The relationship between indices of parasympathetic nervous activity and cardiovascular health in men

Background: Cardiovascular disease is a primary cause of death worldwide. Low parasympathetic nervous activity (PNA) is associated with negative cardiovascular health (CVH) [1]. Central augmentation pressure (CAP), aortic pulse pressure (APP) and augmentation index (Alx) are all strong indicators of CVH. Heart rate variability (HRV) and recovery heart rate (RHR) are both indices of PNA but they do not correlate [2]. Since these indices do not correlation we hypothesized that there would be a difference in their relationship with CVH as determined by CAP, APP and Alx75. Aim: To determine if there is a difference in the relationships between HRV, RHR and CAP, APP and Alx in men. Methods: Seventeen healthy college aged men were examined for HRV via power spectral density analysis. Recovery heart rate was examined at minute one (RHR1) and two (RHR 2)) following a VO2max test. Pulse wave analysis via applanation tonometry and a generalized transfer function was used to determine CAP, APP and Alx. Results: There was a significant correlation between HRV and CAP (r = 0.61, P = 0.01) and Alx (r = 0.51, P = 0.05). No correlation was observed between RHR 1, RHR 2 and CAP, Alx and APP. Central augmentation pressure was significantly correlated with APP (r = 0.67, P = 0.01) and Alx r = 0.64, P = 0.01). Conclusions: Findings suggest a difference in the relationship between HRV, RHR and CVH. Here HRV was positively correlated with indices of CVH, while RHR did not correlate with these indices. Indicating that HRV seem to be more indicative of CVH versus RHR.