Relation of aortic stiffness to factors modifying the risk of atherosclerosis in healthy people.

Abstract

To identify factors predicting aortic stiffness, we studied the modulus of elasticity of the thoracic aorta in relation to sex, obesity, blood pressure, physical activity, smoking, ethanol consumption, salt intake, and serum lipid and insulin levels in 55 healthy people born in 1954. A transverse cine magnetic resonance image of the thoracic aorta was made, and the modulus of elasticity was determined as brachial artery cuff pulse pressure/aortic strain, where strain was determined as the ratio of pulsatile aortic luminal area change to the diastolic luminal area. The average of measurements made in the ascending and descending aorta was used as the elastic modulus of the thoracic aorta. Habitual physical activity, smoking, and alcohol use were quantified by 2-month prospective daily recording and salt intake by 7-day food records. The aortic elastic modulus ranged from 100 to 2091 10 3 dyne/cm 2 (median, 390 10 3 dyne/cm 2 ). In multiple regres-T he stiffness of the thoracic aorta influences aortic conduit function, contributes to blood pressure and left ventricular load, and may also modify the aortocoronary blood flow. 13 People with coronary artery disease have abnormally rigid aortas, 3 " 6 and noninvasive measurement of aortic distensibility has been considered for a targeted screening of coronary atheroma.7 For these reasons it has become timely to know what factors modify aortic pulsatility and in what way. It is generally agreed that the stiffness of the aorta increases with age and in hypertension,'-2 -6 -10 but knowledge of other potential predictors is insufficient and partly contradictory.6 ' 813 Concerning the relation of aortic stiffness to blood cholesterol level, some reports show a positive association, 1112 others a negative one, 613 and the rest no association. 810 Although part of these differences may be attributed to the modifying effect of age, 11 -13 confusing contrasts between the data 6 -12 still remain.The purpose of this study was to examine the predictors of aortic stiffness in a sample of the general adult population homogeneous for age and free of significant cardiovascular disease. In principle, aortic stiffness can be assessed noninvasively either by studying the relation between pulsatile changes in blood pressure and aortic luminal size or more indirectly by measuring the pulse wave velocity through the thoracoabdominal aorta. Key Words • aortic stiffness • magnetic resonance imaging • lipids • insulin • physical activity • sodium intake this study, we used cine magnetic resonance imaging (MRI) to measure the systolic and diastolic crosssectional areas of the ascending and descending thoracic aorta and calculated the modulus of elasticity 14 as an index of aortic stiffness. The present report describes the relations of aortic stiffness to those factors known to modify the risk of cardiovascular diseases, such as sex, obesity, blood lipid levels, physical activity, smoking, alcohol consumption, sodium intake, and serum insulin level. Methods Study PopulationThis wo...

Relation between insulin and aortic stiffness: a population-based study

“…Generally, a positive association has been found between insulin levels and arterial stiffness, but in many of these studies no adequate adjustments for HR were made. [28][29][30][31][32][33] However, in the three recently published studies, using the same methods as in the present study to measure PWV, no independent relationship between insulin and PWV could be identified after adjustment was made for SBP or mean BP, HR, sex, and age, 10-12 so at first glance our findings are not consistent with these results. Another finding that at first glance appears to be in contrast with the findings in the present study comes from Yki-Jarvinen and coworkers, who in different groups of subjects have shown that infusion of insulin producing acute hyperinsulinaemia leads to a marked decrease in large arterial stiffness.…”

“…1 Several other studies have examined the relationship between insulin and arterial stiffness. [15][16][17][18][28][29][30][31][32][33] Many different methods and indices have been used Table 4 because P>0.05: log of VLDL cholesterol, LDL cholesterol, HDL cholesterol, log of triglycerides, log of glucose, history of diabetes, diastolic BP, treatment of hypertension, BMI, waist/hip ratio, microalbuminuria, left ventricular mass index, smoking, alcohol consumption; X vs o5 beverages per day, physical activity.…”

Large-Artery Elastic Properties in Young Men

“…Similarly, some previous studies have shown an inverse association between insulin levels and arterial elasticity. 5,9,31 The mechanisms by which insulin level may effect arterial distensibility are not well elucidated but may include the effects of insulin, promoting vascular wall smooth muscle hypertrophy 37 and collagen tissue synthesis.…”

“…Furthermore, reports concerning serum lipoproteins in the context of arterial stiffness have been controversial. Some investigations have reported positive associations between serum cholesterol concentration and aortic distensibility 6,8,9 ; some, negative associations 10,11 ; and others, no association. 12,13 In the current study, we investigated the elastic properties of large arteries in the ascending and descending parts of the thoracic aorta by using magnetic resonance imaging (MRI) and in the extracranial common carotid artery by using high-resolution ultrasound.…”

Relation of Apolipoprotein E Polymorphism to Markers of Early Atherosclerotic Changes in Young Adults The Cardiovascular Risk in Young Finns Study

“…[1][2][3][4][5][6] Convential cardiovascular risk factors (eg, high low-density lipoprotein (LDL)-cholesterol), in turn, have been associated with increased carotid IMT, decreased brachial FMD and decreased arterial elasticity. 1,[7][8][9][10][11][12][13] Circulation Journal Vol.72, January 2008 Genetic factors play a role in the pathogenesis of atherosclerosis, partly by influencing plasma lipoprotein concentrations. 4,[14][15][16][17][18] Heritability estimates of interindividual differences in IMT range from 30% to 40% but the specific genes contributing to this variability are unknown.…”