Etiology of the Protein-Energy Wasting Syndrome in Chronic Kidney Disease: A Consensus Statement From the International Society of Renal Nutrition and Metabolism (ISRNM)

The value of bioimpedance analysis in the assessment of hydration and nutritional status in children on chronic peritoneal dialysis

Bioimpedance analysis (BIA)-body composition monitoring (BCM) has been used to evaluate the hydration and nutritional status of adults and children on dialysis. However, its clinical application still has challenges, so further exploration is valuable. We used BIA-BCM to evaluate the hydration and nutritional status of children undergoing chronic peritoneal dialysis from 1 July 2021 to 31 December 2022 in the Children's Hospital of Fudan University to explore the clinical value of this method. A total of 84 children on chronic peritoneal dialysis (PD) were included. In the PD group, 16 (19.05%) and 31 (36.90%) had mild and severe overhydration (OH), respectively; 41.27% (26/63) had a low lean tissue index (LTI). In the PD group, patients with relative OH (Re-OH) > 5.6% had significantly higher systolic blood pressure (SBP) and SBP z score (SBPz). Patients with LTI > 12% had significantly higher body mass index (BMI) and BMI z score (BMIz). Canonical correlation analysis indicated a linear relationship (ρ = 0.708) between BIA-BCM hydration and the clinical hydration indicator and a linear relationship (ρ = 0.995) between the BIA-BCM nutritional indicator and the clinical nutritional indicator. A total of 56% of children on chronic peritoneal dialysis had OH, and 41% had a low LTI. In PD patients, SBP and SBPz were correlated with BIA-BCM Re-OH, and BMI and BMIz were correlated with BIA-BCM LTI. BIA-BCM indicators have good clinical value in evaluating hydration and nutrition.

Malnutrition, protein energy wasting and sarcopenia in patients attending a haemodialysis centre in sub-Saharan Africa

BACKGROUND

Haemodialysis (HD) patients are reported to be at greater risk of malnourishment, and at risk of increased morbidity and mortality. However, most studies report from economically advanced countries. We therefore assessed the nutritional status and diet among HD patients attending a public university hospital in a sub-Saharan African country.

SUBJECTS

We performed nutritional assessments in HD patients attending the largest dialysis centre, in the country, collecting demographic and clinical data, dietary intake, along with anthropometric and bioimpedance body composition measurements in May 2022. Malnutrition was classified according to subjective global assessment score (SGA). Additional assessments of protein energy wasting (PEW), clinical frailty, and sarcopenia were made.

RESULTS

All 97 HD patients were recruited, mean age 44.7 ± 12.2 years, with 55 (56.7%) males. Malnutrition was present in 43.8%, PEW 20.6%, frailty 17.6% and sarcopenia 4.1%. On multivariable logistic regression higher serum albumin (adjusted odds ratio (AOR) 0.89, 95% confidence intervals (CI) 0.85-0.95, p < 0.001), creatinine (AOR 0.99, 95%CI 0.98-0.99, p < 0.001), greater mid upper arm circumference (AOR 0.89, 95%CI 0.83-0.95, p = 0.001), body cell mass (BCM) (AOR 0.79, 95%CI 0.67-0.95, p = 0.013) and employment (AOR 0.45, 95%CI 0.23-0.87, p = 0.017), were are all protective against malnourishment. Almost 75% had reduced dietary protein intake.

CONCLUSIONS

Despite a younger, less co-morbid patient population, malnutrition is common in this resource poor setting. The staple diet is based on maize, a low protein foodstuff. Employment improved finances and potentially allows better nutrition. Further studies are required to determine whether additional dietary protein can reduce the prevalence of malnutrition in this population.

99mTc-DMSA and 99mTc-DTPA identified renal dysfunction due to microplastic polyethylene in murine model

In the previous study (Im et al., 2022), we revealed microplastic (MP) was accumulated and cleared through the kidneys via PET imaging. Here, we aimed to identify the renal dysfunction due to polyethylene (PE) MP in the kidney tissue. Mice were exposed to 100 ppm (∼equivalent to 0.1mg/mL) /100 μL of PE for 12 weeks (n =10). PE uptake in the kidney tissues was confirmed using confocal microscopy. QuantSeq analysis was performed to determine gene expression. Renal function assessment was performed using 99mTc-Diethylene triamine penta acetic acid or 99mTc-Dimercaptosuccinic acid. Measurement of creatinine, BUN, and albumin levels in serum and urine samples was also estimated. [18F]-FDG was also acquired. PE increased expression of Myc, CD44, Programmed Death-Ligand 1 (PD-L1), and Hypoxia-Inducible Factor (HIF)-1α, which indicates a potential link to an increased risk of early-onset cancer. An increase in glucose metabolism of [18F]-FDG were observed. We assessed renal failure using 99mTc-Diethylene triamine penta acetic acid and 99mTc-Dimercaptosuccinic acid scintigraphy to determine the renal function. Renal failure was confirmed using serum and urine creatinine, serum blood urea nitrogen levels, serum albumin levels, and urine albumin levels in PE exposed mice, relative to the control. In sum, PE exposure induced renal dysfunction in a murine model.

External validation of a novel nomogram for diagnosis of Protein Energy Wasting in adult hemodialysis patients

Background

Protein Energy Wasting (PEW) has high incidence in adult hemodialysis patients and refers to a state of decreased protein and energy substance. It has been demonstrated that PEW highly affects the quality of survival and increases the risk of death. Nevertheless, its diagnostic criteria are complex in clinic. To simplify the diagnosis method of PEW in adult hemodialysis patients, we previously established a novel clinical prediction model that was well-validated internally using bootstrapping. In this multicenter cross-sectional study, we aimed to externally validate this nomogram in a new cohort of adult hemodialysis patients.

Methods

The novel prediction model was built by combining four independent variables with part of the International Society of Renal Nutrition and Metabolism (ISRNM) diagnostic criteria including albumin, total cholesterol, and body mass index (BMI). We evaluated the performance of the new model using discrimination (Concordance Index), calibration plots, and Clinical Impact Curve to assess its predictive utility.

Results

From September 1st, 2022 to August 31st, 2023, 1,158 patients were screened in five medical centers in Shanghai. 622 (53.7%) hemodialysis patients were included for analysis. The PEW predictive model was acceptable discrimination with the area under the curve of 0.777 (95% CI 0.741-0.814). Additionally, the model revealed well-fitted calibration curves. The McNemar test showed the novel model had similar diagnostic efficacy with the gold standard diagnostic method (p > 0.05).

Conclusion

Our results from this cross-sectional external validation study further demonstrate that the novel model is a valid tool to identify PEW in adult hemodialysis patients effectively.

The value of multi-modal ultrasound in the assessment of sarcopenia in maintenance hemodialysis patients

INTRODUCTION

Sarcopenia is one of the common complications in maintenance hemodialysis (MHD) patients and is associated with poor prognosis. We aimed to study the validity and reliability of ultrasound in the assessment of sarcopenia in MHD patients.

METHODS

MHD patients were categorized into the sarcopenia group and the non-sarcopenia group according to the diagnostic criteria of the Asian Working Group on Sarcopenia (AWGS) 2019. Ultrasonography of the left medial head of the gastrocnemius muscle was performed in MHD and healthy controls to obtain muscle thickness (MT), pinnation angle (PA), fascicle length (FL), cross-sectional area (CSA), echo intensity (EI), elastic modulus (E), shear wave velocity (SWV), and microvascular velocity (MV). Compare the differences in ultrasound parameters among different groups, and determine the cut-off values suitable for diagnosing sarcopenia in MHD patients.

RESULTS

The MT, CSA, PA, and MV in the sarcopenia group were lower than those in the non-sarcopenia group and the control group; while the EI was higher, the FL of the sarcopenia group was lower than that of the non-sarcopenia group, while the E and SWV of the sarcopenia group were higher than those of the control group. Receiver operating characteristic curve analyses indicated that ultrasound combined index had a good diagnostic value, model Y = 13.511-0.121*MT-0.609*CSA-0.172*PA+0.011*EI-2.205*MV(P < 0.05), with a cut-off value of 0.69.

CONCLUSIONS

Multi-modal ultrasound is a safe, non-invasive, and real-time imaging examination method, and can provide information on muscle structure, stiffness, and perfusion, which is expected to be a promising potential tool for predicting sarcopenia in MHD patients.

Association between famine exposure during infancy and childhood and the risk of chronic kidney disease in adulthood

BACKGROUND

Famine exposure in childhood is proven to be associated with multiple chornic disease in adult but has not been studied with chronic kidney disease (CKD).

AIMS

This study was conducted to identify the relationship between famine exposure during infancy and childhood - specifically, the Chinese famine of 1959-1961 - and the risk of adult-onset chronic kidney disease (CKD) among Chinese individuals.

METHODS

This study included 2937 individuals from the Qingdao Diabetes Prevention Program. They were stratified by birth year into infancy-exposed (1956-1958), childhood-exposed (1950-1955) and unexposed (1963-1971) groups. The estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation. CKD was defined as an eGFR of <90 mL/min/1.73 m2.

RESULTS

The mean eGFR values for the infancy-exposed and childhood-exposed groups were 107.23 ± 12.53 and 103.23 ± 12.44 mL/min/1.73 m2, respectively, both of which were lower than that of the unexposed group (114.82 ± 13.39 mL/min/1.73 m2; P < 0.05). In the crude model, the odds ratio (OR) for CKD was 2.00 (95% confidence interval (CI): 1.39-2.88) in the infancy-exposed group and 2.92 (95% CI: 2.17-3.93) in the childhood-exposed group. Further adjustments for urban/rural residence, body mass index, age, current smoking, type 2 diabetes, systolic blood pressure, diastolic blood pressure and total cholesterol did not significantly alter the association between famine exposure and CKD. The corresponding ORs were 1.71 (95% CI: 1.17-2.50) and 2.48 (95% CI: 1.81-3.40) for the infancy-exposed and childhood-exposed groups respectively.

CONCLUSIONS

Famine exposure during infancy and childhood is associated with a long-term decline in eGFR and an increased adult-onset CKD risk. Early intervention for high-risk individuals may mitigate the risk of adult-onset CKD.

A Prospective Cohort Study Evaluating Impact of Sarcopenia on Hospitalization in Patients on Continuous Ambulatory Peritoneal Dialysis

Data regarding the association of sarcopenia with hospitalization has led to inconclusive results in patients undergoing dialysis. The main goal of this research was to investigate the association between sarcopenia and hospitalization in Chinese individuals on continuous ambulatory peritoneal dialysis (CAPD). Eligible patients on CAPD were prospectively included, and followed up for 48 weeks in our PD center. Sarcopenia was identified utilizing the criteria set by the Asian Working Group on Sarcopenia in 2019 (AWGS 2019). Participants were categorized into sarcopenia (non-severe sarcopenia + severe sarcopenia) and non-sarcopenia groups. The primary outcome was all-cause hospitalization during the 48-week follow-up period. Association of sarcopenia with all-cause hospitalization was examined by employing multivariate logistic regression models. The risk of cumulative incidence of hospitalization in the 48-week follow-up was estimated using relative risk (RR and 95% CI). The cumulative hospitalization time and frequency at the end of 48-week follow-up were described as categorical variables, and compared by χ2 test or fisher's exact test as appropriate. Subgroup and sensitivity analyses were also conducted to examine whether the potential association between sarcopenia and hospitalization was modified. A total of 220 patients on CAPD (5 of whom were lost in follow-up) were included. Prevalences of total sarcopenia and severe sarcopenia were 54.1% (119/220) and 28.2% (62/220) according to AWGS 2019, respectively. A total of 113 (51.4%) participants were hospitalized during the 48-week follow-up period, of which, the sarcopenia group was 65.5% (78/119) and the non-sarcopenia group was 34.7% (35/101), with an estimated RR of 1.90 (95%CI 1.43-2.52). The cumulative hospitalization time and frequency between sarcopenia and non-sarcopenia groups were significantly different (both P < 0.001). Participants with sarcopenia (OR = 3.21, 95%CI 1.75-5.87, P < 0.001), non-severe sarcopenia (OR = 2.84, 95%CI 1.39-5.82, P = 0.004), and severe sarcopenia (OR = 3.66, 95%CI 1.68-8.00, P = 0.001) demonstrated a significant association with all-cause hospitalization compared to individuals in non-sarcopenia group in the 48-week follow-up. Moreover, participants in subgroups (male or female; < 60 or ≥ 60 years) diagnosed with sarcopenia, as per AWGS 2019, were at considerably high risk for hospitalization compared to those with non-sarcopenia. In sensitivity analyses, excluding participants lost in the follow-up, the relationships between sarcopenia and hospitalization (sarcopenia vs. non-sarcopenia; severe sarcopenia/non-severe sarcopenia vs. non-sarcopenia) were consistent. This research involving Chinese patients on CAPD demonstrated a significant association between sarcopenia and incident hospitalization, thereby emphasizing the importance of monitoring sarcopenia health in this population.

Lower energy intake associated with higher risk of cardiovascular mortality in chronic kidney disease patients on a low-protein diets

OBJECTIVE

An increasing number of studies shown that inadequate energy intake causes an increase in adverse incidents in chronic kidney disease (CKD) patients on low-protein diets (LPD). The study aimed to investigate the relationship between energy intake and cardiovascular mortality in CKD patients on a LPD.

METHODS

This was a cross-sectional study, a total of 4264 CKD patients were enrolled from the NHANES database between 2009 and 2018. Restricted cubic spline plots and Cox regression analysis were used to analyze the association between energy intake and cardiovascular mortality in CKD patients on a LPD. Additionally, a nomogram was constructed to estimate cardiovascular survival in CKD patients on a LPD.

RESULTS

Among CKD patients on a LPD in the United States, 90.05% had an energy intake of less than 25 kcal/kg/day, compared to 36.94% in CKD patients on a non-LPD. Energy intake and cardiovascular mortality showed a linear relationship in CKD patients on a LPD, while a 'U-shaped' relationship was observed in CKD patients on a non-LPD. Multifactorial Cox regression models revealed that for Per-standard deviation (Per-SD) decrement in energy intake, the risk of cardiovascular mortality increased by 41% (HR: 1.41, 95% CI: 1.12, 1.77; P = 0.004) in CKD patients on a LPD. The concordance index of the nomogram was 0.79 (95% CI, 0.75, 0.83).

CONCLUSION

CKD patients, especially those on a LPD, have significantly inadequate energy intake. Lower energy intake is associated with higher cardiovascular mortality in CKD patients on a LPD.

Association between protein energy wasting and peritoneal membrane transport in peritoneal dialysis

BACKGROUND

fast peritoneal transport (FT) has been associated with peritoneal albumin loss and protein energy wasting (PEW); however, this relationship has not been fully studied.

AIM

the aim of this study was to analyze the differences in nutritional parameters between fast-transport peritoneal membrane (FT-PET) and slow-transport peritoneal membrane (ST-PET), and analyze the association between FT-PET and PEW in peritoneal dialysis (PD) patients.

METHODS

a cross-sectional study of patients on PD. Peritoneal transport characteristics were assessed using the peritoneal equilibration test (PET). Malnutrition inflammation score (MIS) was used for PEW identification. Clinical and biochemical characteristics between patients with and without PEW were assessed. Association between FT-PET status and PEW were evaluated using univariate and multivariate logistic regression.

RESULTS

a total of 143 patients were included. FT-PET group showed a higher prevalence of hypoalbuminemia, edema, lower phase angle, lower energy intake, and higher values of MIS score. FT-PET was significantly associated with PEW on univariate (OR: 3.5, 95 % CI: 1.56-7.83, p = 0.002) and multivariate models (OR: 2.6, 95 % CI: 1.02-6.6, p = 0.04). This association was maintained in patients where baseline PET was performed after initiating PD therapy (OR: 6.2, 95 % CI: 1.01-38.6, p = 0.04).

CONCLUSION

FT-PET is associated with PEW evaluated by MIS score. Clinical trials to study nutritional interventions personalized to peritoneal-membrane transport characteristics should be designed.

Correlation of physical function and physical activity with muscle mass measured with computed tomography in adult hemodialysis patients

BACKGROUND

muscle mass (MM) plays an important role in the physical function of hemodialysis patients; however, muscle mass measurement can be unreliable and expensive. In contrast, the measurement of physical function (PF) is simple and inexpensive and may serve as an alternative. The aim of this study was to correlate the measurement of MM by computed tomography (CT) with physical function measurements and physical activity (PA) levels in HD patients.

METHODS

this was a cross-sectional study that included 38 HD patients from a single HD clinic. Each participant had a CT scan to measure mid-thigh muscle mass. Physical function tests were assessed using the six-minute walk test (SMWT), handgrip strength (HGS) test, 5 x sit-to-stand test (STS5), timed up and go test (TUGT) and Short Physical Performance Battery (SPPB), while physical activity levels were measured using the Godin-Shephard leisure-time physical activity questionnaire. Correlation analysis was used to examine the relationship between variables.

RESULTS

handgrip strength was strongly positively correlated with thigh muscle area (r = 0.656, p ≤ 0.001) and weakly correlated with arm muscle area (r = 0.396, p = 0.002), SMWT (r = 0.373, p = 0.004), SPPB (r = 0.269, p = 0.041) and physical activity (r = 0.323, p = 0.013). There was also a trend for an inverse correlation between handgrip strenght and TUGT (r = -0.235, p = 0.076). Positive correlations were found between the thigh muscle area and the SPPB (r = 0.339, p = 0.009) and PA (r = 0.293, p = 0.025), while there was a trend for an inverse correlation between thigh muscle area and STS5 (r = -0.256, p = 0.052).

CONCLUSION

several measures of PF and strenght were correlated with objectives measurements of MM, thus provide options for low-cost measurements related to muscle mass.

The Role of Muscle Ultrasonography to Diagnose Malnutrition and Sarcopenia in Maintenance Hemodialysis

BACKGROUND

Sarcopenia and malnutrition are commonly seen and fundamental indicators of prognosis and are directly associated with increased mortality in maintenance hemodialysis (MHD) patients. We aimed to reveal the frequency of malnutrition and sarcopenia in patients undergoing MHD and investigate the role of muscle ultrasound (US) parameters to predict sarcopenia and malnutrition.

METHODS

A total of 45 patients who have undertaken MHD for more than 6 months three times a week were evaluated for the present study. The US measurement was performed on gastrocnemius medialis, rectus femoris (RF), and abdominal muscles, including rectus abdominis, external oblique abdominalis, internal oblique abdominalis, and transversus abdominis. Nutritional status of the participants was assessed by mini-nutritional assessment short-form (MNA-SF).

RESULTS

The prevalence of probable and confirmed sarcopenia was 51.1% (n = 23) and 35.6% (n = 16), respectively. The malnutrition and risk of malnutrition were observed in 31.1% of the whole study population (n = 14). All muscle US measurements were lower in the sarcopenic group; however, the difference is meaningful only for RF cross-sectional area (CSA) (P = .046). The malnourished group had substantially lower muscle thickness and CSA, except for the gastrocnemius muscle thickness. The value of RFCSA to predict sarcopenia and malnutrition was observed as 4.61 cm2, respectively (P < .05). RFCSA was independently associated with sarcopenia (odds ratio: 0.37; 95% confidence interval: 0.17-0.79; P = .011) and malnutrition (odds ratio: 0.45; 95% confidence interval: 0.23-0.87; P = .017).

CONCLUSION

RFCSA may be a useful and simple predictor for predicting patients undergoing hemodialysis who are at risk of sarcopenia and malnutrition.

Effect of Egg-White Protein Alone or Combined With Niacin on Nutritional Status, and Phosphorus Control in Maintenance Hemodialysis Patients: A Randomized Controlled Trial

OBJECTIVE

Niacin is reported to decrease phosphorus concentration in maintenance hemodialysis (MHD) patients. Egg white is one of the main substitutable proteins in MHD patients due to its low phosphorus content. Therefore, we aimed to evaluate the effects of combined egg white and niacin supplementation on dialysis patients' serum phosphorus and nutritional biomarkers.

DESIGN AND METHODS

In this randomized controlled clinical trial, 98 patients on MHD were randomly allocated to four groups for 8 weeks: 24 g egg white (n = 25), 600 g niacin daily (n = 24), egg white combined with niacin (n = 24), and control (n = 24). Calcium, phosphorus, fibroblast growth factor-23, and other nutritional markers were assessed.

RESULTS

There was a significant difference among the groups only in phosphorus at the end of the trial, which was significantly lower in the niacin group (4.38 + 0.812 mg/dL) than in both the egg white (5.07 + 0.49 mg/dL) and egg white with niacin supplementation (5.41 + 0.662 mg/dL) groups. In this regard, albumin increased in egg white and egg white with niacin supplementation, while albumin did not change significantly in the niacin group. Urea reduction ratio and Kt/V rose only in the egg-white group, while aspartate aminotransferase increased only in the niacin and control groups.

CONCLUSION

Niacin decreases serum phosphorus concentration more than egg-white protein or a combined intervention. Egg white protein supplementation has beneficial effects on some nutritional statuses other than phosphorus control without the side effects of niacin.

Feeling gutted in chronic kidney disease (CKD): Gastrointestinal disorders and therapies to improve gastrointestinal health in individuals CKD, including those undergoing dialysis

Chronic kidney disease (CKD) affects 9.1% of the population worldwide. CKD may lead to structural and functional gastrointestinal alterations, including impairment in the intestinal barrier, digestion and absorption of nutrients, motility, and changes to the gut microbiome. These changes can lead to increased gastrointestinal symptoms in people with CKD, even in early grades of kidney dysfunction. Gastrointestinal symptoms have been associated with lower quality of life and reduced nutritional status. Therefore, there has been considerable interest in improving gastrointestinal health in this clinical population. Gastrointestinal health can be influenced by lifestyle and medications, particularly in advanced grades of kidney dysfunction. Therapies focused on gastrointestinal health have been studied, including the use of probiotics, prebiotics, and synbiotics, yielding limited and conflicting results. This review summarizes the alterations in the gastrointestinal tract structure and function and provides an overview of potential nutritional interventions that kidney disease professionals can provide to improve gastrointestinal health in individuals with CKD.

Beyond sarcopenia: frailty in chronic haemodialysis patients

Background

Frailty, characterized by vulnerability, reduced reserves and increased susceptibility to severe events, is a significant concern in chronic haemodialysis (HD) patients. Sarcopenia, corresponding to the progressive loss of muscle mass and strength, may contribute to frailty by reducing functional capacity, mobility and autonomy. However, consensus lacks on the optimal bedside frailty index for chronic HD patients. This study investigated the influence of frailty on chronic HD patient survival and explored the associated factors.

Methods

A total of 135 patients were enrolled from January to April 2019 and then followed up prospectively until April 2022. At inclusion, frailty was assessed by the Timed Up and Go (TUG) and Short Physical Performance Battery (SPPB) tests including gait speed, standing balance and lower limb muscle strength.

Results

From a total of 114 prevalent chronic HD patients (66% men, age 67.6 ± 15.1 years), 30 died during the follow-up period of 23.7 months (range 16.8-34.3). Deceased patients were older, had more comorbidities and a higher sarcopenia prevalence (P < .05). The TUG and SPPB test scores were significantly reduced in patients who had died [SPPB total score: 7.2 ± 3.3 versus 9.4 ± 2.5; TUG time 8.7 ± 5.8 versus 13.8 ± 10.5 (P < .05)]. Multivariate analysis showed that a higher SPPB score (total value >9) was associated with a lower mortality risk [hazard ratio 0.83 (95% confidence interval 0.74-0.92); P < .03). Each component of the SPPB test was also associated with mortality in univariate analysis, but only the SPPB balance test remained protective against mortality in multivariate analysis. Older age, lower handgrip strength and lower protein catabolic rate were associated with SPPB total scores <9, SPPB balance score and TUG time >10 s.

Conclusions

Screening for frailty is crucial in chronic HD patients, and incorporating SPPB, especially the balance test, provides valuable insights. Diminished muscle strength and inadequate protein intake negatively influence the SPPB score and balance in chronic HD patients. Effective identification and management of frailty can therefore improve outcomes.

CLINICAL TRIAL REGISTRATION ClinicalTrialsgov

NCT03845452.

Frailty in Kidney Disease: A Comprehensive Review to Advance Its Clinical and Research Applications

Frailty is a multisystem syndrome of decreased physiologic reserve that has been shown to strongly and independently predict morbidity and mortality. Frailty is prevalent in patients living with kidney disease and occurs earlier in individuals with kidney disease as compared to the general population. In this comprehensive review, we examine clinical and research applications of frailty in kidney disease populations. Specifically, we clarify the definition of frailty and address common misconceptions, review the mechanisms and epidemiology of frailty in kidney disease, discuss challenges and limitations in frailty measurement, and provide updated evidence related to risk factors for frailty, its associated adverse outcomes, and interventions. We further add to the literature in this topic by highlighting the potential applications of frailty measurement in the care of patients with kidney disease and conclude with our recommendations for future research related to this important syndrome.

Early Detection of Inflammation and Malnutrition and Prediction of Acute Events in Hemodialysis Patients through PINI (Prognostic Inflammatory and Nutritional Index)

Protein-energy wasting and inflammation are major risk factors for complications in hemodialysis patients. As these risk factors are triggered by a pro-inflammatory state, oxidative stress and hemodynamic dysfunction, which overlap in hemodialyzed subjects, we aimed to assess the efficacy of a cost-effective and straightforward screening tool, the Prognostic Inflammatory and Nutritional Index (PINI), in regularly screening maintenance hemodialysis (MHD) patients, to detect early signs of inflammation and malnutrition. A 12-month follow-up was carried out on a cohort of 102 adult patients undergoing maintenance dialysis, during which the Prognostic Inflammatory and Nutritional Index (PINI) was calculated using the formula alpha1-Acid Glycoprotein (AGP) × C-reactive protein (CRP)/albumin (ALB) × transthyretin (TTR). A PINI score < 1 was considered normal. The patients were stratified based on their PINI score: 66 patients (64.70%) had a normal score, below 1, while 36 patients (35.30%) had a PINI score ≥ 1. Despite the absence of clinical evidence of inflammation at enrollment, the latter group exhibited higher levels of CRP. During the follow-up period, all patients with a PINI score ≥ 1 experienced at least one acute event, compared to only 6% of patients with a normal PINI score, which presented COVID-19 infection as an acute event. The evaluation of the PINI can effectively identify the silent malnutrition-inflammation syndrome and predict the risk of acute events. This straightforward test appears to be a rapid tool that is independent of the examiner's experience and subjectivity, thereby potentially reducing hospitalization costs.

Associations between bioelectrical impedance analysis-derived phase angle, protein-energy wasting and all-cause mortality in older patients undergoing haemodialysis

AIM

Protein-energy wasting (PEW) is a common syndrome in patients undergoing haemodialysis (HD) and is associated with poor prognosis. Bioelectrical impedance analysis (BIA)-derived phase angle (PA) is useful for predicting PEW, but sex and age need to be considered. We aimed to reveal sex-specific cut-off values of PA predicting PEW in HD patients aged ≥65.

METHODS

This two-centre retrospective cohort study included patients on HD who underwent BIA. PEW was detected using the International Society of Renal Nutrition and Metabolism (ISRNM) criteria as a reference. The PA was measured using a multifrequency bioimpedance device. Sex-specific cut-off values of PA predicting PEW were detected by receiver-operator characteristic analysis. We investigated the association between PEW determined using sex-specific cut-off values for PA and all-cause mortality.

RESULTS

This study included 274 patients undergoing HD, with a median age of 75 (70-80) years, mean PA of 3.8 ± 1.1° and PEW of 43%. Over a median follow-up duration of 1095 (400-1095) days, 111 patients died. Cut-off values of PA predicting PEW were as follows: female, 3.00° (sensitivity, 87.3%; specificity, 77.5%), and male, 3.84° (sensitivity, 77.6%; specificity, 71.4%). The kappa coefficient between sex-specific cut-off values of the PA and ISRNM criteria had a moderate coincidence level of 0.55. PEW detected by PA was independently associated with all-cause mortality (hazard ratio: 2.40; 95% confidence interval: 1.51-3.85; p < .001).

CONCLUSIONS

Sex-specific cut-off values for PA in older HD patients may be useful as a screening tool for predicting PEW and mortality.

Sarcopenia and mild kidney dysfunction and risk of all-cause and cause-specific mortality in older adults

BACKGROUND

Sarcopenia has been identified as a risk factor for increased mortality in individuals with CKD. However, when considering individuals with mild kidney dysfunction prior to CKD, the impact of sarcopenia on adverse outcomes, particularly mortality, remains uncertain.

METHODS

This study included 323 801 participants from the UK Biobank. Mild kidney dysfunction was defined as estimated glomerular filtration rate between 60 and 89.9 mL/min/1.73 m2, and sarcopenia was defined according to the criteria of the 2019 European Working Group of Sarcopenia in Older People. Cox proportional hazard models with inverse probability weighting and competing risk models were used for analysis.

RESULTS

During a median follow-up of 11.8 years, 20 146 participants died from all causes. Compared with participants with normal kidney function and without sarcopenia, those with mild kidney dysfunction or sarcopenia had significantly increased risks of all-cause mortality [hazard ratio (HR) 1.16, 95% confidence interval (CI) 1.12-1.19; HR 1.29, 95% CI 1.20-1.37]; those with both mild kidney dysfunction and sarcopenia had an even higher risk of all-cause mortality (HR 1.61, 95% CI 1.52-1.71), with a significant overall additive interaction (relative risk due to interaction 0.17, 95% CI 0.05-0.29). Further subgroup analyses revealed that the associations of probable sarcopenia with all-cause and cause-specific mortality (non-accidental cause, non-communicable diseases and cancer) were stronger among participants with mild kidney dysfunction than those with normal kidney function.

CONCLUSIONS

The study indicates that sarcopenia and mild kidney dysfunction synergistically increase the risk of all-cause and cause-specific mortality. Early recognition and improvement of mild kidney function or sarcopenia in older people may reduce mortality risk but would require more prospective confirmation.

A study of the low-protein diet in delaying the course of chronic kidney disease

A low-protein diet (LPD) has become an important way to delay the progression of chronic kidney disease (CKD) and to delay the need for dialysis. A review of the literature reveals the low-protein diet's influence on the course of chronic kidney disease. An artificial low-protein food, wheat starch, for example, can not only increase the high-quality protein intake ratio, but can ensure adequate energy intake on a low-protein diet while meeting the nutritional needs of the body, effectively reducing the burden on the damaged kidneys. The purpose of this review is to provide a reference for the clinical implementation of diet and nutrition therapy in patients with chronic kidney disease.

Skeletal Muscle Injury in Chronic Kidney Disease-From Histologic Changes to Molecular Mechanisms and to Novel Therapies

Chronic kidney disease (CKD) is associated with significant reductions in lean body mass and in the mass of various tissues, including skeletal muscle, which causes fatigue and contributes to high mortality rates. In CKD, the cellular protein turnover is imbalanced, with protein degradation outweighing protein synthesis, leading to a loss of protein and cell mass, which impairs tissue function. As CKD itself, skeletal muscle wasting, or sarcopenia, can have various origins and causes, and both CKD and sarcopenia share common risk factors, such as diabetes, obesity, and age. While these pathologies together with reduced physical performance and malnutrition contribute to muscle loss, they cannot explain all features of CKD-associated sarcopenia. Metabolic acidosis, systemic inflammation, insulin resistance and the accumulation of uremic toxins have been identified as additional factors that occur in CKD and that can contribute to sarcopenia. Here, we discuss the elevation of systemic phosphate levels, also called hyperphosphatemia, and the imbalance in the endocrine regulators of phosphate metabolism as another CKD-associated pathology that can directly and indirectly harm skeletal muscle tissue. To identify causes, affected cell types, and the mechanisms of sarcopenia and thereby novel targets for therapeutic interventions, it is important to first characterize the precise pathologic changes on molecular, cellular, and histologic levels, and to do so in CKD patients as well as in animal models of CKD, which we describe here in detail. We also discuss the currently known pathomechanisms and therapeutic approaches of CKD-associated sarcopenia, as well as the effects of hyperphosphatemia and the novel drug targets it could provide to protect skeletal muscle in CKD.

Long-term Effects of Kidney Transplantation Compared With Dialysis on Intima-media Thickness in Children-Results From the 4C-T Study

BACKGROUND

Children requiring kidney replacement therapy experience high burden of cardiovascular (CV) disease leading to increased mortality. Intima-media thickness (IMT) indicating atherosclerosis is a validated surrogate marker for future CV events.

METHODS

We investigated the effect of different treatment modalities (dialysis, preemptive kidney transplantation (KTx), late KTx after dialysis) on IMT by multivariable linear mixed-effect modeling. Patients were enrolled in a prospective cohort study.

RESULTS

A total of 261 analyzed children had a mean follow-up of 3 y. Children after preemptive and late KTx had lower levels of IMT when compared with dialysis. Using an interaction term, a significant progression of IMT over time was seen during dialysis (β = 0.0053 mm/y, P   =  0.004). IMT before the start of therapy was the most influential determinant in all models. Low IMT was associated with maintenance steroid treatment after preemptive KTx. High IMT on dialysis was associated with higher systolic blood pressure, lower body mass index, lower serum albumin, and lower bicarbonate.

CONCLUSIONS

IMT remained rather stable in children several years after KTx. In contrast, children on dialysis had higher IMT values, which increased over time. In these children, blood pressure control, calorie and protein intake, and acid-base homeostasis seem important. Taken together, children might profit from early transplantation to limit accumulation of CV risk.

Nutrition Support for Older Adults With Pressure Injuries Receiving Maintenance Hemodialysis: A Case Study

Hemodialysis (HD) and pressure injuries (PI) are both hypercatabolic states that may contribute to protein-energy wasting development. These conditions require increased energy and protein to prevent losses from HD and support wound healing. Nutrition support therapy using intradialytic parenteral nutrition (IDPN) with or without a combination of oral nutrition supplements has yielded positive outcomes among patients receiving HD with protein-energy wasting. However, IDPN is not a standard of care for patients with PI and receiving HD. No existing guidelines support its use with these combined complex medical conditions. We present a case of an older adult with PI receiving HD who required supplemental IDPN. This case demonstrated that IDPN helps wound healing, reduces the hospital length of stay, and enhances quality of life.

Shenshuai Yingyang Jiaonang ameliorates chronic kidney disease-associated muscle atrophy in rats by inhibiting ferroptosis mediated by the HIF-1α/SLC7A11 pathway

Objective

Shenshuai Yingyang Jiaonang (SSYYJN), a traditional Chinese medicine formula, can ameliorate muscle atrophy associated with chronic kidney disease (CKD). However, its mechanisms of action remain unclear. This study is to investigate the molecular mechanisms involved in the effects of SSYYJN in ameliorating muscle atrophy associated with CKD in rats. Methods: The chemical compounds of SSYYJN were identified by UPLC-Q-Orbitrap HRMS. Considering the dose-response relationship of the identified compounds, male SD rats were randomly divided into Sham, Model, SSYYJN, and α-Keto Acid (KA) groups. Subsequently, we assessed the therapeutic and anti-ferroptotic effects of SSYYJN. Network pharmacology studies were used to predict the molecular mechanism of SSYYJN on ferroptosis and were further verified for accuracy.

Results

A total of 42 active compounds were identified from SSYYJN. SSYYJN alleviated muscle atrophy caused by CKD, as evidenced by changes in body weight, serum biochemical indices, mass and histopathology of the skeletal muscle, and the levels of MuRF1. SSYYJN reduced the levels of iron, MDA, and ROS, increased the levels of GSH, NAPDH, and Gpx4. Network pharmacology analysis indicated that SSYYJN exerted anti-ferroptotic effects that were closely related to the HIF-1α signaling pathway. Molecular protein and genetic test results showed that SSYYJN increased HIF-1α protein and increased SLC7A11.

Conclusions

SSYYJN attenuates muscle atrophy in CKD by inhibiting ferroptosis through the activation of the HIF-1α/SLC7A11 pathway and might be a promising traditional Chinese medicine for muscle atrophy in CKD.

Association between the serum zinc level and nutritional status represented by the geriatric nutritional Rrisk index

BACKGROUND

Although it is widely known that patients with chronic kidney disease (CKD) can develop zinc deficiency, in our previous analysis, the estimated glomerular filtration rate (eGFR) was not independently associated with the serum zinc level. Thus, a post hoc analysis was conducted to investigate the involvement of nutritional status.

METHODS

A total of 655 subjects not on dialysis (402 males; mean age, 57 ± 18 years) who underwent serum zinc level measurements at Jikei University Hospital between April 2018 and March 2019 were selected using the Standardized Structured Medical Information eXchange2 (SS-MIX2) system. In addition, anthropometric data and the Geriatric Nutritional Risk Index (GNRI) representing nutritional status were obtained, and the relationship between the serum zinc level and nutritional status was investigated by multiple regression analysis.

RESULTS

The serum albumin level and the GNRI were lower in the zinc-deficiency group, and both were positively associated with the serum zinc level (rho = 0.44, P < 0.01 and rho = 0.44, P < 0.01, respectively). On multiple regression analysis, the GNRI (t = 3.09, P < 0.01) and serum albumin level (t = 4.75, P < 0.01) were independently associated with the serum zinc level. Although a higher eGFR was associated with a higher serum zinc level, this association disappeared on multivariate analysis.

CONCLUSION

In this post hoc analysis, the GNRI, as well as the serum albumin level, were correlated with the serum zinc level, indicating that nutritional status is an important determinant of the zinc level. Further investigations are needed to clarify the effects of nutritional status and kidney function on zinc deficiency.

The association between blood nickel level and handgrip strength in patients undergoing maintenance hemodialysis

BACKGROUND

Progressive loss of peripheral muscle strength is highly pronounced in patients receiving maintenance hemodialysis (MHD), of which the pathological mechanism tends to be multifactorial. Plasma nickel was reportedly correlated with muscular strength in non-dialysis patients. However, scarce is known regarding the association between blood nickel level and handgrip strength among the patients undergoing MHD.

METHODS

This cross-sectional study included patients undergoing MHD at our center in October 2021. Blood samples were collected before the hemodialysis sessions. Nickel level was measured using inductively coupled plasma mass spectrometry. Eligible patients were stratified into three groups by the blood nickel level: tertile 1 (≥ 5.2 ug/L); tertile 2 (< 5.2 ug/L and ≥ 4.5 ug/L); and tertile 3 (< 4.5 ug/L). Handgrip strength measurement was used to evaluate the muscle status. Spearman's analyses and multivariable linear regression analyses were performed to study the relationship between blood nickel level and handgrip strength.

RESULTS

A total of 236 patients were enrolled, with an average age of 55.51 ± 14.27 years and a median dialysis vintage of 83 (IQR: 48-125) months. Patients in group with a higher blood nickel level (tertile 1) tended to be female, had longer dialysis vintage and higher Kt/V, but lower BMI, serum creatinine, hemoglobin, and handgrip strength level (all p < 0.05). After adjustment for confounding factors in multivariable models, for every 1ug/L increase in nickel level, the patient's handgrip strength decreases by 2.81 kg (β: - 2.810, 95% confidence interval: - 5.036 to - 0.584, p = 0.014). Restricted cubic spline confirmed the relationship was nearly linear.

CONCLUSIONS

Our study highlighted that blood nickel level was related to handgrip strength in patients undergoing MHD. Prospective studies with larger sample sizes are still needed to confirm the result.

Decreased abdominal wall muscle mass defined by muscle ultrasound is associated with malnutrition according to Global Leadership Initiative on Malnutrition criteria in renal transplant recipients: A cross-sectional study

BACKGROUND

Changed body composition with increased fat content and decreased muscle mass is seen in renal transplantation recipients (RTRs). Increased fat mass might mask underlying muscle mass loss; measuring low body mass index and weight reduction alone may not be sensitive enough to diagnose malnutrition in RTRs. We aimed to determine the prevalence of malnutrition in stable RTRs using the Global Leadership Initiative on Malnutrition (GLIM) criteria and to assess the use of muscle ultrasonography (US) to compare the performance of various muscle US measurements in the diagnosis of reduced muscle mass.

METHODS

Ninety-one patients who had renal transplantation >6 months ago were enrolled in the study. GLIM criteria were performed for all patients, but not those at risk of malnutrition. Bioelectrical impedance analysis and muscle US were performed to identify reduced muscle mass.

RESULTS

The prevalence of malnutrition according to GLIM criteria was 25.3% (n = 23). All muscle US measurements were lower in the malnourished group than the well-nourished group; however, the malnourished group had substantially lower muscle thicknesses in abdominal muscles, specifically the external oblique (EO) and internal oblique (IO) muscles, than the well-nourished group (P = 0.001 and P = 0.007, respectively). There was a significant association between malnutrition and EO (odds ratio [OR] = 0.338, 95% CI = 0.163-0.699; P = 0.003) and IO (OR = 0.620, 95% CI = 0.427-0.900; P = 0.012) regardless of age and sex.

CONCLUSION

One in four RTRs experience malnutrition. Muscle US could be used effectively for the diagnosis of reduced muscle mass and malnutrition in RTRs according to GLIM criteria.

Predictors of Skeletal Muscle Index for Patients Treated With Hemodialysis

OBJECTIVE

There is an increased risk of skeletal muscle mass (SMM) loss among patients with stage 5 chronic kidney disease treated with maintenance hemodialysis (MHD). The reduced SMM considerably influences the development of protein-energy wasting (PEW). Patients who develop PEW have higher hospitalization and mortality rates than those without PEW. This study determined if key variables could predict SMM Index (SMM adjusted for height) in patients receiving MHD.

METHODS

We conducted a secondary analysis of cross-sectional data obtained from the Rutgers Nutrition and Kidney Database (n = 178). Data were used to calculate both SMM and SMM Index. Univariate and multiple linear regression models explored the relationship between SMM Index and the following variables: serum albumin, urea clearance normalized treatment ratio, normalized protein catabolic rate, serum creatinine, and urea reduction ratio (URR).

RESULTS

Most participants were Black/African American (82.9%), male (59.1%), and obese (39%), with a mean age of 55.9 ± 11.9 years. The median Subjective Global Assessment score was 5, indicating a lower risk of malnutrition. Participants had a mean SMM of 26.4 kg and a median SMM Index of 8.9 kg/m2. Univariate regression modeling found URR to be a significant predictor of SMM Index, with increases in the percentage of URR predicting lower SMM Index values. The adjusted regression modeling found similar results, with increases in URR percentage predicting declines in SMM Index.

CONCLUSION

This study found that URR was a predictor of SMM Index in patients receiving MHD. Further research is required to explore these relationships and provide clinicians with a more extensive array of tools to recognize early signs of SMM loss to prevent the progression of PEW.

Common mouse models of chronic kidney disease are not associated with cachexia

The 5/6 nephrectomy and adenine-induced nephropathy mouse models have been extensively used to study Chronic Kidney Disease (CKD)-related cachexia. One common caveat of these CKD models is the cross-sectional nature of comparisons made versus controls. We here performed a comprehensive longitudinal assessment of body composition and energy metabolism in both models. The most striking finding is that weight loss is largely driven by reduced food intake which promotes rapid loss of lean and fat mass. However, in both models, mice catch up weight and lean mass a few days after the surgery or when they are switched back to standard chow diet. Muscle force and mass are fully recovered and no sign of cachexia is observed. Our data demonstrate that the time-course of kidney failure and weight loss are unrelated in these common CKD models. These data highlight the need to reconsider the relative contribution of direct and indirect mechanisms to muscle wasting observed in CKD.

Exercise for patients with chronic kidney disease: from cells to systems to function

Chronic kidney disease (CKD) is among the leading causes of death and disability, affecting an estimated 800 million adults globally. The underlying pathophysiology of CKD is complex creating challenges to its management. Primary risk factors for the development and progression of CKD include diabetes mellitus, hypertension, age, obesity, diet, inflammation, and physical inactivity. The high prevalence of diabetes and hypertension in patients with CKD increases the risk for secondary consequences such as cardiovascular disease and peripheral neuropathy. Moreover, the increased prevalence of obesity and chronic levels of systemic inflammation in CKD have downstream effects on critical cellular functions regulating homeostasis. The combination of these factors results in the deterioration of health and functional capacity in those living with CKD. Exercise offers protective benefits for the maintenance of health and function with age, even in the presence of CKD. Despite accumulating data supporting the implementation of exercise for the promotion of health and function in patients with CKD, a thorough description of the responses and adaptations to exercise at the cellular, system, and whole body levels is currently lacking. Therefore, the purpose of this review is to provide an up-to-date comprehensive review of the effects of exercise training on vascular endothelial progenitor cells at the cellular level; cardiovascular, musculoskeletal, and neural factors at the system level; and physical function, frailty, and fatigability at the whole body level in patients with CKD.

The Association of Frailty and Malnutrition With Dietary Intake and Gastrointestinal Symptoms in People With Kidney Failure: 2-Year Prospective Study

BACKGROUND

Frailty and malnutrition are both associated with worsening morbidity and mortality and become more prevalent in the elderly and as kidney function declines. Anorexia and reduced oral intake are common features of both frailty and malnutrition. However, there are sparse data evaluating the impact of other gastrointestinal (GI) symptoms, such as taste changes, on rates of frailty and malnutrition in people with kidney failure. The aim of this study is to describe the prevalence of frailty and malnutrition and their association with dietary intake and nutrition-related symptoms in people with kidney failure.

METHODS

This observational study recruited people with kidney failure who were commencing Conservative Kidney Management or elderly people (aged > 75 years) newly commenced on dialysis from 3 renal units. Participants underwent assessments of frailty, nutritional status, dietary intake, and GI symptom burden when they attended clinic appointments, approximately every 6 months.

RESULTS

Of the 85 participants, 57% were assessed as being frail and 33% were assessed as being malnourished. Participants assessed as frail reported more GI symptoms (3 vs. 2, P < .001) that were more severe (1.75 vs. 1.0, P < .001) compared to nonfrail participants. Being malnourished was associated with a 5 times higher chance of being frail (odds ratio 5.8; 95% confidence interval 1.5, 21.8; P = .015) and having more severe symptoms was associated with a 2 times higher chance (odds ratio 2.8; 95% CI 1.1, 7.0; P = .026) of being frail. In addition to experiencing more GI symptoms, that were more severe, participants who were malnourished consumed significantly less energy (1234 kcal vs. 1400 kcal, P = .01) and protein (51 g vs. 74 g, P < .001).

CONCLUSIONS

Frailty and malnutrition are common and are associated with a higher GI symptom burden and poorer dietary intake. Future research is needed to determine effective interventions targeting frailty and malnutrition, including nutrition-related symptoms and optimal protein intake.

Does intradialytic oral nutrition impact hemodialysis patients' quality of Life, appetite, and safety? A pilot study of a crossover clinical trial

INTRODUCTION

due to the catabolic characteristics of hemodialysis (HD), patients should consume foods or supplements during this treatment to meet their energy requirements and maintain a neutral nitrogen balance; however, there are some outcomes in which the effect of intradialytic oral nutrition (ION) is scarcely known.

OBJECTIVES

this study aims to evaluate the effect of two types of ION (liquid and solid) on QoL, appetite, and safety in HD patients.

METHODS

a pilot randomized, crossover clinical trial was performed in 18 patients on chronic HD. One group received ION for 18 HD sessions, after the crossover continued for 18 more sessions in the control group, and vice versa. We recorded QoL, appetite, systolic blood pressure (SBP), and intradialytic hypotension (IH) events.

RESULTS

clinical improvement was observed for most QoL components. Regardless of the consistency of supplementation, SBP increased to 4.10 mmHg. Both study groups reported a "very good-to-good" appetite.

CONCLUSION

favorable clinical changes were observed in QoL scores during the study. Five of six IH events were reported for patients in the ION group, and SBP increased within the safe range (≤ 10 mmHg); appetite remained stable in both groups. Therefore, we concluded that this strategy, regardless of implementation consistency, is safe to be used in stable patients.

Hyperparathyroidism, Serum Phosphorus and Dietary Intake in Hemodialysis Patients: Is There a Novel Relationship?

The management of hyperparathyroidism (intact parathyroid hormone (iPTH) serum levels > 585 pg/mL), frequently focuses on the appropriate control of mineral and bone markers, with the decrease in serum and dietary phosphorus as two of the targets. We aimed to investigate the association between iPTH, serum phosphorus levels and dietary intake. This was a cross-sectional, multicenter, observational study with 561 patients on hemodialysis treatment. Clinical parameters, body composition and dietary intake were assessed. For the analysis, patients were divided into three groups: (a) iPTH < 130, (b) iPTH between 130 and 585 and (c) iPTH > 585 pg/mL. The association between PTH, serum phosphorus and dietary intake was analyzed using linear regression models. In the whole sample, 23.2% of patients presented an iPTH > 585 pg/mL. Patients with higher iPTH levels were those with longer HD vintage and lower ages, higher serum phosphorus, serum calcium, Ca/P product, albumin and caffeine intake, and a lower dietary intake of phosphorus, fiber, riboflavin and folate. Higher serum phosphorus predicted higher iPTH levels, even in the adjusted model. However, lower dietary phosphorus and fiber intake were predictors of higher iPTH levels, including in the adjusted model. Our results bring new data to the relationship between dietary intake and iPTH values. Despite higher serum phosphorus being observed in patients with HPTH, an opposite association was noted regarding dietary phosphate and fiber.

Development and validation of the patient-reported outcome scale for chronic kidney disease

PURPOSE

The patient-reported outcomes (PROs) measuring patient's experience and perception of disease are important components of approach to care. However, no tools are available to assess the PROs of chronic kidney disease (CKD). This study aims to develop and verify a PROs scale to evaluate clinical outcomes in CKD patients.

METHODS

The theoretical structure model and original item pool were formed through a literature review, patient interviews and references to relevant scales. The Delphi method, classical test theory methods and item response theory method were used to select items and adjust dimensions to form the final scale. Altogether 360 CKD patients were recruited through convenience sampling. CKD-PROs could be evaluated from four aspects, namely reliability, content validity, construct validity, responsibility, and feasibility.

RESULTS

The CKD-PROs scale covers 4 domains, including the physiological, psychological, social, and therapeutic domain, and 12 dimensions, 54 items. The Cronbach's α is 0.939, the split reliability coefficient is 0.945, and the correlation of the scores each item and domain's coefficients range from 0.413 to 0.669. The results of structure validity, content validity and reactivity showed that the multidimensional measurement of the scale met professional expectations. The recovery rate and effective rate of the scale were over 99%.

CONCLUSION

The CKD-PROs scale has great reliability, validity, reactivity, acceptability and is capable of being used as one of the evaluation tools for the clinical outcomes of CKD patients.

Brazil Nut-Enriched Diet Modulates Enteric Glial Cells and Gut Microbiota in an Experimental Model of Chronic Kidney Disease

Introduction: Chronic kidney disease (CKD) promotes gut dysbiosis, and enteric glial reactivity, a feature of intestinal inflammation. Brazil nut modulated enteric glial profile in healthy animals and could modulate these cells in 5/6 nephrectomized rats.Methods: A 5/6 nephrectomy-induced CKD and Sham-operated rats were divided as follows: CKD and Sham received a standard diet and CKD-BN and Sham-BN received a 5% Brazil nut enriched-diet. The protein content of glial fibrillary acid protein (GFAP), enteric glial marker, and GPx protein content and activity were assessed in the colon. The major phyla of gut microbiota were assessed.Results: CKD-BN group presented a decrease in GFAP content (p = 0.0001). The CKD-BN group modulated the abundance of Firmicutes, increasing its proportion compared to the CKD group. The CKD-BN group showed increased GPx activity in the colon (p = 0.0192), despite no significant difference in protein content.Conclusion: Brazil nut-enriched diet consumption decreased enteric glial reactivity and modulated gut microbiota in the CKD experimental model.

A randomized controlled pilot trial of anakinra and pioglitazone for protein metabolism in patients on maintenance haemodialysis

BACKGROUND

Chronic inflammation and insulin resistance are highly prevalent in patients on maintenance haemodialysis (MHD) and are strongly associated with protein energy wasting. We conducted a pilot, randomized, placebo-controlled trial of recombinant human interleukin-1 receptor antagonist (IL-1ra) and pioglitazone to explore the safety, feasibility and efficacy for insulin-mediated protein metabolism in patients undergoing MHD.

METHODS

Twenty-four patients were randomized to receive IL-1ra, pioglitazone or placebo for 12 weeks. Changes in serum inflammatory markers and insulin-mediated protein synthesis, breakdown and net balance in the whole-body and skeletal muscle compartments were assessed using hyperinsulinaemic-hyperaminoacidemic clamp technique at baseline and Week 12.

RESULTS

Among 24 patients, median (interquartile range) age was 51 (40, 61), 79% were African American and 21% had diabetes mellitus. All patients initiated on intervention completed the study, and no serious adverse events were observed. There was a statistically significant decrease in serum high-sensitivity C-reactive protein in the pioglitazone group compared with placebo, but not in the IL-1ra group. No significant differences in the changes of whole-body or skeletal muscle protein synthesis, breakdown and net balance were found between the groups.

CONCLUSIONS

In this pilot study, there were no statistically significant effects of 12 weeks of IL-1ra or pioglitazone on protein metabolism in patients on MHD.

CLINICALTRIALS

gov registration: NCT02278562.

Calf circumference predicts sarcopenia in maintenance hemodialysis

BACKGROUND

Early recognition of sarcopenia in hemodialysis (HD) patients will be of great importance in preventing adverse outcomes and improving the quality of life in these patients. The main goal of this study was to evaluate the diagnostic accuracy of calf circumference (CC) measurement in detecting sarcopenia among CKD patients undergoing maintenance HD.

METHODS

This cross-sectional study included 52 patients (53 ± 17 years) who were currently in a maintenance HD. Muscle strength was evaluated using handgrip strength, and smooth muscle mass index (SMI) was assessed through bioelectrical impedance analysis, and CC was measured at the widest part of the calf with the foot pressed against a hard surface.

RESULTS

Out of the total patient population, sarcopenia was identified in 32.7% (n = 17). The two groups were comparable in terms of age, weight, and height, but the median body mass index of sarcopenic group was statistically lower than nonsarcopenic group (21.6 kg/m2 [18.9-24.6] vs 24.7 kg/m2 [21.4-27.3]. The sarcopenic group had a substantially smaller CC than the nonsarcopenic group (30.0 cm [26.5-32.0] vs 31.5 cm [30.3-34.8], P = 0.013; respectively). In the regression analysis, CC was found to be independently associated with post-HD SMI (P < 0.001; odds ratio, 1.938; and 95% CI, 1.020-2.856). CC was positively but weakly correlated with handgrip strength, however strong and significant correlation was found between CC and SMI (r = 0.277, P = 0.047 and r = 0.733, P < 0.001; respectively). A CC of 31 cm or less predicted confirmed sarcopenia in HD patients (area under the curve = 0.709, P = 0.006, specificity = 0.556, sensitivity = 0.765).

CONCLUSIONS

Low muscle mass and potentially low muscle strength in HD patients can be accurately identified through the use of CC measurements. Specifically, a CC measurement below 31 cm has found to be a useful indicator to identify individuals on maintenance HD.

The Impact of Combined Nutrition and Exercise Interventions in Patients with Chronic Kidney Disease

Combined nutrition and exercise interventions potentially improve protein-energy wasting/malnutrition-related outcomes in patients with chronic kidney disease (CKD). The aim was to systematically review the effect of combined interventions on nutritional status, muscle strength, physical performance and QoL. MEDLINE, Cochrane, Embase, Web of Science and Google Scholar were searched for studies up to the date of July 2023. Methodological quality was appraised with the Cochrane risk-of-bias tool. Ten randomized controlled trials (nine publications) were included (334 patients). No differences were observed in body mass index, lean body mass or leg strength. An improvement was found in the six-minute walk test (6-MWT) (n = 3, MD 27.2, 95%CI [7 to 48], p = 0.008), but not in the timed up-and-go test. No effect was found on QoL. A positive impact on 6-MWT was observed, but no improvements were detected in nutritional status, muscle strength or QoL. Concerns about reliability and generalizability arise due to limited statistical power and study heterogeneity of the studies included.

Impairments of functional exercise capacity, muscle strength, balance and kinesiophobia in patients with chronic kidney disease: a cross-sectional study

BACKGROUND

Muscle weakness, balance, and functional capacity are affected in patients with chronic kidney disease (CKD) in dialysis. However, studies about kinesiophobia, peripheral and respiratory muscle strength, balance, exercise capacity, fatigue, and physical activity level in patients with CKD 3-4 are limited. The study aimed to compare the functional exercise capacity, peripheral and respiratory muscle strength, pulmonary function, balance, kinesiophobia, physical activity, fatigue, and dyspnea between patients with CKD 3-4 and controls.

METHODS

This cross-sectional study included 43 patients and 45 controls. Functional exercise capacity [6-Minute Walking Test (6MWT)], peripheral and respiratory muscle strength, pulmonary function, dyspnea, fatigue, physical activity, balance [Berg Balance Scale (BBS)], and kinesiophobia were evaluated.

RESULTS

Demographic characteristics were similar in patients [53(50-57) y, 26 M/17F] and controls [51(4.506-55) y, 33 M/12F] (p > 0.05). The 6MWT, respiratory and peripheral muscle strength, pulmonary function, physical activity, and BBS were significantly lower, and the level of dyspnea and kinesiophobia were higher in patients compared with controls (p < 0.05).

CONCLUSIONS

Patients had impaired functional exercise capacity, upper and lower extremity muscle strength, respiratory muscle strength, pulmonary function, and balance, increased perception of dyspnea and kinesiophobia, and reduced physical activity level compared with controls. Patients should be directed to cardiopulmonary rehabilitation programs.

Gut microbiota dysbiosis and protein energy wasting in patients on hemodialysis: an observational longitudinal study

Background

Protein energy wasting (PEW) is common in patients on hemodialysis, and its development may involve gut microbial dysbiosis. However, the exact relationship between the composition of different flora and the development of PEW remains unclear.

Methods

This is an observational longitudinal study on 115 patients undergoing hemodialysis who were followed up for 1 year. All the patients were evaluated at baseline, and different microbiota compositions were determined. After a 1 year follow-up period, the correlations between clinical parameter variations and the relative abundance of different gut flora were assessed using Spearman correlation. Moreover, the associations of the abundance of different gut microbiota with decrease in lean tissue mass and the development of PEW were analyzed using ROC curve and logistical regression analyses.

Results

We found that the relative abundances of Actinobacteria and Bifidobacteriaceae were significantly lower in patients with PEW than in those who did not develop PEW (p < 0.05). The abundance of Actinobacteria and Bifidobacteriaceae correlated positively with variations in serum albumin levels (r = 0.213, p = 0.035 and r = 0.214, p = 0.034, respectively), lean tissue mass (r = 0.296, p = 0.007 and r = 0.238, p = 0.002, respectively), and lean tissue index (r = 0.377, p < 0.001 and r = 0.419, p < 0.001, respectively). The area under the ROC curve or AUC values of Actinobacteria and Bifidobacteriaceae for the prediction of lean tissue mass decrease ranged from 0.676 to 0.708 (p < 0.05). Thus, decrease in the abundance of Actinobacteria and Bifidobacteriaceae may be associated with decrease in lean tissue mass and the occurrence of PEW.

Conclusion

The present findings imply Actinobacteria and Bifidobacteriaceae may be potential markers for predicting skeletal muscle mass decrease and PEW development in patients on hemodialysis.

Adaptive Nutrition Intervention Stabilizes Serum Phosphorus Levels in Hemodialysis Patients: A Multicenter Decentralized Clinical Trial Using Real-World Data

OBJECTIVE

This study aims to evaluate the effect of an adaptive nutritional and educational intervention for patients on hemodialysis (HD) in a routine care setting, using real-world data from electronic health records.

METHODS

Decentralized clinical trial of seven HD facilities recruited patients who have been on HD for over 3 months (N = 153) for an 8-week adaptive intervention protocol. Patients were divided into four groups: (1) control (2) education intervention (3) meal intervention (4) education and meal interventions. Educational contents were digitally delivered via mobile phones and premade meals tailored on laboratory findings were home-delivered. Changes in serum electrolytes and malnutrition inflammation score (MIS) were analyzed.

RESULTS

Meal intervention statistically significantly stabilized serum phosphorus level (β = -0.81 mg/dL, 95% confidence interval = [-1.40, -0.22]) at week 8, with increased likelihood of being within target serum value range (odds ratio = 1.21, 95% confidence interval = [1.04, 1.40]). Meal group showed better nutritional status (MIS = 3.65) than the education group (MIS = 5.10) at week 8 (adjusted p < .05). No significant changes were observed in serum potassium level, depression, and self-efficacy.

CONCLUSION

It was demonstrated that an adaptive meal intervention in a real-world care setting may benefit serum phosphorus control and nutritional status of patients on HD, without negative effect on depression levels or self-efficacy. More work is needed to develop an effective educational intervention.

Quality characteristics and sensory evaluation of protein-rich baked snacks for adults with chronic kidney disease: a proof of concept study

BACKGROUND

Adults with chronic kidney disease (CKD) have different protein requirements than the general population. Limited protein-rich baked snack options are available for CKD adults. The purpose of this proof of concept study was to develop two protein-rich baked snacks made with whey protein isolate and soy protein isolate and to evaluate their quality characteristics and sensory perceptions for adults with CKD.

METHODS

A control formulation was obtained from the American Association of Cereal Chemists to develop three formulations-dried milk (control), whey protein isolate and soy protein isolate at an unbaked weight of 30 g. Product quality characteristics included moisture content, water activity, shape and size, and texture profile. For the sensory perception, healthy adults (n = 101) and adults with CKD (n = 57) completed a 9-point hedonic scale for appearance, flavor, texture, and overall acceptability.

RESULTS

Protein content for the whey protein isolate and soy protein isolate reached 20% total weight. Despite containing similar moisture, both formulations were harder than the control (p < 0.001). Healthy participants preferred the whey protein isolate-based snack over the soy protein isolate-based snack for all attributes (p < 0.05). Differences in the same attributes were not perceived among CKD participants (p > 0.05). Open-ended responses from both healthy and CKD participants indicated that the soy protein isolate formulation was softer and sweeter compared to the whey protein isolate formulation.

CONCLUSION

Overall, adults with CKD preferred both the whey protein isolate-and soy protein isolate-formulated snacks. These protein-rich baked snacks can be further modified to serve as an alternative snack choice for adults with CKD and used in future clinical trials.

Identification of molecular mediators of renal sarcopenia risk: a mendelian randomization analysis

BACKGROUND

Observational studies have shown an association between reduced renal function and the risk of sarcopenia. However, the causal relationship and the underlying biological mechanisms remain uncertain. Using a Mendelian randomization (MR) framework, we investigated the causal role of 27 hypothetical risk mediators, including metabolites, hormones, inflammation, and stress traits, on the risk of sarcopenia.

METHODS

Instrumental variables (IVs) to proxy renal function were identified by selecting single nucleotide polymorphisms (SNPs) reliably associated with creatinine and cystatin C-based glomerular filtration rate (GFR) in CKDGen summary data. IVs for putative risk traits and sarcopenia traits were constructed from relevant genome-wide association studies (GWAS). MR estimated effects were obtained using an inverse-variance weighted effects model, and various sensitivity analyses were performed. The mediating role of hypothetical risk factors in the relationship between GFR and sarcopenia was assessed through multivariate MR.

RESULTS

Genetically predicted reduced GFRcrea was associated with higher odds of appendicular lean mass (ALM) (odds ratio (OR): 0.64, 95% confidence interval (CI) 0.37 to 0.68) and grip strength (OR: 0.67; 95% CI 0.58 to 0.78). Likewise, GFRcys highlighted a causal relationship with ALM (OR: 0.52; 95% CI 0.42 to 0.65) and grip strength (OR: 0.66; 95% CI 0.59 to 0.74). Both estimated GFR (eGFR) were negatively associated with IGF-1, IL-16, 25(OH)D, triglycerides (range of effect size per standard deviation: -0.81 to -0.30), and positively correlated with HDL cholesterol (0.62, 0.31). There was a positive correlation between IGF-1, fasting insulin and ALM as well as grip strength (OR range: 1.04-1.67) and a negative correlation between serum CRP and ALM (OR: 0.95) as well as grip strength (OR: 0.98). Additionally, genetically predicted IL-1β (OR: 0.95) and total cholesterol (OR: 0.96) were negatively associated with ALM. We found evidence that IGF-1 mediates the relationship between eGFR and risk for muscle mass and strength.

CONCLUSIONS

This MR study provides insight into the potential causal mechanisms between renal function and the risk of sarcopenia and proposes IGF-1 as a potential target for the prevention of renal sarcopenia.

Dietary Intake and Nutritional Status in Diabetic and Nondiabetic Patients With Chronic Kidney Disease Stage 4-5 (NutriDiab Study)

OBJECTIVES

The aim of the present study was to assess the dietary intake and nutritional status of patients with chronic kidney disease (CKD) stage 4-5 according to the presence of diabetes.

METHODS

This observational and cross-sectional study included adult patients with CKD stage 4-5 referred to a nephrology unit, between October 2018 and March 2019. Daily dietary intake was evaluated by 24-hour dietary inquiry and urine excretion. Nutritional status was assessed by measuring body composition using bioimpedance analysis and muscle function using handgrip strength. Undernutrition was considered using the protein energy wasting score.

RESULTS

A total of 75 CKD patients were included, 36 (48%) of whom had diabetes; median age (interquartile range) was 71 (60-80) years. The median weight-adjusted dietary energy intake (DEI) was 22.6 (19.1-28.2) kcal/kg/day and the mean weight-adjusted dietary protein intake (DPI) was 0.86 ± 0.19 g/kg/day. There was no significant difference in DEI and DPI between patients with diabetes and those without, except for weight-adjusted DPI which was significantly lower in diabetic patients (P = .022). In univariate analysis, diabetes was associated with weight-adjusted DPI (coefficient [95% confidence interval] -0.237 [-0.446; -0.004] kcal/kg/day; P = .040), but this association did not remain significant in multivariate analysis. Nutritional status did not differ significantly between diabetic and nondiabetic patients except for lean tissue mass, which was lower in diabetic patients (P = .046). The proportion of patients with protein energy wasting was not significantly different between diabetic and nondiabetic patients (13.9% vs. 10.2%, respectively).

CONCLUSIONS

In the present cohort, DPI and DEI were not significantly different between diabetic and nondiabetic CKD patients. Diabetes was not found to be associated with dietary intakes in CKD stage 4-5 patients.

Muscle Mass and Serum Creatinine Concentration by Race and Ethnicity among Hemodialysis Patients

SIGNIFICANCE STATEMENT

Serum creatinine is a product of skeletal muscle metabolism. Differences in serum creatinine concentration between Black and non-Black individuals have been attributed to differences in muscle mass but have not been thoroughly examined. Furthermore, other race and ethnic groups have not been considered. If differences in body composition explain differences in serum concentration by race or ethnicity, then estimates of body composition could be used in eGFR equations rather than race. Adjustment for intracellular water (ICW) as a proxy of muscle mass among patients with kidney failure in whom creatinine clearance should minimally influence serum concentration does not explain race- and ethnicity-dependent differences.

BACKGROUND

Differences in serum creatinine concentration among groups defined by race and ethnicity have been ascribed to differences in muscle mass. We examined differences in serum creatinine by race and ethnicity in a cohort of patients receiving hemodialysis in whom creatinine elimination by the kidney should have little or no effect on serum creatinine concentration and considered whether these differences persisted after adjustment for proxies of muscle mass.

METHODS

We analyzed data from 501 participants in the A Cohort Study to Investigate the Value of Exercise in ESKD/Analyses Designed to Investigate the Paradox of Obesity and Survival in ESKD study who had been receiving hemodialysis for >1 year. We examined the independent associations among race and ethnicity (Black, Asian, non-Hispanic White, and Hispanic), serum creatinine, and ICW (L/m 2 ), a proxy for muscle mass, derived by whole-body multifrequency bioimpedance spectroscopy, using multivariable linear regression with adjustment for several demographic, clinical, and laboratory characteristics. We examined the association of race and ethnicity with serum creatinine concentration with and without adjustment for ICW.

RESULTS

Black, Asian, and Hispanic patients had higher serum creatinine concentrations (+1.68 mg/dl [95% confidence interval (CI), 1.09 to 2.27], +1.61 mg/dl [95% CI, 0.90 to 2.32], and +0.83 [95% CI, 0.08 to 1.57], respectively) than non-Hispanic White patients. Overall, ICW was associated with serum creatinine concentration (0.26 mg/dl per L/m 2 ICW; 95% CI, 0.006 to 0.51) but was not statistically significantly different by race and ethnicity. Black, Asian, and Hispanic race and ethnicity remained significantly associated with serum creatinine concentration after adjustment for ICW.

CONCLUSION

Among patients receiving dialysis, serum creatinine was higher in Black, Asian, and Hispanic patients than in non-Hispanic White patients. Differences in ICW did not explain the differences in serum creatinine concentration across race groups.

In the "Plant-Based" Era, Patients With Chronic Kidney Disease Should Focus on Eating Healthy

In the era of plant-based diets, it is important for Nephrology providers to know the evidence regarding their healthfulness in patients with chronic kidney disease (CKD). A whole food, plant-based diet, which emphasizes fresh, minimally processed or refined plant-based foods and limits animal products, has shown benefits for patients with CKD. These include reduced dietary acid load, lower bioavailability of potassium and phosphorus, increased dietary fiber intake, nutritional adequacy, and cardiovascular and mortality benefits. Potential drawbacks include the need for specific knowledge, skills, and cost involved in preparing varied, healthy, and appetizing plant-based meals, leading to lower acceptability and accessibility to certain populations. Liberalization of the standard CKD diet to include healthy, minimally processed foods such as fruits, vegetables, nuts, legumes, and whole grains is likely beneficial, though more research is needed to determine whether a plant-based-only diet is the optimal way to achieve healthier eating in patients with CKD.

Malnutrition and protein energy wasting are associated with severity and progression of pediatric chronic kidney disease

BACKGROUND

Protein energy wasting (PEW), a state of deficient protein storage, is not well understood in children and adolescents with chronic kidney disease (CKD). We aimed to re-define PEW using pediatric malnutrition guidelines from the Academy of Nutrition and Dietetics/American Society for Parenteral and Enteral Nutrition (AND/ASPEN), and to describe the relationship between PEW, malnutrition, and kidney function.

METHODS

This was a retrospective review of outpatients ≤ 20 years old with a diagnosis of CKD from January 1, 2013, to August 31, 2018. Malnutrition was diagnosed by a licensed dietitian, and PEW was diagnosed using an updated definition incorporating AND/ASPEN malnutrition guidelines. Logistic regression and linear mixed effects modeling were performed on the relationship of malnutrition and PEW to estimated glomerular filtration rate (eGFR).

RESULTS

The 142 patients included in this analysis had a median age of 11.1 years and median eGFR of 57 ml/min/1.73 m2 at initial visit. Malnutrition was diagnosed in 50% of patients in at least one visit, and 17.6% met ≥ 2 PEW criteria. Patients with eGFR < 30 ml/min/1.73 m2 had significantly increased risk of malnutrition [OR 2.5, 95% CI 2.0-3.3] (p < 0.001) and PEW [OR 4.9, 95% CI 3.0-8.0] (p < 0.001). A diagnosis of malnutrition or PEW was associated with worse eGFR by logistic regression (p = 0.01 and p = 0.001, respectively) and more rapid eGFR decline by linear mixed effects model (p = 0.002 and p < 0.001, respectively) compared to those without these diagnoses.

CONCLUSIONS

Malnutrition and PEW are prevalent in pediatric CKD and are associated with significantly lower eGFR and more rapid decline in eGFR, emphasizing the need to address nutritional status. A higher resolution version of the Graphical abstract is available as Supplementary information.

Chronic Kidney Disease Interplay with Comorbidities and Carbohydrate Metabolism: A Review

Chronic kidney disease (CKD) poses a global health challenge, engendering various physiological and metabolic shifts that significantly impact health and escalate the susceptibility to severe illnesses. This comprehensive review delves into the intricate complexities of CKD, scrutinizing its influence on cellular growth homeostasis, hormonal equilibrium, wasting, malnutrition, and its interconnectedness with inflammation, oxidative stress, and cardiovascular diseases. Exploring the genetic, birth-related, and comorbidity factors associated with CKD, alongside considerations of metabolic disturbances, anemia, and malnutrition, the review elucidates how CKD orchestrates cellular growth control. A pivotal focus lies on the nexus between CKD and insulin resistance, where debates persist regarding its chronological relationship with impaired kidney function. The prevalence of insulin abnormalities in CKD is emphasized, contributing to glucose intolerance and raising questions about its role as a precursor or consequence. Moreover, the review sheds light on disruptions in the growth hormone and insulin-like growth factor axis in CKD, underscoring the heightened vulnerability to illness and mortality in cases of severe growth retardation. Wasting, a prevalent concern affecting up to 75% of end-stage renal disease (ESRD) patients, is analyzed, elucidating the manifestations of cachexia and its impact on appetite, energy expenditure, and protein reserves. Taste disturbances in CKD, affecting sour, umami, and salty tastes, are explored for their implications on food palatability and nutritional status. Independent of age and gender, these taste alterations have the potential to sway dietary choices, further complicating the management of CKD. The intricate interplay between CKD, inflammation, oxidative stress, and cardiovascular diseases is unraveled, emphasizing the profound repercussions on overall health. Additionally, the review extends its analysis to CKD's broader impact on cognitive function, emotional well-being, taste perception, and endothelial dysfunction. Concluding with an emphasis on dietary interventions as crucial components in CKD management, this comprehensive review navigates the multifaceted dimensions of CKD, providing a nuanced understanding essential for developing targeted therapeutic strategies.

[New nutritional screening tool for hospitalized patients with chronic kidney disease: translation, cross-cultural adaptation of Renal iNUT into Spanish and comparison with classic questionnaires]

Introduction

Introduction: Chronic kidney disease (CKD) is characterized by its high prevalence of malnutrition, difficult to detect as it is underestimated by the usual tools. There is no valid or hospital-level nutritional screening tool in Spanish to identify patients with CKD at risk of malnutrition. Objective: to translate and accomplish the transcultural adaptation of Jackson's questionnaire (Renal Inpatient Nutrition Screening Tool [Renal iNUT]) to Spanish, which detects the risk of malnutrition in CKD inpatients and compares it with other nutritional tools. Methods: phase 1: translation, back-translation and transcultural adaptation of the questionnaire from the English to the Spanish version. A pilot test was carried out by nursing staff together with a satisfaction questionnaire. Phase 2: comparison of Renal iNUT with Malnutrition Universal Screening Tool (MUST) and Subjective Global Assessment (SGA). Results: phase 1: the nursing staff's perception was highly favorable. They found it easy or very easy to use and 90 % of them did it in a maximum of ten minutes. Phase 2: from 48 patients included, Renal iNUT detected 44 % at low risk of malnutrition, 28 % at intermediate risk and 28 % at high risk. Increased sensitivity of Renal iNUT (p < 0.007) vs MUST (62.5 vs 33.3 %) and similar specificity (87.1 vs 90.6 %) were found, together with an acceptable correlation compared to SGA (r = 0.75, 95 % CI: 0.67 to 0.83). Conclusions: the Spanish version of Renal iNUT is a useful and easy-to-understand tool for health professionals. We also confirm its good correlation with SGA, with greater sensitivity than MUST for the risk of malnutrition detection in CKD inpatients.