Serum myostatin levels are associated with physical function and hospitalization in peritoneal dialysis patients.

BACKGROUND: Myostatin functions as a negative regulator of skeletal muscle growth. The association of myostatin with muscle parameters in dialysis patients is inconsistent, and there are no studies associating myostatin with physical function and outcomes in peritoneal dialysis (PD) patients. Therefore, we assessed the association of serum myostatin with lean mass, physical function, and hospitalization in a prospective cohort of PD patients. METHODS: Lean mass, physical function, and serum myostatin were assessed at baseline. Patients were followed up for at least 24 months and hospitalization was recorded. RESULTS: Serum myostatin levels were positively correlated with handgrip strength and Appendicular Lean Mass Index among male patients. Binary logistic regression models were performed including myostatin levels and physical function parameters as independent variables. Serum myostatin, handgrip strength, gait speed, and Short Physical Performance Battery were associated with hospitalization. CONCLUSION: Lower serum myostatin and physical function were associated with hospitalization in PD patients.

Handgrip Strength Thresholds are Associated With Malnutrition Inflammation Score (MIS) in Maintenance Hemodialysis Patients.

OBJECTIVE: The aim is to verify the association between nutritional status and muscle strength, considering handgrip strength (HGS) cutoffs associated with sarcopenia and mortality. METHODS: Cross-sectional analysis, including hemodialysis patients. Malnutrition Inflammation Score (MIS) was used to assess nutritional status. Muscle function was assessed by HGS, and the considered cutoffs were established by other studies. Cutoffs for sarcopenia diagnosis were 27 and 16 kg for males and females, respectively; cutoffs associated with mortality were 22 and 7 kg for males and females, respectively. Two binary logistic regression models were built, with HGS categorized according to the cutoff for sarcopenia and mortality as dependent variables. RESULTS: Of the 218 patients who were included, 56.9% were male, the mean age was 58.3 years, and 44.7% diabetic; 132 patients (60.6%) had HGS <27 or 16 kg. Age, prevalence of diabetes, and MIS were higher, creatinine and albumin were lower in patients with HGS below these values; 77 patients (35.2%) had HGS <22 or 7 kg. Age, male, and diabetes prevalence, CRP and MIS were higher, midarm muscle circumference (MAMC), creatinine, albumin, and urea were lower in patients with HGS below these values. In the logistic regression MIS (OR 1.202; 95% CI 1.073-1.347; P < .01), age, male, diabetes, and MAMC were associated with the risk of HGS below the cutoffs for sarcopenia. MIS (OR 1.322; 95% CI 1.192-1.467; P < .01), age, male, and diabetes were associated with the risk of HGS below the cutoffs associated with mortality. CONCLUSION: Worse nutritional status increases the risk of HGS below the cutoffs associated with sarcopenia and mortality in hemodialysis patients.

Sarcopenia diagnosis in patients receiving hemodialysis: Agreement among different consensuses.

BACKGROUND: There are many consensuses to diagnose sarcopenia, and their agreement in patients receiving hemodialysis (HD) is not clear. We described the sarcopenia prevalence in patients receiving HD using different consensuses and analyzed their level of agreement. METHODS: Sixty-seven patients (43 men, 55 ± 14.6 years) were evaluated for appendicular skeletal muscle mass using dual-energy x-ray absorptiometry and muscle strength using handgrip strength. Patients were classified according to different sarcopenia consensuses (European Working Group on Sarcopenia in Older People [EWGSOP], Revised EWGSOP [EWGSOP2], Foundation for the National Institutes of Health Project [FNIH], and Asian Working Group for Sarcopenia 2019 [AWGS2]). Kappa analysis identified the level of agreement. RESULTS: The prevalence of sarcopenia ranged from 1.5% to 11.9% depending on the sarcopenia consensus. The agreement between the different consensuses ranged from poor to almost perfect. FNIH and EWGSOP showed the lowest agreement (κ = 0.20; 95% CI, -0.14 to 0.54; P < 0.05), whereas EWGSOP2 and AWGS2 had the largest κ = 0.90 (95% CI, 0.71 to 1.00; P < 0.001). When stratified by age (≥60 years), the sarcopenia prevalence was higher in the older group (27% vs 2%; P = 0.004). In addition, male participants seemed to be more prone to sarcopenia compared with female counterparts, but this difference was not statistically confirmed (16% vs 4%; P = 0.242). CONCLUSION: The sarcopenia consensuses showed from poor to almost perfect agreement, which varied the sarcopenia prevalence rates in patients receiving HD. EWGSOP2 and AWGS2 showed the largest agreement.

According to Revised EWGSOP Sarcopenia Consensus Cut-Off Points, Low Physical Function Is Associated With Nutritional Status and Quality of Life in Maintenance Hemodialysis Patients.

OBJECTIVE: The aim of this study is to assess the association of nutritional status and quality of life with low physical function, according to the revised European Working Group on Sarcopenia in Older People (EWGSOP) - sarcopenia consensus cut-offs in maintenance hemodialysis patients. DESIGN AND METHODS: This is a cross-sectional study including patients on maintenance hemodialysis. Participants were submitted to a single evaluation of physical function, nutritional status, and quality of life. Handgrip strength, Short Physical Performance Battery (SPPB), sit-to-stand test, and gait speed were performed to evaluate physical function. Cut-offs proposed by the revised EWGSOP consensus were considered. Malnutrition Inflammation Score was used to assess nutritional status. Quality of life was assessed by the 36-Item Short Form Health Survey. RESULTS: Seventy-seven patients were enrolled, 64.9% male, mean age 55 ± 14 years. According to the cut-offs proposed by the most recent EWGSOP consensus, 55.8% of patients presented SPPB <8, 48.1% gait speed test ≤0.8 m/seconds, sit-to-stand test >15 seconds, and 39.0% handgrip strength <27 kg and <16 kg for men and women, respectively. Malnutrition Inflammation Score was significantly associated with all physical function parameters, except gait speed, in receiver operating characteristic curve and logistic regression. The 36-Item Short Form Health Survey domains or component summary were associated with SSPB, gait speed, and handgrip strength in logistic regression. CONCLUSION: Poor nutritional status and quality of life are associated with low physical function (according to the cut-offs proposed by EWGSOP) in hemodialysis patients.

Association of Phase Angle, but Not Inflammation and Overhydration, With Physical Function in Peritoneal Dialysis Patients.

Introduction: Muscle mass depletion, overhydration, and inflammatory state have been related to impaired physical function in chronic kidney disease patients. The relationship between bioelectrical impedance analysis (BIA) parameters, such as hydration status and phase angle (PhA), with physical function in peritoneal dialysis (PD), is still not well-established. Therefore, the objective was to evaluate the association of BIA parameters (overhydration index and PhA) and inflammatory markers with physical function in patients on PD. Methods: The present cross-sectional study enrolled PD patients. Multifrequency BIA was performed to obtain overhydration index and PhA. The Short Physical Performance Battery (SPPB) test battery was applied to assess physical function. The time to complete the 4-m gait test and sit-to-stand test was also considered for physical function assessment. The inflammatory markers tumor necrosis factor-alpha and C-reactive protein levels were determined. Multiple linear regression models were performed, with the physical function variables as dependent variables, adjusted for age, diabetes, and sex. Results: Forty-nine PD patients were enrolled, 53.1% (n = 26) women; mean age, 55.5 ± 16.3 years. There were significant correlations between PhA and SPPB (r = 0.550, p < 0.001), time of 4-m gait test (r = -0.613, p < 0.001) and sit-to-stand test and (r = -0.547, p < 0.001). Overhydration index was significantly correlated with SPPB, 4-m gait test (r = 0.339, p = 0.017), and sit-to-stand test (r = 0.335, p = 0.019). Inflammatory markers were not significantly correlated with physical function parameters. In the multiple linear regression analysis, PhA was associated with physical function parameters, even after adjustments. Overhydration index was associated with all physical function tests only in the models with no adjustments. Conclusion: PhA was independently associated with physical function in PD patients. Inflammatory markers and overhydration index were not associated with physical function.

Age, diabetes mellitus, and dialysis modality are associated with risk of poor muscle strength and physical function in hemodialysis and peritoneal dialysis patients.

BACKGROUND: Due to the poor outcomes associated with the impairment of physical function and muscle strength in patients on maintenance dialysis, it is important to understand the factors that may influence physical function and muscle strength. The aim of this study was to explore the factors associated with physical function in hemodialysis and peritoneal dialysis patients. METHODS: Patients with chronic kidney disease on dialysis for at least 3 months, aged 18 years old or above, were enrolled. Physical function was assessed by handgrip strength, gait and sit-to-stand tests, and the Short Physical Performance Battery (SPPB). Clinical and laboratory data were collected to verify the association with physical function parameters through binary logistic regression. RESULTS: One-hundred ninety patients on maintenance dialysis were included; 140 patients (73.7%) on hemodialysis and 50 (26.3%) on peritoneal dialysis. The mean age was 57.3 ± 14.9 years, 109 (57.4%) were male, and 87 (45.8%) were older than 60 years. The median SPPB was 8.0 points (6.0-10.0 points) and the mean ± standard deviation of handgrip strength was 24.7 ± 12.2 kg. Binary logistic regression showed that age, type of renal replacement therapy, diabetes mellitus, and serum creatinine were significantly associated with both higher 4-meter gait test times and lower SPPB scores. Only age and diabetes mellitus were associated with higher sit-to-stand test times, while age and ferritin were associated with lower handgrip strength. CONCLUSION: Age, diabetes mellitus, serum creatinine, and hemodialysis modality are factors related to physical function in dialysis patients.

Vitamin D and skeletal muscle: A narrative review focusing on chronic kidney disease and dialysis.

Morphological, molecular, and physiological effects of vitamin D on skeletal muscle have been analyzed both in animals and humans. Vitamin D may be a potential therapeutic for increasing muscle mass and function. The presence of vitamin D receptors in skeletal muscle cells is already established. However, there is still need for more evidence about the effect of vitamin D on muscle. Some studies have associated vitamin D and skeletal muscle in chronic kidney disease (CKD) patients; most of these studies enrolled hemodialysis patients. FGF-23 and Klotho were recently described in mineral and bone disorders in CKD, resulting in reductions in calcitriol levels. Therefore, both Klotho and FGF-23 may play a role in muscle loss in CKD, which is related to morbidity and mortality risk. Therefore, this article presents a narrative review, aiming to discuss the available information associating skeletal muscle and vitamin D, highlighting the results in CKD and dialysis patients.

Which Method Should Be Used to Assess Protein Intake in Peritoneal Dialysis Patients? Assessment of Agreement Between Protein Equivalent of Total Nitrogen Appearance and 24-Hour Dietary Recall.

OBJECTIVES: After dialysis initiation, a high protein diet is recommended due to significant nutrient losses through dialysate and increased risk of protein energy wasting. In peritoneal dialysis (PD) patients, protein intake can be assessed through different methods that have some advantages and limitations, which affect its use on routine care. The aim of this study is to evaluate the agreement between 2 different methods (24-hour dietary recall and PNA-protein equivalent of total nitrogen appearance) on estimating protein intake in PD patients. DESIGN AND METHODS: Patients on PD for at least 3 months, aged 18 years old or more, were enrolled. To estimate protein intake, 24-hour dietary recall and PNA was used. PNA was calculated from 24-hour urine on the same day of the 24-hour dietary recall. RESULTS: Fifty individuals on PD were included, mean age 55.7 ± 16.2 years, and body mass index 26.0 ± 4.5 kg/m2. The average energy consumption was 1788.79 ± 504.40 kcal/day, which corresponds to 26.81 ± 9.11 kcal/kg current body weight (BW)/day and 29.82 ± 8.39 kcal/kg ideal body weight (IBW)/day. The median of total daily and normalized protein intake estimated using dietary recall was 61.43 (45.28-87.40) g/day, 0.90 (0.58-1.22) g/kg current BW/day, and 1.04 (0.77-1.32) g/kg IBW/day, respectively. Daily protein intake estimated by PNA was 55.75 (48.27-67.74) g/day, protein intake normalized by current BW was 0.81 (0.72-0.99) g/kg and 0.92 (0.83-1.06) g/kg IBW/day. Bland-Altman analysis indicates no systematic bias for the assessment of total protein intake and normalized protein intake for current and ideal BW. Significant proportionality bias was observed for both evaluations, showing there is a dispersion of the values. CONCLUSIONS: Despite the absence of systematic bias in the Bland-Altman analysis, there is no agreement in the assessment of protein intake by dietary recall and PNA, due to the existence of proportionality bias. Thus, values can be influenced biased by the magnitude of the measures.

Correction: Update of the European consensus on sarcopenia: what has changed in diagnosis and prevalence in peritoneal dialysis?

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Role of parathyroid hormone in anorexia on maintenance hemodialysis patients.

BACKGROUND AND AIM: Anorexia, which is a common condition in patients on hemodialysis (HD), is characterized by impaired appetite, a subjective condition that hinders anorexia diagnosis. Anorexia is frequently associated with protein energy wasting and inflammation, increasing morbidity and mortality risk. The aim of the study was to evaluate the association between appetite and nutritional, inflammatory, hormonal, and dietary intake parameters in patients on maintenance HD. METHODS: Cross-sectional study with clinical, laboratory, and anthropometric parameters, body composition, muscle function, and dietary intake assessment. To evaluate appetite, a three simple questions questionnaire previously validated was used. After appetite classification, the sample was dichotomized in "normal appetite" and "impaired appetite" and compared. Multiple logistic regression was used to identify association between variables and outcome. RESULTS: 125 patients on HD were included, aged 60.6 ± 14.12 years old, median HD vintage 35.5 months. In dichotomized sample, 78.4% patients showed "normal appetite", and 21.6% "impaired appetite". "Impaired appetite" was independently associated with increased serum PTH (OR 1.001; 95% CI 1.000-1.002; p = 0.03), low zinc intake (OR 0.860; 95% CI 0.746-0.991; p = 0.03) and lower urea serum (OR 0.982; 95% CI 0.965-0.999; p = 0.04). Both groups showed insufficient dietary intake. CONCLUSIONS: Appetite was independently associated with increased serum of PTH, low serum concentration of urea, and low zinc intake which may infer association of appetite with mineral bone disease, protein intake and zinc deficiency.

Update of the European consensus on sarcopenia: what has changed in diagnosis and prevalence in peritoneal dialysis?

Patients on peritoneal dialysis (PD) may be affected by sarcopenia, which is a progressive and generalized skeletal muscle disorder characterized by muscle mass atrophy with decline of muscle strength and function. The aim was to evaluate differences in the diagnosis and prevalence of sarcopenia according to European Working Group on Sarcopenia in Older People (EWGSOP). The screening for sarcopenia was performed in PD patients older than 18 years, with evaluation of appendicular skeletal muscle mass index (ASMMI), handgrip strength (HGS) and gait speed (GS). The diagnosis was according to the 2010 and 2019 versions of EWGSOP consensus on sarcopenia. Fifty subjects on PD were included, mean age 55.74 ± 16.22 years old, 52% female. The prevalence of sarcopenia ranged from 4 to 10% according to cut points and references used.

Twelve-week combined resistance and aerobic training confers greater benefits than aerobic training alone in nondialysis CKD.

There is a growing consensus that patients with chronic kidney disease (CKD) should engage in regular exercise, but there is a lack of formal guidelines. In this report, we determined whether combined aerobic and resistance exercise would elicit superior physiological gains, in particular muscular strength, compared with aerobic training alone in nondialysis CKD. Nondialysis patients with CKD stages 3b-5 were randomly allocated to aerobic exercise {AE, n = 21; 9 men; median age 63 [interquartile range (IQR) 58-71] yr; median estimated glomerular filtration rate (eGFR) 24 (IQR 20-30) ml·min-1·1.73 m-2} or combined exercise [CE, n = 20, 9 men, median age 63 (IQR 51-69) yr, median eGFR 27 (IQR 22-32) ml·min-1·1.73 m-2], preceded by a 6-wk run-in control period. Patients then underwent 12 wk of supervised AE (treadmill, rowing, or cycling exercise) or CE training (as AE plus leg extension and leg press exercise) performed three times per week. Outcome assessments of knee extensor muscle strength, quadriceps muscle volume, exercise capacity, and central hemodynamics were performed at baseline, following the 6-wk control period, and at the end of the intervention. AE and CE resulted in significant increases in knee extensor strength of 16 ± 19% (mean ± SD; P = 0.001) and 48 ± 37% ( P < 0.001), respectively, which were greater after CE ( P = 0.02). AE and CE resulted in 5 ± 7% ( P = 0.04) and 9 ± 7% ( P < 0.001) increases in quadriceps volume, respectively ( P < 0.001), which were greater after CE ( P = 0.01). Both AE and CE increased distance walked in the incremental shuttle walk test [28 ± 44 m ( P = 0.01) and 32 ± 45 m ( P = 0.01), respectively]. In nondialysis CKD, the addition of resistance exercise to aerobic exercise confers greater increases in muscle mass and strength than aerobic exercise alone.

Recognition of visceral obesity beyond body fat: assessment of cardiovascular risk in chronic kidney disease using anthropometry

Evaluation of body fat and its distribution are important because they can predict several risk factors, mainly cardiovascular risk. Imaging techniques have high precision and accuracy for body fat measurement. However, trained personnel are required and the cost is high. Anthropometric indices might be used to evaluate body fat and its distribution in general population. In chronic kidney disease patients, studies have been indicating that overweight status improves survival rates. On the other hand, visceral fat accumulation is associated with inflammatory responses and insulin resistance. This narrative review discusses particularities of fat distribution in metabolic context and the relevance of available methods for abdominal adiposity evaluation in chronic kidney disease and end-stage renal disease patients.

Malnutrition Inflammation Score cut-off predicting mortality in maintenance hemodialysis patients.

BACKGROUND: Malnutrition is a strong predictor of mortality on hemodialysis patients, especially when it is associated with inflammation. Malnutrition Inflammation Score (MIS) is a simple and low cost tool which assesses the presence of malnutrition associated with inflammation. Therefore, the aim is to evaluate if MIS is associated with mortality in patients on maintenance hemodialysis and establish a cut-off to predict mortality at different follow-up periods. METHODS: Observational retrospective cohort study including 215 patients on hemodialysis between July 2012 and June 2014, censored until November 2015. MIS was used to assess patient's nutritional status at the moment they were enrolled in the study. They were followed for at least 18 months. RESULTS: At the end of 18 months, 38 (17.7%) deaths, 20 renal transplants (9.3%), four facilities transference (1.9%), three dialysis method change (1.4%) and one renal function recovery (0.5%) were observed. One hundred seventy one patients completed at least 24 months of follow-up, and during this additional period, there were five deaths and one renal transplant more. Score higher than 7 points was able to predict mortality for both follow-up periods using sensitivity and specificity analysis and ROC curves. Using this cut-off on Kaplan-Meier survival curve, it was possible to confirm the association of MIS with all-cause mortality at 18 months and 24 or more months of follow-up. Finally, Cox multivariate analysis adjusted for demographic, clinical and nutritional variables showed MIS as the only significant predictor of mortality. CONCLUSION: MIS is an independent predictor of mortality in hemodialysis patients.

Influence of different dialysis modalities in the measurement of resting energy expenditure in patients with acute kidney injury in ICU.

BACKGROUND: Currently, the execution of indirect calorimetry, which is considered the gold standard for measuring energy expenditure, is not indicate during dialysis, and it may interfere on nutritional therapy of these patients. This study aimed to evaluate the resting energy expenditure (REE) in patients with severe acute kidney injury treated by different modalities of dialysis and to identify whether dialysis influences on REE. METHODS: This was a prospective cohort study that evaluated patients admitted in intensive care units with diagnosis of acute kidney injury AKIN-3, mechanically ventilated, and submitted to conventional hemodialysis (CHD), extended hemodialysis (EHD) or high volume peritoneal dialysis (HVPD). Indirect calorimetry was performed at pre dialysis time and during the dialysis procedure. Parameters that could change REE were also evaluated. RESULTS: One-hundred patients undergoing 290 dialysis sessions were evaluated, with mean age 60.3 ± 17 years, 69% were male and 74% have died. There was no significant difference between REE of predialysis time and during dialysis time (2156 ± 659 kcal vs. 2100 ± 634 kcal, respectively, p = 0.15). No difference was observed in the REE before and during dialysis of different modalities. There were no differences between parameters pre and during dialysis of each modality. There was only a difference in norepinephrine dose, which was higher in pre dialysis time in HVPD and EHD modalities, compared with CHD modality. Moreover, during dialysis time, EHD modality had significantly higher VAD compared to other dialysis modalities. CONCLUSION: The three evaluated modalities did not change REE. Indirect calorimetry can be performed during dialysis procedures and there was no difference between ventilation parameters, sedatives use, body temperature and VAD in both moments.

Handgrip strength is an independent predictor of all-cause mortality in maintenance dialysis patients.

BACKGROUND & AIMS: Muscle wasting is associated with mortality in dialysis patients. The measurement of muscle mass has some limitations, while muscle strength assessment is simple, safe and allows the recognition of patients at risk of progressing to poor outcomes related to malnutrition. The aim of this study is verify if handgrip strength (HGS) is associated with all-cause mortality in patients in maintenance haemodialysis (HD) and peritoneal dialysis (PD). METHODS: This was an observational retrospective cohort study which included all patients in maintenance HD and PD from July 2012 to October 2014. Patients were followed-up until June 2015. RESULTS: Two-hundred sixty five patients were enrolled (218 HD and 47 PD) and they were followed for 13.4 ± 7.9 months. During the follow-up period, 53 patients (20%) have died, 36 patients (13.6%) have undergone renal transplantation, 13 patients (4.9%) have switched off dialysis method and 5 patients (1.9%) have transferred to another facility. The cut-off of HGS able to predict mortality was 22.5 kg for men and 7 kg for women. Using this cut-off to fit the Kaplan-Meier survival curve, the association of HGS with all-cause mortality for both genders was confirmed. Finally, in the multivariate analysis adjusted for demographic, clinical and nutritional variables, HGS remained significant predictor of mortality, independent of dialysis modality. CONCLUSIONS: HGS cut-offs that predict mortality were 22.5 kg for men and 7 kg for women. HGS was associated with mortality independent of dialysis modality.

Anthropometric Indicators Predict Metabolic Syndrome Diagnosis in Maintenance Hemodialysis Patients.

BACKGROUND: Obesity has been considered the key in metabolic syndrome (MetS) development, and fat accumulation may be responsible for the occurrence of metabolic abnormalities in hemodialysis patients. The use of gold-standard methods to evaluate obesity is limited, and anthropometric measures may be the simplest methods. However, no study has investigated the association between anthropometric indexes and MetS in these patients. Therefore, the aim was to determine which anthropometric indexes had the best association and prediction for MetS in patients undergoing hemodialysis. METHODS: Cross-sectional study that included patients older than 18 years, undergoing hemodialysis for at least 3 months. Patients with liver disease and cancer or those receiving corticosteroids or antiretroviral therapy were excluded. Diagnostic criteria from Harmonizing Metabolic Syndrome were used for the diagnosis of MetS. Anthropometric indexes evaluated were body mass index (BMI); percent standard of triceps skinfold thickness and of middle arm muscle circumference; waist circumference (WC); sagittal abdominal diameter; neck circumference; waist-to-hip, waist-to-thigh, and waist-to-height ratios; sagittal index; conicity index; and body fat percentage. RESULTS: Ninety-eight patients were included, 54.1% male, and mean age was 57.8 ± 12.9 years. The prevalence of MetS was 74.5%. Individuals with MetS had increased accumulation of abdominal fat and general obesity. Waist-to-height ratio was the variable independently associated with MetS diagnosis (odds ratio, 1.21; 95% confidence interval, 1.09-1.34; P < .01) and that better predicts MetS, followed by WC and BMI (area under the curve of 0.840, 0.836, and 0.798, respectively, P < .01). CONCLUSION: Waist-to-height ratio was the best anthropometric predictor of MetS in maintenance hemodialysis patients.