Determining autonomic sympathetic tone and reactivity using Baevsky’s stress index

• DOI: 10.1152/ajpregu.00243.2024
• Publication Date: 2025-02-27T14:32:47Z
• Authors: Jan D. Huizinga; Ji-Hong Chen; Amer Hussain; Difei Zheng; Lijun Liu; Hansel Lui; Maxwell Pan; Xurui Chen; Brienna DiBattista; Marzia Alam; Julia Niro
• Keywords: Supine position; Vagal Tone; Sympathetic nervous system

The extrinsic autonomic nervous system is critical in controlling most organ functions and involved the pathophysiology of many chronic diseases. However, its assessment plays a minor role clinical practice diagnosis treatment outside cardiology. Since sympathetic dysfunction related to diseases such as diabetes, stress, urinary gastrointestinal motor dysfunction, an warranted. Here, we evaluate Baevsky Stress Index (SI) assess tone reactivity based on heart rate variability. We start with discussing Baevsky’s original stress index. propose optimized calculation SI 73 self-declared healthy subjects age groups 16-35, 35-50, 50+ at supine baseline response postural change from standing. Normality kernel density analysis identified two subgroups: one deemed have normal functioning, outlier group significantly higher index Using Gaussian mixture model, determined values for dysfunction. This study provides needed using