Standardized phase angle: relationship with functionality, muscle mass and postoperative outcomes in surgical cancer patients

To evaluate the association of standardized phase angle (SPA) with nutritional status, functional parameters, and postoperative outcomes in surgical cancer patients. This prospective study includes 59 cancer patients from Pelotas (Brazil) admitted for elective cancer surgery. We obtained the phase angle through Bioelectrical Impedance Analysis (BIA) and standardized it according to the population's reference values. We estimated the muscle mass using BIA for later calculation of the Skeletal Muscle Index (SMI) and performed handgrip strength (HGS) and gait speed (GS) tests. We used the Patient-Generated Subjective Global Assessment (PG-SGA) to assess the nutritional status. Postoperative complications and duration of hospital stay were evaluated as the outcomes. The prevalence of malnutrition in the sample was 28.8%, according to ASG-PPP. SPA was statistically lower in patients with malnutrition, with lower HGS and reduced GS. For postoperative outcomes, patients with severe complications and those with prolonged hospitalization also had lower SPA values. The greater the number of functional alterations in patients, the lower the SPA value, mainly when associated with reduced muscle mass assessed by BIA, suggesting that muscle mass reduction plays an important role in the association between functional alterations and phase angle in patients with cancer. According to the parameters used in this study, low SPA value was associated with impaired nutritional and functional status and negative outcomes in the analyzed sample.

Phase angle, physical quality of life and functionality in cancer patients undergoing chemotherapy

INTRODUCTION

Nutritional deficiency, especially malnutrition, is frequent in cancer patients and is associated with changes in body composition, such as low muscle mass. Phase angle (PhA) has been used as a prognostic indicator and may be related to nutritional status, functionality, and quality of life in these patients. The objectives of this study were to assess the effect of chemotherapy treatment on PhA values, comparing the PhA variation before and after treatment, and to evaluate the PhA correlation, as a muscle mass surrogate, with the physical domain of quality of life, functionality, and nutritional risk in a sample of patients with cancer.

METHODS

A longitudinal study was conducted in patients with cancer undergoing chemotherapy for the first time. All patients aged 18 years or older, newly diagnosed, and undergoing chemotherapy for the first time were included. To analyze the difference in the PhA means according to the different classification variables, the t-test - or ANOVA - was used. The variation of the final and initial PhA was evaluated through the linear regression test.

RESULTS

A total of 175 patients were analyzed, of which 66.3% were female. The mean PhA of the initial assessment was significantly higher when compared to the final assessment of the patients PhA (p = 0.018). In both the initial and final assessments, PhA was correlated with the physical domain (r = 0.29; p < 0.001 and r = 0.19; p = 0.021) and with the functionality score (r = - 0.32; p < 0.001 and r = - 0.30; p < 0.001) and total PG-SGA (r = - 0.31; p < 0.001 and r = - 0.23; p = 0.006).

CONCLUSION

PhA can be considered a predictor of physical quality of life and functionality in cancer patients receiving chemotherapy treatment.