The clinical application value of the extracellular-water-to-total-body-water ratio obtained by bioelectrical impedance analysis in people with advanced cancer

Objectives: Body-composition analysis using bioelectrical impedance analysis is gradually becoming more widely used in clinical practice. The ratio of extracellular water (ECW) to total body water (TBW) is thought to be related to the prognosis of a variety of diseases. However, its performance in people with advanced can-cer deserves further discussion. Methods: A retrospective analysis was performed on 784 people with advanced cancer. Anthropometric indi-cators, serologic indicators, nutritional status, health-related quality of life, and body composition were ana-lyzed. Participants were grouped into two groups according to ECW/TBW ratio. We used t tests and chi(2) tests to analyze differences between the groups. Univariate and multivariate Cox regressions were conducted to analyze the factors influencing overall survival. Logistic regression was used to analyze the related factors of malnutrition, and linear regression for factors of health-related quality of life. Results: Age, body mass index, Patient-Generated Subjective Global Assessment score, Karnofsky Performance Status questionnaire score, skeletal muscle mass index, and fat-free mass index were statistically different between the non-overhydrated and overhydrated groups. Univariate and multivariate Cox regression models showed that an ECW/TBW >= 0.40 isa risk factor for poor prognosis in people with advanced cancer (hazard ratio =1.511; 95% confi-dence interval, 1.103-2.070; P = 0.010). Subgroup analyses were next conducted according to tumor type, with ECW/TBW >= 0.40 emerging as a risk factor for poor prognosis for people with advanced breast cancer and advanced gastric cancer. Logistic regression showed that ECW/TBW >= 0.40 is a risk factor for malnutrition in people with advanced cancer (odds ratio =1.988; 95% confidence interval, 1.049-3.767; P = 0.035). The univariate and multivari-ate linear regression models showed that the ECW/TBW ratio is an influencing factor for health-related quality of life in the domains of physical functioning, role functioning, and constipation. Conclusion: We found that in people with cancer, an ECW/TBW >= 0.40 was a risk factor for malnutrition and lower health-related quality of life, and in people with advanced cancer, it was a risk factor for poor prognosis. (C) 2021 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)