Diastolic Wall Shear Stress in the Internal Carotid Artery Is Associated with Different Cardiovascular Risk Factors than Systolic Wall Shear Stress

Abstract

Background and Purpose: Wall shear stress (WSS) is the frictional force exerted by the circulating blood on the endothelium. Low systolic WSS is identified as an atherosclerotic risk factor. Recently, also the importance of diastolic WSS has been described. Still, it is unknown whether diastolic WSS carries similar cardiovascular risk factors compared to systolic WSS. Methods: Of 379 subjects (70–82 years, 56% male) diastolic and systolic WSS in the internal carotid arteries was determined. Results: After adjustment for age and gender, diastolic blood pressure was associated with systolic WSS (p = 0.02). Body mass index was associated with diastolic WSS (p = 0.04). Smoking was associated with diastolic WSS (p = 0.05). Myocardial infarction was associated with both systolic WSS (p = 0.04) and diastolic WSS (p < 0.01). No associations between cholesterol, HDL, LDL, triglycerides, history of diabetes, hypertension, angina pectoris, claudication, stroke, or any vascular disease were found with systolic or diastolic WSS. Conclusions: Our data indicates different cardiovascular risk factors for diastolic WSS compared to systolic WSS.