Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Oxidized low-density lipoproteins (LDL) are highly suspected of initiating the atherosclerosis process. Hypothyroidism is frequently associated with hypercholesterolemia and carries increased risk for atherosclerosis. In contrast to hypothyroidism, hyperthyroidism is not associated with increased LDL cholesterol, but is associated with increased oxidized LDL. This study was designed to evaluate the changes in LDL oxidation in subjects with hypothyroidism or hyperthyroidism, and to reveal the effects of treatment in hypothyroidism and hyperthyroidism on LDL oxidation and lipid profiles. Thirty-two patients with hypothyroidism and 16 patients with hyperthyroidism were studied before the therapy and thereafter, when they were euthyroid with appropriate treatment. Plasma lipids and lipoproteins, and the oxidizability of LDL by determining the levels of malonaldehyde bis (dimethyacetyl) (MDA) and diene conjugation, were determined at baseline and after the patients were rendered euthyroid. The actual content of dienes in LDL particles was increased in hypothyroidism, with a decrease after T4 supplementation (p < .001). Dienes in LDL particles were increased in hyperthyroidism, with a decrease after treatment (p < .05). In hypothyroid patients, the lag phase was shorter in the pretreatment period than in the euthyroid period (p > .05). The lag phase of hyperthyroid patients was shorter in the pretreatment period than in the euthyroid period and hypothyroid state (p < .001). The Cu2+-catalyzed dienes of LDL and MDA oxidation in the hypothyroid state and the subsequent euthyroid states were decreased (p < .001). The Cu2+-catalyzed dienes of LDL (p < .01) and MDA oxidation (p < .001) in hyperthyroid patients after treatment were decreased. The enhanced LDL oxidation may play a role in the cardiac disease process in both hypothyroidism and hyperthyroidism.
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PMID:Effect of thyroid function on LDL oxidation in hypothyroidism and hyperthyroidism. 1555 63

Hypothyroidism is associated with increased morbidity from cardiovascular disease, and adiponectin (ApN) is a newly-identified adipocytokine, which is expressed in human adipose cells and may have a protective effect against the development of coronary artery disease. The aim of the study was to evaluate the involvement of ApN secretion in hypothyroid patients with normal thyroid function following levothyroxine (L-T(4)) replacement therapy, and to associate plasma ApN levels with intima-media thickness (IMT) in the common carotid artery (CCA), an indicator of early atherosclerosis, and cardiovascular parameters including soluble thrombomodulin (sTM), a plasma endothelial injury marker. The CCA IMT and plasma levels of ApN and sTM were measured in 52 hypothyroid patients and in age-, sex- and body mass index (BMI)-matched normal control subjects. Thirty-six of the hypothyroid patients were further monitored for changes in these markers during 1 year in a euthyroid state induced by L-T(4) replacement therapy. Although the basal CCA IMT was significantly higher in hypothyroid patients [0.633 +/- 0.018 mm (mean +/- S.E.)] than in control subjects (0.552 +/- 0.022 mm, P < 0.005), both groups had similar baseline ApN and sTM levels [10.23 +/- 0.76 vs. 10.10 +/- 0.93 microg/ml: NS; and 2.58 +/- 0.14 vs. 2.68 +/- 0.20 ng/ml: NS, respectively]. Simple regression analysis revealed that plasma ApN was significantly correlated in a positive manner with age (r = 0.339, P = 0.015), HDL-cholesterol (r = 0.295, P = 0.048), and sTM (r = 0.490, P = 0.0005), but not with CCA IMT (r = 0.059, P = 0.742). In multivariate analysis, the plasma ApN level was significantly associated with that of sTM (r = 0.546, P = 0.0001) and with serum high-density lipoprotein (HDL)-cholesterol levels (r = 0.291, P = 0.029) in hypothyroid patients. During 1 year of L-T(4) replacement therapy, hypothyroid patients showed a significant decrease in CCA IMT, to 0.553 +/- 0.016 mm (P < 0.0001), a level comparable to normal controls, but no significant change in ApN (from 10.79 +/- 1.07 to 10.6 9+/- 1.14 microg/ml, NS) or sTM (from 2.59 +/- 0.15 to 2.74 +/- 0.18 ng/ml, NS). Hence, we provide evidence that ApN and sTM might not contribute to enhanced atherosclerosis, as reflected by increased CCA IMT in hypothyroid patients. However, this is the first report to demonstrate a positive and significant association of sTM with ApN. These data support the hypothesis that sTM is one of the determinant of ApN and thus suggest the presence of an sTM-associated regulatory mechanism for ApN secretion in hypothyroid patients.
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PMID:Plasma levels of adiponectin and soluble thrombomodulin in hypothyroid patients with normal thyroid function following levothyroxine replacement therapy. 1620 56

Cardiovascular consequences of thyroid diseases, their prevalence and treatment, particularly in cases with subclinical hyper- and hypothyroidism. The aim of the study was to draw attention to an association between the thyroid and cardiovascular diseases. The main topic was to lay emphasis on the importance of cardiovascular diseases caused by subclinical hyper- and hypothyroidism in the relation to the practice. The subclinical states precede the overt hyper- and hypothyroidism, and they are often present during their treatments. The changes in the levels of thyrotropin demonstrating subclinical thyroid diseases, could be detected in different non-thyroid diseases and resulted from the effect of some drugs. Particularly, the subclinical thyroid diseases become more frequent in older age. In the background of the high prevalences of atrial fibrillation, hypertension and psychosomatic events subclinical hyperthyroidism could be revealed. Subclinical hypothyroidism is characterized by an increased prevalence of elevated serum lipid levels, atherosclerosis, ischemic heart disease and hypertension often associating with the presence of anti-thyroid antibodies. It is important to reveal subclinical thyroid diseases in time for the effective treatment and for stopping of the cardiovascular damages before manifestations of cardiovascular diseases. The paper gives advice for the practice and the rational management. At the end, a survey of the association between thyroid and heart diseases in own department of internal medicine at the last three years is given.
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PMID:[Cardiovascular consequences of thyroid diseases, their prevalence and treatment, particularly in cases with subclinical hyper- and hypothyroidism]. 1625 35

Previous studies showed that subclinical hypothyroidism (SH) was associated with cardiovascular disorders, such as endothelial dysfunction, atherosclerosis and myocardial dysfunction. Only one study investigated left ventricular (LV) function using pulsed tissue Doppler echocardiography (TDE) in patients with SH. However, no study has used this technique in the identification of right ventricular (RV) function in these patients. We aimed to investigate the effect of SH on RV and LV function using TDE technique. The present study included 36 newly diagnosed SH patients and 28 healthy controls. For each subjects, serum free T3 (FT3), free T4 (FT4), total T3 (TT3), total T4 (TT4), TSH, peroxidase antibody (TPOab) and thyroglobulin antibody (TGab) levels were measured, and standard echocardiography and TDE were performed. In patients with SH, TSH levels were significantly higher, and TPOab and TGab levels were significantly higher when compared to healthy controls. TDE showed that the patients had significantly lower early diastolic mitral and tricuspid annular velocity (Ea) and early/late (Ea/Aa) diastolic mitral and tricuspid annular velocity ratio (p<0.05, p<0.05 and p<0.001, p<0.001, respectively), and significantly longer isovolumetric relaxation time (IRT) of left and right ventricles (p<0.001 and p<0.001, respectively). However, Aa, Sa, and isovolumetric contraction time (ICT) and ET (ejection time) of left and right ventricle did not significantly differ (p=ns for all). In addition, a negative correlation between TSH and TD-derived tricuspid Ea velocity and Ea/Aa ratio, and a positive correlation between TSH and IRT of right ventricle were observed. Our findings demonstrated that SH is associated with impaired RV diastolic function in addition to impaired LV diastolic function.
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PMID:Evaluation of right and left ventricular function using pulsed-wave tissue Doppler echocardiography in patients with subclinical hypothyroidism. 1627 66

This review summarizes present knowledge from clinical and epidemiological studies with respect to cardiovascular complications in thyroid disorders, focusing on cardiovascular morbidity and mortality. Consistently, good evidence exists for an increased cardiovascular morbidity in overt hyperthyroidism, and an association with predictors of cardiovascular mortality like ventricular hypertrophy, ventricular dysfunction, and atrial fibrillation. As for subclinical hyperthyroidism evidence is conclusive only with respect to an up to 5.2-fold elevated risk for atrial fibrillation. The cardiovascular risk profile of overt hypothyroidism is characterized mainly by risk factors of atherosclerosis such as hypercholesterolemia and hypertension, but also by possible development of heart failure. In contrast, data on such parameters are inconsistent for subclinical hypothyroidism. Although many of these cardiovascular alterations may hypothetically worsen prognosis, results from cohort and retrospective studies do not consistently point towards increased mortality. Only for overt hyperthyroidism an up to 1.7 fold elevated risk for cardiovascular diseases and up to 1.7 fold increased cardiovascular mortality rates have been demonstrated. However, the evidence for similarly increased cardiovascular morbidity and mortality rates in subclinical hyperthyroidism and hypothyroidism is inconclusive, and the evidence is non-existent for overt hypothyroidism. Further randomized clinical studies and population-based cohort-studies are required and should consider major cardiovascular risk factors and adverse cardiovascular events and mortality.
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PMID:Cardiovascular morbidity and mortality in thyroid dysfunction. 1631 9

Several reports have appeared in the literature proving that hypothyroidism is associated with increased risk for cardiovascular disease, especially coronary heart disease. This increased risk for premature atherosclerosis is supported by autopsy and epidemiological studies in patients with thyroid hormone deficiency. Hypothyroid patients have increased diastolic blood pressure (as a result of increased systemic vascular resistance), altered lipid profile (elevated levels of total cholesterol, LDL-cholesterol and apolipoprotein B). More recently homocysteine, C-reactive protein, increased arterial stiffness, endothelial dysfunction and altered coagulation parameters have been recognized as a "new" risk factors for atherosclerosis in patients with thyroid hormone deficiency. The plasma total homocysteine concentration, an independent risk factor for atherosclerosis, is moderately elevated in overtly hypothyroid patients and it decreases with thyroid replacement therapy. Several experimental study have shown that hypothyroidism affects folate metabolism and the enzymes involved in the remetylation pathway of homocysteine (particularly 5,10-methylenotetrahydrofolate reductase - MTHFR). In hypothyroid condition the hepatic activity of flavoenzyme - MTHFR, is decreased. Thyroid hormone may affect the availability of FMN and FAD - necessary for stabilizing MTHFR. An impairment of enzyme involved in transsulfuration pathway is suggested. The increased serum creatinine level in hypothyroidism probably reflects a reduced glomerular filtration rate, which is linked to impaired renal homocysteine clearance and hyperhomocysteinemia.
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PMID:[The influence of thyroid hormones on homocysteine and atherosclerotic vascular disease]. 1633 88

Radiotherapy increases the risk of cardiovascular morbidity. We examined arteria carotis atherosclerosis and stenosis in Hodgkin's lymphoma patients. We examined arteria carotis of 120 Hodgkin's lymphoma patients who have been in complete remission for at least 5 years. 70 patients received neck irradiation (mean age at the time of the examination was 44.6 years). Twenty-four (34.3%) of them had carotis sclerosis or stenosis, and it was significantly more than in the control group [8 out of 60 patients 13.3%)]. Twelve patients of the 50 who did not receive radiotherapy had carotis lesions, and there was no significant difference compared to the control group. Significant stenosis (>50%) was detected in only 3 patients (in the irradiated group). TIA, stroke or amaurosis fugax did not occur. Carotis stenosis does not seem to play a role in late mortality in Hodgkin's lymphoma, but if the patient has an increased risk for atherosclerotic changes, then regular examinations are necessary, and other risk factors (smoking, hypertension, diabetes mellitus, hypothyroidism, early menopause) need to be treated.
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PMID:[Differences of arteria carotis in patients with Hodgkin's lymphoma]. 1651 80

Type-1 5'-iodothyronine deiodinase (5'-DI) is responsible for conversion of T4 to T3. Selenium (Se) is an integral part of this enzyme. Keeping in view the strong association between atherosclerosis and hypothyroidism, the present study examined the behavior of 5'-DI in liver, aorta and thyroid during hypercholesterolemia following different Se status, i.e., Se deficiency (0.02 ppm), adequate (0.2 ppm) and excess dose (1 ppm) in SD male rats. Animals were fed a control or high-cholesterol diet (2%) for 1 and 2 months. 5'-DI activity and mRNA expression was measured by RIA and RT-PCR respectively. In liver and aorta, 5'-DI expression significantly decreased with the Se-deficient and the high-cholesterol diet. The trend was opposite in thyroid, i.e., mRNA expression increased significantly during selenium deficiency and with a high-cholesterol feeding. But with 1 ppm Se supplementation, the 5'-DI expression increased in all the three tissues. The present study indicates that hypercholesterolemia along with selenium deficiency is co-responsible for differential regulation of 5'-DI enzyme in thyroidal vs. extrathyroidal tissues. Distinct regulation of 5'-DI in the thyroid reflects the clinical importance of this selenoprotein during hypercholesterolemia as this enzyme is essential for T3 production, which further has a vital role in the maintenance of lipid metabolism.
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PMID:Hypercholesterolemia and tissue-specific differential mRNA expression of type-1 5'-iodothyronine deiodinase under different selenium status in rats. 1687 6

Postprandial lipoprotein metabolism is suggested to play a role in the pathogenesis of atherosclerosis. In this study, we investigated postprandial lipemia and its relationship to cardiovascular risk factors in patients with overt and subclinical hypothyroidism. Twenty-nine female patients with TSH levels greater than 5 microIU/mL and 12 euthyroid control female subjects were included in the study. Fifteen patients had subclinical hypothyroidism and 14 had overt hypothyroidism. All subjects underwent an oral lipid tolerance test. If triglyceride levels increased by 80% or more, subjects were considered postprandial lipemia positive. Control, overt hypothyroid, and subclinical hypothyroid groups were not statistically different with respect to anthropometric measurements, fasting blood C-reactive protein, uric acid, homocysteine, glucose, insulin, lipoprotein (a), apolipoprotein B levels, and homeostasis model assessment index. Fasting triglyceride levels correlated positively with TSH levels. Postprandial lipemia frequency was higher in overt hypothyroid subjects than in the control group. The subclinical hypothyroid group did not differ from the hypothyroid group with respect to postprandial lipemia frequency. In subjects with TSH levels higher than 5 microIU/mL, PPL risk was increased sevenfold. The results of this study show that postprandial triglyceride metabolism is affected in hypothyroidism.
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PMID:Postprandial lipemia as a risk factor for cardiovascular disease in patients with hypothyroidism. 1694 84

Thyroid hormone has been studied in cardiovascular disease but rarely in cerebrovascular disease (CVD). Recently, hypothyroidism has been suggested to be related to risk factors such as atherosclerosis but not directly to CVD. We reported a 52-year-old woman with acute ischemic stroke, and greatly improved general conditions after thyroid hormone replacement. Hypothyroidism is reported to be one of the causes of hypertension or elevated cholesterol levels, the established risk factors of CVD. Further studies of the possible association of thyroid hormone and CVD are warranted. Thyroid hormone might need to be surveyed in CVD patients especially if there are symptoms and signs of thyroid disorders.
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PMID:Hypothyroidism and cerebral infarction: a case report and literature review. 1699


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