Higher Daily Physical Activity Level Is Associated with Lower RBC Aggregation in Carotid Artery Disease Patients at High Risk of Stroke.

Pauline Mury,Vincent Pialoux,Patrick Lermusiaux,Philippe Joly,Antoine Millon,Nellie Della Schiava,Sarah Skinner,Céline Renoux,Mathilde Mura,Virginie Nicaise,Camille Faes,Philippe Connes

doi:10.3389/fphys.2017.01043

Abstract

Aim: Carotid artery disease (CAD) is an atherosclerotic inflammatory disease that affects the arterial wall, specifically at points of bifurcation where blood flow is disturbed. Abnormal blood rheology could participate in the pathophysiology of ischemic cardiovascular disease. Physical activity (PA) is known to improve blood rheology in several chronic disorders. This study aims to (i) compare the hemorheological profile of CAD patients and controls and (ii) investigate the associations between daily PA and hemorheological parameters in CAD patients.Methods: Blood viscosity, red blood cell (RBC) aggregation and RBC deformability were assessed in 80 patients (15 symptomatic and 65 asymptomatic) and 14 age-matched controls. Patients' PA levels were evaluated using questionnaires.Results: Symptomatic patients showed increased blood viscosity and RBC aggregation compared to healthy controls. RBC aggregation was significantly lower in the most physically active patients compared to the least physically active ones. Blood viscosity and RBC deformability did not vary according to physical activity level.Conclusions: Our results showed greater hemorheological abnormalities (blood hyper-viscosity and hyper-aggregation of red blood cells) in the most severe CAD patients, which could exacerbate the risk of stroke in patients with stenosis. As the most physically active patients had lower RBC aggregation than those who were less physically active, it is possible that regular PA may limit hemorheological alterations in CAD patients.

Highlights

Atherosclerosis is the leading cause of mortality and morbidity in western countries, and will likely become the leading cause of death worldwide in the near future
Blood viscosity was significantly higher in symptomatic patients (p < 0.05) compared to healthy individuals and a trend
BMI, body mass index; red blood cells (RBC), red blood cell count, WBC, white blood cell count, Hb, hemoglobin. **p < 0.01 significant difference compared to symptomatic patients

Summary

Introduction

Atherosclerosis is the leading cause of mortality and morbidity in western countries, and will likely become the leading cause of death worldwide in the near future. Atherosclerosis is a complex inflammatory disease that affects the arterial wall, leading to atherosclerotic plaque formation (Redgrave et al, 2008). Atherosclerotic plaques build up in specific regions of the arterial system, such as in carotid bifurcations, the aortic arch, and in the femoral arteries. In these regions, blood flow is disturbed and the expression of biomarkers of atherogenesis and thrombosis correlates with the extent of flow recirculation patterns (Martorell et al, 2014). RBC aggregation has been shown to affect blood flow in both micro- and macro-vessels where shear rate is high, notably because of its effects on several rheological phenomena such as axial migration, cell free layer formation, and the Fahraeus effect, the latter occurring mainly in the microcirculation (Baskurt and Meiselman, 2008). Abnormal blood rheology could be involved in the pathophysiology of ischemic stroke

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