Cardiovascular Autonomic Modulation Procedures for spectral analysis of pulse interval (heart rate variability) and systolic blood pressure variability have been described in the literature41-44. Each heartbeat will be identified using a specialized algorithm implemented in Matlab MT software (MATLAB 6.0, Mathworks, USA ) and which automatically detects PAS and PAD waves. The pulse interval or R-R interval will be calculated as the difference between the start and end points of the cycle (t1-t0). The power spectral density of the PAS and R-R interval will be calculated using the Fast Fourier Transform and the Welch method over 16,384 points with a Hanning window and 50% overlap. The spectral bands evaluated for humans were defined according to literature references: very low frequency (MBF: 0.007-0.04Hz), low frequency (BF: 0.04-0.15Hz), high frequency (AF: 0. 15-0.4 Hz) and full power \[130\]. Baroreflex sensitivity will be inferred from the alpha index (HR BF ratio in ms2 / SBP BF ratio in mmHg).
ABPM - It will be performed with the CardioMAPA Monitor - Cardios - Brazil, with standardized measurements every 15 minutes during the waking period, and every 20 minutes during the sleeping period. The data will be considered valid when monitoring takes place for a minimum period of 21 hours with a minimum number of forty measurements during wakefulness and ten measurements during sleep.
Determination of Central Blood Pressure and Amplification Index (AIx) - The SphygmoCor CPV system (AtCor Medical, USA) is a sophisticated non-invasive diagnostic tool for clinical assessment of central blood pressure. This system derives central aortic pulse wave pressure (systolic, diastolic, and pulse) using pulse wave pressure recorded by the radial artery. Pulse wave analysis predicts parameters including PAC and indications of vascular stiffness. Measurements are made using a pressure transducer (tonometer) positioned in the required artery and then the pulse wave is recorded. Furthermore, this equipment provides information on arterial stiffness by analyzing the Augmentation Index \[Amplification Index (AIx)\], defined by the ratio between the pressure determined by the reflected wave and the ejection wave capable of providing information on arterial stiffness.
Assessment of Clinical Parameters - BP measurements will be taken according to the recommendations recommended by the VIII Brazilian Guidelines on Arterial Hypertension using a digital sphygmomanometer (Omron HEM-711DLX). Pulse pressure (PP) will be calculated from the difference between SBP and DBP values. All individuals will undergo ambulatory BP monitoring (ABPM) for a period of 24 hours using the Spacelabs 90217 equipment (Spacelabs Inc, Redmon, WA, USA). Patients will be instructed to maintain and record normal daily activities. The averages of SBP, DBP and PP will be evaluated.
Assessment of Biochemical and Inflammatory Parameters - Fasting blood samples will be collected and the following tests will be carried out: glucose, glycated hemoglobin A1C, total cholesterol and fractions, urea, creatinine, renin, aldosterone, cortisol, creatinine clearance and microalbuminuria. The biomarkers norepinephrine, dopamine, adrenaline, adrenocorticotropic hormones (ACTH) and cortisol, acetylcholinesterase, ultrasensitive C-reactive protein, interleukins 2, 8, 10 and 12 (IL-2, IL-8, IL-10 and IL-12) will be determined by ELISA according to the manufacturer's instructions.
