Interaction between autonomic nervous system and vascular function in resistant hypertension

Author(s)

Wladimir Mignone Gordo

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas
• Defense date: 2014-03-12

Examining board members

Heitor Moreno Junior; Luiz Claudio Martins; Marcos Mello Moreira; Juan Carlos Yugar Toledo; Marcelo Nicolas Muscara

• Advisor: Heitor Moreno Junior

Abstract

Resistant hypertensive patients are generally overweight or obese, either high blood pressure as obesity contribute to vascular damage. Moreover, previous data showed that autonomic imbalance is related to obesity as well as hypertension. Reduced heart rate variability (HRV) may represent a risk factor for hypertension. In order to better understand the relationship between impaired autonomic function and resistant hypertension (RHTN), we aimed to evaluate the association between HRV, obesity and vascular function in RHTN. Thirty-seven resistant hypertensive patients were selected. Parameters of HRV were derived from the simultaneous recording of 24-hour Holter ambulatory electrocardiographic /ABPM and analyzed in time domain. Endothelial function was assessed by flow mediated dilation (FMD) technique and arterial stiffness by pulse wave velocity (PWV). We found positive correlation between standard deviation of all normal RR intervals (SDNN) and standard deviation of mean RR interval in all 5-minute segments of a 24-hour recording (SDANN) with FMD (r = 0.56, p= 0.001; r = 0.48, p = 0.006, respectively) but not with PWV. In addition, SDNN was negatively correlated with body mass index and waist circumference (r = -0.44, p = 0.01; r = -0.34, p = 0.04, respectively). These data strengthen the importance of sympathetic overactivity in obese resistant hypertensive subjects. Furthermore, the relationship between HRV parameters with endothelial dysfunction and obesity suggest a potential pathophysiological mechanism in RHTN (AU)

• FAPESP's process: 11/09329-0 - Mapping of factors on resistant hypertension in obese patients: the integration between the autonomic nervous system and endocrine adipose tissue
• Grantee: Wladimir Mignone Gordo
• Support Opportunities: Scholarships in Brazil - Doctorate