Phase Angle as a Marker of Muscular Strength in Breast Cancer Survivors

Abstract

Background: accurate prognostic tools are relevant for decision-making in cancer care. Objective measures, such as bioelectrical impedance (BI), have the potential to improve prognostic accuracy for these patients. This cross-sectional study aimed to investigate whether phase angle (PhA) derived from the electrical properties of the body tissues is a predictor of muscular strength in breast cancer survivors (BCS). Methods: a total of 41 BCS (age 54.6 ± 9.2 years) were evaluated. PhA, obtained at frequency 50 kHz, was assessed with BI spectroscopy, and muscular strength with a handgrip dynamometer. Moderate-to-vigorous physical activity (MVPA) was assessed using the International Physical Activity Questionnaire (IPAQ). Measurements were performed in the morning after an overnight fast. Results: linear regression analysis showed that PhA accounted for 22% (r2 = 0.22) of muscular strength variance. PhA remained a borderline predictor of muscular strength variance independently of age and MVPA. Conclusions: the findings of this study suggest that PhA is a significant predictor of maximal forearm isometric strength and a potential indicator of disease-related functionality in BCS.

Phase angle cutoff value as a marker of the health status and functional capacity in breast cancer survivors

“…The present study aimed at assessing the usefulness of proposed phase angle cutoff, as a marker of bioelectrical impedance analysis (BIA) assessed health-status, and functional capacity in breast cancer (BC) survivors. Retrospective observational data on the studied topic has been considered scarce in the studied population (8,28).…”

“…BIA analysis is an easy-to-use, non-invasive method that measures the electrical properties of the patient's tissues and has been used for many years to assess body composition including fat-free mass [6,8,9]. Previous studies have found that patients with a high fat-free mass index (FFMI) (calculated from fat-free mass/weight) had a significantly better prognosis than did patients with a low FFMI [9][10][11].…”

“…Previous studies have found that patients with a high fat-free mass index (FFMI) (calculated from fat-free mass/weight) had a significantly better prognosis than did patients with a low FFMI [9][10][11]. Recently, it has been used for clinical assessment of the phase angle (PhA) [8][9][10][11], extracellular water (ECW), intracellular water (ICW) [10,12], body cell mass (BCM) [12,13] and different compartments ratios [4,14]. The PhA is a non-invasive simple measure directly retrieved from resistance (R) and reactance (Xc) raw data [9][10][11], which appears to be even more interesting for cancer survival [9,11,15].…”

“…The PhA is a non-invasive simple measure directly retrieved from resistance (R) and reactance (Xc) raw data [9][10][11], which appears to be even more interesting for cancer survival [9,11,15]. From a biophysical point of view, PhA is calculated from the arctangent of the ratio between the R and Xc, where R arises from ECW and ICW distribution, and, conversely, Xc arises from the cell membrane's ability to take an electric load and liberate it at a later moment, after a brief delay [7,8,16]. BCM is highly clinically relevant as it is defined as the total mass of all metabolically active, living, and functional cellular elements [12,13].…”

“…Although clinical studies using these parameters have been previously conducted, the present study emerged from the need to increase the robustness of the PhA cutoff values standardization [8,28]. This study aimed at exploring the usefulness of proposed phase angle cutoff [11], as a marker of BIA assessed health-status, and functional capacity in BC survivors.…”