Lower bioelectrical impedance phase angle is associated with COPD and is a marker for increased risks in elderly COPD patients

In this cross-sectional study, a lower PhA is independently associated with muscle weakness and impaired physical performance in men with COPD. These findings suggest that PhA may serve as a useful biomarker for assessing nutritional and functional status in this population. However, the cross-sectional design precludes causal inference, and the diagnostic utility of PhA for COPD itself is not established.