Endocrine Abstracts

Background: Phase angle (PA) is defined as the angular displacement between the current and voltage waveforms due to capacitor interference, measured in degrees or radians. [1] The fat-free mass (FFM) is made up of water and electrolytes and is characterized by a low impedance, while the FM (fat mass) is water-free and, therefore, with a high impedance. The larger the FM, the higher the resistance, and this parameter affects the PA. Body mass index (BMI) is the most widely used measure of overweight and obesity, but does not analyze body composition. Several studies evaluated the link between phase angle (PA) and adipokines, fasting glucose, insulin, and HOMA index; however, there has not yet been an established link between phase angle and insulin resistance. The gold standard measure of insulin resistance is the hyper-insulinemic-euglycemic clamp, but this method is time- consuming and costly.

Materials and Methods: A spectral bioelectrical impedance device (BIA) (AKERN 101 BIVA PRO body composition analyzer) was used to estimate resistance (R) and reactance (Xc), and subsequently PA was calculated as arctangent (Xc/R) ×180°/π.

Results: BIA scans (N =85) measured FM% in women of reproductive age (18-49 years) in the outpatient clinic. PA was significantly correlated with FM% (r = 0,794; P < 0,001)

Conclusions: Although more data are needed to confirm these preliminary findings, the results suggest that phase angle is a valuable non-invasive and easily usable tool to identify risk in the early stages of obesity-related health consequences, PA could be a surrogate marker to detect insulin resistance. Woman with the same BMI had quite different amounts of fat mass and associated cardiometabolic risk. In addition, we will perform correlation analysis to assess the relationship between PA and HOMA2-B, HOMA2-IR, and adipokines as well.

Reference

1. Howe CA, Corrigan RJ, Djalali M, McManaway C, Grbcich A, Aidoo GS. Feasibility of Using Bioelectrical Impedance Analysis for Assessing Youth Weight and Health Status: Preliminary Findings. doi:10.3390/ijerph181910094