Protein-Energy Wasting/Malnutrition and the Inflammatory Response

The importance of enhanced inflammatory response as a leading cause of diminished reserves of protein stores in chronic kidney disease (CKD) has been extensively described as part of the uremic phenotype in the last 20 years. The persistent low-grade inflammation observed in end-stage renal disease (ESRD) patients plays a crucial role in protein energy wasting (PEW) by promoting increased energy expenditure and protein catabolism while decreasing protein synthesis. This cycle can result in a negative nitrogen balance with loss of muscle mass and consequent wasting. In addition, inflammation, which has a pivotal role in the atherogenic process, worsens cardiovascular mortality and can further aggravate the detrimental outcomes, especially if wasting is present. The cardiovascular mortality of ESRD patients is further increased in those with inflammation (C-reactive protein [CRP] ≥10 mg/L) and malnutrition (assessed by subjective global assessment (SGA)), as compared with those with only inflammation or malnutrition, or in the absence of both conditions. Since inflammation is believed to be a leading cause of PEW and cardiovascular disease (CVD) in ESRD, and inflammation therefore represents a potential target for therapeutic – pharmacological as well as nonpharmacological – interventions, this chapter aims to review the interrelation between inflammation and nutritional disorders, especially PEW, and to discuss potential strategies of treatment targeting inflammation, PEW, and sarcopenia.