Assessment of the elasticity properties of the ascending aorta in patients with subclinical hypothyroidism by tissue Doppler imaging

Abstract

Objective: We aimed to investigate whether aortic elastic properties were affected in subclinical hypothyroidism (SCH) by using tissue Doppler imaging (TDI). Subjects and methods: Forty-three patients with newly diagnosed SCH and forty-eight healthy controls were included to the study. Systolic and diastolic diameters of the ascending aorta were measured by M-mode transthoracic echocardiography, and the upper wall velocities of ascending aorta and mitral annulus velocities were measured by TDI. Aortic stiffness index (ASI) and aortic distensibility were computed using the formulas accepted in literature. Results: The clinical and demographic features of both groups were comparable. Aortic distensibility was significantly lower, and ASI was significantly higher in SCH patients than in controls. Systolic aortic upper wall velocity (Sao) was also significantly lower in SCH patients. Early (Eao) and late diastolic aortic upper wall (Aao) velocities did not differ between the two groups. Mitral annulus (Sm, Em, and Am) velocities were also similar between the groups. Sao was negatively correlated with ASI, and positively correlated with aortic distensibility. TSH level was positively correlated with ASI, total cholesterol and low-density lipoprotein-cholesterol, and negatively correlated with aortic distensibility and Sao. Conclusions: In this study, our results showed that SCH is associated with impaired elasticity of the ascending aorta. Elastic properties of the ascending aorta can be directly evaluated by the reproducibly measurement of the upper wall movements of the ascending aorta by TDI in SCH patients. Arq Bras Endocrinol Metab. 2013;57(2):132-8 Keywords Tissue Doppler imaging; subclinical hypothyroidism; stiffness RESUMO Objetivo: Nosso objetivo foi investigar se as propriedades elásticas da aorta são afetadas no hipotireoidismo subclínico (HSC), utilizando o Doppler tecidual (UDT). Sujeitos e métodos: Quarenta e três pacientes com diagnóstico recente de HSC e 48 indivíduos saudáveis foram incluí-dos no estudo. Os diâmetros sistólico e diastólico da aorta foram medidos por ecocardiografia transtorácica modo M e as velocidades de fluxo da parede superior da aorta ascendente e de fluxo transvalvar mitral foram medidas por UDT. O índice de rigidez da aorta (IRA) e a distensibilidade aórtica foram calculados usando fórmulas aceitas na literatura. Resultados: As características clínicas e demográficas dos dois grupos foram comparáveis. A distensibilidade aórtica foi significativamente menor e IRA significativamente maior nos pacientes com HSC do que nos controles. A velocidade de fluxo sistólico na parede aórtica superior (Sao) foi significantemente menor em pacientes com HSC. A velocidade de fluxo diastólico inicial (Eao) e tardio (Aao) na parede aórtica superior e as velocidades de fluxo transvalvar (Sm, Em e Am) não diferiram entre os dois grupos. Sao foi negativamente correlacionada com IRA e positivamente correlacionada com a distensibilidade aórtica. O nível de TSH foi positivamente correlacionado ...

The role of type 2 diabetes mellitus on hypertensive‐related aortic stiffness

“…The study has some limitations. First, even if aortic tissue strain is a new application of TDI which has proved to be useful in studying the aortic elastic properties of patients with hypertension, diastolic dysfunction with elevated filling pressures, type 1 diabetes mellitus, coronarosclerosis, subclinical hypothyroidism, and previously preeclamptic women, this methodology is not yet widespread and accepted. Echocardiography is an operator‐dependent method and TDI is angle‐dependent, needing to be interpreted with caution if the angle between tissue and beam direction is more than 30°.…”

Aortic stiffness is increased in patients with premature coronary artery disease: A tissue Doppler imaging study

“…Pulse wave or strain TDI of the ascending aorta may be used to measure aortic wall velocities. These parameters have been found to be abnormal in patients with CAD, hypertension, diabetes mellitus, LV diastolic dysfunction, and subclinical hypothyroidism [11,13,14,[28][29][30][31]. Recently, Sen et al reported that aortic propagation velocities are lower in CAD patients compared to non-CAD subjects and are correlated with aortic stiffness parameters [32].…”

Thyroid hormone dysfunctions affect the structure of rat thoracic aorta: a histological and morphometric study

“…The previous authors added that at physiologic pressure, the stiffness is determined by both elastin and collagen content [27]. The impairment of the elastic properties of the aorta and the marked increase in its collagen content are associated mostly with increased stiffness of the aorta and decrease of its distensibility [20,30]. The impairment of aortic elastic properties in hyperthyroidism may be due to the direct effect of the thyroid hormones on the aorta and due to the modulate effects of thyroid hormones on the vascular renin-angiotensin system [1].…”