RESUMO
BACKGROUND: Protein-energy wasting is a common complication and an important predictive factor for mortality in chronic dialysis patients. Therefore, nutritional status needs to be regularly assessed in these patients, by using several methods, and, if malnutrition is present, its possible causes should be thoroughly searched for and properly treated. MATERIAL AND METHODS: In 149 prevalent haemodialysis patients (82 men, mean age 53.9 +/- 13.7 years), we evaluated the nutritional status by anthropometrics [post-dialysis height (H), body weight (BW), body mass index (BMI), mid-arm circumference (MAC), tricipital skin-fold thickness (TST), mid-arm muscle circumference (MAMC), corrected mid-arm muscle area (cMAMA) and three-category subjective global assessment score (SGA)], biochemical tests [protein equivalent of nitrogen appearance (nPNA), and pre-dialysis serum albumin, creatinine, total cholesterol, bicarbonate and haemoglobin (Hb) levels] and bioelectrical impedance analysis (BIA) to estimate body composition [percent body fat (%BF), fat-free mass (%FFM), body cell mass (%BCM), extracellular mass (%ECM) and the phase angle (PhA)]. RESULTS: Age was found to be positively correlated with BMI (P = 0.001), and inversely correlated with %BCM (P = 0.013). Patients with A-category SGA were significantly younger (50.1 versus 63.7 years) than those with B-category SGA. Patients with diabetes had lower %BCM (32.9 versus 35.9%; P = 0.035) and PhA (5.5 versus 6.9 degrees ; P = 0.0007) than those without diabetes. The presence of heart failure was associated with significantly reduced nPNA (1.17 versus 1.34 g/kg day; P = 0.014), MAMC (22.0 versus 23.6 cm(2); P = 0.041), %BCM (33.0 versus 36.1; P = 0.021), PhA (5.8 versus 7.0 degrees ; P = 0.031), serum albumin (39.7 versus 42.4 g/l; P = 0.013) and serum creatinine (8.1 versus 9.4 mg/dl; P = 0.010), and with a higher percent of B-category SGA (47.8% versus 22.6%; P = 0.019). Eleven deaths (7.4%) occurred during the follow-up period. Among general factors, age >or= 55, the presence of diabetes, and dialysis vintage <2 years were associated with significantly reduced survival. Among nutritional factors, B-category SGA, nPNA <1.2 g/kg day, %BF <15% and PhA <6 degrees significantly predicted mortality in both Kaplan-Meier and Cox analyses. The most important risk factor appeared to be nPNA; for every 0.1 g/kg day increase in nPNA, death risk decreased by 15%. CONCLUSIONS: In our haemodialysis patients, advancing age, diabetes and heart failure were associated with worse nutritional status, as estimated by anthropometry, biochemical markers and BIA. Age >or=55 years, the presence of diabetes, nPNA <1.2 g/kg day, lower SGA score, %BF <15% and PhA <6 degrees were associated with significantly increased death risk.
