ABSTRACT
Objective To assess the differences in carotid artery stiffness properties and endothelium-independent dilation (EID)between elderly and young patients,and evaluate the echotracking (ET)system for vascular stiffness at different ages.Methods A total of 79 outpatients with multiple cardiovascular risks were recruited.Clinical data including medical history,height,weight,blood pressure,fasting blood glucose and blood lipid were collected.We evaluated the arterial stiffness parameters of carotid artery and EID using an ultrasonic ET system in 46 elderly subjects,compared with 33 sex-matched non-elderly subjects.The impaired EID function was defined as brachial artery nitroglycerin mediated dilation (NMD)below 4％.Results All stiffness parameters including pressure-strain elasticity modulus stiffness index β (Ep),pulse wave velocity β (PWVβ)and augmentation index (AI)were significantly increased in elderly group compared with the non-elderly group [(138.9±64.7)kPa vs.(100.6±30.8)kPa,(10.9±4.7)vs.(8.2±2.3),and (6.9±1.4)m/s vs.(6.1±0.9)m/s,P＜0.05 respectively],while the exception of arterial compliance (AC)was reduced (0.9±0.3)mm2/kPa vs.(1.0±0.5)mm2/kPa(P＜0.05).The incidence of impaired EID in elderly group was higher than in non-elderly group [56.5％ (26 cases) vs.33.3％ (11 cases),P＜0.05].ET parameters including Ep,stiffness index β,PWVβ,AC and AI were related to age (r=-0.44,-0.45,-0.40,-0.40,0.34,all P＜0.01)； Ep,stiffness index β,PWVβ and AC were also related to impaired EDI (r=-0.38,-0.40,-0.34,-0.29,all P＜0.01).Conclusions Arterial stiffness properties and EID measured by ET system was more serious in elderly with multiple cardiovascular risks than in non-elderly subjects.As a convenient and accurate assessment of stiffness parameters,ET system is optimal option for measuring arterial stiffness and EID in elderly people.