Abstract: Objective Malnutrition is a major complication in peritoneal dialysis (PD) patients. However, there are no efficient and accurate approaches for nutritional assessment in these patients so far. The aim of this study was to validate the bioelectrical impedance analysis (BIA) for malnutrition assessment in PD patients
and to analyze malnutrition in PD patients. Methods Clinically stable patients with PD for more than 3 months, willing to take part in this study, and without acute coronary syndrome, surgery, and intravenous antibiotics treatment for severe infection in recent days were recruited. Nutrition status was evaluated by malnutrition inflammation score (MIS) that consists of 10 items with a total score ranging from 0～30 points. Patients were divided into two groups, well- nutritional group (MIS 0～8) and malnutritional group (MIS≥9). BIA was performed to evaluate body composition of the PD patients. Clinical and laboratory data including age, residual renal function, Kt/V and nutritional biomarkers (albumin, hs-CRP, feritin and creatinine) at the beginning of PD were recorded. Results We recruited 183 PD patients (113 males and 70 females) with an average age of 51.9±16.15 years and an average PD period of 23 (10～46) months. The primary diseases for end-stage renal disease included glomerulonephritis (67.2%), diabetic nephropathy (7.7%), hypertensive nephropathy (9.3%), other diseases (14.2%) and unknown origin (1.6%). Forty-one patients (22.4%) had moderate to severe malnutrition evaluated by MIS. MIS level was positively correlated with age (r= 0.249), hs-CRP (r= 0.285), feritin (r=0.168), edema index (EI) (r=0.354) and ECW/BCM (r=0.358), and negatively correlated with BMI (r=-0.227), mean arterial pressure (r=-0.254), albumin (r=-0.208), residual renal function (r=-0.214) and body cell mass (r=-0.270). Multiple linear regression analysis found that elder (β=0.172, P=0.038), elevated feritin (β=0.226, P=0.001) and higher ECW/BCM (β=2.494, P=0.04) were the independent risk factors for
malnutrition; while female (β=-0.336, P=0.003), higher level of skeletal muscle (β=-0.592, P=1.79E-08), and higher percentage of body fat (β =-0.183, P=0.041) were the protect factors for malnutrition. ROC analysis showed that the BIA parameters including ECW/BCM, EI, skeletal muscle and body fat percentage could effectively predict malnutrition. Conclusion In this study, the malnutrition rate evaluated by MIS system was 22.4% in PD patients. BIA parameters including ECW/BCM, EI, skeletal muscle and body fat percentage are useful for the assessment of nutrition status in PD patients.