Abstract
The relationship between the Renin-Angiotensin-Aldosterone System (RAAS) and modulation of the Autonomic Nervous System (ANS) is reported as complex and bidirectional. Thus, the present study aimed to compare autonomous heart control, through symbolic analysis parameters, in the older adults carrying different ACE I/D gene polymorphisms (rs4646994). Two hundred four older adults comprised the study population and were grouped according to the ACE I/D gene polymorphism: II + ID genotype and DD genotype. Successive RR intervals were recorded along 5 min and analyzed with Symbolic Analysis (SA) method. 0 V%, 1 V% and 2 V% patterns were quantified and compared between groups. A linear mixed model analysis was used to determine between-group differences in symbolic analysis parameters (0 V%, 1 V% and 2 V%), taken groups as fixed factor and sex, use of ACE inhibitors and Angiotensin II receptor type I blockers as random factors. The Bayesian analysis was carried out to check the magnitude of the evidence. The results of this study indicate that older adults carrying the DD genotype have statistically greater sympathetic modulation (0 V%) and poor sympathovagal balance (1 V%), but the Bayesian analysis indicate only an anecdotal effect. Sympathetic predominance is recognized a worrying condition, since may predisposes to cardiovascular risk.