Phase angle and body composition in patients with overweight and obesity

Abstract

Background Phase angle(PHA) unveils a new insight to evaluate nutrition change in patients , but no researches verify the relationship between PHA and body composition in patients with overweight and obesity stratified by body mass index(BMI).Our study aimed to investigate the link between PHA and body composition stratified according to BMI, and to predict how PHA variability can be explained by body composition in this population.Methods This was a cross-sectional study including 257 patients that was conducted in a single hospital. The population was divided into four groups by BMI. Pearson correlation coefficients and Spearman correlation coefficients were used to analyze the relationship between PHA and body composition. Stepwise linear regression analysis was used to determine the influence of body composition on PHA.Results Total body water(TBW), intracellular water(ICW), ratio of extracellular water and intracellular water(ECW/ICW), fat mass(FM), fat-free mass(FFM), skeletal muscle mass(SMM), body cell volume(BCV) and protein had correlations with PHA in all of the four groups. The volume of minerals was positively correlated with PHA in three obese groups but not the overweight group. Only 42% of PHA variability could be explained by body composition in the overweight group whereas 85.8% in the obese graded I group,82.3% in the obese graded II group, and 87.6% in the obese graded III group.Conclusions The determinants of phase angle differ between different BMI range. The body composition of patients with obesity is more closely linked to PHA.