RESUMEN
The structure and function of central arteries are altered with advancing age. These changes comprise arterial dilation, intima-media thickening and increase in stiffness. Arterial wall hypertrophy and increased stiffness are associated with major cardiovascular disease. In contrast to this, physical activity has been found to be inversely related to the incidence of major cardiovascular disease and mortality in humans. However, conflicting data exist on the effect of physical activity on arterial stiffness and very little data about its association with structural arterial properties. We therefore investigated the association of the self-selected leisure-time physical activity (LTPA), assessed by a self-administered questionnaire, with the structure and function of the common carotid artery, examined with high-resolution ultrasound, in 51 male subjects aged between 16 and 78 years. We found that men with a higher level of LTPA (> 38.1 MET*h/week = H-LTPA) (metabolic equivalent value; 1 MET= energy expended by a person at rest, i.e. approximately 3.5 ml oxygen uptake/kg body mass or 1 kcal/kg per h) had a significantly lower arterial stiffness (P = 0.02) than men with lower levels ( < 38.1 MET*h/week = L-LTPA) (4.32+/-1.17 versus 5.75+/-1.21 x 10(6) cm(-2)). In multiple regression analyses, with several atherosclerotic risk factors as correlating variables with arterial stiffness, LTPA persisted as an independent predictor of arterial stiffness (adjusted R2=0.19) in addition to apolipoprotein B level (adjusted R2 = 0.33). The study could not, however, show an association of LTPA with reduced intima-media thickness (L-LTPA = 0.66+/-0.15 versus H-LTPA 0.66+/-0.14) or arterial dilation of diastolic diameter (L-LTPA = 6.34 + 0.64 versus H-LTPA 6.08+/-0.69). However, the positive association of LTPA with several parameters, which correlated inversely with intima-media thickness, may be taken as an indicator for a possible positive (not visible in an ultrasonic examination of the common carotid artery) effect of LTPA on the arterial wall structure.
Asunto(s)
Arteria Carótida Común/diagnóstico por imagen , Ejercicio Físico , Adolescente , Adulto , Anciano , Apolipoproteínas/sangre , Arteriosclerosis/diagnóstico por imagen , Arteriosclerosis/fisiopatología , Presión Sanguínea , Índice de Masa Corporal , Arteria Carótida Común/fisiología , Colesterol/sangre , Elasticidad , Metabolismo Energético , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Análisis de Regresión , Factores de Riesgo , Encuestas y Cuestionarios , Ultrasonografía DopplerRESUMEN
Aging of the common carotid artery (CCA) is associated with different principal structural, functional, and hemodynamic changes, which are often influenced by several atherosclerotic risk factors, so that it is difficult to estimate the exclusive effect of aging on this process. Studies dealing with vascular aging of the CCA usually assess only single, dimensional, or functional parameters, although it is likely that there are interactions and probably differences between them. Moreover, regional vascular blood flow characteristics are often not taken into consideration. Therefore, the aim of the study was to assess the age-related multiparametric changes of the CCA properties with ultrasound in 69 male subjects between the ages of 16 and 75 (42.4+/-16.5 years), who were screened for the absence of major atherosclerotic risk factors or existing vascular disease. As a result, the intima media thickness (0.052 mm/10 y) and diastolic diameter (0.17 mm/10 y) increased nearly linearly with age (r=0.60, P<0.001; and r=0.46, P<0.001, respectively). The absolute diastolic/systolic diameter change diminished by 0.10 mm/10 y (r=-0. 73, P<0.001) and peak expansion velocity dropped by 0.12 cm/s per 10 years (r=-0.62, P<0.001) highly significantly with age. The peak blood flow velocity decreased continuously with age (r=-0.67, P<0. 00) by 9.3 cm/s per 10 years. According to multiple regression analysis, peak blood flow velocity seems to reflect the changes of several structural and functional parameters in one; intima-media thickness was determined by diastolic arterial diameter and age as independent variables. The data indicate that a multiparametric assessment may contribute to a better understanding of vascular aging and might be the basis for further studies to evaluate the association of atherosclerotic risk factors and/or major vascular disease with local changes in the CCA.
Asunto(s)
Envejecimiento/fisiología , Arteria Carótida Común/anatomía & histología , Arteria Carótida Común/fisiología , Hemodinámica/fisiología , Adolescente , Adulto , Anciano , Presión Sanguínea , Índice de Masa Corporal , Arteria Carótida Común/diagnóstico por imagen , Elasticidad , Humanos , Masculino , Persona de Mediana Edad , Túnica Íntima/citología , UltrasonografíaRESUMEN
In this study, the wall motion of the common carotid artery was characterized by measuring wall-motion velocity (Wv) with tissue Doppler imaging (TDI) in 78 male and female subjects (16-75 y) with no history of cardiovascular disease. The near and far arterial wall showed essentially different Wv patterns. To assess the vascular systolic distension, the Wv of the near and far arterial walls were measured and a Wv index was calculated by subtracting the far Wv from the near Wv. Aging was associated with a 2.0-2.5-fold decrease of peak Wv index. Corrected for carotid diameter and blood pressure, the peak Wv index and mean systolic acceleration to the peak Wv correlated highly with arterial distensibility (r = 0.81 resp. r = 0.75) and compliance (r = 0.73 resp. r = 0.68). This study demonstrates the feasibility of TDI in the characterization of wall motion patterns and in the assessment of common carotid artery stiffness.