Nutritional and Inflammatory Axis of Racial Survival Disparities - eScholarship (2012)

NIH Public Access Author Manuscript Semin Dial. Author manuscript; available in PMC 2014 January 01. Published in final edited form as: Semin Dial. 2013 January ; 26(1): 36–39. doi:10.1111/sdi.12025. Nutritional and Inflammatory Axis of Racial Survival Disparities $watermark-text Paungpaga Lertdumrongluk 1,2 , Csaba. P. Kovesdy 3,4 , Keith C. Norris 5 , and Kamyar Kalantar-Zadeh 1,6 1 Harold Simmons Center for Kidney Disease Research and Epidemiology, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California 2 Royal Irrigation Hospital, Srinakharinwirot University, Nonthaburi, Thailand 3 University of Tennessee Health Science Center, Memphis, TN, USA 4 Memphis VA Medical Center, Memphis, Tennessee 5 Charles R. Drew University of Medicine and Science, Los Angeles, California 6 David Geffen School of Medicine at UCLA, and Fielding School of Public Health at UCLA, Los Angeles, California $watermark-text Protein energy wasting (PEW) is highly prevalent in the dialysis population (1, 2). Several studies have shown that PEW tends to occur concomitantly with inflammation and both conditions are strongly associated with higher mortality in dialysis patients (3-7). It has been proposed that the combination of PEW and inflammation in dialysis patients be designated as malnutrition-inflammation complex syndrome (MICS) (8-10) or malnutrition, inflammation and atherosclerosis (MIA) syndrome (11). $watermark-text Conditions leading to PEW and inflammation appear to overlap. Causes of MICS include inadequate nutrient intake, nutrient loss during dialysis, inflammation caused by comorbid conditions and dialysis treatment, endocrine disorders of uremia, oxidative and carbonyl stress, uremic toxins, volume overload and reduced clearance of pro-inflammatory cytokines. The presence of MICS in dialysis patients is signaled by hypoalbuminemia, hypocholesterolemia, hypohomocysteinemia, increased levels of inflammatory markers and low body mass index, and its possible consequences include erythropoietin hyporesponsiveness, increased risks of atherosclerotic cardiovascular events, poor quality of life, and increased hospitalization and mortality rates in dialysis patients (Figure 1) (8). Race-ethnicity and survival paradoxes in CKD and ESRD The annual mortality rate for US dialysis patients is approximately 20%; the extremely low 5-year survival rate (<35%) is lower than that for many cancer patients (12, 13). It has been recognized that ESRD is more commonly encountered in certain races/ethnicities particularly in African Americans and Hispanics (14). In 2009, incidence rates of ESRD in the United States for African Americans and Hispanics were 3.5 and 1.5 times higher than that seen in non-Hispanic whites, respectively (15). Contributing factors to these racial/ ethnicity discrepancies include, but are not limited to a genetic susceptibility to select glomerular diseases, increased rates of major risk factors such as diabetes mellitus, and hypertension, disparities in socioeconomic status affecting access to care, and cultural differences such as diet and lifestyle choices (14). Even though African Americans comprise only 12% of the general population in the United States (16), approximately 37% of the Correspondence: Kamyar Kalantar-Zadeh, MD, MPH, PHD Professor & Chief (8/1/2012) Division of Nephrology & Hypertension University of California Irvine (UCI) School of Medicine 101 The City Drive South, City Tower, Suite 400 - ZOT: 4088 Orange, California 92868-3217 Tel: (714) 456-5142 Fax : (714) 456-6034 kkz@uci.edu. Potential Conflict of Interest: None declared.