Abstract
Short-term complexity of heart period (HP) and systolic arterial pressure (SAP) was computed to detect age and gender influences over cardiovascular control in resting supine condition (REST) and during standing (STAND). Healthy subjects (n = 110, men = 55) were equally divided into five groups (21–30; 31–40; 41–50; 51–60; and 61–70 years of age). HP and SAP series were recorded for 15 min at REST and during STAND. A normalized complexity index (NCI) based on conditional entropy was assessed. At REST we found that both NCIHP and NCISAP decreased with age in the overall population, but only women were responsible for this trend. During STAND we observed that both NCIHP and NCISAP were unrelated to age in the overall population, even when divided by gender. When the variation of NCI in response to STAND (ΔNCI = NCI at REST-NCI during STAND) was computed individually, we found that ΔNCIHP progressively decreased with age in the overall population, and women were again responsible for this trend. Conversely, ΔNCISAP was unrelated to age and gender. This study stresses that the complexity of cardiovascular control and its ability to respond to stressors are more importantly lost with age in women than in men.
Highlights
Aging is associated with a reduced ability of the physiological regulatory mechanisms to interact, leading to less flexible cardiovascular control [1,2]
The abovementioned studies indicate that aging reduces the complexity of the cardiovascular control and prove the gender dependence, it is still unclear whether the complexity reduction and the gender relation are observable from heart period (HP) and systolic arterial pressure (SAP) variabilities and if it persists during a cardiovascular control challenge
The aging and gender effects on the complexity of HP and SAP variability are assessed by means of a univariate approach assessing irregularity as the amount of information carried by a series that cannot be derived from the knowledge of its own past values through the corrected conditional entropy [24] in several age groups in resting supine condition and during sympathetic activation induced by active standing in healthy subjects
Summary
Aging is associated with a reduced ability of the physiological regulatory mechanisms to interact, leading to less flexible cardiovascular control [1,2]. Protocols assessing the effect of aging on the complexity of the cardiovascular control are mainly limited to the evaluation of the complexity of the HP variability [13,14,15,19,20,21,22,23] and mostly do not deliberately challenge the cardiovascular control according to an experimental maneuver or pharmacological intervention [13,14,15,16,17,18,19,22,23]. The aging and gender effects on the complexity of HP and SAP variability are assessed by means of a univariate approach assessing irregularity as the amount of information carried by a series that cannot be derived from the knowledge of its own past values through the corrected conditional entropy [24] in several age groups in resting supine condition and during sympathetic activation induced by active standing in healthy subjects
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
