Optimum dietary protein requirement in nondiabetic maintenance hemodialysis patients

Sex-based variations in the nutritional and functional status of hemodialysis patients in Palestine: a cross-sectional study

INTRODUCTION

Hemodialysis affects patients' nutritional status in several ways, resulting in malnutrition, which, in turn, increases the rates of morbidity and mortality worldwide. The main aim of this study was to comprehensively examine the effect of sex-based differences on the nutritional status of Palestinian patients on hemodialysis.

METHODOLOGY

This study involved hemodialysis patients from An-Najah National University Hospital (NNUH) at Nablus/Palestine. A structured questionnaire was used in this study to collect data about sociodemographic data, medical history, lifestyle habits, and functional status, as well as nutritional status, which was assessed using 4 components (anthropometric measurements, biochemical data, clinical data, and dietary data). Patients' reports were reviewed to obtain laboratory values. The malnutrition-inflammation score was used to assess the prevalence of malnutrition. Data were analyzed using univariate and multivariate analysis.

RESULTS

A total of 188 hemodialysis patients participated in the study. The mean age was 57.8 ± 14.0 years, ranging from 19 to 86 years old. Females were more likely to experience nausea and headache during hemodialysis than men (p < 0.05). The findings also showed that the MIS score was significantly higher in women than in men. Biochemical findings revealed that female patients had significantly lower levels of blood urea nitrogen (p = 0.003), carbon dioxide (p = 0.020), ferritin levels (p = 0.025), and serum phosphate levels (p = 0.000). In addition, women had significantly lower intakes of total carbohydrate, total fat, saturated fat, monounsaturated fatty acids, water, vitamin B1, vitamin B2, vitamin B3, calcium, phosphate, sodium, and zinc, except for vitamin B12, which was higher in females. Furthermore, functional assessments indicated that males have significantly higher handgrip strength than females, while females represented more severe malnutrition compared to males.

CONCLUSION

Our data indicates that women have more severe malnutrition compared to men, suggesting the need to consider sex-based nutritional and functional differences in hemodialysis patients by healthcare professionals.

Methods and Nutritional Interventions to Improve the Nutritional Status of Dialysis Patients in JAPAN-A Narrative Review

Patients receiving dialysis therapy often have frailty, protein energy wasting, and sarcopenia. However, medical staff in Japan, except for registered dietitians, do not receive training in nutritional management at school or on the job. Moreover, registered dietitians work separately from patients and medical staff even inside a hospital, and there are many medical institutions that do not have registered dietitians. In such institutions, medical staff are required to manage patients' nutritional disorders without assistance from a specialist. Recent studies have shown that salt intake should not be restricted under conditions of low nutrition in frail subjects or those undergoing dialysis, and protein consumption should be targeted at 0.9 to 1.2 g/kg/day. The Japanese Society of Dialysis Therapy suggests that the Nutritional Risk Index-Japanese Hemodialysis (NRI-JH) is a useful tool to screen for older patients with malnutrition.

Fibroblast growth factor 21 and protein energy wasting in hemodialysis patients

INTRODUCTION

Protein energy wasting (PEW) is the most important risk factor for morbidity and mortality in hemodialysis patients. Inadequate dietary protein intake is a frequent cause of PEW. Recent studies have identified fibroblast growth factor 21 (FGF21) as an endocrine protein sensor. This study aims to investigate the potential of FGF21 as a biomarker for protein intake and PEW and to investigate intradialytic FGF21 changes.

METHODS

Plasma FGF21 was measured using an enzyme-linked immunoassay. Complete intradialytic dialysate and interdialytic urinary collections were used to calculate 24-h urea excretion and protein intake. Muscle mass was assessed using the creatinine excretion rate and fatigue was assessed using the Short Form 36 and the Checklist Individual Strength.

RESULTS

Out of 59 hemodialysis patients (65 ± 15 years, 63% male), 39 patients had a low protein intake, defined as a protein intake less than 0.9 g/kg/24-h. Patients with a low protein intake had nearly twofold higher plasma FGF21 compared to those with an adequate protein intake (FGF21 1370 [795-4034] pg/mL versus 709 [405-1077] pg/mL;P < 0.001). Higher plasma FGF21 was associated with higher odds of low protein intake (Odds Ratio: 3.18 [1.62-7.95] per doubling of FGF21; P = 0.004), independent of potential confounders. Higher plasma FGF21 was also associated with lower muscle mass (std β: -0.34 [-0.59;-0.09];P = 0.009), lower vitality (std β: -0.30 [-0.55;-0.05];P = 0.02), and more fatigue (std β: 0.32 [0.07;0.57];P = 0.01). During hemodialysis plasma FGF21 increased by 354 [71-570] pg/mL, corresponding to a 29% increase.

CONCLUSION

Higher plasma FGF21 is associated with higher odds of low protein intake in hemodialysis patients. Secondarily, plasma FGF21 is also associated with lower muscle mass, less vitality, and more fatigue. Lastly, there is an intradialytic increase in plasma FGF21. FGF21 could be a valuable marker allowing for objective assessment of PEW.

The Impact of Serum Zinc Levels on Abdominal Fat Mass in Hemodialysis Patients

BACKGROUND

Zinc deficiency is highly prevalent and is caused by inadequate dietary intake, malabsorption and removal by treatment in hemodialysis patients. This study investigated the relationship between serum zinc levels and nutritional status in hemodialysis patients.

METHODS

A cross-sectional study examining 87 hemodialysis patients was performed. The serum concentrations of zinc were studied to evaluate their association with nutritional status, which was assessed by measuring abdominal muscle and fat areas with computed tomography.

RESULTS

Serum zinc levels were significantly and positively correlated with subcutaneous and visceral fat areas (r = 0.299, p < 0.01, and r = 0.298, p < 0.01, respectively), but not abdominal muscle areas. Multiple regression analyses demonstrated that serum zinc levels were a significant independent predictor of visceral fat areas (p < 0.01), but not subcutaneous fat areas (p = 0.631).

CONCLUSIONS

Our findings suggest that serum zinc levels could play a crucial role in determining abdominal fat mass in hemodialysis patients.

Effects of keto acid supplements on Chinese patients receiving maintenance hemodialysis: a prospective, randomized, controlled, single-center clinical study

BACKGROUND

The effects of keto acid (KA) supplements on Chinese patients receiving maintenance hemodialysis (MHD) are unclear. This study aimed to evaluate the effects of KA supplementation on nutritional status, inflammatory markers, and bioelectric impedance analysis (BIA) parameters in a cohort of Chinese patients with MHD without malnutrition.

METHODS

This was a prospective, randomized, controlled, single-center clinical study conducted in 2011 till 2014. Twenty-nine patients with MHD were randomly assigned to a control (n = 14) or a KA (n = 15) group. The control group maintained a dietary protein intake of 0.9 g/kg/day. The KA group received additional KA supplement (0.1 g/kg/day). BIA was used to determine the lean tissue mass, adipose tissue mass, and body cell mass. The patients' nutritional status, dialysis adequacy, and biochemical parameters were assessed at the ends of the third and sixth months with t test or Wilcoxon rank-sum test.

RESULTS

The daily total energy intake for both groups was about 28 kcal/kg/day. After 6 months, the Kt/V (where K is the dialyzer clearance of urea, t is the dialysis time, and V is the volume of the distribution of urea) was 1.33 ± 0.25 in KA group, and 1.34 ± 0.25 in the control group. The median triceps skin-fold thickness in KA group was 12.00 and 9.00 mm in the control group. In addition, the median hand-grip strength in KA group was 21.10 and 25.65 kg in the control group. There were no significant differences between the groups with respect to the anthropometry parameters, dialysis adequacy, serum calcium and phosphorus levels, inflammatory markers, and amino-acid profiles, or in relation to the parameters determined by BIA. Both groups achieved dialysis adequacy and maintained nutritional status during the study.

CONCLUSIONS

In this cohort of Chinese patients with MHD, the patients in the control group whose dietary protein intake was 0.9 g/kg/day and total energy intake was 28 kcal/kg/day, maintained well nutritional status during study period. The KA supplement (0.1 g/kg/day) did not improve the essential amino acid/non-essential amino acid ratio, nor did it change the patients' mineral metabolism, inflammatory parameters, or body compositions.

High rates of protein intake are associated with an accelerated rate of decline of residual kidney function in incident peritoneal dialysis patients

BACKGROUND

Preservation of residual kidney function (RKF) is a relevant objective in peritoneal dialysis (PD) patients. The influence of dietary protein intake (PI) on this variable has not been adequately investigated.

METHODS

Following an observational design, we studied 336 patients incident on PD, with a minimum follow-up of 6 months. The main study variable was the mean PI [normalized rate of protein nitrogen appearance (nPNA)] during the first 4 months on PD. The main outcome variables were the absolute rate of decline of RKF and the proportion of patients presenting a >50% decay of their RKF during the first year of follow-up. We applied univariate and multivariate strategies of analysis, taking into consideration the main control variables bearing a correlation with nPNA and/or RKF.

RESULTS

Mean nPNA (first 4 months) was 1.23 ± 0.33 g/kg/day, while the overall rate of decline of RKF was -0.13 ± 0.29 mL/min/month; 69 patients (25.1%) had lost >50% of their initial RKF by the end of the first year. Univariate analysis disclosed consistent associations between the main study variable on one hand and baseline RKF (r = 0.32, P < 0.0005) and its rate of decline (r = -0.23, P < 0.0005) on the other. The latter two variables were also significantly correlated (r = -0.36, P < 0.0005). Multivariate analysis identified mean nPNA as an independent predictor of the rate of decline of RKF [odds ratio 1.09 per 0.10 g/kg/day, 95% confidence interval (CI) 0.99-1.19, P = 0.058] and, in particular, of the probability of losing >50% of the baseline RKF during the first year of treatment (odds ratio 1.15 per 0.10 g/kg/day, 95% CI 1.04-1.27, P = 0.006).

CONCLUSION

Higher rates of PI during the first months of therapy are associated with a faster decline of RKF among patients incident on PD. Our results underline the convenience of keeping an adequate balance between sufficient protein ingestion, to prevent malnutrition and wasting, and sensible restriction in stable, adequately nourished individuals with rates of intake in the higher range or above-recommended allowances.

Impact of nutritional index on the association between phosphorus concentrations and mortality in haemodialysis patients: a cohort study from dialysis outcomes and practice pattern study in Japan

OBJECTIVES

While maintenance of both phosphorus concentration and nutritional status is a major concern in managing haemodialysis patients, the interaction between these parameters is not well understood. The aim of this study was to assess whether or not nutritional index influences the association between phosphorus concentration and all-cause mortality.

DESIGN

A cohort study.

SETTING

The Dialysis Outcomes and Practice Pattern Study, which included 99 representative dialysis facilities in Japan between 1997 and 2010.

PARTICIPANTS

A total of 6230 adult haemodialysis patients who had spent at least 6 months on haemodialysis.

MAIN PREDICTORS

Six categories based on time-averaged factors of the geriatric nutritional risk index (GNRI; the lowest two and highest tertiles) and phosphorus concentration (<3.5, 3.5 to <6 and ≥6 mg/dL).

PRIMARY OUTCOME MEASURE

All-cause mortality rate.

ANALYSIS

Time-dependent Cox regression adjusting for potential confounders.

RESULTS

During the follow-up period (12 294 person-years), we noted 561 deaths (4.6 per 100 person-years), and both high phosphorus concentrations and low-middle GNRI were separately associated with all-cause mortality. The harmful effect of high phosphorus concentrations on all-cause mortality was stronger in patients with high GNRI than in those with low-middle GNRI. On the other hand, the harmful effect of low phosphorus concentrations was stronger in those with low-middle GNRI than in those with high GNRI. Relative excess risk due to interaction (RERI) between high phosphorus concentrations and low-middle GNRI was -0.57, indicating an antagonistic interaction. We also observed a significant statistical multiplicative interaction between phosphorus concentrations and GNRI (p=0.05 by likelihood ratio test).

CONCLUSIONS

The association between time-averaged serum phosphorus concentration and all-cause mortality differs across the nutritional index. Accordingly, nutritional index should be considered when the impact of phosphorus concentration on mortality in haemodialysis patients is evaluated.

Lower thigh muscle mass is associated with all-cause and cardiovascular mortality in elderly hemodialysis patients

BACKGROUND/OBJECTIVES

Higher body mass index appears protective in hemodialysis patients, although it remains to be determined which component of muscle or fat mass is primarily associated with this survival advantage.

SUBJECTS/METHODS

Eighty-one hemodialysis patients in our institution were prospectively followed from July 2011 to August 2015. Muscle and fat mass were evaluated by measuring the cross-sectional areas of the thigh and abdomen using computed tomography. The relationship between muscle and fat mass, and all-cause and cardiovascular mortality was studied using the Kaplan-Meier analyses and multivariate Cox proportional hazard models.

RESULTS

During more than 4 years of follow-up, 26 patients (32%) died. In the Kaplan-Meier curve analyses, lower thigh muscle mass was significantly associated with all-cause and cardiovascular mortality (log-rank test, P<0.01 and P<0.001, respectively), but there was no such association with thigh fat, abdominal muscle and fat mass levels. In multivariate Cox proportional hazard models, each 0.1 cm²/kg increase in the thigh muscle area adjusted by dry weight was associated with an estimated 22% lower risk of all-cause mortality (95% confidence interval (95% CI), 0.64-0.95, P<0.05) and a 30% lower risk of cardiovascular mortality (95% CI, 0.54-0.90, P<0.01).

CONCLUSIONS

Lower thigh muscle mass is significantly associated with all-cause and cardiovascular mortality in hemodialysis patients. Our findings indicate the importance of focusing on the muscle mass of lower extremities to predict the clinical outcomes of hemodialysis patients.

Clinical research in a modern Chinese peritoneal dialysis center

A prerequisite for enhancing the quality of peritoneal dialysis is the continuous review and analysis of clinical data from routine clinical care and research. Here, we describe our strategy (Peking University First Hospital, Beijing, China) to achieve that objective.

Daily protein intake and survival in patients on peritoneal dialysis

BACKGROUND

The decreased protein intake may lead to protein-energy wasting and poor survival. It is unknown what the appropriate protein intake in patients on peritoneal dialysis (PD) is. We aimed to explore the appropriate levels of daily protein intake (DPI) in favor of outcome in a large PD cohort.

METHODS

Our study enrolled 305 incident patients, who could be followed regularly. Demographic data were collected at baseline. Biochemical, dietary and nutritional data and dialysis adequacy were measured at the baseline and thereafter at regular intervals. Outcome events included all-cause death, cardiovascular disease (CVD) death and first-episode peritonitis.

RESULTS

A total of 127 patients died during the 44.5-month follow-up, 41.7% of whom died from CVD. A total of 129 cases first-episode peritonitis were observed. Patients with a high tertile of baseline DPI (≥ 0.94 g/kg/day) had significantly higher serum albumin, prealbumin, hemoglobin, lean body mass and handgrip strength compared to the low tertile group (≤ 0.73 g/kg/day) (P < 0.05-0.001). They also had significantly lower risk for all-cause, CVD death and first-episode peritonitis than the low tertile group adjusted for commonly recognized confounders. Although patients in the middle tertile of DPI (0.74-0.93 g/kg/day) did not show significant differences in the majority of nutritional markers, all-cause and CVD mortality compared to high tertile group, they had a trend to a negative nitrogen balance and similar risk for first-episode peritonitis to the low tertile group. The DPI included as a time-dependent variable could not predict any outcome events in multivariate Cox models.

CONCLUSIONS

Our study revealed that DPI <0.73 g/kg/day was associated with protein-energy wasting and worst outcome for PD patients. The DPI >0.94 g/kg/day was in favor of nutrition status and long-term outcome in this population.

Improved nutrition after conversion to nocturnal home hemodialysis

BACKGROUND

Protein-energy malnutrition is a frequently observed problem in hemodialysis patients. Nocturnal home hemodialysis (NHHD; 6 x 8hours during the night) seems to improve patient outcomes, including nutritional state.

METHODS

In a single-center, prospective, nonrandomized study, the effects of NHHD on various aspects of nutrition in 14 hemodialysis patients during 1 to 2 years were investigated, using dietary records, appetite questionnaires, laboratory tests, and patient data.

RESULTS

Appetite, body weight, and energy and protein intakes improved. Patients could drink more. Serum phosphate, calcium, and potassium intake increased. Laboratory results remained excellent, without phosphate-binding agents or potassium-binding resins. However, fat intake also increased, with a risk for overweight status.

CONCLUSIONS

Nocturnal home hemodialysis has a positive effect on nutritional state.

An update on nutrition in chronic kidney disease

The prevalence of malnutrition in the course of chronic kidney disease has not changed recently and is still between 30 and 50%. About 10% of patients on maintenance dialysis show signs of severe malnutrition. Recent progress has been made on protein metabolism, the validation of new diagnostic tools, and the use of anabolic compounds. Large clinical trials have characterized the use of medications for renutrition, and international guidelines are currently updated. Neverthless, physicians will be mostly efficient at the stage of malnutrition prevention, by implementing an early, interactive dietary and nutritional care programs in close collaboration with specialized dietitians.

Normalization of protein intake by body weight and the associations of protein intake with nutritional status and survival

OBJECTIVE

To examine the associations of total protein intake (TPI) and dietary protein intake (DPI) with baseline nutrition and subsequent mortality.

DESIGN

Retrospective analysis of incident dialysis patients.

SETTING

National cohort from The United States Renal Data System data.

PATIENTS

Incident dialysis patients (n = 5,059) with blood urea nitrogen (BUN) and urea clearances reported on form 2728.

METHODS

TPI was calculated from BUN and urea clearance. DPI was defined as TPI divided by weight. Urinary creatinine (UCr) calculated from creatinine clearance and serum creatinine was used as a marker of muscle mass. The associations of TPI and DPI with each of serum albumin < or = 3.3 g/dL (50th percentile), UCr < or = 0.56 g/d (25th percentile), body mass index < 18.5, and death were examined.

RESULTS

Compared with patients in the highest quartile of TPI (> 60.2 g/d), those in the lowest quartile (< or = 32.4 g/d) had 1.89-fold higher odds (P < .001) of low serum albumin, 10.22-fold higher odds (P < .001) of low UCr, and 3.83-fold higher odds (P < .001) of low body mass index in multivariable logistic regression models, and an 18% increase (P < .001) in hazard of death. Compared with patients with DPI > 1.2 g/kg/d, those with DPI < 0.8 g/kg/d had nonsignificantly higher odds of low serum albumin, 2.38-fold higher odds (P < .001) of low UCr, and 0.44-fold lower odds (P < .001) of low body mass index, and a 15% (P = .04) decrease in hazard of death.

CONCLUSIONS

Higher TPI is associated with better nutrition at baseline and subsequent survival. Normalization of TPI by body weight provides contradictory information on nutritional status as well as survival.