Nutrition in Older Adults on Peritoneal Dialysis

Exercise intolerance and malnutrition associated with all-cause mortality in elderly patients undergoing peritoneal dialysis: a single-center prospective cohort study

BACKGROUND

Low physical function and malnutrition in elderly patients undergoing peritoneal dialysis (PD) are important issues that may be associated with prognosis. We aimed to determine the association between physical function and nutritional status and survival in elderly patients undergoing PD.

METHODS

This single-center, prospective cohort study included 45 stable, ambulatory patients undergoing PD. Physical function was measured using the 6-min walk distance (6MWD) test, 10-m walk speed, handgrip strength, lower extremity muscle strength, and short physical performance battery. Nutritional status was assessed using albumin levels and the Geriatric Nutritional Risk Index (GNRI). Patients were divided into two groups according to adverse events. Receiver operating characteristic curve analysis was used to predict mortality. The relationships between all-cause mortality and physical function and nutritional status were studied using Kaplan-Meier analysis and the log-rank test.

RESULTS

The mean patient age was 75.3 ± 6.5 years. The median follow-up time was 32 (interquartile range 18-51) months, during which 11 deaths occurred. Death during follow-up was significantly associated with lower 6MWD (237.4 ± 120.2 vs. 355.2 ± 105.9 m), lower GNRI (77.3 ± 16.3 vs. 89.3 ± 8.1), and lower albumin levels (2.8 ± 0.6 vs. 3.3 ± 0.4 mg/dL) at baseline (p < 0.05). The cut-off values were 338 m, 83.3, and 2.95 g/dL for the 6MWD, GNRI, and albumin levels, respectively. The 6MWD test, GNRI, and albumin levels were significantly associated with all-cause mortality (p < 0.05). Additionally, the group with combined exercise intolerance and malnutrition had a lower survival rate (p < 0.05).

CONCLUSION

Lower 6MWD and malnutrition are predictors of mortality in elderly patients undergoing PD.

Prediction of premature all-cause mortality in patients receiving peritoneal dialysis using modified artificial neural networks

Premature all-cause mortality is high in patients receiving peritoneal dialysis (PD). The accurate and early prediction of mortality is critical and difficult. Three prediction models, the logistic regression (LR) model, artificial neural network (ANN) classic model and a new structured ANN model (ANN mixed model), were constructed and evaluated using a receiver operating characteristic (ROC) curve analysis. The permutation feature importance was used to interpret the important features in the ANN models. Eight hundred fifty-nine patients were enrolled in the study. The LR model performed slightly better than the other two ANN models on the test dataset; however, in the total dataset, the ANN models fit much better. The ANN mixed model showed the best prediction performance, with area under the ROC curves (AUROCs) of 0.8 and 0.79 for the 6-month and 12-month datasets. Our study showed that age, diastolic blood pressure (DBP), and low-density lipoprotein cholesterol (LDL-c) levels were common risk factors for premature mortality in patients receiving PD. Our ANN mixed model had incomparable advantages in fitting the overall data characteristics, and age is a steady risk factor for premature mortality in patients undergoing PD. Otherwise, DBP and LDL-c levels should receive more attention for all-cause mortality during follow-up.

Hypomagnesemia Is a Risk Factor for Cardiovascular Disease- and Noncardiovascular Disease-Related Mortality in Peritoneal Dialysis Patients

PURPOSE

Recent research has shown that hypomagnesemia is associated with increased all-cause mortality in hemodialysis patients. However, the relationship between the long-term prognosis of peritoneal dialysis (PD) and the study is not yet clear. This study will analyze the effects of hypomagnesemia on all-cause, cardiovascular diseases (CVD), and non-CVD mortality in PD patients.

METHOD

In a retrospective cohort study, 1,004 samples were selected from 7 PD centers in China. Based on the baseline blood magnesium level at the beginning of stable dialysis, all patients were classified into blood magnesium <0.7 mmol/L group, 0.7-1.2 mmol/L group, and >1.2 mmol/L group (the end event was death). The Kaplan-Meier method was used to calculate the difference in cumulative survival rate; the Cox proportional hazard model was used to analyze the risk factors of all-cause, CVD, and non-CVD death causes.

RESULTS

Cox multiple regression analysis results (reference comparison of 0.7-1.2 mmol/L group): patients with serum magnesium <0.7 mmol/L have a higher risk ratio of all-cause mortality (HR = 1.580, 95% CI: 1.222-2.042, p = 0.001), and it is also obvious after correction by multiple models (HR = 1.578, 95% CI: 1.196-2.083, p = 0.001). Subgroup analysis of the causes of death was as follows: CVD risk (HR = 1.628, 95% CI: 1.114-2.379, p = 0.012) and non-CVD risk (HR = 1.521, 95% CI: 1.011-2.288, p = 0.044). Further analysis of the causes of infection-related death in non-CVD is also significant (HR = 1.919, 95% CI: 1.131-3.1257, p = 0.016). On the other hand, the serum magnesium>1.2 mmol/L group had lower all-cause mortality after correction (HR = 0.687, 95% CI: 0.480-0.985, p = 0.041), and subgroup analysis of the cause of death had no statistical significance (p > 0.05).

CONCLUSIONS

Hypomagnesemia (serum magnesium <0.7 mmol/L) during stable dialysis in PD patients is a risk factor for CVD- and non-CVD-related mortality, especially infection-related death causes.

Change in appendicular lean mass in patients established on peritoneal dialysis as measured by dual x-ray absorptiometry (DXA) scanning

BACKGROUND/OBJECTIVES

Peritoneal dialysis (PD) patients are at increased risk of malnutrition and cachexia, definitions of which include weight loss. However, PD patients can absorb glucose from the dialysate and loss of muscle mass may be overlooked by fat weight gain. As such, we wished to review changes in body composition in prevalent PD patients.

SUBJECTS/METHODS

We compared changes in body composition measured by dual x-ray absorptiometry (DXA) in adult PD patients, and calculated glucose absorption based on 24-h collections of PD dialysate.

RESULTS

Overall, 73 prevalent PD patients, 60.3% male, mean age 62.5 ± 16.4 years, had DXA scans a median of 24 (15-27) months apart. Weight did not change (70.7 ± 16.8 vs. 70.9 ± 16.8 kg), with a median 198 (88-295) mmol glucose absorbed/day. Appendicular lean mass (ALM) decreased in most of the male (59%) and female (52%) patients, and the change in ALM was negatively associated with the change in percentage body fat mass (%BFM) r = -0.54, p < 0.001. Overall, 56 patients (76.7%) were admitted to hospital with intercurrent illnesses. Women who lost ALM and gained %BFM had more hospital admissions and those with an increase in %BFM had more admissions due to PD peritonitis while, in males, these outcomes were not seen.

CONCLUSION

Although overall weight did not change, the majority of PD patients lost ALM, and this loss of muscle mass was masked by a gain in fat mass. Definitions of malnutrition and cachexia, which include unintentional weight loss criteria will underestimate the prevalence of PD patients with loss of muscle mass.

Nutritional Status in Peritoneal Dialysis: Nutritional Guidelines, Adequacy and the Management of Malnutrition

The positive impact of nutritional status on the health and treatment adequacy of peritoneal dialyzed patients has been well established. Protein intake is an important factor used to stratify malnutrition, with inadequate intake leading to protein-energy wasting during the course of therapy. In this review, we discuss the recommendations made by nephrological societies regarding nutrition in this population of dialysis patients. Special attention is given to the intake of protein, and recommendations on the intake of micronutrients are also discussed. Furthermore, factors that may impair nutritional intake and balance are discussed, with mention of the innovative strategies utilized to combat them. In light of inconsistent recommendations that vary between each respective society, as well as a general lack of concise information, it is our intention to call for further research regarding nutritional recommendations in peritoneal dialysis (PD), as well as to advocate for clear and accessible information for patients.

The relationship between lymphocyte subsets, nutritional status and tuberculin reactivity in continuous ambulatory peritoneal dialysis and hemodialysis patients

Aim

Skin test anergy is common in patients with uremia and during maintenance hemodialysis treatment. However, up to date only one study concerning skin test in peritoneal dialysis patients has focused on the issue. Our cross-sectional controlled study was conducted to analyze the correlation of purified protein derivative (PPD) test response with demographical features, nutritional parameters and the distribution of peripheral blood lymphocyte subsets in peritoneal dialysis and hemodialysis patients

Patients and methods

Stable 30 hemodialysis (HD) patients (16 men, 14 women) and 30 continuous ambulatory peritoneal dialysis (PD) patients (17 men, 13 women) were included. Thirty healthy cases (15 men, 15 women) with a mean age of 32.4 ± 9.4 constituted the control group.

Results

In the HD group, 14 patients (46.6%) were PPD positive, and ın the PD group 16 patients (53.3%) were PPD positive. In the PPD-positive HD patients 64.2% (9/14), and in the PPD-positive PD patients 62.4% (10/16) had an induration of 10 mm or greater. In the control group, 21 of 30 patients (70%) were PPD positive. Comparison of both HD and PD groups with the control group showed significant differences in PPD reactivity (p < 0.01). Albumin levels were significantly high in the control groups (p < 0.01), and cholesterol levels were significantly high in the PD and the control groups (p < 0.05). Transferrin levels were significantly high in the PD (p < 0.01). The lymphocyte counts were significantly high in the control group compared to the HD patients (p < 0.05). The lymphocyte subset percentages CD19 were high in the control groups (p < 0.05), and CD16/56 was significantly high in the PD groups (p < 0.05). All the parameters were also similar between PPD-positive and -negative same groups.

Conclusion

The prevalence of PPD positivity was lower in the PD and HD groups. The PPD test responses were not related to the peripheral lymphocyte counts, subsets and malnutrition parameters.

Development of a risk prediction model for infection-related mortality in patients undergoing peritoneal dialysis

Background

Assessment of infection-related mortality remains inadequate in patients undergoing peritoneal dialysis. This study was performed to develop a risk model for predicting the 2-year infection-related mortality risk in patients undergoing peritoneal dialysis.

Methods

The study cohort comprised 606 patients who started and continued peritoneal dialysis for 90 at least days and was drawn from the Fukuoka Peritoneal Dialysis Database Registry Study in Japan. The patients were registered from 1 January 2006 to 31 December 2016 and followed up until 31 December 2017. To generate a prediction rule, the score for each variable was weighted by the regression coefficients calculated using a Cox proportional hazard model adjusted by risk factors for infection-related mortality, including patient characteristics, comorbidities, and laboratory data.

Results

During the follow-up period (median, 2.2 years), 138 patients died; 58 of them of infectious disease. The final model for infection-related mortality comprises six factors: age, sex, serum albumin, serum creatinine, total cholesterol, and weekly renal Kt/V. The incidence of infection-related mortality increased linearly with increasing total risk score (P for trend <0.001). Furthermore, the prediction model showed adequate discrimination (c-statistic = 0.79 [0.72–0.86]) and calibration (Hosmer–Lemeshow test, P = 0.47).

Conclusion

In this study, we developed a new model using clinical measures for predicting infection-related mortality in patients undergoing peritoneal dialysis.

Peritoneal dialysis has optimal intradialytic hemodynamics and preserves residual renal function: Why isn't it better than hemodialysis?

Rates of cardiovascular mortality are disproportionately high in patients with end stage kidney disease receiving dialysis. However, it is now generally accepted that patient survival is broadly equivalent between the two most frequently used forms of dialysis, in-center hemodialysis (HD) and peritoneal dialysis (PD). This equivalent patient survival is notable when considering how specific aspects of HD have been shown to contribute to morbidity and mortality. These include more rapid loss of residual renal function (RRF), HD-induced myocardial and cerebral ischemia, and risk factors associated with the intermittent delivery of HD. Potential mechanisms specific to PD that may drive cardiovascular disease include the metabolic consequences of excessive absorption of glucose and glucose degradation products (GDPs), inadequate volume control, and high rates of hypokalemia. The aim of this review is to compare and contrast the different drivers of adverse outcomes between the dialysis modalities, as greater understanding of this may help in patient-centered decision-making when considering options for renal replacement therapy.

Age modifies the association between serum obestatin, appetite and nutritional status in maintenance hemodialysis patients

BACKGROUND/OBJECTIVES

Increased age is strongly associated with anorexia and protein-energy wasting (PEW) in maintenance hemodialysis (MHD) population. We hypothesized that the association of obestatin, a recently discovered anorexigenic gut hormone, with appetite and nutritional status differs by age groups.

SUBJECTS/METHODS

We performed a cross-sectional study on 261MHD patients. Obestatin, acyl-ghrelin, markers of inflammation (CRP, IL-6, TNF-α) and nutrition (self-reported appetite, dietary intake, biochemical nutritional parameters, and body composition) were measured.

RESULTS

Obestatin was associated with appetite in multivariate analyses even after controlling for such confounders as lean body mass (LBM), IL-6 and acyl-ghrelin in patients younger than 71 years. For each ng/ml increase in obestatin levels, the odds for diminished appetite was 0.75 (95% CI: 0.59-0.96). However, these associations were not observed in patients 71 years and older. Multivariable logistic regression models (including appetite) also showed increasing odds for PEW (defined by ESPEN consensus-based criteria for the diagnosis of malnutrition) across increasing serum obestatin levels (OR: 1.51, 95% CI: 1.05-2.18) in patients 71 years and older. However, after lean body mass (LBM) was added to this model, the association between obestatin and malnutrition was abolished (OR: 1.26, 95% CI: 0.83-1.91).

CONCLUSIONS

The association between serum obestatin, appetite and PEW differs depending on age in MHD patients. A positive link with appetite exists in patients younger than 71 years, whereas this relationship disappears by the age of 71. In older MHD patients, obestatin is associated with PEW through mechanisms related to LBM, but not to appetite.

The Relevance of Geriatric Impairments in Patients Starting Dialysis: A Systematic Review

BACKGROUND AND OBJECTIVES

With aging of the general population, patients who enter dialysis therapy will more frequently have geriatric impairments and a considerable comorbidity burden. The most vulnerable among these patients might benefit from conservative therapy. Whether assessment of geriatric impairments would contribute to the decision-making process of dialysis initiation is unknown.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A systematic Medline and Embase search was performed on December 1, 2015 to identify studies assessing the association between risk of mortality or hospitalization and one or more geriatric impairments at the start of dialysis therapy, including impairment of cognitive function, mood, performance status or (instrumental) activities of daily living, mobility (including falls), social environment, or nutritional status.

RESULTS

Twenty-seven studies were identified that assessed one or more geriatric impairments with respect to prognosis. The quality of most studies was moderate. Only seven studies carried out an analysis of elderly patients (≥70 years old). Malnutrition and frailty were systematically assessed, and their relation with mortality was clear. In addition, cognitive impairment and functional outcomes at the initiation of dialysis were related to an increased mortality in most studies. However, not all studies applied systematic assessment tools, thereby potentially missing relevant impairment. None of the studies applied a geriatric assessment across multiple domains.

CONCLUSIONS

Geriatric impairment across multiple domains at dialysis initiation is related to poor outcome. However, information in the elderly is sparse, and a systematic approach of multiple domains with respect to poor outcome has not been performed. Because a geriatric assessment has proved useful in predicting outcome in other medical fields, its potential role in the ESRD population should be the subject of future research.