The additional benefit of weighted subjective global assessment (SGA) for the predictability of mortality in incident peritoneal dialysis patients: A prospective study

Malnutrition as a potential predictor of mortality in chronic kidney disease patients on dialysis: A systematic review and meta-analysis

BACKGROUND & AIMS

Malnutrition, a significant problem in patients with chronic kidney disease (CKD), is linked to lower health-related quality of life, longer and more frequent hospital admissions, worse functional capacity, and higher levels of morbidity. However, the extent of its impact on mortality is poorly elucidated. This systematic review and meta-analysis aimed to investigate the impact of malnutrition on mortality among CKD patients on dialysis.

METHODS

This meta-analysis was designed and performed in accordance with the PRISMA guidelines (CRD42023394584). A systematic electronic literature search was conducted in PubMed, ScienceDirect, and Embase to identify relevant cohort studies. The studies that reported nutritional status and its impact on mortality in patients were considered for analysis. The generic inverse variance method was used to pool the hazard ratio effect estimates by employing a random effects model. The Newcastle-Ottawa scale was used for the quality assessment. The statistical analysis was performed by utilizing RevMan and CMA 2.0.

RESULTS

A total of 29 studies that comprised 11,063 patients on dialysis whose nutritional status was evaluated were eligible for quantitative analysis. Based on a comparison between the "malnutrition" category and the reference "normal nutrition status" category, the results showed that the overall pooled hazard risk (HR) for mortality was (HR 1.49, 95% CI: 1.36-1.64, p < 0.0001). According to the subgroup analysis, the hemodialysis subgroup had greater mortality hazards (HR 1.53; 95% CI 1.38-1.70, p < 0.0001), compared to the peritoneal dialysis subgroup (HR 1.26; 95% CI 1.15-1.37, p < 0.00001). Additionally, the overall incidence of mortality was explored but the authors were unable to combine the results due to limitations with the data.

CONCLUSION

The findings conclude that malnutrition is a strong predictor of mortality among patients on dialysis, with the hemodialysis subgroup having a higher mortality hazard compared to the peritoneal dialysis subgroup. The results of this study will advocate for early nutritional evaluation and timely dietary interventions to halt the progression of CKD and death.

Dynamic serum albumin and outcome of peritoneal dialysis patients: A retrospective study in China

Introduction

Serum albumin levels at a single time point have been shown to predict mortality in peritoneal dialysis (PD) patients. However, we believe that the dynamic change in albumin after PD may be more significant. In this study, we investigated the relationship between dynamic serum albumin and the clinical outcome of patients undergoing continuous ambulatory peritoneal dialysis (CAPD).

Methods

The participants in this study enrolled 586 patients who underwent CAPD at the peritoneal dialysis center of Second Xiangya Hospital in China. We retrospectively reviewed medical records from January 1, 2010, to December 31, 2019. Baseline serum albumin (Alb), time-averaged albumin level (TA-ALB) and serum albumin reach rate (SR: defined as the percentage of serum albumin measurements that reached ≥ 35 g/L) were applied as the predictor variables. All-cause mortality and cardiovascular mortality were used as the outcome variables. Hazard function of all-cause mortality and cardiovascular mortality in the study participants were examined by using Cox proportional hazard regression models.

Results

Age (HR = 1.03, 95% CI 1.00–1.05), cardiovascular disease (HR = 1.80, 95% CI 1.07–3.03) and TA-ALB (HR = 0.92, 95% CI 0.85–0.99) were independent risk factors for all-cause mortality in PD patients. Patients with TA-ALB of <33 g/L (HR = 2.33, 95% CI 1.17–4.62) exhibited a higher risk for all-cause mortality than those with TA-ALB ≥ 36 g/L. Stratified SR showed a similar trend. Patients with a <25% SR exhibited a significantly increased risk for all-cause mortality (HR = 2.72, 95% CI, 1.24–5.96) by fully adjusted analysis. However, neither TA-ALB nor SR were associated with the risk of cardiovascular mortality after adjusted analysis.

Conclusion

This study demonstrated that age, cardiovascular disease, and TA-ALB were independent risk factors for all-cause mortality in PD patients. TA-ALB and SR can better predict the prognosis of PD patients than baseline Alb. Dynamic changes in Alb are more clinically significant than baseline Alb in predicting mortality risk.

Severity of protein-energy wasting and obesity are independently related with poor quality of life in peritoneal dialysis patients

Protein-energy wasting (PEW) and poor health-related quality of life (HRQoL) are independently associated with morbi-mortality in continuous ambulatory peritoneal dialysis (CAPD). PEW may reduce HRQoL; however, we hypothesized HRQoL is affected differentially by PEW degrees or by individual criteria of nutritional status. AIM: To evaluate HRQoL according to PEW severity and nutritional status indicators in CAPD. This is a cross-sectional study in 151 patients. Subjective global assessment (SGA) was employed, and nutritional status classified as normal, mild-moderate PEW, and severe PEW. HRQoL was evaluated using Kidney Disease Quality of Life Short Form™, including physical (PCS), mental (MCS) and kidney disease (KDCS) components, and their subscales. Dietary intake, anthropometric and biochemical variables were measured. Forty-six percent of patients were well-nourished, 44% had mild-moderate PEW, and 10% severe PEW. Compared with well-nourished patients, those with mild-moderate (p=0.06) and severe (p=0.005) PEW had lower HRQoL score [68 (52-75), 55 (45-72), 46 (43-58), respectively]. PCS, MCS, and KDCS and their subscales had lower values as PEW was more severe. Patients with obesity and hypoalbuminemia had significantly lower HRQoL overall and component scores than their counterparts. Dietary intake was not associated with quality of life. In multivariate analysis obesity, PEW (by SGA), hypoalbuminemia, and low educational level predicted poor HRQoL (χ² 58.2, p<0.0001). As conclusion, PEW severity was related with worse HRQoL, either as overall score or in every component or subscale in CAPD patients. Poor HRQoL was predicted independently by PEW severity and obesity; additional predictors were hypoalbuminemia and low education.

Subjective global nutritional assessment [SGNA] in children on chronic dialysis- A prospective observational study

Introduction:

Nutritional assessment in children undergoing chronic dialysis is challenging as no single objective reference tool is available. There is a need to explore the application of the subjective global nutritional assessment (SGNA) tool in these children. This study assessed the nutritional status of children on chronic dialysis using SGNA, evaluated the utility of SGNA parameters in the longitudinal assessment of nutrition, and compared the SGNA tool with other nutritional measures.

Methods:

Children 2-18 years of age on chronic dialysis for at least 1 month were prospectively studied over a period of 18 months with two follow-up visits at least 3 months apart. Malnutrition was diagnosed by SGNA (well-nourished, moderately, and severely malnourished), mid-arm circumference <5^th centile for age and gender, and serum albumin <3.8 g/l at baseline and follow-up.

Results:

In 41 children on dialysis (age: 124.8 ± 32 months), 73% had moderate or severe malnutrition by SGNA. Height for age (P = 0.008), weight for height (P = 0.004), dietary intake (P = 0.025) functional capacity (P = 0.001), loss of subcutaneous fat (P < 0.001), and muscle wasting (P < 0.001) were significantly associated with the presence and severity of malnutrition. SGNA showed a poor agreement with MUAC and serum albumin. On follow-up, there was no significant change in the category of nutritional status (P = 0.63) and no individual SGNA parameter was associated with the presence or severity of malnutrition.

Conclusion:

Two-thirds of the children on chronic dialysis were diagnosed with moderate to severe malnutrition by SGNA, while the majority remained in the same category of nutritional status on follow-up. Only half of the parameters used for assessment were strongly associated with the presence and severity of malnutrition. SGNA showed a poor agreement with objective nutritional measures and was not responsive in identifying a change in the nutritional status on follow-up.

Severity of protein-energy wasting and obesity are independently related with poor quality of life in peritoneal dialysis patients

Protein-energy wasting (PEW) and poor health-related quality of life (HRQoL) are independently associated with morbi-mortality in continuous ambulatory peritoneal dialysis (CAPD). PEW may reduce HRQoL; however, we hypothesized HRQoL is affected differentially by PEW degrees or by individual criteria of nutritional status. AIM: To evaluate HRQoL according to PEW severity and nutritional status indicators in CAPD. This is a cross-sectional study in 151 patients. Subjective global assessment (SGA) was employed, and nutritional status classified as normal, mild-moderate PEW, and severe PEW. HRQoL was evaluated using Kidney Disease Quality of Life Short Form™, including physical (PCS), mental (MCS) and kidney disease (KDCS) components, and their subscales. Dietary intake, anthropometric and biochemical variables were measured. Forty-six percent of patients were well-nourished, 44% had mild-moderate PEW, and 10% severe PEW. Compared with well-nourished patients, those with mild-moderate (p=0.06) and severe (p=0.005) PEW had lower HRQoL score [68 (52-75), 55 (45-72), 46 (43-58), respectively]. PCS, MCS, and KDCS and their subscales had lower values as PEW was more severe. Patients with obesity and hypoalbuminemia had significantly lower HRQoL overall and component scores than their counterparts. Dietary intake was not associated with quality of life. In multivariate analysis obesity, PEW (by SGA), hypoalbuminemia, and low educational level predicted poor HRQoL (χ2 58.2, p<0.0001). As conclusion, PEW severity was related with worse HRQoL, either as overall score or in every component or subscale in CAPD patients. Poor HRQoL was predicted independently by PEW severity and obesity; additional predictors were hypoalbuminemia and low education.

Subjective global assessment of nutrition, dialysis quality, and the theory of the scientific method in Nephrology practice

In an era of evidence-based medicine and dialysis performance measures, there is strong motivation to find specific, objective, quantifiable, and reproducible parameters to characterize the clinical condition of chronic kidney disease patients and to present population-wide statistics that may describe quality of care in dialysis centers. Yet, in the last three decades, several studies demonstrated that while parameters including Kt/V urea, serum phosphorus, parathyroid hormone, serum cholesterol fulfill all these criteria, efforts to optimize these lab parameters failed to improve survival on dialysis. However, subjective assessments of nutrition including subjective global assessment and malnutrition-inflammation score, while not ideally suited for statistical analysis and not optimal from the point of view of scientific methodology due to their general, semi-quantifiable, subjective nature have, nevertheless, proved themselves as some of the strongest predictors of clinical outcomes in the dialysis population. Where does this paradox leave us? We propose that a deeper understanding of relevance of these variables in the dialysis population may improve appreciation of the clinical situation of individual patients and may result in a paradigm shift from dialysis adequacy to quality dialysis.

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.

Time-varying serum albumin levels and all-cause mortality in prevalent peritoneal dialysis patients: a 5-year observational study

BACKGROUND

In this study, we investigated the association of time-varying serum albumin levels with mortality over a 5-year period in one cohort of patients undergoing long-term peritoneal dialysis (PD) therapy.

METHODS

The participants in this study enrolled 302 patients who underwent long-term PD at a single PD center in Taiwan. We reviewed medical records from 2011 to 2015 retrospectively. Time-averaged albumin level and serum albumin reach rate (defined as the percentage of serum albumin measurements that reached ≥3.5 g/dL) were applied as the predictor variables in the first 2 years (2011-2012). All-cause mortality was used as the outcome variable in the subsequent 3 years (2013-2015). Hazard function of all-cause mortality in the study participants was examined by using Cox proportional hazard regression models .

RESULTS

Patients with different albumin reach rates (75-< 100%, 50-< 75%, 1-< 50%) did not exhibit a significantly increased risk for all-cause mortality. Patients with a 0% albumin reach rate exhibited a significantly increased risk for all-cause mortality (hazard ratio [HR] 7.59, 95% confidence interval [CI], 2.38-24.21) by fully adjusted analysis. Patients with time-averaged albumin levels of < 3.5 g/dL (HR 15.49, 95% CI 1.74-137.72) exhibited a higher risk for all-cause mortality than those with serum albumin levels ≥4.0 g/dL.

CONCLUSIONS

This study demonstrated that higher serum albumin reach rates and higher time-averaged serum albumin levels are associated with a lower mortality rate over a 5-year period among patients undergoing long-term PD.

The Effect of Aspirin on Preventing Vascular Access Dysfunction in Incident Hemodialysis Patients: A Prospective Cohort Study in Korean Clinical Research Centers for End-Stage Renal Disease (CRC for ESRD)

Background: Aspirin is often prescribed empirically to improve the patency of hemodialysis (HD) vascular access. Therefore, this study aimed to investigate the impact of aspirin on the survival of vascular access in incident HD patients with arteriovenous fistula (AVF) or arteriovenous graft (AVG). Methods: A prospective cohort of 881 incident HD patients was enrolled between 2009 and 2014. The primary outcome was defined as the first AVF/AVG intervention or salvage procedure, including percutaneous transluminal angioplasty or surgery for vascular access failure. Cox analyses were performed to determine the association between aspirin usage and the occurrence of the primary outcome. Results: The mean age of the patient group was 57.9 ± 13.4, and 63.8% of the patients were male. Aspirin was prescribed in 241 (27.4%) patients, and the median follow-up duration was 30 months. During follow-up, 180 (20.4%) patients experienced the primary outcome event. Univariate analysis showed that age, gender, presence of diabetes mellitus (DM), preexisting peripheral arterial disease, and the type of vascular access used (AVG versus AVF) were significantly associated with the development of the primary outcome. However, aspirin usage from the baseline was not significantly associated with primary outcome events (hazard ratio (HR): 1.16; 95% confidence interval (CI): 0.84–1.60; p = 0.378). Multivariate analysis showed that gender, the presence of DM, and the type of vascular access were still significantly associated with the occurrence of the primary outcome. Moreover, we did not observe the protective effect of taking aspirin on primary vascular access failure, even in subgroup analyses stratified according to gender, the presence of DM, and the type of vascular access. Conclusion: Physicians should carefully consider when they prescribe aspirin for the prevention of primary vascular access failure in Korean incident HD patients. In addition, larger prospective interventional studies are needed to elucidate the effect of aspirin on vascular access failure.

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.