Appetite and inflammation, nutrition, anemia, and clinical outcome in hemodialysis patients

Background: Mal nutrition-inflammation complex syndrome, an outcome predictor in maintenance hemodialysis (MHD) patients, may be related to anorexia. Objectives: We examined whether subjectively reported appetite is associated with adverse conditions and increased morbidity and mortality in MHD patients. Design: A cohort of 331 MHD outpatients was asked to rate their recent appetite status on a scale from I to 4 (very good, good, fair, and poor appetite. respectively). Anemia indexes and nutritional and inflammatory markers-including serum concentrations of C-reactive protein, tumor necrosis factor a, and interleukin 6-were measured. The malnutrition-inflammation score was used to evaluate the malnutrition-inflammation complex syndrome, and the SF36 questionnaire was used to assess quality of life (QoL). Mortality and hospitalization were followed prospectively for up to 12 mo. Results: Patients were aged 54.5 +/- 14.4 y. Diminished appetite (fair to poor) was reported by 124 patients (38%). Hemoglobin, protein intake, and QoL scores were progressively lower, whereas markers of inflammation, malnutrition-inflammation scores, and the required erythropoietin dose were higher across the worsening categories of appetite. The adjusted odds ratios of diminished versus normal appetite for increased serum tumor necrosis factor a and C-reactive protein concentrations were significant. Significant associations between a poor appetite and an increased rate of hospitalization and mortality were observed. The hazard ratio of death for diminished appetite was 4.74 (95% CI: 1.85, 12.16; P = 0.001). Conclusion: Diminished appetite (anorexia) is associated with higher concentrations of proinflammatory cytokines and higher levels of erythropoietin hyporesponsiveness and poor clinical outcome, including a 4-fold increase in mortality, greater hospitalization rates, and a poor QoL in MHD patients. Appetite status may yield significant insight into the clinical status of dialysis patients.