Myocardial perfusion and intima-media thickness in patients with subclinical hypothyroidism
Section snippets
INTRODUCTION
Subclinical hypothyreosis (SH) is featured by elevated concentration in plasma TSH concomitant with normal concentration in plasma free thyroxine (fT4). The literature data indicate clearly that patients with SH have increased incidence of coronary heart disease (CHD) and increased risk of death as a consequence of cardiovascular complications [1]. It was shown that SH is also accompanied by increased plasma concentration of LDL-cholesterol and increased incidence of arteriosclerotic plaques in
MATERIAL AND METHODS
The experimental protocol was approved by the Ethical Committee for Human Studies of the Medical University of Bialystok. The subjects gave written consents for the study. 40 women, aged 34.8±4.1 years with diagnosed SH in the course of Hashimoto disease were included. The diagnosis of SH was confirmed by elevation in TSH concentration coexisting with normal concentration of fT4, the presence of antibodies against thyroid peroxidase (aTPO) and hypogenic (typical) picture of ultrasonographic
RESULTS
The characteristics of the investigated subjects is presented in the Tab. 1. The patients with SH had elevated concentration in the plasma total cholesterol and LDL-cholesterol as compared to the control group (p<0.03 and 0.006, respectively). The subjects with SH were not obese but their BMI was higher than in the control group (p<0.03).
DISCUSSION
A relationship between thyroid disorders and the condition of the vascular bed is not thoroughly recognized. SH occurs quite often. According to the Third National Health and Nutrition Examination Survey, it occurs in 4.3% of adults in the United States of America and the incidence of its prevalence increases with ageing. It concerns ∼10% of women above the age of sixty [5]. There are a few theories trying to explain the mechanism of the influence of SH on the cardiovascular system. According
CONCLUSIONS
In patients with SH, echocardiographic stress test with the use of ultrasonographic contrast is safe and seems to be helpful to detect the reduction of myocardial perfusion at the level of microcirculation. The results obtained clearly show that in patients with SH increased thickness of IMT which is an early and sensitive parameter indicating the degree of atherosclerosis and allowing a selection of patients much threatened with cardiovascular disorders. Both employed echocardiographic methods
ACKNOWLEDGMENTS
This work was supported by Medical University of Bialystok (Poland) grant: 3-53726L. The authors thank Professor Maria Gorska, the Head of the Department of Endocrinology for help in the requirement of the study patients.
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