Predictors of mortality in dialysis patients: Association between malnutrition, inflammation and atherosclerosis (Mia syndrome)

Abstract

Introduction Numerous recent studies have shown increased comorbidity and mortality in dialysis patients with malnutrition. Protein-energy malnutrition with muscle wasting occurs in a large proportion of patients with chronic renal failure and is, in addition to atherosclerosis, a strong risk factor for mortality in patients undergoing dialysis. Malnutrition is also associated with increased cardiovascular mortality in dialysis patients. Pathogenic factors of malnutrition in dialysis patients Malnutrition is associated with a number of metabolic and vascular abnormalities. These factors include hypoalbuminemia, dyslipidemia with raised triglyceride concentrations, low-density lipoprotein and very low-density lipoprotein centrations, insulin resistance and high concentrations of acute-phase proteins. Low serum albumin concentration, usually used as an index of malnutrition, is highly associated with increased mortality risk in dialysis patients. However, serum albumin is affected by factors other than malnutrition and high concentrations of acute-phase proteins, such as C-reactive protein (CRP), which correlate with low serum albumin in malnourished patients on dialysis. Oxidative stress has emerged as an important cofactor for development of endothelial dysfunction as premature atherosclerosis. In this context, malnutrition, inflammation and markers of oxidative stress are associated with vascular diseases. Etiology of malnutrition in dialysis patients In recent studies several reports have suggested that inflammation, alone or in combination with low protein intake, plays a significant role in etiology of malnutrition in uremic patients. Lipid abnormalities may not only be a consequence of renal disease, but also contribute to its progression. Lipoprotein (a) is also associated with various atherosclerotic diseases. Therapy options New treatment strategies, such as high protein/energy vs. standard protein/energy nutritional regimens, are necessary as well as food intake and dietary supplements. Intensive supplementation of (1,5 g protein/kg/d and 45 kcal/kg/d) is necessary to improve nutritional status of dialysis patients. Conclusion Cellular basis of pathogenetic factors in malnutrition is unclear. It is, however, now recognized that oxidative stress and inflammatory cytokine aggravates the nutritional status of these patients.