Analysis of factors influencing the increase of extracellular water ratio in tumor patients without edema signs

Abstract Objective This study aims to examine the factors contributing to the increase in extracellular water to total body water ratio (ECW/TBW) among tumor patients without visible edema, and to offer insights into the diagnosis and prompt management of early water retention in such patients. Methods A cohort of 274 tumor patients admitted to Anqing First People's Hospital, affiliated with Anhui Medical University between December 2020 and December 2022, were selected, excluding those with clinically observable edema. General clinical data, main laboratory test outcomes, and body composition indices were gathered. Valuable variables were identified for linear regression analysis using ECW/TBW, based on professional knowledge and univariate analysis results. Results Age, gender, hemoglobin, serum sodium, serum potassium, and phase angle (PA) were determined as independent influencing factors for elevated ECW/TBW. ECW/TBW increased with age (partial regression coefficient B=0.009, P=0.001), was higher in males than in females (B=-0.349, P<0.001), and was negatively affected by hemoglobin (Hgb) (B=-0.003, P=0.039). Serum sodium had a positive influence on ECW/TBW (B=0.019, P=0.011), while serum potassium exhibited a negative effect (B=-0.180, P=0.001). PA was the most influential factor among all independent variables affecting ECW/TBW (B=-1.006, P<0.001). Nonetheless, Performance Status (PS) score, Patient-Generated Subjective Global Assessment (PG-SGA) score, tumor stage, prealbumin, albumin, and body fat percentage were not identified as independent factors influencing elevated ECW/TBW. Conclusion The early factors influencing water retention in tumor patients primarily stem from abnormal cell membrane function, but are also impacted by age, gender, anemia, and electrolyte levels. Timely body composition testing can assist in subsequent intervention decision-making.