Gender-based Differences in Cardiac Sympathetic and Parasympathetic Activity Among Healthy Individuals

Gender and associated anatomical and physiological features likely convey specific characteristics to autonomic nervous system dynamics. Nevertheless, prior studies have provided conflicting findings. In this study, leveraging the ESGCO 2024 challenge, we estimated the Sympathetic Activity Index (SAI) and Parasympathetic Activity Index (PAI) from Heart Rate Variability (HRV) series recorded from 276 healthy subjects during a resting supine state, obtained from the Hypol open-access database. SAI and PAI were derived by applying an orthonormal Laguerre expansion on the RR interval series and were compared with the classical HRV spectral powers. Results revealed that, while standard HRV powers did not display statistically significant differences by gender, PAI was significantly higher in males compared to females. Moreover, we noted a decreased variability of SAI in male subjects. In conclusion, SAI and PAI are more sensitive indices for detecting gender differences compared to spectral HRV indices. We suggest that male subjects may be associated with higher parasympathetic activity and lower sympathetic variability than female subjects.