P6.14 THE EFFECT OF PHYSICAL ACTIVITY ON 24-HOUR AUGMENTATION INDEX

Abstract

Introduction: Augmentation Index (AIx) is a surrogate measure of systemic arterial stiffness and wave reflections. Clinic measures of AIx are considered to be a sensitive measure of risk in young adults and are lower in individuals who take part in high levels of physical activity (PA). The development of an ambulatory blood pressure monitoring (ABPM) system, which also calculates AIx, now allows usual AIx to be assessed. The aim of this study was to assess the association between 24-hour AIx and levels of physical activity in a young healthy cohort. Methods: Forty-six adults (23±5years, 28% male) took part in the study. 24-hour AIx@75 (AIx at heart rate 75bpm) was measured using the ABPM device (Mobil-O-Graph, IEM). Weekly PA levels were recorded using a detailed PA questionnaire (total minutes per week). Results: An inverse association between 24-hour AIx@75, Night-time AIx@75 and levels of PA (r =−0.420, P<0.01 and r =−0.403, P<0.01, respectively) were observed. Interestingly, no associations were observed between 24-hour blood pressure and levels of PA. Conclusion: These novel data, in a young normotensive cohort illustrate the beneficial effect of increased PA on 24-hour AIx. 24-hour measurements of vascular function may provide a more robust tool to understand the chronic effects of PA on vascular health. Further studies are needed to understand the use of ABPM for 24-hour monitoring of vascular stiffness.