Vascular Dynamics During Respiratory Arousal From Sleep Assessed by Oximeter‐Based Vascular Stiffness Measures

. Dynamic, short-term changes in PPG-derived PPT are significantly associated with cortical arousals following respiratory events in OSA patients. This parameter provides independent predictive information beyond established PPG metrics, likely reflecting rapid, arousal-induced alterations in vascular tone. These findings highlight a novel PPG-based marker that could quantify the vascular stress in OSA.