Rise in serum albumin and creatinine in the first half year on hemodialysis

Real-World Performance of High-Flux Dialyzers in Patients With Hypoalbuminemia

There is little research on factors that influence the choice of dialyzer in patients undergoing hemodialysis. In patients at risk for poorer outcomes, including those with hypoalbuminemia, understanding how this choice impacts clinical parameters could inform patient management. The objective of this real-world analysis was to evaluate the use and performance of four single-use (i.e., nonreuse [NR]), high-flux Optiflux dialyzers with varying surface areas (F160NR [1.5 m2], F180NR [1.7 m2], F200NR [1.9 m2], and F250NR [2.5 m2]) in patients (N = 271) with baseline hypoalbuminemia (≤3.5 g/dl) receiving hemodialysis at a medium-sized dialysis organization. Thrice weekly, in-center dialysis was delivered for 6 months without adjustments to the hemodialysis prescription. Larger dialyzers were more frequently used in men, patients with higher body mass indices, and those with diabetes. Increases in serum albumin from baseline (month 1) to month 6 (p < 0.05) were observed with all dialyzer sizes. A mean increase in hemoglobin of 0.31 g/dl was also observed (p < 0.001). Among patients exhibiting increased serum albumin levels (n = 177), reductions in the neutrophil-to-lymphocyte ratio, a marker of inflammation, were observed (mean: 0.90; p < 0.001). These results support the use of high-flux dialyzers in patients with hypoalbuminemia.

An effective model for predicting serum albumin level in hemodialysis patients

Patients on hemodialysis (HD) are known to be at an increased risk of mortality. Hypoalbuminemia is one of the most important risk factors of death in HD patients, and is an independent risk factor for all-cause mortality that is associated with cardiac death, infection, and Protein-Energy Wasting (PEW). It is a clinical challenge to elevate serum albumin level. In addition, predicting trends in serum albumin level is effective for personalized treatment of hypoalbuminemia. In this study, we analyzed a total of 3069 records collected from 314 HD patients using a machine learning method that is based on an improved binary mutant quantum grey wolf optimizer (MQGWO) combined with Fuzzy K-Nearest Neighbor (FKNN). The performance of the proposed MQGWO method was evaluated using a series of experiments including global optimization experiments, feature selection experiments on open data sets, and prediction experiments on an HD dataset. The experimental results showed that the most critical relevant indicators such as age, presence or absence of diabetes, dialysis vintage, and baseline albumin can be identified by feature selection. Remarkably, the accuracy and the specificity of the method were 98.39% and 96.77%, respectively, demonstrating that this model has great potential to be used for detecting serum albumin level trends in HD patients.

Impact of serum albumin level and variability on short-term cardiovascular-related and all-cause mortality in patients on maintenance hemodialysis

Studies have shown that low serum albumin (Salb) levels are associated with a high risk of mortality among patients on maintenance hemodialysis (MHD); however, the impact of Salb variability on short-term cardiovascular mortality remains unclear. Herein, we investigated the association between Salb levels and Salb variability on short-term all-cause and cardiovascular-related mortality in patients on MHD.Eligible patients on MHD at Chongqing General Hospital between June 2017 and June 2020 were recruited in this study. Patients were grouped by Salb levels (normal Salb, ≥3.8 g/dL; low Salb, 3.4-3.8 g/dL; and lower Salb, 2-3.4 g/dL) and Salb variability (decreased, >5% loss; increased, >5% gain; and steady, 5% loss to 5% gain). Associations between Salb levels, Salb variability, and all-cause and cardiovascular-related mortality were analyzed using Cox regression models. A survival analysis was performed using the Kaplan-Meier analysis.We enrolled a total of 181 patients on MHD with an average age of 65 years (interquartile range [IQR], 53-75 years). The mean Salb level was 3.8 ± 0.6 g/dL (IQR 2.9-4.4 g/dL), and the median Salb variability was 2.6% per year (IQR, -4.1 to 6.5). Fifty-two (29%) patients died, including 31 (17%) patients who died due to cardiovascular-related causes. Compared with the other groups, the lower Salb group had higher all-cause mortality (P < .01). Cox regression analyses revealed that lower Salb levels and decreased Salb variability were independently associated with all-cause mortality (hazard ratio [HR] = 1.95, 95% confidence interval [CI] 1.103-3.452; HR = 2.245, 95% CI 1.084-4.650), whereas increased Salb variability was independently associated with cardiovascular-related mortality (HR = 2.919, 95% CI 1.178-7.234; P < .05).Lower Salb levels were an independent predictor of all-cause mortality in patients on MHD. Increased Salb variability was strongly associated with cardiovascular-related mortality in the same population, especially in the short-term and in patients with normal Salb levels. Significantly elevated Salb variability should be evaluated to reduce cardiovascular-related mortality.

Significance of Adipose Tissue Maintenance in Patients Undergoing Hemodialysis

In the general population, obesity is known to be associated with adverse outcomes, including mortality. In contrast, high body mass index (BMI) may provide a survival advantage for hemodialysis patients, which is known as the obesity paradox. Although BMI is the most commonly used measure for the assessment of obesity, it does not distinguish between fat and lean mass. Fat mass is considered to serve as an energy reserve against a catabolic condition, while the capacity to survive starvation is also thought to be dependent on its amount. Thus, fat mass is used as a nutritional marker. For example, improvement of nutritional status by nutritional intervention or initiation of hemodialysis is associated with an increase in fat mass. Several studies have shown that higher levels of fat mass were associated with better survival in hemodialysis patients. Based on body distribution, fat mass is classified into subcutaneous and visceral fat. Visceral fat is metabolically more active and associated with metabolic abnormalities and inflammation, and it is thus considered to be a risk factor for cardiovascular disease and mortality. On the other hand, subcutaneous fat has not been consistently linked to adverse phenomena and may reflect nutritional status as a type of energy storage. Visceral and subcutaneous adipose tissues have different metabolic and inflammatory characteristics and may have opposing influences on various outcomes, including mortality. Results showing an association between increased subcutaneous fat and better survival, along with other conditions, such as cancer or cirrhosis, in hemodialysis patients have been reported. This evidence suggests that fat mass distribution (i.e., visceral fat and subcutaneous fat) plays a more important role for these beneficial effects in hemodialysis patients.

Body Composition Changes Following Dialysis Initiation and Cardiovascular and Mortality Outcomes in CRIC (Chronic Renal Insufficiency Cohort): A Bioimpedance Analysis Substudy

Rationale & Objective

Bioelectrical impedance analysis (BIA) provides a noninvasive assessment of body composition. BIA measures of nutritional (phase angle) and hydration (vector length) status are associated with survival among individuals with chronic kidney disease (CKD), including those receiving maintenance dialysis. However, little is known regarding changes in these parameters with CKD following the high-risk transition to maintenance dialysis.

Study Design

Observational study.

Settings & Participants

427 adults enrolled in the Chronic Renal Insufficiency Cohort (CRIC) Study, with BIA measurements performed within 1 year before and after initiation of maintenance dialysis.

Exposures

We calculated the changes in vector length and phase angle for patients with CKD transitioning to maintenance dialysis.

Outcomes

We examined the association of changes in vector length and phase angle during the transition to maintenance dialysis with risk for all-cause mortality or nonfatal myocardial infarction, stroke, or heart failure, adjusting for demographics, comorbid conditions, and nutritional parameters.

Results

Mean age was 58 ± 12 years and mean estimated glomerular filtration rate using the CKD Epidemiology Collaboration equation before dialysis initiation was 17.0 ± 8.7 mL/min/1.73 m². After covariate adjustment, mean changes in vector length and phase angle were 18 (95% CI, 7 to 30) Ω/m and -0.6  (95% CI, -1.3  to 0.1 ), respectively. Changes in both BIA parameters were not associated with risk for heart failure, stroke, myocardial infarction, or all-cause mortality: HR, 1.02 (95% CI, 0.91-1.14) per 1-SD increment in change for vector length and HR, 1.11 (95% CI, 0.88-1.41) per 1-SD increment in change for phase angle.

Limitations

Observational study, relatively small sample size.

Conclusions

In a multicenter cohort of patients with CKD who progressed to kidney failure, the transition to maintenance dialysis was associated with changes in body composition reflecting poorer cellular integrity and improved volume control. However, these longitudinal changes were not associated with adverse clinical events after dialysis initiation.

Comparison of accuracy between pre-hemodialysis and post-hemodialysis levels of nutritional factors for prediction of mortality in hemodialysis patients

BACKGROUND

The nutritional status of hemodialysis (HD) patients is usually assessed using pre-HD laboratory data. However, it remains unclear whether the most diluted laboratory value is appropriate for assessment. We compared the pre-HD and post-HD laboratory data for their accuracy in predicting mortality.

METHODS

Maintenance HD patients (n = 96 700; men, 61.5%) were enrolled. The outcome events were one-year and five-year mortalities. Their laboratory data included body mass index (BMI), and serum albumin, creatinine, and blood urea nitrogen (BUN) levels. Bootstrap resampling was used to compare the accuracy in predicting the mortalities between pre-HD and post-HD levels using area under receiver operating characteristic curves (AUCs) adjusted for baseline characteristics.

RESULTS

The mean age ± standard deviation was 65.7 ± 12.2 years, and the vintage was 8.3 ± 6.7 years. The numbers of patients who died were 6442 (6.7%) in one year and 30 965 (32.0%) in five years. The adjusted AUCs for predicting the one-year and five-year mortalities showed that the pre-HD albumin and creatinine levels and the pre-HD BMI and BUN levels were more accurate than the post-HD levels (each p < 0.0001). The pre-HD albumin and creatinine levels showed the highest adjusted AUC for predicting one-year mortality [0.613 (95% CI 0.598, 0.629)] and five-year mortality [0.591 (95% CI 0.586, 0.595)], respectively.

CONCLUSIONS

Pre-HD albumin and creatinine levels are more accurate than post-HD levels and other nutritional indices in predicting one-year and five-year mortalities in HD patients.

Aging and death-associated changes in serum albumin variability over the course of chronic hemodialysis treatment

Background

Several epidemiological studies have demonstrated associations between variability in a number of biological parameters and adverse outcomes. As the variability may reflect impaired homeostatic regulation, we assessed albumin variability over time in chronic hemodialysis (HD) patients.

Methods

Data from 1346 subjects who received chronic HD treatment from May 2001 to February 2015 were analyzed according to three phases of HD treatment: post-HD initiation, during maintenance HD treatment, and before death. The serum albumin values were grouped according to the time interval from HD initiation or death, and the yearly trends for both the albumin levels and the intra-individual albumin variability (quantified by the residual coefficient of variation: Alb-rCV) were examined. The HD initiation and death-associated changes were also analyzed using generalized additive mixed models. Furthermore, the long-term trend throughout the maintenance treatment period was evaluated separately using linear regression models.

Results

Albumin levels and variability showed distinctive changes during each of the 3 periods. After HD initiation, albumin variability decreased and reached a nadir within a year. During the subsequent maintenance treatment period (interquartile range = 5.2–11.0 years), the log Alb-rCV showed a significant upward trend (mean slope: 0.011 ± 0.035 /year), and its overall mean was -1.49 ± 0.08 (equivalent to an Alb-rCV of 3.22%). During the 1–2 years before death, this upward trend clearly accelerated, and the mean log Alb-rCV in the last year of life was -1.36 ± 0.17. The albumin levels and variability were negatively correlated with each other and exhibited exactly opposite movements throughout the course of chronic HD treatment. Different from the albumin levels, albumin variability was not dependent on chronological age but was independently associated with an individual’s aging and death process.

Conclusion

The observed upward trend in albumin variability seems to be consistent with a presumed aging-related decline in homeostatic capacity.

Changes in urine volume and serum albumin in incident hemodialysis patients

INTRODUCTION

Hypoalbuminemia is a predictor of poor outcomes in dialysis patients. Among hemodialysis patients, there has not been prior study of whether residual kidney function or decline over time impacts serum albumin levels. We hypothesized that a decline in residual kidney function is associated with an increase in serum albumin levels among incident hemodialysis patients.

METHODS

In a large national cohort of 38,504 patients who initiated hemodialysis during 1/2007-12/2011, we examined the association of residual kidney function, ascertained by urine volume and renal urea clearance, with changes in serum albumin over five years across strata of baseline residual kidney function, race, and diabetes using case-mix adjusted linear mixed effects models.

FINDINGS

Serum albumin levels increased over time. At baseline, patients with greater urine volume had higher serum albumin levels: 3.44 ± 0.48, 3.50 ± 0.46, 3.57 ± 0.44, 3.59 ± 0.45, and 3.65 ± 0.46 g/dL for urine volume groups of <300, 300-<600, 600-<900, 900-<1,200, and ≥1,200 mL/day, respectively (P_trend  < 0.001). Over time, urine volume and renal urea clearance declined and serum albumin levels rose, while the baseline differences in serum albumin persisted across groups of urinary volume. In addition, the rate of decline in residual kidney function was not associated with the rate of change in albumin.

DISCUSSION

Hypoalbuminemia in hemodialysis patients is associated with lower residual kidney function. Among incident hemodialysis patients, there is a gradual rise in serum albumin that is independent of the rate of decline in residual kidney function, suggesting that preservation of residual kidney function does not have a deleterious impact on serum albumin levels.

Assessment of Nutritional Status of Nepalese Hemodialysis Patients by Anthropometric Examinations and Modified Quantitative Subjective Global Assessment

OBJECTIVE

To assess the nutritional status of patients on maintenance hemodialysis by using modified quantitative subjective global assessment (MQSGA) and anthropometric measurements.

METHOD

We Conducted a cross sectional descriptive analytical study to assess the nutritional status of fifty four patients with chronic kidney disease undergoing maintenance hemodialysis by using MQSGA and different anthropometric and laboratory measurements like body mass index (BMI), mid-arm circumference (MAC), mid-arm muscle circumference (MAMC), triceps skin fold (TSF) and biceps skin fold (BSF), serum albumin, C-reactive protein (CRP) and lipid profile in a government tertiary hospital at Kathmandu, Nepal.

RESULTS

Based on MQSGA criteria, 66.7% of the patients suffered from mild to moderate malnutrition and 33.3% were well nourished. None of the patients were severely malnourished. CRP was positive in 56.3% patients. Serum albumin, MAC and BMI were (mean + SD) 4.0 + 0.3 mg/dl, 22 + 2.6 cm and 19.6 ± 3.2 kg/m² respectively. MQSGA showed negative correlation with MAC (r = −0.563; P = <0.001), BMI (r = −0.448; P = <0.001), MAMC (r = −0.506; P = <.0001), TSF (r = −0.483; P = <.0002), and BSF (r = −0.508; P = <0.0001). Negative correlation of MQSGA was also found with total cholesterol, triglyceride, LDL cholesterol and HDL cholesterol without any statistical significance.

CONCLUSION

Mild to moderate malnutrition was found to be present in two thirds of the patients undergoing hemodialysis. Anthropometric measurements like BMI, MAC, MAMC, BSF and TSF were negatively correlated with MQSGA. Anthropometric and laboratory assessment tools could be used for nutritional assessment as they are relatively easier, cheaper and practical markers of nutritional status.

Longitudinal measures of serum albumin and prealbumin concentrations in incident dialysis patients: the comprehensive dialysis study

OBJECTIVE

Serum albumin and prealbumin concentrations are strongly associated with the risk of death in dialysis patients. Our study examined the association among demographic characteristics, body composition, comorbidities, dialysis modality and access, inflammation, and longitudinal measures of albumin and prealbumin concentrations in incident dialysis patients. DESIGN, SETTING, SUBJECTS, AND OUTCOME MEASURES: The Comprehensive Dialysis Study is a prospective cohort study of incident dialysis patients; in this report, we examined the data from 266 Nutrition substudy participants who donated serum. The independent variables of interest were baseline age, sex, race, Quetélet's (body mass) index, dialysis modality and access, diabetes, heart failure, atherosclerotic vascular disease, serum creatinine level, and longitudinal measures of C-reactive protein. The outcomes of interest (dependent variables) were longitudinal measures of albumin and prealbumin concentrations, recorded at study entry and thereafter every 3 months for 1 year.

RESULTS

In multivariable mixed linear models, female sex, peritoneal dialysis, hemodialysis with a catheter, and higher C-reactive protein concentrations were associated with lower serum albumin concentrations, and serum albumin concentrations increased slightly over the year. In comparison, prealbumin concentrations did not significantly change over time; female sex, lower body mass index, diabetes, atherosclerotic vascular disease, and higher C-reactive protein concentrations were associated with lower prealbumin concentrations. Serum creatinine had a curvilinear relation with serum albumin and prealbumin.

CONCLUSIONS

Serum albumin level increases early in the course of dialysis, whereas prealbumin level does not, and the predictors of serum concentrations differ at any given time. Further understanding of the mechanisms underlying differences between albumin and prealbumin kinetics in dialysis patients may lead to an improved approach to the management of protein-energy wasting.

Frailty and protein-energy wasting in elderly patients with end stage kidney disease

Older people constitute an increasingly greater proportion of patients with advanced CKD, including those patients undergoing maintenance dialysis treatment. Frailty is a biologic syndrome of decreased reserve and resistance to stressors that results from cumulative declines across multiple physiologic systems and causes vulnerability to adverse outcomes. Frailty is common in elderly CKD patients, and it may be associated with protein-energy wasting (PEW), sarcopenia, dynapenia, and other complications of CKD. Causes of frailty with or without PEW in the elderly with CKD can be classified into three categories: causes primarily caused by aging per se, advanced CKD per se, or a combination of both conditions. Frailty and PEW in elderly CKD patients are associated with impaired physical performance, disability, poorer quality of life, and reduced survival. Prevention and treatment of these conditions in the elderly CKD patients often require a multifaceted approach. Here, we examine the causes and consequences of these conditions and examine the interplay between frailty and PEW in elderly CKD patients.

The effect of frequent hemodialysis on nutrition and body composition: frequent Hemodialysis Network Trial

We investigated the effects of frequency of hemodialysis on nutritional status by analyzing the data in the Frequent Hemodialysis Network Trial. We compared changes in albumin, body weight and composition among 245 patients randomized to 6- or 3-times per week in-center hemodialysis (Daily Trial) and 87 patients randomized to 6-times per week nocturnal or 3-times per week conventional hemodialysis, performed largely at home (Nocturnal Trial). In the Daily Trial, there were no significant differences between groups in changes in serum albumin or the equilibrated protein catabolic rate by 12 months. There was a significant relative decrease in pre-dialysis body weight of 1.5 ± 0.2 kg in the 6 times per week group at one month, but this significantly rebounded by 1.3 ± 0.5 kg over the remaining 11 months. Extracellular water decreased in the 6 times per week compared to the 3 per week hemodialysis group. There were no significant between-group differences in phase angle, intracellular water or body cell mass. In the Nocturnal Trial, there were no significant between-group differences in any study parameter. Any gain in “dry” body weight corresponded to increased adiposity rather than muscle mass but was not statistically significant. Thus, frequent in-center hemodialysis reduced extracellular water but did not increase serum albumin or body cell mass while frequent nocturnal hemodialysis yielded no net effect on parameters of nutritional status or body composition.

Proteinuria: an ignored marker of inflammation and cardiovascular disease in chronic hemodialysis

BACKGROUND

Cardiovascular disease is the leading cause of morbidity and mortality in hemodialysis (HD) patients, the main etiologies being diabetes and hypertension. Cardiac and inflammatory biomarkers are usually employed to assess risk or damage, or during follow-up. Proteinuria is considered a strong predictor of morbidity, a cause of inflammation, oxidative stress, hemodynamic alteration, and progression of chronic kidney disease. However, proteinuria is rarely considered in the clinical assessment of HD patients.

METHODS

This was a concurrent, cohort-observational, cross-sectional study in which 52 chronic HD subjects were divided into three groups according to the degree of proteinuria: Group (G) A: <1 g/day, n = 25; GB: 1-3 g/day, n = 13; GC: >3 g/day, n = 14. Baseline hemoglobin, albuminemia, cholesterol, body mass index, Malnutrition-Inflammatory Score, pro-B-type natriuretic peptide, troponin T, C-reactive protein (CRP), and ultrafiltration rates were analyzed.

RESULTS

There was no difference between groups in terms of baseline age, gender, hypertension, cause of renal failure, hemoglobin, cholesterol, albumin, CRP levels, cardiac biomarkers, adiponectin, body mass index, or Malnutrition-Inflammatory Score. Time on HD: GA, 34.56 ± 23.3 (range [r]: 6-88); GB, 25.15 ± 19.40 (r: 6-58); GC, 18.21 ± 9.58 (r: 6-74) months; P = 0.048. Proteinuria: GA, 0.33 ± 0.30 (r: 0.0-0.88); GB, 1.66 ± 0.54 (r: 1.03-2.75); GC, 7.18 ± 2.80 (r: 3.04-21.5) g/day; P < 0.001. Mean ultrafiltration rates were significantly different: GA, 2.80 ± 0.73; GB: 1.85 ± 0.96 liters/session; P = 0.003. Fourteen diabetic patients were identified (27%): GA, 3 (12%); GB, 3 (23%); GC, 8 (57%); P = 0.009. A positive and significant correlation was observed between diabetes and proteinuria >3 g/day: rho 0.438, P = 0.027. Although troponin T, pro-B-type natriuretic peptide, adiponectin, and CRP were not different among groups, the positive correlation between troponin T and CRP elevated significantly as proteinuria increased: GA, rho 377, P = 0.063; GB, rho 663, P = 0.013; GC, rho 687, P = 0.007.

CONCLUSION

In chronic HD, nephrotic-range proteinuria was significantly higher in diabetic nephropathy patients versus other causes. This was associated with inflammation and cardiac stress and was independent of fluid removal. Proteinuria >3 g/day was associated with shorter time on HD. Whether severe proteinuria is associated with shorter survival in HD, independent of diabetes, is to be determined. Proteinuria should be considered in the assessment of cardiovascular and inflammatory states in HD patients.

Low resting energy expenditure in middle-aged and elderly hemodialysis patients with poor nutritional status

Due to high resting energy expenditure (REE) in maintenance hemodialysis patients, an increase in energy intake is usually recommended to improve their nutritional status. However, some patients appear to have poor appetite and low energy intake. In such patients low energy metabolism is expected. We hypothesized that in maintenance hemodialysis patients there are two types of the energy metabolism, high and low. This study was aimed at finding the energy metabolism in maintenance hemodialysis patients, especially in those with poor nutritional status. Subjects were hemodialysis out-patients (34 males and 20 females, mean age 59.1+/-10.7 y). REE was measured by an indirect calorimeter. Protein intake was obtained from normalized protein catabolic rate (nPCR), and physical activity level (PAL) was obtained by time study. Nutritional status assessed by serum albumin concentration was poor (3.7+/-0.2 g/dL) in spite of the adequate protein intake (1.1+/-0.3 g/kg per day). Only 11% of the subjects had appropriate serum albumin concentration. Mean REE was 24.6 kcal/kg per day which was lower than that of healthy Japanese (26.5 kcal/kg per day). REE and PAL positively correlated with serum albumin concentration (p<0.01). The results suggest that maintenance hemodialysis patients with poor nutritional status may have low REE.

Revisiting mortality predictability of serum albumin in the dialysis population: time dependency, longitudinal changes and population-attributable fraction

BACKGROUND

Hypoalbuminaemia is a marker of malnutrition-inflammation complex syndrome (MICS) and a strong predictor of cardiovascular (CV) death in maintenance haemodialysis (MHD) patients. However, serum albumin may change over time. Hence, its time-varying associations with outcome may be different.

METHODS

Associations between 3-month averaged serum albumin levels, measured in a single laboratory using bromocresol green, and CV mortality were studied longitudinally in a 2-year cohort of 58,058 MHD patients. Mortality predictability of fixed baseline and trimonthly-varying serum albumin concentrations were compared.

RESULTS

Hazard ratios (HRs) of CV death strictly increased across decrements of baseline serum albumin, whereas the HR for time-varying serum albumin decrements below 3.8 g/dl did not differ. A drop in serum albumin in the first 6 months was associated with increasing all-cause and CV death risks in the subsequent 18 months, while a rise in serum albumin was a predictor of better survival independent of baseline serum albumin. The multivariate adjusted population-attributable fraction of death due to baseline serum albumin <3.8 g/dl was 19%.

CONCLUSIONS

Time-varying hypoalbuminaemia predicts all-cause and CV death differently from fixed measures of serum albumin in MHD patients. An increase in serum albumin over time is associated with better survival independent of baseline serum albumin or other MICS surrogates. If this association is causal, an intervention that could increase serum albumin >3.8 g/dl might reduce the number of MHD deaths in the USA by approximately 10,000 annually. Nutritional interventions examining benefits of increasing serum albumin in MHD patients are urgently needed.

The effect of dialysis dose and membrane flux on nutritional parameters in hemodialysis patients: Results of the HEMO Study

BACKGROUND

The effect of standard or high dialysis dose and low or high dialysis flux on nutritional status was ascertained in 1846 maintenance hemodialysis patients enrolled in the HEMO Study.

METHODS

Serum albumin levels, equilibrated protein catabolic rate, and postdialysis weight were obtained monthly, while adjusted protein and energy intake, self-reported appetite assessment, upper arm circumference, and calf circumference were obtained yearly. To account for patient attrition due to death or transfer, three statistical models were used to test the effects of the study interventions on longitudinal changes in nutritional parameters.

RESULTS

During the first 3 years of follow-up, neither mean serum albumin levels, which declined by 0.21 g/dL, nor mean postdialysis weight, which declined by 2.7 kg, were significantly affected by either study intervention. Mean levels of all anthropometric measures declined during follow-up. For years 1, 2, and 3, the mean +/- SE declines in upper arm and calf circumferences were 0.35 +/- 0.16 cm (P= 0.031) and 0.31 +/- 0.13 (P= 0.015) cm less, respectively, in the high flux compared to the low flux group. Appetite scores and mean equilibrated protein catabolic rate also declined in all randomized groups; however, the average decline in equilibrated protein catabolic rate during years 1, 2, and 3 was 0.019 +/- 0.007 g/kg/day less in the high dose than the standard dose group (P= 0.007). There was no significant change in either mean energy or protein intake from diet records over time, and neither parameter was affected by the study interventions.

CONCLUSION

Although the dose and flux interventions may subtly influence certain nutritional parameters, neither intervention prevented deterioration in nutritional status over time.

End-stage renal disease in Scotland: Outcomes and standards of care

BACKGROUND

The number of patients starting renal replacement therapy (RRT) for end-stage renal disease (ESRD) in the United Kingdom rises annually. Patients are increasingly elderly with a greater prevalence of comorbid illness. Unadjusted survival, from the time of starting RRT, is not improving. The United Kingdom Renal Association has published recommended standards of treatment, which all United Kingdom nephrologists strive to attain. This study was devised to define the impact of attaining recommended treatment standards, adjusting for patient age and comorbid illnesses, upon survival on RRT in the United Kingdom population.

METHODS

A prospective, registry based, observational study of all patients starting RRT in Scotland over a 1-year period, followed for the first 2 years of RRT.

RESULTS

Of the 523 patients who were studied, 217 (41.5%) had died by 2 years of follow-up, 32% excluding deaths within the first 90 days. Age, comorbidity, weight when starting RRT, and attaining the recommended standards for albumin and hemoglobin had a significant impact upon survival.

CONCLUSION

This study has emphasized the very high mortality of patients starting RRT in Scotland. By paying close attention to the attainment of recommended standards of care for patients with ESRD, it may be possible to improve upon current mortality figures. The monitoring of such success is only possible if correction is made for age and comorbidity.

Nutrition in hemodialysis patients previously on a supplemented very low protein diet

BACKGROUND

Nutritional safety of protein-restricted diets in patients with chronic renal failure is controversial. In the present study, we have assessed the evolution of nutritional status after initiation of hemodialysis in patients previously treated by a supplemented very low protein diet (SVLPD).

METHODS

Nutritional data were prospectively collected during the first year of hemodialysis from 15 consecutive patients treated with a SVLPD (0.3 g protein/kg/day supplemented with essential amino acids, calcium, iron, and vitamins) and compared to 15 age- and gender-matched end-stage renal disease (ESRD) patients previously on a less-restricted diet (0.90 +/- 0.21 g protein/kg/day) who started hemodialysis during the same period. Dual-energy x-ray absorptiometry (DEXA) was used to assess body composition at 0, 6, and 12 months. Hemodialysis prescriptions, biologic data and 3-day food records were collected every 3 months.

RESULTS

Protein intake was higher than 1.2 g/kg/day in both groups as soon as 3 months after the start of hemodialysis. Albumin and prealbumin increased significantly during the first 6 months in all patients. Body mass index (BMI) increased in all patients (+0.97 +/- 1.31 kg/m2; P < 0.001) reflecting a gain in fat mass in the overall population (+2.36 +/- 2.94 kg/m2; P < 0.001) while lean body mass remained stable overall.

CONCLUSION

Once on hemodialysis, SVLPD patients rapidly increased protein intake. Nutritional status improved in all patients, with a gain in fat mass in all, and a gain in lean body mass in SVLPD men only. These data indicate that treatment with a SVLPD prior to hemodialysis initiation is nutritionally safe.

Body fat mass in hemodialysis patients

BACKGROUND

Changes in body fat mass in a large number of hemodialysis patients is unknown.

METHODS

Body fat mass and lean body mass were measured by dual x-ray absorptiometry (DXA) in 561 patients with hemodialysis duration less than 180 months (62.3 +/- 11.5 years old; mean +/- SD).

RESULTS

Fat mass tended to increase during the first 3 years of hemodialysis, and it tended to decrease thereafter. Between hemodialysis duration and the fat mass index, there was a significant positive correlation within the first 36-month period of hemodialysis (r = 0.124; P < 0.05; n = 245), and a significant negative correlation during the period of 36 to 180 months. (r = -0.192; P < 0.001; n = 316). There was no tendency of change in the lean body mass index.

CONCLUSION

Considering the results together with the authors previous prospective study results, which show significant fat mass increase in the first year of hemodialysis, the present cross-sectional study may suggest that fat mass gradually increases in the first 3 years and decreases thereafter. Fat mass is suggested to be a nutritional parameter in hemodialysis patients.

Improvement of nutritional status after initiation of maintenance hemodialysis

BACKGROUND

Recent data suggest that serum albumin concentrations increase during the several month-period that follows the initiation of maintenance hemodialysis (MHD) therapy. Some investigators have shown that the rate of increase in serum albumin level is related directly to 24-hour urine protein losses before the initiation of dialysis therapy. However, serum albumin levels increase even in patients starting MHD therapy without significant proteinuria, suggesting that this increase may be one manifestation of improving protein-energy nutritional status associated with commencing MHD therapy. We examined this question by reviewing records of all patients admitted to our outpatient dialysis unit within 30 days of initiation of MHD therapy.

METHODS

Ninety-seven patients qualified for the study. Their routine laboratory test results beginning with the time of admission to the outpatient unit until month 6 of chronic dialysis therapy were analyzed.

RESULTS

Between months 1 and 6, there was a statistically significant increase in values for predialysis serum albumin, iron, transferrin saturation, creatinine, and normalized protein equivalent of total nitrogen appearance (nPNA). Many of these values were still increasing by month 6. Body weight declined initially until month 4, then increased. There was a strong curvilinear relationship between mean nPNA and final serum albumin level.

CONCLUSIONS

Our results suggest that an improvement in nutritional status, including an increase in dietary protein intake and serum albumin level, often occurs with the initiation of MHD therapy. The improvement in nutritional status may be related to the increase in dietary protein intake.

Improvement in nutritional parameters after initiation of chronic hemodialysis

BACKGROUND

Protein-calorie malnutrition is highly prevalent in patients with chronic renal failure and on chronic dialysis therapy. Longitudinal studies evaluating nutritional outcomes after the initiation of chronic dialysis therapy in incident dialysis patients are limited.

METHODS

This prospective cohort study evaluated time-dependent changes in several well-defined markers of nutritional status before and after initiation of chronic hemodialysis therapy. Fifty incident hemodialysis (HD) patients (60% men, 38% white, 32% with insulin-dependent diabetes mellitus) were studied. Multiple nutritional markers, including biochemical parameters and analysis of body composition, were assessed before the initial outpatient CHD treatment and every 3 months thereafter for 12 months.

RESULTS

At baseline, nutritional markers correlated well with each other. After the initiation of HD therapy, there were marked improvements in most nutritional parameters, including serum albumin, serum prealbumin, normalized protein catabolic rate, fat mass, reactance, and phase angle (P < 0.05 for all). Improvements in nutritional parameters were influenced by baseline nutritional status; ie, baseline nutritional parameters were predictors of their end-of-study value.

CONCLUSION

Initiation of CHD therapy is associated with improvements in most nutritional markers. Nutritional benefits of increased solute clearance provided by the initiation of chronic dialysis therapy prevail over its potential catabolic effects. However, the extent of improvement was dependent on nutritional status at the time of initiation of dialysis therapy, which remained an important determinant of subsequent nutritional improvements during the first year of treatment.

Changes in body fat mass in male hemodialysis patients: a comparison between diabetics and nondiabetics

Nutritional status is an important factor that affects morbidity and mortality of hemodialysis patients. We investigated 1-year changes in body fat mass of male patients undergoing hemodialysis (duration, 4.9 +/- 2.5 years). Fat mass of 217 male patients (age 60 +/- 13 years) was measured by dual x-ray absorptiometry twice in a 1-year interval. The patients consisted of 70 with diabetes mellitus and 147 without diabetes. At the second measurement compared with the first, a significant decrease in fat mass was observed in diabetic patients (12.1 +/- 4.4 kg versus 11.0 +/- 4.7 kg; P < 0.01); there were no significant changes in fat mass in nondiabetic patients (12.2 +/- 5.0 kg versus 11.9 +/- 4.9 kg; P = 0.15). Significant differences in percent fat mass changes per year were seen between diabetic and nondiabetic patients (P < 0.05). Protein catabolic rates of diabetic patients were significantly lower than those of nondiabetic patients (0.86 +/- 0.18 g/kg/d versus 0.93 +/- 0.19 g/kg/d; P < 0.05). In all patients, there was a significant correlation between protein catabolic rates and percent fat mass changes per year (r = 0.15; P < 0.05). These results showed that body fat mass was decreased significantly in 1 year in male diabetic patients with maintenance hemodialysis, suggesting poorer nutritional status in these patients. Poor protein intake may be one of the risk factors for the decrease in fat mass. Dual x-ray absorptiometry assessment of fat mass changes is suggested as a useful method to examine clinically the nutritional status of hemodialysis patients.

Increasing body fat mass in the first year of hemodialysis

Nutritional status affects well-being and survival in patients who are undergoing hemodialysis. It was examined how maintenance hemodialysis altered body fat mass. In 72 patients with chronic renal failure (age, 62 +/- 12 yr; 42 men, 30 women), body fat was measured by dual x-ray absorptiometry 1 mo after initiation of maintenance hemodialysis and approximately 1 yr later (mean +/- SD, 11 +/- 2 mo). The second measurement showed significantly greater body fat mass than the first (11.38 +/- 3.84 versus 10.09 +/- 4.12 kg; P < 0.0001). After calculation of the change in body fat mass per month, no significant differences were evident in relation to gender or to presence of diabetes. Changes in body fat mass per month correlated negatively with baseline serum albumin concentration (r = -0.449, P < 0.0001) and baseline body fat mass (r = -0.423, P < 0.001). These factors independently influenced the change according to multiple regression analysis (R(2) = 0.323, P < 0.0001). In conclusion, body fat mass increases significantly in the first year of maintenance hemodialysis, especially in patients with poor nutritional status. More general, dual x-ray absorptiometry assessment of body fat mass was found to be useful for evaluating the nutritional status of hemodialysis patients.

Cross-sectional and longitudinal predictors of serum albumin in hemodialysis patients

BACKGROUND

Lower serum albumin concentrations predict increased mortality in hemodialysis (HD) patients. Many demographic, comorbidity, and modifiable treatment-related factors that predict HD patient outcomes may be associated with serum albumin.

METHODS

Cross-sectional predictors of baseline albumin on December 31, 1993 were sought (N = 3981). Additional effects of the same baseline predictors on subsequent trends in albumin over one year were examined in a nested subsample of patients (N = 2245). Wave-1 of the United States Renal Data System Dialysis Morbidity and Mortality special study provided the data.

RESULTS

Significant associations (P < 0.05) are summarized as older age, female gender, peripheral vascular disease, chronic obstructive pulmonary disease, and cancer predicted a lower baseline albumin and negatively influenced subsequent albumin trends. Baseline albumin was higher for blacks (vs. whites), lower for smoking and diabetes, and lower during the first year of HD treatment (<3 months and 3 to 12 months, vs.> 1 year). Trend analysis showed more positive albumin slopes for patients in their first year on HD and more negative slopes for Native Americans (vs. whites). Baseline albumin was correlated with the type of vascular access being used [arteriovenous (AV) fistulas > AV grafts > permanent catheters > temporary catheters]. Trend analysis predicted more negative albumin slopes for AV grafts and permanent catheters (vs. AV fistula access). Baseline albumin correlated inversely with bicarbonate and directly with hematocrit. Dialysis with unmodified cellulose membranes, without reuse, predicted lower baseline albumin than the other membrane-reuse categories.

CONCLUSIONS

Several exposures, which may be modifiable, were associated with serum albumin.

Treatment of advanced renal failure: low-protein diets or timely initiation of dialysis?

Until 1996, no guidelines existed for the initiation of dialysis in patients with progressive renal failure. The publication of the National Kidney Foundation-Dialysis Outcome Quality Initiative guidelines has generated a debate on the management of advanced renal failure and the role of low-protein diets (LPDs). We performed a review of the literature to identify articles on the initiation of dialysis and LPDs, particularly those since 1996. Delayed referral of patients is widespread in both the United States and Europe, and almost 25% of patients are started on dialysis at a glomerular filtration rate (GFR) of <5 mL/min/1.73 m2. There is a high prevalence of malnutrition at the time of first dialysis, which progressively improves upon initiation of dialysis. There is no evidence regarding the efficacy or safety of LPDs in nondiabetic patients younger than 70 years old [approximately 40% of U.S. incident end-stage renal disease (ESRD) patients] and in diabetics with GFR <25 mL/min/1.73 m2 (>40% of incident U.S. ESRD). In nondiabetics who are younger than 70 years old, adherence to LPD for four to five years can be estimated to result in a delay in dialysis by 6 to 11 months. However, suboptimal energy intake is widespread in advanced renal failure, which declines further upon institution of LPD. Even nutritionally sound patients develop subclinical nutritional decline despite intense counseling. There are no data on the efficacy or safety of LPD in subgroups that constitute approximately 80% of incident ESRD patients. Concerns still exist regarding their nutritional safety in the remainder. Initiation of dialysis results in improved nutritional status and should be considered in a timely fashion.