Purpose of review Protein-energy wasting (PEW) is a state of metabolic and nutritional derangements in chronic disease states including chronic kidney disease (CKD). Cumulative evidence suggests that PEW, muscle wasting and cachexia are common and strongly associated with mortality in CKD, which is reviewed here. Recent findings The malnutrition-inflammation score (KALANTAR Score) is among the comprehensive and outcome-predicting nutritional scoring tools. The association of obesity with poor outcomes is attenuated across more advanced CKD stages and eventually reverses in form of obesity paradox. Frailty is closely associated with PEW, muscle wasting and cachexia. Muscle loss shows stronger associations with unfavorable outcomes than fat loss. Adequate energy supplementation combined with low-protein diet (LPD) for the management of CKD may prevent the development of PEW and can improve adherence to LPD, but dietary protein requirement may increase with aging and is higher under dialysis therapy. Phosphorous burden may lead to poor outcomes. The target serum bicarbonate concentration is normal range and ≥23 mEq/L for non-dialysis-dependent and dialysis-dependent CKD patients, respectively. A benefit of exercise is suggested but not yet conclusively proven. Summary Prevention and treatment of PEW should involve individualized and integrated approaches to modulate identified risk factors and contributing comorbidities.

A B S T R A C TBackground: Vitamin B12 (B12) and folate are essential vitamins that play important roles in physiological processes. In the general population, many studies have evaluated the association of these vitamins with clinical outcomes, yet this association in hemodialysis (HD) patients remains unclear. Methods: We examined the association of serum folate and B12 with mortality in a 5-year cohort of 9517 (folate) and 12 968 (B12) HD patients using Cox models with hierarchical adjustment for sociodemographics, comorbidities, and laboratory variables associated with the malnutrition and inflammation complex syndrome. The associations of baseline B12 and folate (separately) with all-cause mortality were evaluated across five categories of B12 [<400 (reference), 400-<550, 550-<650, 650-<750 and !750 pg/mL] and folate [<6.2, 6.2-<8.4, 8.4-<11 (reference), 11-<14.3 and !14.3 ng/mL]. Results: The study cohort with B12 measurements had a mean 6 standard deviation age of 63 6 15 years, among whom 43% were female, 33% were African-American, and 57% were diabetic. Higher B12 concentrations !550 pg/mL were associated with a higher risk of mortality after adjusting for sociodemographic and laboratory variables. However, only lower serum folate concentrations <6.2 ng/mL were associated with a higher risk of all-cause mortality when adjusted for sociodemographic variables [adjusted hazard ratio (95% confidence-interval): 1.18 (1.03-1.35)]. Conclusions: Higher B12 concentrations are associated with higher all-cause mortality in HD patients independent of sociodemographics and laboratory variables, whereas lower folate concentrations were associated with higher all-cause mortality after accounting for sociodemographic variables. Further studies are warranted to determine the optimal B12 and folate level targets in this population.

Introduction and Aims: Serum folate levels are significantly lower in patients with end-stage renal disease than in the general population but the association between folate levels and risk of death in hemodialysis (HD) patients is unknown. Here, we examined the association between baseline folate levels and all-cause mortality in HD patients Methods: We examined the association of baseline folate levels [<6.2, 6.2 to <8.5, 8.5 to <11, 11 to <14.2 (reference) and ≥14.2 ng/ml] with all-cause mortality in 9,517 incident HD patients who initiated dialysis between 2007 through 2011 using Cox models with 2 levels of adjustment: unadjusted, and adjusted for case-mix covariates. Results: Patients were 61±15 years old, and included 43% women, 36% blacks and 58% diabetics. In the unadjusted model, compared to HD patients with 11 to <14.2 ng/ml of serum folate, those with ≥14.2 ng/ml had a 23% increased risk of death (HR: 1.23, 95%