Global prevalence of protein-energy wasting in kidney disease: A meta-analysis of contemporary observational studies from the international society of renal nutrition and metabolism

Objective: To better define the prevalence of protein-energy wasting (PEW) in kidney disease is poorly defined. Methods: We performed a meta-analysis of PEW prevalence from contemporary studies including more than 50 subjects with kidney disease, published during 2000-2014 and reporting on PEW prevalence by subjective global assessment or malnutrition-inflammation score. Data were reviewed throughout different strata: (1) acute kidney injury (AKI), (2) pediatric chronic kidney disease (CKD), (3) nondialyzed CKD 3-5, (4) maintenance dialysis, and (5) subjects undergoing kidney transplantation (Tx). Sample size, period of publication, reporting quality, methods, dialysis technique, country, geographical region, and gross national income were a priori considered factors influencing between-study variability. Results: Two studies including 189 AKI patients reported a PEW prevalence of 60% and 82%. Five studies including 1776 patients with CKD stages 3-5 reported PEW prevalence ranging from 11% to 54%. Finally, 90 studies from 34 countries including 16,434 patients on maintenance dialysis were identified. The 25th-75th percentiles range in PEW prevalence among dialysis studies was 28-54%. Large variation in PEW prevalence across studies remained even when accounting for moderators. Mixed-effects meta-regression identified geographical region as the only significant moderator explaining 23% of the observed data heterogeneity. Finally, two studies including 1067 Tx patients reported a PEW prevalence of 28% and 52%, and no studies recruiting pediatric CKD patients were identified. Conclusion: By providing evidence-based ranges of PEW prevalence, we conclude that PEW is a common phenomenon across the spectrum of AKI and CKD. This, together with the well-documented impact of PEW on patient outcomes, justifies the need for increased medical attention.

Diagnostic validation and prognostic significance of the Malnutrition-Inflammation Score in nondialyzed chronic kidney disease patients.

BACKGROUND: Malnutrition and inflammation are highly prevalent and intimately linked conditions in chronic kidney disease (CKD) patients that lead to a state of protein-energy wasting (PEW), the severity of which can be assessed by the Malnutrition-Inflammation Score (MIS). Here, we applied MIS and validated, for the first time, its ability to grade PEW and predict mortality in nondialyzed CKD patients. METHODS: We cross-sectionally evaluated 300 CKD stages 3-5 patients [median age 61 (53-68) years; estimated glomerular filtration rate 18 (12-27) mL/min/1.73 m(2); 63% men] referred for the first time to our center. Patients were followed during a median 30 (18-37) months for all-cause mortality. RESULTS: A worsening in MIS scale was associated with inflammatory biomarkers increase (i.e. alpha-1 acid glycoprotein, fibrinogen, ferritin and C-reactive protein) as well as a progressive deterioration in various MIS-independent indicators of nutritional status based on anthropometrics, dynamometry, urea kinetics and bioelectric impedance analysis. A structural equation model with two latent variables (assessing simultaneously malnutrition and inflammation factors) demonstrated good fit to the observed data. During a follow-up, 71 deaths were recorded; patients with higher MIS were at increased mortality risk in both crude and adjusted Cox models. CONCLUSIONS: MIS appears to be a useful tool to assess PEW in nondialyzed CKD patients. In addition, MIS identified patients at increased mortality risk.

Comparison of the malnutrition–inflammation score in chronickidney disease patients and kidney transplant recipients

Background Protein–energy wasting (PEW) is a commoncondition in patients with chronic kidney disease (CKD)including dialysis and kidney transplant recipients (TX)and frequently assessed with malnutrition–inflammationscore (MIS). We hypothesized that (1) the MIS and PEWparameters are correlated with kidney function and (2) theMIS and PEW parameters are more severe in TX than innon-dialysis (ND) CKD patients with similar eGFR.Methods In this study, we matched 203 ND-CKD and 203TX patients from two independently assembled cohorts ofpatients based on estimated glomerular filtration rate (eGFR)and compared various PEW parameters between the two groups using unadjusted and case-mix adjusted linear regressionand conditional logistic regression analysis models.Results In the combined cohort (n = 406) of patients, themean ± SD age was 57 ± 12 years; included 55 % men and35 % diabetics; and demonstrated a mean ± SD baselineeGFR of 29 ± 11 ml/min/1.73 m2. The eGFR correlated positivelywith serum albumin (ρ = 0.26, p < 0.001) and negatively(ρ = −0.33, p < 0.001) with MIS. ND-CKD and TX patientshad similar MIS, PEW parameters such as waist circumference,serum CRP, albumin, and leptin levels. After case-mixadjustment, TX status was associated with higher waist circumference(standardized coefficient: 0.187, p < 0.001), lowerBMI (standardized coefficient: −0.204, p < 0.001), and lowerSGA score (standardized coefficient: 0.156, p = 0.006).Conclusions We found associations between lower eGFRand various PEW measures in both the ND-CKD and TXpopulations. Additionally, we did not observe significantdifferences in the burden of PEW parameters between theCKD and TX populations.

Diagnostic validation and prognostic significance ofthe Malnutrition-Inflammation Score in nondialyzed chronickidney disease patients

Malnutrition and inflammation are highlyprevalent and intimately linked conditions in chronic kidneydisease (CKD) patients that lead to a state of protein-energywasting (PEW), the severity of which can be assessed by theMalnutrition-Inflammation Score (MIS). Here, we appliedMIS and validated, for the first time, its ability to grade PEWand predict mortality in nondialyzed CKD patients.Methods. We cross-sectionally evaluated 300 CKD stages 3–5patients [median age 61 (53–68) years; estimated glomerularfiltration rate 18 (12–27) mL/min/1.73 m2; 63% men] referredfor the first time to our center. Patients were followed during amedian 30 (18–37) months for all-cause mortality.Results. A worsening in MIS scale was associated withinflammatory biomarkers increase (i.e. alpha-1 acidglycoprotein, fibrinogen, ferritin and C-reactive protein) aswell as a progressive deterioration in various MIS-independentindicators of nutritional status based on anthropometrics, dynamometry,urea kinetics and bioelectric impedance analysis.A structural equation model with two latent variables (assessingsimultaneously malnutrition and inflammation factors)demonstrated good fit to the observed data. During a followup,71 deaths were recorded; patients with higher MIS were atincreased mortality risk in both crude and adjusted Coxmodels.Conclusions. MIS appears to be a useful tool to assess PEW innondialyzed CKD patients. In addition, MIS identified patientsat increased mortality risk.