Journal of Renal Nutrition最新文献

Because of increased risks of cardiovascular disease and death, patients with hyperphosphatemia receiving maintenance dialysis are advised to limit phosphorus consumption and are prescribed phosphate binders in an effort to better control serum phosphate concentrations. Because of large pill size, pill burden, and tolerability issues, phosphate binder adherence is relatively poor. On ingestion, phosphate is absorbed from the intestine via transcellular or paracellular transport. Data show that inhibiting sodium-hydrogen exchanger 3 modulates paracellular phosphate absorption (the predominant pathway in humans). Tenapanor is a first-in-class, minimally absorbed, phosphate absorption inhibitor that selectively inhibits sodium-hydrogen exchanger 3, with a mechanism distinct from, and complementary to, that of phosphate binders. In phase 3 and postregistrational studies, tenapanor conferred statistically significant and clinically meaningful reductions in serum phosphate in patients receiving maintenance dialysis with hyperphosphatemia. Here, we review the available preclinical and clinical data on the effects of tenapanor on controlling intestinal phosphate absorption.

Objectives: The association between high-density lipoprotein (HDL) cholesterol levels and mortality in elderly patients undergoing hemodialysis is not well established. Thus, this study investigated HDL levels and mortality in elderly Korean patients undergoing hemodialysis.

Methods: We recruited 1860 incident hemodialysis patients aged greater than 70 years from a retrospective cohort of the Korean Society of Geriatric Nephrology. The primary outcome measure was all-cause mortality.

Results: The mean age of the cohort was 77.8 years, and 1049 (56.4%) were men. When we grouped the patients into HDL cholesterol tertiles, the T1 group (HDL level <30 mg/dL in men and <33 mg/dL in women) had a higher proportion of patients with end-stage kidney disease due to diabetic nephropathy. During the median follow-up period of 3.1 years, 1109 (59.7%) deaths occurred. In a multivariable Cox regression model, the T1 group had a significantly higher risk of mortality (hazard ratio [HR], 1.28; 95% confidence interval, 1.10-1.50; P = .002) compared to the T3 group. A nonlinear analysis using a restrictive spline curve showed that low HDL cholesterol levels were associated with increased HR when HDL cholesterol levels were <40 mg/dL; however, there was no association between HDL cholesterol and mortality when HDL cholesterol levels were >40 mg/dL. Triglyceride/HDL ratio was not significantly associated with the risk of mortality (HR per 1 log increase, 1.08; 95% confidence interval, 0.99-1.18; P = .069).

Conclusions: Low HDL cholesterol levels are associated with an increased risk of mortality in elderly patients undergoing hemodialysis. However, there was no significant relationship between HDL cholesterol levels and mortality when levels were below 40 mg/dL. Therefore, low HDL cholesterol levels may be a useful risk factor for predicting mortality in elderly patients undergoing hemodialysis.

Objective: Dietary sodium restriction is important in the prognosis of patients with chronic kidney disease (CKD). The association between saltiness perception and sodium intake among CKD patients is unclear, and the factors that influence saltiness are also not fully understood. We evaluated saltiness perception in CKD patients employing a cost-effective saltiness perception test using sodium solutions and evaluated the association between saltiness perception, sodium intake, and the influencing factors.

Design and methods: CKD outpatients not undergoing dialysis were enrolled from two medical centers and underwent saltiness perception tests together with 24-hour urine collections to measure daily sodium intake. Participants who perceived saltiness using the test solution containing 25 mM sodium were regarded to have "preserved" saltiness perception, while those unable to perceive saltiness were regarded as having "impaired" saltiness perception.

Results: Of the total 132 participants, the median daily sodium intake was 3.36 g (range; 0.51-9.95 g/day), and 43 (32.6%) were ex- or current smokers. When participants were divided into 3 groups (G) according to daily sodium intake level: low (G1; 0.51-2.61 g/day), middle (G2; 2.62-3.99 g/day), and high (G3; 4.06-9.95 g/day), there was an obvious difference in impaired saltiness perception between three groups: 6.8% in G1, 50.0% in G2 and 86.4% in G3 (P value = 8.035 × 10^-14, Cochran-Armitage test). In a multiple regression analysis in which the saltiness perception was adopted as a subjective variable, smoking habit (ex- or current smoker) and nonadherence to dietary sodium restriction were identified as significant explanatory variables.

Conclusion: We revealed the clear relationship between higher daily sodium intake and impaired saltiness perception that is related to nonadherence to dietary sodium restriction and smoking habit, both of which could be intervened by nutritional counseling and public health education.

Objectives: Chronic kidney disease (CKD) significantly contributes to the socio-economic burden both in China and worldwide. Previous research has shown that experiencing childhood famine is linked to various chronic conditions like diabetes, hypertension, and proteinuria. However, the long-term effects of early-life famine exposure on adult kidney function remain unclear. This study investigates whether exposure to the Chinese Great Famine (1959-1962) is associated with a decline in glomerular filtration rate (GFR) later in life.

Design and methods: China Health and Retirement Longitudinal Study is a population-based observational study. We analyzed data from 8,828 participants in the 2011-2012 baseline survey, updated in 2014. Participants were categorized based on their birth year into fetal-exposed (1959-1962), childhood-exposed (1949-1958), adolescence/adult-exposed (1912-1948), and nonexposed (1963-1989) groups. The estimated GFR (eGFR) was calculated using the CKD-EPI-Cr-Cys equation (2021), with CKD defined as an eGFR below 60 mL/min/1.73 m².

Results: Average eGFR values were 103.0, 96.8, 91.2, and 76.3 mL/min/1.73 m² for the fetal-exposed, childhood-exposed, adolescence/adult-exposed, and nonexposed groups, respectively. The eGFR in the exposed groups was significantly lower compared to the nonexposed group. Specifically, famine exposure correlated with a lower eGFR (coefficient estimates [CE] -9.14, 95% confidence interval [CI] -9.46, -8.82), with the strongest association observed in the adolescence/adult-exposed group (CE -26.74, 95% CI -27.75, -25.74). Adjusting for variables such as demographics, physical and laboratory tests, complications, and personal habits like smoking and drinking did not qualitatively alter this association (CE -1.38, 95% CI -1.72, -1.04). Further stratification by sex, body mass index, alcohol consumption history, hypertension, diabetes, Center for Epidemiologic Studies Depression score, and education level showed that the association remained consistent.

Conclusions: Exposure to famine during different life stages can have enduring effects on GFR decline in humans.

Objective: Malnutrition is highly prevalent in patients with kidney failure. Since body weight does not reflect body composition, other methods are needed to determine muscle mass, often estimated by fat-free mass (FFM). Bioimpedance spectroscopy (BIS) is frequently used for monitoring body composition in patients with kidney failure. Unfortunately, BIS-derived lean tissue mass (LTM_BIS) is not suitable for comparison with FFM cutoff values for the diagnosis of malnutrition, or for calculating dietary protein requirements. Hypothetically, FFM could be derived from BIS (FFM_BIS). This study aims to compare FFM_BIS and LTM_BIS with computed tomography (CT) derived FFM (FFM_CT). Secondarily, we aimed to explore the impact of different methods on calculated protein requirements.

Methods: CT scans of 60 patients with kidney failure stages 4-5 were analyzed at the L3 level for muscle cross-sectional area, which was converted to FFM_CT. Spearman rank correlation coefficient and 95% limits of agreement were calculated to compare FFM_BIS and LTM_BIS with FFM_CT. Protein requirements were determined based on FFM_CT, FFM_BIS, and adjusted body weight. Deviations over 10% were considered clinically relevant.

Results: FFM_CT correlated most strongly with FFM_BIS (r = 0.78, P < .001), in males (r = 0.72, P < .001) and in females (r = 0.60, P < .001). A mean difference of -0.54 kg was found between FFM_BIS and FFM_CT (limits of agreement: -14.88 to 13.7 kg, P = .544). Between LTM_BIS and FFM_CT a mean difference of -12.2 kg was apparent (limits of agreement: -28.7 to 4.2 kg, P < .001). Using FFM_CT as a reference, FFM_BIS best predicted protein requirements. The mean difference between protein requirements according to FFM_BIS and FFM_CT was -0.7 ± 9.9 g in males and -0.9 ± 10.9 g in females.

Conclusion: FFM_BIS correlates well with FFM_CT at a group level, but shows large variation within individuals. As expected, large clinically relevant differences were observed in calculated protein requirements.

Objective: An increase in proximal tubule fluid phosphate concentration is caused by increased serum fibroblast growth factor-23 (FGF23) levels, which resulted in renal tubular damage in a mouse model of chronic kidney disease (CKD). However, few human studies have supported this concept. This study aimed to explore the association among estimated proximal tubule fluid phosphate concentration (ePTFp), serum FGF23 levels, and renal tubular damage biomarkers in middle-aged and older populations with mild decline in renal function.

Methods: This cross-sectional study included 218 participants aged ≥45 with CKD stages G2-G4. Anthropometric measurements, blood tests, spot urine biomarkers, renal ultrasonography, cardiovascular assessment, smoking status, and medication usage were obtained in the morning in fasted states. The ePTFp was calculated using serum creatinine, urine phosphate, and creatinine concentrations. Urinary β2-microglobulin (β2-MG) and liver-type fatty acid-binding protein (L-FABP) levels were evaluated to assess renal tubular damage.

Results: PTFp, serum FGF23, urinary β2-MG, and urinary L-FABP levels increased with CKD stage progression (stages G2, G3, and G4). However, serum and urine phosphate concentrations were comparable across the CKD stages. Univariate analysis revealed a stronger correlation of ePTFp with serum FGF23, urinary β2-MG, and urinary L-FABP levels than with the corresponding serum and urine phosphate concentrations. Multivariate analyses demonstrated that increased ePTFp was independently associated with elevated serum FGF23 and urinary β2-MG levels, even after adjusting for potential covariates, including the estimated glomerular filtration rate and urinary albumin-to-creatinine ratio.

Conclusions: Our results are consistent with the concept in mouse model and suggest that increased ePTFp are associated with increased serum FGF23 levels and renal tubular damage during the early stages of CKD.

Objective: Potassium-based sodium substitutes (PBSS) can be used to replace sodium during food processing. How potassium and sodium content is associated with PBSS is not known. The objectives of the study were to describe the prevalence of PBSS by sodium content claim category and describe how PBSS are associated with sodium and potassium concentrations by sodium level.

Design and methods: This cross-sectional analysis used the July 2018 version of the United States Department of Agriculture's Branded Food Products Database. Products were divided into sodium content claim category and were analyzed for the presence of PBSS. Products with nonmissing values for sodium and potassium were grouped by sodium level and analyzed for the prevalence of PBSS to explore potassium and sodium concentration. Column proportion z-test with the Bonferroni correction was used to explore the occurrence of PBSS by sodium content claim category. Mann-Whitney U-test was used to assess differences in potassium and sodium concentrations across sodium levels and within levels by the presence/absence of PBSS.

Results: The prevalence of PBSS in the categories "without a sodium content claim" (2.4%), "lightly salted" (0.5%), and "unsalted" claims (0.6%) were statistically significantly lower than prevalence of PBSS in the "sodium free" (9.5%), "low sodium" (10.3%), and "reduced sodium" claim categories (23.3%; all P < .01). Among the group of products with serving sizes more than 30 g containing PBSS, there was a 357 mg per serving higher median sodium concentration and a 160 mg per serving higher median potassium concentration compared to the group without PBSS (both P < .01).

Conclusion: In the "reduced sodium" claim category, a higher prevalence of PBSS was found compared to other sodium claim categories. The presence of PBSS was associated with higher potassium and sodium concentrations in foods.

Nowadays, numerous studies have developed risk prediction models for sarcopenia in dialysis patients. However, the quality and performance of these models have not been integrated. The purpose of our study is to provide a comprehensive overview of the current risk prediction models for sarcopenia in dialysis patients and to offer a reference for the development of high-quality prediction models. Ten electronic databases were searched from inception to March 8, 2024. Two researchers independently assessed the risk of bias and applicability of the studies, and used Revman, 5.4, software to conduct a meta-analysis of common predictors in the models. A total of 12 studies described 13 risk prediction models for dialysis patients with sarcopenia. In dialysis patients, the prevalence of sarcopenia ranged from 6.60% to 63.73%. The area under curve (AUC) of the 13 models ranged from 0.776 to 0.945. Only six models (AUC ranging from 0.73 to 0.832) were internally validated, while two were externally evaluated (AUC ranging from 0.913 to 0.955). Most studies had a high risk of bias. The most common effective predictors in the models were age, body mass index, muscle circumference, and C-reactive protein. Our study suggests that developing a prediction model for the onset of sarcopenia in dialysis patients requires a rigorous design scheme, and future verification methods will necessitate multicenter external validation.

The benefits of dietary fiber are widely accepted. Nevertheless, a substantial proportion of children fail to meet the recommended intake of dietary fiber. Achieving adequate fiber intake is especially challenging in children with chronic kidney disease (CKD). An international team of pediatric renal dietitians and pediatric nephrologists from the Pediatric Renal Nutrition Taskforce (PRNT) has developed clinical practice recommendations (CPRs) for the dietary intake of fiber in children and adolescents with CKD. In this CPR paper, we propose a definition of fiber, provide advice on the requirements and assessment of fiber intake, and offer practical guidance on optimizing dietary fiber intake in children with CKD. In addition, given the paucity of available evidence and to achieve consensus from international experts, a Delphi survey was performed in which all the clinical practice recommendations were reviewed.