive protein and interleukin-6 levels were observed in sarcopenia patients.

CONCLUSION

The prevalence of sarcopenia in MHD patients varies greatly according to the timing of measurements. Although predialysis measurement is preferred, it underestimates the prevalence of sarcopenia in MHD patients.

Agreement of Single-Frequency Electrical Bioimpedance in the Evaluation of Fat Free Mass and Fat Mass in Peritoneal Dialysis Patients

Background: Protein-energy wasting is related to impairment of quality of life and lower survival of end-stage kidney disease (ESKD) patients. The evaluation of body composition, especially fat free mass (FFM) and fat mass (FM), is important for the prediction of outcomes in these individuals. The aim of this study was to compare the FFM and FM measurements obtained by single-frequency bioimpedance (SF-BIA) and by a multiple frequency bioimpedance (MF-BIA) device, using dual energy X-ray absorptiometry (DXA) peritoneal dialysis (PD) patients. Methods: This was a cross-sectional study involving adult patients undergoing regular PD, in which we performed SF-BIA, MF-BIA, and DXA at the same visit. To compare the bioimpedance values with DXA, we used: Person correlation (r), intraclass correlation coefficient (ICC), and Bland-Altman concordance analysis. Results: The sample consisted of 50 patients in the PD, with mean age of 55.1 ± 16.3 years. Both bioimpedance methods showed a strong correlation (r > 0.7) and excellent reproducibility (ICC > 0.75) compared to DXA. According to the Bland-Altman diagram, SF-BIA showed agreement in body compartment measurements, with no proportionality bias (p > 0.05), without systematic bias for FFM (-0.5 ± 4.9, 95% CI -1.8 to 0.9, p = 0.506), and for FM (0.3 ± 4.6, p = 0.543). MF-BIA did not present a proportionality bias for the FFM, but it underestimated this body compartment by 2.5 ± 5.4 kg (p = 0.002). In addition, MF-BIA presented proportionality bias for FM. Conclusion: SF-BIA was a more accurate assessing method than MBIA for FFM and FM measurements in PD patients. Because it is a low-cost, non-evaluator-dependent measurement and has less systematic bias, it can also be recommended for fat mass and free-fat mass evaluation in PD patients.

Validation of the SARC-F for Assessing Sarcopenia in Patients on Peritoneal Dialysis

OBJECTIVE

Proper screening or diagnosis of sarcopenia (SP) is important to obtain favorable outcomes in patients on peritoneal dialysis (PD). Previous studies have shown that the SARC-F is associated with various parameters of SP in elderly populations. In this study, we aimed to validate the SARC-F questionnaire for predicting SP in patients on PD.

METHODS

This cross-sectional study was conducted at a tertiary medical center. We identified all patients prevalent on PD patients (n = 127). A version of the original SARC-F was used to assess the questionnaire. Patients with a total score of ≥4 points were defined as the high group and those with <4 points were defined as the normal group. The hand grip strength and appendicular skeletal muscle mass index were measured in all patients. SP was defined as previously reported.

RESULTS

Of the 127 total patients, 29 (22.8%, high group) had an SARC-F score of ≥4. The sensitivity and specificity of the SARC-F for predicting SP were 70.0% and 81.2%, respectively. The negative predictive and positive predictive values were 96.9% and 24.1%, respectively. The area under curve of the SARC-F score for SP was 0.791 (0.709-0.858, P < .001). The hand grip strength of the normal and high groups was 26.4 ± 8.5 and 19.5 ± 6.8 kg, respectively (P < .001). The appendicular skeletal muscle mass index in the normal and high groups was 7.6 ± 1.3 and 7.2 ± 1.8 kg/m², respectively (P = .152). An increase in the SARC-F score as a continuous variable or classification into the high group as a categorical variable was associated with a higher odds ratio for SP in univariate and multivariate analyses.

CONCLUSION

The SARC-F has a high negative predictive value and a high specificity for predicting SP in patients on PD.

Using Bioimpedance Spectroscopy for Diagnosis of Malnutrition in Chronic Kidney Disease Stage 5-Is It Useful?

OBJECTIVE

Malnutrition is common in chronic kidney disease stage 5 (CKD5) and has negative clinical impacts. The aim of the present study is to evaluate bioimpedance spectroscopy (BIS) in diagnosing malnutrition in CKD5 including hemodialysis and peritoneal dialysis patients (CKD5D) using cutoff values for fat-free mass index (FFMI) according to the Global Leadership Initiative on Malnutrition criteria. Dual-energy X-ray absorptiometry (DXA) was used as a reference method.

DESIGN AND METHODS

We performed a single-center cross-sectional diagnostic study of 90 patients with CKD5 or CKD5D.

RESULTS

BIS-derived FFMI estimates were significantly higher compared with those obtained by DXA (18.5 ± 2.6 vs.17.8 ± 2.0, P < .05). The mean difference in FFMI estimates between the methods (DXA-BIS) and Bland-Altman 95% limits of agreements is -0.38 (2.76, -3.52) kg/m². Overhydration (B = 0.67, P < .001), age (B = 0.02, P = .037), and interactions between overhydration and CKD5 subgroups (P = .034) independently predicted bias in BIS-derived FFMI. BIS-derived FFMI showed poor sensitivity (64%) and positive predictive value (48%) in diagnosing malnutrition in the present study population.

CONCLUSION

The present study showed a limited agreement between estimates of FFMI derived by BIS and DXA due to a large interindividual variation. Using BIS as a clinical tool for assessing FFMI has limited accuracy and poor sensitivity in diagnosing malnutrition in patients with CKD5 and CKD5D.

Role of Muscle Mass and Nutritional Assessment Tools in Evaluating the Nutritional Status of Patients With Locally Advanced Nasopharyngeal Carcinoma

Objective: This study was to explore the role and necessity of muscle mass [fat-free mass index (FFMI) and appendicular skeletal muscle index (ASMI) measured by bioelectrical impedance analysis (BIA)] in nutritional status evaluation of patients with locally advanced (III, IVa) nasopharyngeal carcinoma (NPC). Methods: One hundred and thirty locally advanced NPC patients were recruited. Their nutritional status was assessed by albumin (ALB), body mass index (BMI), Nutritional Risk Screening 2002 (NRS 2002), Patient generated-Subjective Global Assessment (PG-SGA), and muscle mass. Consistency test and McNemar test were used to evaluate the consistency of muscle mass with ALB, BMI, NRS 2002, and PG-SGA, and correlation analysis was performed on muscle mass and PG-SGA or BMI. Results: 61/130 (46.9%) of the patients had nutritional risks according to NRS 2002, 68/130 (53.1%) of the patients had malnutrition according to PG-SGA assessment. FFMI and ASMI could determine the loss of muscle mass that cannot be detected by albumin (30.2 and 65.6%), BMI (28.0 and 35.3%), NRS 2002 (26.1 and 25.0%), and PG-SGA (18.6 and 55.6%). McNemar test showed that the malnutrition results assessed by FFMI and BMI were inconsistent (P <0.001), but further Pearson correlation analysis showed that BMI was positively correlated with FFMI (rs = 0.300, P = 0.001). Conclusion: The commonly used nutritional assessment scale/parameters cannot identify the muscle mass loss in patients with locally advanced NPC. Analysis of human body composition is important for nutritional assessment in patients with locally advanced NPC.

Comparison of Body Composition Monitor and InBody 720 Bioimpedance Devices for Body Composition Estimation in Hemodialysis Patients and Healthy Controls

Bioelectric impedance devices have become a standard of care not only for peritoneal dialysis but also for hemodialysis patients. We compared the most important body composition variables (extracellular water, intracellular water, total body water and fat mass) measured with the multifrequency bioelectric impedance device InBody 720 (MF-BIA) and bioimpedance spectroscopy body composition monitor Fresenius (BIS BCM) in hemodialysis patients (n = 51, 175.1 + 7.8 cm, 82.2 + 15.2 kg) and healthy controls (n = 51, 175.1 + 7.6 cm, 82.3 + 15.3 kg). The MF-BIA InBody 720 device compared to the BIS BCM device showed significantly larger total body water and intracellular water estimates and significantly smaller extracellular water and body fat estimates in hemodialysis patients (p < 0.001). These differences (p < 0.001) were similar in the cohort of healthy controls; moreover, we observed high correlations in all variables between the hemodialysis patients and the healthy controls (0.80–0.95, p < 0.001). The mean relative differences in the order of 8% were lower for extracellular water and total body fat, but the limits of agreement were still wide enough to be clinically significant. We conclude that the results of the measurements with InBody 720 and BCM Fresenius cannot be used interchangeably. Physicians and nutritionists involved in the care of hemodialysis patients should be aware of this discrepancy between the two devices and should try to use the same device to track the body in their hemodialysis population in a longitudinal direction.

Peritoneal sodium removal compared to glucose absorption in peritoneal dialysis patients treated by continuous ambulatory peritoneal dialysis and automated peritoneal dialysis with and without a daytime exchange

Sodium removal in peritoneal dialysis (PD) depends on convective clearance, typically generated by a glucose gradient, but this can result in glucose absorption. We wished to determine which factors determine peritoneal sodium losses to glucose absorption (PD Na/Gluc). Peritoneal sodium losses and glucose absorption were calculated from measured 24-h collections of PD effluent, in patients attending for assessment of peritoneal membrane function. Five hundred and fifty eight patients; 317 (56.8%) males, mean age 56.1 ± 16.0 years, were studied, 281 treated by automated peritoneal dialysis (APD) with a daytime exchange (50.4%); 179 (32.1%) by APD and 98 (17.6%) by continuous ambulatory peritoneal dialysis (CAPD). All patients used glucose containing dialysates, with 352 (63.1%) using icodextrin and 210 (37.6%) hypertonic (22.7 g/L glucose) dialysates. The ratio of PD Na/Gluc was 0.14 (0.02-0.29). Patients using icodextrin had a higher ratio (0.16 (0.03-0.32) versus 0.11 (-0.02-0.26), P < .001), as did those using 22.7 g/L glucose versus 13.6 g/L (0.16 (0.06-0.32) versus 0.13 (-0.01-0.19), P < .01), and CAPD versus APD (0.18 (0.05-0.36) versus 0.11 (0.0-0.27), P < .05), respectively. A multivariable model showed that 24-h ultrafiltration (odds ratio [OR] 7.6 (95% confidence interval [3.9-14.8]), P < .001 was associated with increased PD Na/Gluc, whereas APD (OR 0.19 (0.06-0.62), P < .01 and increased extracellular water to total body water (OR 0.001 [0-0.08], P = .03) were associated with lower ratios. Twenty four-hour peritoneal ultrafiltration was strongly associated with PD Na/Gluc, whereas patients treated with APD cyclers without a daytime icodextrin exchange and those with an increased extracellular water to total body water had lower peritoneal sodium losses but with greater peritoneal glucose absorption.

Screening Tests for Sarcopenia in Patients with Chronic Kidney Disease

BACKGROUND

Patients with chronic kidney disease (CKD) are at increased risk of muscle wasting. Screening tools for sarcopenia, including the Sarc-F questionnaire are now advocated for clinical practice. We wished to compare using the Sarc-F tool with standard measurements of hand grip (HGS) strength and appendicular muscle mass index (APMI).

METHODS

We retrospectively reviewed Sarc-F questionnaires completed by patients with CKD, along with contemporaneous measurements of HGS and bioimpedance measured APMI.

RESULTS

146 patients; 94 male (64.4%), mean age 70.5 ± 15 years, body mass index 28.7 ± 6.3 kg/m² were screened, and 46 screened positive for sarcopenia, with a lower median HGS (19.3 (14.2-24.7) vs 25.6 (19.7-32) kg) and greater body fat (38.3 ± 11.5 vs 30.6 ± 11.5%), both p < 0.001,, with more non-white ethnicity (63 vs 44%), p < 0.05, but there were no other differences. Step-wise adding HGS, and then APMI cut offs, the prevalence of sarcopenia fell from 31.5% to 20.7-24.7% and 2.8-4.8% respectively, with 45.5-62.8% having reduced HGS strength and 11.0-28.1% reduced APMI, depending on which guidelines were applied. Using the most recent European, and ethnicity adjusted cut-off values then there were no statistical differences in the prevalence of sarcopenia with or without the Sarc-F screening tool.

CONCLUSIONS

By starting with the Sarc-F screening tool, a number of our patients with CKD would then have been excluded from subsequent investigation for sarcopenia. However, overall screening with the Sarc-F tool did not lead to a significant difference in the prevalence of sarcopenia, when using current and ethnicity adjusted guidelines, compared to combining HGS and APMI alone.

Total body water by BIA in children and young adults with normal and excessive weight

Background

Estimation of total body water (TBW) is essential for clinical care.

Objective

Evaluation of changes in TBW by bioelectrical impedance analysis (BIA) in children and young adults with excessive weight.

Design

Data was collected in individuals aged 3–21 years with normal (n = 202) or excessive body weight (n = 133). The BIA results from individuals with normal weight were compared with two previously published studies in children by isotope dilution methods.

Results

Individuals with excessive weight had a higher mean TBW (27.87 L, SE 0.368) for height and age as compared to individuals with normal weight (23.95 L, SE 0.298), P<0.001. However, individuals with excessive weight had lower mean TBW (24.93 L, SE 0.37) for weight and body surface area (BSA) as compared to individuals with normal weight (26.94 L, SE 0.287), P<0.001. Comparison with two previously published studies showed no significant differences in mean TBW with one ((p = 1.00) but a significant difference with another study (p = 0.001).

Conclusions

Individuals with excessive weight had 16.5% higher mean TBW for height and age and 7.4% lower TBW for weight and BSA as compared to normal weight individuals. Our study validates the feasibility of data collection in pediatric outpatient setting by BIA.

The Comparison of Segmental Multifrequency Bioelectrical Impedance Analysis and Dual-Energy X-ray Absorptiometry for Estimating Fat Free Mass and Percentage Body Fat in an Ambulatory Population

BACKGROUND

Despite malnutrition being associated with increased mortality and morbidity, there continues to be great difficulty in defining criteria and implementing widespread screening. Tools used to diagnose decreased fat-free mass (FFM [sarcopenia]) should be easy to use, relatively inexpensive, and safe. Bioelectrical impedance analysis (BIA) has the potential to meet these criteria, but reliability across body mass index (BMI) classes is a concern.

METHODS

A total of 176 healthy ambulatory participants (aged 18-65 years) were recruited equally (n = 44) in 4 BMI categories: (1) 18.5-24.9, (2) 25.0-29.9, (3) 30-34.9, and (4) ≥35.0. Participants were fasting overnight and had S-MFBIA (InBody 770) measurements the next morning, with DXA being performed subsequently within 30 minutes.

RESULTS

The measurement (mean ± SD) for FFM with DXA was 52.8 ± 11.0, and BIA was 53.6 ± 11.0. Delta (S-MFBIA vs DXA) was 0.8 ± 2.2 (5% limits of agreement -3.5 to +5.2), and concordance correlation coefficient (CCC) was 0.98 (95% CI, 0.97-0.98). The measurements (mean ± SD) for PBF with DXA was 37.5 ± 10.6% and S-MFBIA was 36.6 ± 11.3%. Delta (S-MFBIA vs DXA) was -0.9 ± 2.6 (5% limits of agreement 6.0 to +4.2), and CCC was 0.97 (95% CI, 0.96-0.98). The CCC according to the 4 BMI groups for FFM and PBF was between 0.96-0.98 and 0.90-0.94, respectively.

CONCLUSIONS

FFM and PBF measured by S-MFBIA had good agreement with DXA across all BMI categories measured in the current study of ambulatory participants.

Changes in aortic pulse wave velocity in peritoneal dialysis do not mirror changes in extracellular water measured by bioimpedance

BACKGROUND

Pulse wave velocity is a measurement of arterial stiffness and associated with increased cardiovascular mortality. Previous reports in peritoneal dialysis have linked increased pulse wave velocity with an expansion in extracellular water. As cardiovascular mortality is increased in peritoneal dialysis patient, we wished to determine whether changes in pulse wave velocity mirrored changes in extracellular water.

METHODS

We repeated aortic pulse wave velocity and bioimpedance-derived extracellular water measurements in peritoneal dialysis patients attending for assessment of peritoneal membrane function.

RESULTS

Sixty-six patients, 41 males (62.1%), mean age of 66.2 ± 13.9 years, median duration of peritoneal dialysis treatment (14.3 (3.1-31.9) months) had repeated measurement 6.4 (5.8-10.2) months apart, with no significant change in aortic pulse wave velocity (10.1 ± 3.2 to 9.9 ± 2.8 m/s). In univariate analysis, the initial aortic pulse wave velocity was associated with extracellular water (r = 0.26, p = 0.034) and serum N-terminal pro brain-type natriuretic peptide (r = 0.25, p = 0.04), and on follow-up, aortic pulse wave velocity with N-terminal pro brain-type natriuretic peptide (r = 0.31, p = 0.01). Aortic pulse wave velocity increased in 50% of patients, and these patients had greater serum C-reactive protein 3(2-10) versus 2(1-4) mg/L, and ferritin (778(444-1099) versus 585(313-811), p < 0.05), but there were no differences in either absolute or adjusted extracellular water. Both log C-reactive protein (odds ratio 4.7 (95% confidence limits 1.3-17.1), p = 0.019) and prescription of calcium channel blockers (odds ratio 4.9 (95% confidence limits 1.2-19.1), p = 0.024) were independently associated with an increase in aortic pulse wave velocity.

CONCLUSION

We did not find an independent association between a change in aortic pulse wave velocity and extracellular water, suggesting that changes in aortic stiffness in peritoneal dialysis patients are more complex than simply following changes in extracellular water.

Glucose absorption from peritoneal dialysate is associated with a gain in fat mass and a reduction in lean body mass in prevalent peritoneal dialysis patients

The majority of peritoneal dialysates use glucose to generate an osmotic gradient for the convective removal of water and Na. Although glucose can potentially be absorbed, previous studies have failed to establish whether this leads to increased fat weight gain. We measured body composition using bioimpedance in peritoneal dialysis (PD) patients, electively starting PD, attending for their first assessment of peritoneal membrane function after 2-3 months, and then after 12 months. We studied 143 patients: eighty-nine (62·2 %) males, fifty-three (37·1 %) diabetics, mean age 61·3 (SD 14·9) years, with ninety (62·1 %) patients treated by automated PD cyclers with a daytime icodextrin exchange and thirty-seven (25·9 %) by continuous ambulatory PD. Median fat mass increased by 1·8 (-0·5 to 4·1) kg, whereas fat-free mass fell -1·3 (-2·9 to 1·0) kg, and the increase in fat mass was negatively associated with the fall in soft lean mass (r -0·41, P < 0·001). Increased fat mass was associated with measured peritoneal glucose absorption (r 0·69, P < 0·001), and glucose absorption was associated with the amount of 22·7 g/l glucose dialysate (OR 2·0, 95 % CI 1·5, 2·5, P < 0·001), peritoneal urea clearance (OR 9·5, 95 % CI 2·4, 37·1, P = 0·001) and male sex (OR 4·8, 95 % CI 1·5, 14·9, P = 0·008). We report an observational study in prevalent PD patients following body composition from their first assessment of PD membrane function for approximately 12 months, and despite the majority of patients prescribed icodextrin, we have demonstrated not only an association between intra-peritoneal glucose absorption and fat weight gain but also loss of fat-free mass.

Differences between anthropometric and bioimpedance measurements of muscle mass in the arm and hand grip and pinch strength in patients with chronic kidney disease

BACKGROUND & AIMS

Chronic kidney disease (CKD) patients are at increased risk of sarcopenic muscle wasting, with increased mortality risk. Simple screening tests are required to detect sarcopenia to allow for interventional therapies. We wished to compare anthropometric and multifrequency bioimpedance (MFBIA) measurements of arm composition and muscle strength.

METHODS

We measured segmental MFBIA, mid arm upper circumference (MUAC) and triceps skin fold thickness (TSF), hand grip strength (HGS) and pinch strength (PS) in CKD patients attending out-patient review.

RESULTS

We reviewed 146 patients; 94 male (64.4%), 93 (63.7%) diabetic, mean age 70.5 ± 15 years, weight 77.6 ± 17.1 kg, with a mean HGS of 25.2 ± 10.4, and PS 5.0 ± 1.9 kg. HGS and PS were correlated (r = 0.63, p < 0.001). Male patients had greater HGS and PS (28.3 ± 10.1 vs 19.7 ± 7.0 kg; and 5.3 ± 2.0 vs 4.3 ± 1.1 kg, p < 0.05) with greater arm muscle (3.2 ± 0.7 vs 2.4 ± 0.7 kg, p < 0.05) and less arm fat (1.8 ± 1.3 vs 2.9 ± 1.8 kg, p < 0.05), whereas there was no difference in anthropometric measurements of mid upper arm muscle or fat area. Whereas both HGS and PS correlated positively with MFBIA arm lean mass (r = 0.55, r = 0.37, p < 0.001) and negatively for arm fat mass (r = -0.4, p < 0.001, r = -0.32, p = 0.001) respectively, there were no correlations with anthropometric derived estimates of upper arm muscle or fat.

CONCLUSIONS

In CKD patients, segmental MFBIA measurements of the arm, but not those derived from anthropometric measurements demonstrate gender differences and correlate with arm muscle strength, whereas there were no such correlations with anthropometric estimates of upper arm muscle or fat.

Role of Human Body Composition Analysis and Malnutrition Risk Questionnaire in the Assessment of Nutritional Status of Patients With Initially Diagnosed Crohn's Disease

Objective: This study was carried out to investigate the role and necessity of human body composition analysis in assessing the nutritional status of initially diagnosed Crohn's disease (CD) patients.

Methods: A total of 47 initially diagnosed CD patients were recruited. The skeletal muscle mass index (SMI), fat-free mass index (FFMI), body fat mass, body fat percent, visceral fat area (VFA), and body cell mass were determined with the Biospace Inbody S10 composition analyzer.

Results: In 47 patients with initially diagnosed CD, SMI could determine the muscular mass reduction that could not be determined by the body mass index (BMI) (35.3%), albumin (ALB) (65.6%), nutrition risk screening (NRS)2002 (25.0%), and Patient-Generated Subjective Global Assessment (PG-SGA) (55.6%). FFMI could determine the malnutrition that could not be determined by the BMI (58.8%), albumin (90.6%), NRS2002 (50.0%), and PG-SGA (55.6%). VFA in the fistulizing CD patients was significantly higher than in the stricturing and non-fistulizing, non-stricturing patients (P < 0.05). SMI and BMI had the same performance (P = 1.000) and general consistence (Kappa = 0.487, P = 0.001) in the assessment of malnutrition; SMI and ALB had different performance (P < 0.001) and inconsistence was noted (Kappa = 0.069, P = 0.489) in the assessment of malnutrition; the results of the nutrition assessment were different between SMI and NRS2002 (P = 0.002), and inconsistence was observed (Kappa = 0.190, P = 0.071). SMI and PG-SGA had the same performance in the assessment of nutrition (P = 0.143), but there was inconsistence (Kappa = 0.099, P = 0.464). FFMI and BMI had general consistence in the assessment of malnutrition (Kappa = 0.472, P < 0.001), but the positive rate determined by FFMI (85.1%) was markedly higher than that by BMI (63.8%) (P = 0.002). FFMI and ALB had different performance in the assessment of malnutrition (P < 0.001) and there was inconsistence (Kappa = −0.008, P = 0.877). FFMI and NRS2002 had the same performance in the assessment of malnutrition (P = 0.453), but the consistence was poor (Kappa = 0.286, P = 0.039). The results determined by SMI and PG-SGA were consistent (P = 0.727), but the consistence was poor (Kappa = 0.399, P = 0.006).

Conclusion: Human body composition analysis can identify the patients with muscular mass reduction that cannot be identified by commonly used nutrition assessment scales/parameters. Thus, it is helpful for the assessment of disease severity and also important for the nutrition assessment in CD patients.

The effect of glucose absorption from peritoneal dialysates on changes in lipid profiles in prevalent peritoneal dialysis patients

The majority of peritoneal dialysates contain glucose, which can potentially be absorbed from the peritoneal cavity. Previous studies have reported an observation between dialysate glucose exposure and increases in total cholesterol (TC), low-density lipoproteins (LDLs) and triglycerides (TGs). As most of these studies reported glucose exposure in peritoneal dialysis (PD) patients treated by continuous ambulatory peritoneal dialysis (CAPD), we wished to determine whether measured peritoneal glucose absorption resulted in an increase in lipid profile with CAPD and automated PD (APD) cycler treatments. Glucose absorption was measured in 143 patients; 89 (62.2%) males, 53 (37.1%) diabetics, mean age 61.3 ± 14.9 years, with 90 (62.1%) using a daytime icodextrin exchange; 37 (25.9%) CAPD, attending for their first assessment of peritoneal membrane function, when PD prescriptions were then individualised for peritoneal transporter status and repeated after 12 months. Median glucose absorption was 172.5 (75.5-265.5) mmol/day. Although glycated haemoglobin increased (42 ± 16 to 45.4 ± 17.7 mmol/mol, p = 0.006), there was no change in TC (4.8 ± 1.3 to 4.7 ± 1.3 mmol/L), high-density lipoproteins (1.39 ± 0.45 to 1.33 ± 0.51 mmol/L), LDL (2.48 ± 1.12 to 2.21 ± 0.87 mmol/L) or TGs (2.0 (1.3-2.6) to 2.0 (1.3-2.8) mmol/L, adjusted p > 0.05). We found no association between glucose absorption and either lipid profiles or changes in serum lipids. In the current era of APD cyclers and icodextrin, PD prescriptions can be individualised to accommodate patients with a different peritoneal transport status, so that despite daily glucose absorption from dialysates, and a minor increase in glycated haemoglobin, we were unable to demonstrate any significant increase in standard lipid profiles.

Differences in predicting glucose absorption from peritoneal dialysate compared to measured absorption in peritoneal dialysis patients treated by continuous ambulatory peritoneal dialysis and ambulatory peritoneal dialysis cyclers

Background and aims:

Glucose-containing peritoneal dialysates are used to generate an osmotic gradient for the convective removal of water and sodium. Predictive equations were developed to estimate glucose absorption without having to formally measure changes in dialysate glucose. In view of the changes in peritoneal dialysis prescriptions over time, we compared predicted and measured glucose absorption.

Subjects/methods:

We measured peritoneal glucose losses when peritoneal dialysis patients attended their first assessment of peritoneal membrane function, and compared this to glucose exposure and Kidney Disease Outcomes Quality Initiative, Grodstein and Bodnar predictive equations.

Results:

We studied 689 patients; 329 (56.9%) males, 53 (37.1%) diabetics, with mean age 57.1 ± 16.2 years, with 186 treated by automated peritoneal dialysis cyclers and 377 by automated peritoneal dialysis with a daytime icodextrin exchange and 126 by continuous ambulatory peritoneal dialysis. Using Bland -Altman analysis, all equations demonstrated systematic bias overestimating glucose absorption with increasing glucose absorption. For continuous ambulatory peritoneal dialysis patients, the Kidney Disease Outcomes Quality Initiative formula underestimated glucose absorption (bias 188 (−39 to 437) mmol/day, as did Grodstein (bias 37.9 (−105 to 29) mmol/day, whereas mean bias for Bodnar was −29 (−130 to 180)). There was systematic overestimation for all equations for both automated peritoneal dialysis with and without a daytime exchange, with increasing bias with greater glucose absorption.

Conclusion:

Although formally measuring peritoneal glucose absorption is time consuming and requires patient co-operation, current predictive equations overestimate glucose absorption and do not provide accurate estimations of glucose absorption particularly for automated peritoneal dialysis patients.

Prevalence of obesity and obesity-associated muscle wasting in patients on peritoneal dialysis

BACKGROUND AND AIMS

A progressive decrease in muscle mass until full-blown sarcopenia may occur in patients on peritoneal dialysis (PD) and worsen their life quality and expectancy. Here we investigate the prevalence of obesity and obesity-associated muscle wasting in PD patients.

PATIENTS AND METHODS

The study design was observational, cross sectional. Body composition was assessed with BIA and BIVA in 88 PD patients (53.4 ± 13.1 years; 67% male). Patients with obesity and/or with reduced muscle mass were identified using FMI and SM/BW cutoff values, respectively. Inflammatory status was assessed by measuring CRP and fibrinogen blood levels.

RESULTS

A total of 44.3% of the patients showed a reduced muscle mass (37.5% moderate and 6.8% severe). The prevalence of obesity was 6.1%, 81.8%, and 100% in patients with normal, moderately, and severely reduced muscle mass, respectively (p < 0.05). Of the total, 15.2% of the patients with normal muscle mass, 18.4% of those with moderately reduced muscle mass, and 66.7% of those with severely reduced muscle mass had diabetes. The prevalence of severe muscle mass loss was higher in those with diabetes than in those without diabetes (22.2% vs. 2.8%, p < 0.05). Patients with obesity-associated muscle wasting showed higher fibrinogen (613.9 ± 155.1 vs. 512.9 ± 159.5 mg/dL, p < 0.05) and CPR (1.4 ± 1.3 vs. 0.6 ± 0.8 mg/dL, p < 0.05) blood concentrations than those with normal body composition.

CONCLUSION

Obesity and diabetes were strongly associated with muscle mass loss in our PD patients. It remains to be established whether prevention of obesity with nutritional interventions can halt the occurrence of muscle mass loss in patients on PD.

Aortic Pulse Wave Velocity in Peritoneal Dialysis Patients Is Not Simply Associated with Extracellular Water Expansion

BACKGROUND

Cardiac death is increased in peritoneal dialysis (PD) patients. Pulse wave velocity (PWV) is a measurement of arterial stiffness, and previous reports linked PWV to increased extracellular water (ECW). As cyclers and icodextrin are increasingly used, we wished to determine whether this association between PWV and ECW remains.

METHODS

We measured aortic PWV (aPWV) and bioimpedance (InBody, Seoul, South Korea) in consecutive PD patients attending for peritoneal membrane testing.

RESULTS

189 patients were included, 62.4% male, mean age 63.1 ± 15.2 years, 45.3% diabetic, median dialysis duration 12.3 (6.5-25.1) months, 71.4% using cyclers, weight 73.0 ± 16.1 kg, systolic blood pressure 142 ± 21 mm Hg, aPWV 10.4 ± 5.1 m/s. aPWV was associated with pulse pressure (r = 0.26, p = 0.001), Davies comorbidity score (r = 0.18, p = 0.013), and N-terminal pro-brain-type natriuretic peptide (NTproBNP; r = 0.18, p = 0.011). Patients with aPWV ≥10 m/s were older (65.9 ± 13.6 vs. 60.1 ± 16.3 years, p < 0.01) with a higher ECW-to-total body water ratio (0.400 ± 0.012 vs. 0.396 ± 0.013, p < 0.05), but ECW/height was not different (8.52 ± 2.32 vs. 8.75 ± 1.78 L/m), as was NTproBNP (2,472 [788-5,422] vs. 1,234 [410-6,230] ng/L). On multivariable testing, aPWV was positively associated with β-blocker prescription (standardised β coefficient [Stβ] 0.3, 95% confidence limits [95% CL] 0.7-2.6, p = 0.001) and negatively with icodextrin prescription (Stβ 0.19, 95% CL -0.2 to -2.1, p = 0.04).

CONCLUSIONS

Compared to previous studies, we did not find an independent association between aPWV and ECW and estimates of ECW excess, using the InBody bioimpedance device, suggesting that vascular stiffness in PD patients is more complex than simple ECW volume expansion in PD patients.

Association Between Peritonitis and Low Muscle Mass in Peritoneal Dialysis Patients

OBJECTIVE

Peritoneal dialysis (PD) peritonitis is a common complication in PD patients. The remission of peritonitis is easily achieved, but its presence is associated with local/systemic inflammation in PD patients, which would lead to decreases in muscle mass. Here, we hypothesized that the history of PD peritonitis is associated with low muscle mass (LMM) in PD patients.

METHODS

We identified incident PD patients for whom body composition measurements at baseline and 1 year after PD initiation were available. Finally, we analyzed 230 incident PD patients. The PDP group was defined as patients with a PD peritonitis event during the period and the Non-PDP group was defined as patients without a PD peritonitis event during the period. Body compositions were calculated using bioimpedance and includes regional lean mass (LM), fat mass (FM), and sarcopenia index.

RESULTS

There were no significant intergroup differences in baseline limb LM, total LM, or total FM. Total FM and body mass index at follow-up (FU) increased in both groups compared to that at baseline. There was no significant difference in total LM between baseline and FU in either group. Limb LM at FU increased in only the Non-PDP group compared to that at baseline. Sarcopenia index at FU decreased in only the PDP group compared to that at baseline. The prevalence of LMM at FU was higher in the PDP group than in the Non-PDP group. Among the participants without LMM at baseline, those in the PDP group had a higher prevalence of LMM at FU. Logistic regression showed that the PDP group was associated with a higher odds ratio for LMM at FU in the multivariate analyses.

CONCLUSION

LMM was found to be associated with the presence of PD peritonitis in incident PD patients.

Sodium loss, extracellular volume overload and hypertension in peritoneal dialysis patients treated by automated peritoneal dialysis cyclers

INTRODUCTION

Achieving sodium balance is important for peritoneal dialysis patients, as sodium excess may lead to hypertension and extracellular water expansion. We wished to determine whether greater sodium removal had adverse consequences.

METHODS

We calculated 24-h urinary and peritoneal sodium losses in peritoneal dialysis patients treated by automated cyclers, when attending for peritoneal membrane and bioimpedance assessments.

RESULTS

We reviewed 439 peritoneal dialysis patients, 56.7% male, average age 54.6 years, median sodium loss 110 (68-155) mmol/day. Sodium loss was strongly associated with urine volume, r = 0.37, protein nitrogen appearance rate, r = 0.29, and body cell mass, r = 0.21, all p < 0.001. We found no association with blood pressure or anti-hypertensive medication prescription, or extracellular water. On multivariable logistic regression analysis, sodium loss was associated with greater urine output, odds ratio 1.001, 95% confidence interval 1.00-1.001, p < 0.001, and protein nitrogen appearance (odds ratio 1.023, confidence interval 1.006-1.04), p = 0.008. Adjusting for body weight, sodium loss was associated with urine output (odds ratio 1.001, confidence interval 1.001-1.002, p < 0.001), and negatively with body fat index (odds ratio 0.96, confidence interval 0.93-0.99, p = 0.008) and co-morbidity grade (odds ratio 0.58, confidence interval 0.36-0.39, p = 0.023).

CONCLUSION

Heavier peritoneal dialysis patients with greater estimated dietary protein intake (protein nitrogen appearance), those with greater residual renal function and peritoneal clearances, along with lower co-morbidity, had greater daily sodium losses. Adjusting for body weight, then sodium losses were greater with higher daily urine output, and lower in patients with proportionately more body fat and co-morbidity. Sodium losses would appear to primarily determined by body size and not associated with hypertension or extracellular water expansion.

Factors associated with systolic hypertension in peritoneal dialysis patients

Background

Hypertension is common in peritoneal dialysis (PD) patients and associated with adverse outcomes. Besides solute clearance, PD convective clearance is used to control extracellular water (ECW) volume and sodium balance. Previous studies have reported on hypertension in PD patients treated with continuous ambulatory peritoneal dialysis (CAPD) using hypertonic glucose dialysates. However, increasing numbers of PD patients are now treated with automated peritoneal dialysis (APD) and icodextrin dialysates. As such, we wished to explore factors associated with systolic blood pressure (SBP) in a modern cohort to identify targets to improve blood pressure control in PD patients.

Methods

We retrospectively reviewed the results from PD patients attending for peritoneal membrane assessment who had corresponding bioimpedance ECW and brain natriuretic peptide (NT-proBNP) measurements.

Results

We studied 510 PD patients: 317 (72.2%) male, 216 (42.4%) diabetics, median age 59 (47–72) years, and 51% treated by APD with a day-time icodextrin exchange. Mean systolic blood pressure (SBP) was 140 ± 24.8 mmHg. SBP was independently associated with 4-hour dialysate to plasma creatinine ratio (β = 29.5 (95% confidence limits 11.4–47.5, p = 0.001), N-terminal brain natriuretic peptide [β = 11.9 (7.2–16.7), p < 0.001], and daily urine sodium excretion [β = 1.7 (1.0–2.3), p < 0.001].

Conclusion

In the era of APD cyclers and icodextrin, SBP is associated with increased NT-proBNP, a marker of ECW expansion, and faster peritoneal transport, a risk factor for a positive sodium balance, and increased urinary sodium suggestive of higher dietary sodium intake. Patients should be encouraged to restrict sodium intake and PD prescriptions targeted to control ECW to improve SBP control.

Associations of Cognitive Function with BMI, Body Fat Mass and Visceral Fat in Young Adulthood

Background and objectives: Existing studies concerning the associations of cognitive function with adiposity in young adults are sparse. The purpose of the study was to examine the associations of adiposity with cognitive control in young adults. Materials and Methods: Participants were 213 young adults (98 women and 115 men). Cognitive control was measured using a modified task-switching paradigm. Anthropometrics were measured by standardized procedures. Body fat mass and visceral fat area were measured by bioelectrical impedance analysis. Results: The results showed that increased body mass index (BMI, p = 0.02), body fat percentage (p = 0.02), and visceral fat area (p = 0.01) were significantly correlated with larger global switch costs of accuracy in women. In men, high levels of body fat percentage (p = 0.01) and visceral fat area (p = 0.03) were significantly correlated with larger local switch costs of reaction time. Conclusions: The results indicated that elevated adiposity was associated with worse performance on measures of cognitive control in young adults.