Relationship between baroreflex sensitivity and hsCRP in natural human aging is dependent of gender

Background: Aging promotes increased levels of circulating proinflammatory markers and decrease in cardiac autonomic function that can be evaluated by high sensitivity C-reactive protein (hsCRP) and heart rate variability (HRV), respectively. Studies shown relation between the immune system and HRV, however, few studies are related to the baroreflex sensitivity (BRS). Aim: To evaluate the relationship between cardiovascular autonomic nervous system (BRS) and hsCRP in natural human aging in a wide range of age and gender. Methods: One hundred and ten apparently healthy individuals (without hsCRP values suggestive of acute inflammation, above 3.0 mg/L) were divided into 2 groups (men and women) and then, equally assigned into 5 groups (21-30; 31-40; 41-50; 51-60 and 61-70 years), 11 subjects in each group. The electrocardiographic, respiratory and noninvasive finger arterial pressure signals were recorded for 15 minutes, in rest supine (REST) and in orthostatic position (STAND), and sampled at 400Hz. Stable sequences of 256 points in REST and STAND were chosen. Cross-spectral analysis was performed to compute coherence, phase and BRS in low (LF) frequency. Blood was collected after a 12-hour fasting. The turbidimetry method was used for hsCRP analysis. Results: Spearman correlation test showed a negative significant relationship (p < 0.05) between hsCRP and phase (r = -0.576) and between hsCRP and BRS (r = -0.356) in LF in STAND in women, however, no correlation was found in men. Conclusion: The relationship between proinflammatory marker and cardiovascular autonomic nervous system showed a gender dependency therefore gender should be taken into account in the analysis of the cardiovascular autonomic nervous system. Financial support: FAPESP: 2010/52070-4; CNPq: 311938/2013-2; CNPq: 140164/2015-4.