P5.30 PHYSICAL ACTIVITY, ARTERIAL STIFFNESS AND OBESITY

Abstract

Objectives: To examine the role of physical activity in vascular stiffness and markers of adiposity and inflammation in “healthy” subjects. Methods: Seventy-nine (51 male & 28 female) healthy subjects were recruited. All were lifelong non-smokers, normotensive, normolipidaemic and normoglycaemic. Augmentation index (AIx) and pulse wave velocity (PWV) were measured using applanation tonometry (Sphygmacor & Vicorder). Daily physical activity patterns were measured using triaxial accelerometry and expressed as time spent being sedentary, lightly active and vigorously active. Body composition was estimated using bioimpedence. The adipose associated markers, leptin & adiponectin, and inflammatory markers, IL-6, TNFá & MCP-1 were also measured. Results: Time spent being sedentary was significantly associated with AIx (r=0.38, P<0.001), PWV (r=0.33, P<0.01), body fat composition (r=0.40, P<0.001) and age (r=0.30, P<0.01). Vigorous activity was inversely correlated with AIx (r= −0.28, P<0.05) body fat composition (r=−0.30, P<0.01), post prandial insulin (r=−0.35, P<0.01) and leptin/adiponectin ratio (r=−0.28, P<0.05). The inflammatory cytokines, IL-6, TNFá and MCP-1, were not significantly correlated with any activity categories. Conclusion: The main findings of the study are that people, who spend more time being sedentary, despite being clinically healthy, have stiffer arteries and more body fat compared to those who spend less time being sedentary. Conversely, people that spend more time being active have less arterial stiffness, lower body fat, post prandial insulin and leptin/adiponectin ratio. These results suggest that activity related changes in arterial stiffness in healthy people may be mediated by the hormonal/metabolic consequences of inactivity rather than pro-inflammatory mechanisms.