[Malnutrition in chronic kidney failure: what is the best diagnostic method to assess?]

Protein-energy malnutrition, systemic inflammation, and metabolic disorders are frequent among patients with chronic kidney failure undergoing dialysis, contributing to their morbidity and mortality.

In the present study, the prevalence of malnutrition in chronic renal patients undergoing hemodialysis in one single center in the Northeastern region of Brazil was assessed according to the following: three different methods of subjective global assessment (SGA); body mass index (BMI); percent of standard body weight; adequacy to the 50th percentile of triceps skinfold (TSF) and arm muscle circumference (AMC) thicknesses; pre-dialysis albumin; phase angle; and percentage of body cell mass (%BCM). Agreement of the nutritional status diagnosis performed through SGA with anthropometric, biochemical, and bioelectrical impedance measures was assessed.

The study assessed 58 patients [females, 30 (51.7%); mean age = 49 years]. The prevalence of malnutrition according to the different methods ranged from 12.1% to 94.8%. Conventional SGA showed a moderate agreement with patient-generated SGA (PG-SGA), BMI (cutoff point, 22.0 kg/m²), and AMC; a fair agreement with BMI (cutoff point, 18.5 kg/m²), percent of standard body weight, AC, and phase angle; and a poor agreement with SGA adapted to the renal patient, TSF, and %BCM.

The nutritional assessment methods commonly used in clinical practice are subject to restrictions when applied to the dialysis population, considering the different percentages obtained with the different methods. Longitudinal, prospective studies on the association of nutritional markers with adverse events, such as hospitalization and mortality, should be carried out to clarify remaining issues.