Objective To investigate the correlation between phase angle (PA) and perioperative nutritional status of patients with gastric and colorectal malignancies.

Methods A total of 89 patients with gastric and colorectal malignant tumors were selected for nutritional screening and evaluation at admission through Nutrition Risk Screening 2002 (NRS 2002) and patient generated subjective global assessment (PG-SGA), so as to improve physical measurement, body composition detection and related blood biochemical indicators.

Results There were 37 cases in the low PA group and 52 cases in the normal PA group in 89 patients with malignant tumors.Compared with the normal PA group, the body mass index, upper arm circumference, grip strength, hemoglobin, red blood cells, lymphocytes, total body water, protein, inorganic salts, fat free weight, intracellular water, skeletal muscle, basic metabolism, body cell mass, bone mineral, skeletal muscle mass index (SMI) in the low PA group were lower(P < 0.05 to P < 0.01).PA was positively correlated with hemoglobin, erythrocyte count, grip strength, intracellular moisture, skeletal muscle and SMI, while PA was negatively correlated with NRS2002 score and PG-SGA score (P < 0.05 to P < 0.01).

Conclusions PA can help identify patients with early nutritional risk, and patients can get early intervention, so as to improve the prognosis of patients with gastrointestinal cancer.