IJCS | Volume 33, Nº4, July and August 2020

350 Pereira & Costa Arterial stiffness in the older adult Int J Cardiovasc Sci. 2020; 33(4):349-356 Original Article the pulse wave velocity (PWV) and an earlier return of the reflected waves, leading to an increase of both systolic blood (SBP) and pulse pressure (PP). Therefore, aging-related hypertension (HT) is characterized by a significant increase in SBP and no change or even a decrease in diastolic blood pressure (DBP), and the predominant phenotype in elderly people is thus isolated systolic hypertension (ISH). 13 In addition, it is also known that the arterial stiffening process is accelerated by HT. 14 Frailty has also been linked with CVD in the elderly, and cardiovascular risk factors, in turn, predict frailty. 15 Handgrip strength (HGS) has been proved to be a reliable indicator 16 of frailty, 17 and therefore, an indicator of functional decline. AS is influenced by several factors, such as age, BP, metabolic profile, genetics, medication, body composition, lifestyle, among others. 5,6 Although these factors have been widely studied in the general population and in particular clinical settings, such as HT, diabetes, dyslipidemia and chronic kidney disease, little evidence exists concerning the elderly population. Therefore, the aim of this study was to identify the main determinants of AS in the elderly. Methods Study design, population and ethical considerations This was a cross-sectional, observational, study of participants enrolled in theAGA@4life project. The aimof theAGA@4life project is to evaluate the effects of different interventions (psychological, physical and nutritional therapy) on the promotion of an active and healthy aging. This preliminary analysis aims at identifying the main determinants of baseline AS of the elderly enrolled in the project. The study population was recruited from a day care center in Portugal ( Associação para a Defesa do Idoso e da Criança - ADIC , Vilarinho, Portugal). People aged above 65 years, of both genders, physically autonomous andwith no prior history of cerebrovascular or neurological disorders were invited to participate in the study. The study enrolled 54 elderly volunteers aged between 65 and 94 years, who agreed to participate, i.e., by convenience sampling. The study was conducted according to the guidelines of the Declaration of Helsinki and approved by the Ethics Committee of the Polytechnic Institute of Coimbra. Anonymity and confidentiality of the collected data were assured. The study was conducted for scientific purposes only, and thus, there’s no conflict of interest to be declared. All participants signed an informed consent prior to the study. Blood pressure and arterial stiffness AS was obtained by pulse wave analysis (PWA) using the AGEDIO device (IEM, Stolberg, Germany), which uses the Mobil-O-Graph validated technology for recording brachial blood pressure (bBP) and performing PWA. 7-10 Oscillometric measurement of bBP provides brachial SBP (bSBP) and brachial DBP, mean arterial pressure (MAP) and pulse pressure (PP), as well as heart rate (HR). Immediately after the measurement of bBP, the cuff is reinflated at diastolic phase for approximately 10 seconds, while continuously recording brachial pulse waves with a high-fidelity pressure sensor. 7-10 Brachial SBP and bDBP are used for calibrating the pulse waveforms. Afterwards, the device’s software (HMS, version 5.1) applies a generalized transfer function, the ARCSolver algorithm, to reconstruct the aortic pulse waveforms. 7-10 Wave separation analysis is implemented by decomposition of the aortic pulse waveform into forward (incident) and backward (reflected) pulse waves. These data together with aortic characteristic impedance, age and gender allow the estimation of oscillometric PWV. After quality check, the main parameters derived from the PWA are obtained, including: PWV, which is estimated from the reconstructed aortic pulse waveform, taking into consideration the characteristic impedance and age, and assuming a three-element Windkessel model; 9 the augmentation pressure (AP), the augmentation index (AIx) and the heart-rate adjusted augmentation index (AIx@75), all of themmeasures of the augmentation component of the aortic SBP, dependent on the timing of the reflected wave; total vascular resistance (TVR), also derived from the ARCSolver algorithm. Increased AS was classified considering the reference values for PWV, i.e., two standard-deviations (SDs) above the reference PWV values, adjusted for age and gender. 5 Overall procedure Participants were enrolled in the study in January 2018. During February andMarch 2018, multidisciplinary diagnostic evaluation of each participant was performed at baseline, comprising the analysis of relevant demographic and clinical information, including comorbidities, ongoing treatments, diet, physical activity,