Correlation of the Phase Angle with Muscle Ultrasound and Quality of Life in Obese Females

Phase angle (PhA) has been suggested to be an indicator of body cell mass and nutritional status. Clinically, the phase angle supposedly reflects body cell mass and cell membrane function, and the higher the phase angle, the better is the cell function. Muscle ultrasound (US) is an emerging nutritional assessment technique.

The aim of this study was to investigate the usefulness and correlation of PhA with muscle US of quadriceps rectus femoris (QRF) in obese female subjects and the relationship with quality of life and physical performance. Material and Methods. In a total of healthy 50 obese female patients, anthropometric data by BIA, muscle mass by ultrasound at the QRF level, analytical determination, blood pressure, and quality of life were measured. Physical performance was assessed, too.

In total, 50 female obese patients were included with a mean age of 45.9 ± 2.4 years. The mean body mass index was 32.1 ± 1.6 kg/m² with a mean weight of 83.5 ± 14.6 kg. Correlation analysis showed a positive correlation of PhA with all US parameters corrected by squared height (anteroposterior muscle thickness, circumference, cross-sectional area, and Echo-intensity). The correlation analysis of biochemical parameters with PhA showed a positive correlation with serum albumin and total protein levels. Physical activity and vitality scores of SF36 were correlated with PhA. Finally, PhA was positive correlated with physical performance, doing push-ups in 30 seconds (r =0.42; p =0.03) and doing squats in 30 seconds (r =0.54; p =0.02), without correlation with the time of 1.5 km walk.

PhA was correlated with muscle area, muscle circumference, muscle echo intensity, serum protein, quality of life SF-36, and strength physical performance.