Abstract: 【Abstract】Objective Bioelectrical impedance analysis (BIA) can be used to evaluate the nutrition status by phase angle (PA) and the volume status of overhydration (OH). This study investigated the nutrition status and the volume status by BIA in patients with continuous ambulatory peritoneal dialysis (CAPD), to explore the influencing factors of PA and the prediction of malnutrition by PA. Methods 200 CAPD patients in the Peritoneal Dialysis Center of the Second Hospital, Jilin University during October 2017 to October 2020 were enrolled. Patients subjected to BIA 3 months after peritoneal dialysis. Patients were then divided into
malnutrition group (PA＜4.5° ) and normal nutrition group (PA≥4.5° ) based on the reference PA value. Their clinical and laboratory data were collected and compared. The factors affecting PA in CAPD patients and the optimal value for the prediction of malnutrition were explored. Results The prevalence of malnutrition was 55.50% in the 200 CAPD patients. Compared with normal nutrition group, the prevalence of OH was higher (Z=-5.984, P<0.001), while the levels of albumin and lean tissue index (LTI) were lower (t=3.823 and 6.719, P<0.001) in malnutrition group. Univariate correlation analyses showed that PA was positively correlated with albumin (r=0.232, P=0.003) and LTI (r=0.556, P <0.001), and was negatively correlated with OH (r=- 0.583, P<0.001). ROC curve shows that when the values are set at >2.85L for OH, <12.85kg/m2 for LTI and <35.05g/L for albumin for the prediction of malnutrition in CAPD patients, the specificities are 67.50%, 74.70% and 40.30% respectively, and the sensitivities are 71.40%, 67.10% and 86.30% respectively. Conclusion Malnutrition is relatively prevalent in CAPD patients. Clinically, the values of OH, LTI and albumin are useful to estimate nutrition status in CAPD patients. In addition to nutritional support, correction of OH is also important to treat malnutrition in CAPD patients.

Key words: Continuous ambulatory peritoneal dialysis, Bioelectrical impedance analysis, Phase angle, Malnutrition, Overhydration, Albumin