Objective: Subclinical hypothyroidism affects 5-15% of the general population and is associated with increased morbidity from cardiovascular disease. Brachial-ankle pulse wave velocity (baPWV) is a parameter of arterial stiffening and a good independent predictor for the presence of coronary artery disease. This study was performed to assess whether subclinical hypothyroidism might cause enhanced baPWV.Patients and Methods: baPWV was examined in subclinical hypothyroid patients (n ϭ 50) and normal control subjects (n ϭ 50).Results: Diastolic blood pressure (DBP), a main risk factor for cardiovascular disease, and baPWV were both significantly higher in subclinical hypothyroid patients than normal subjects. baPWV was significantly positively correlated with age and systolic, diastolic, and pulse pressure and significantly negatively correlated with pulse rate in both subclinical hypothyroid patients and normal subjects. In contrast, there was no significant correlation of baPWV with free T 3 , free T 4 , TSH, total, high-density lipoprotein-and low-density lipoproteincholesterol, and the preejection time to ejection time ratio. A comparison of individual values of baPWV and DBP and regression slopes in two groups revealed that baPWV values increase to a larger extent than the increase in DBP in subclinical hypothyroid patients. In both groups, stepwise regression analysis showed a significant and independent association of DBP with baPWV. Conclusions:The present study demonstrated significant increases of baPWV and DBP in subclinical hypothyroid patients. Furthermore, the results suggest that increased DBP might be one of the main factors responsible for increased arterial stiffening in subclinical hypothyroid patients.

This study demonstrated that L-T4 treatment might have the potential to reverse the progression of atherosclerosis in hypothyroid patients. Furthermore, it suggests that increased levels of LDL cholesterol and the total/HDL cholesterol ratio have an important role in the increased common carotid intima-media thickness in hypothyroid patients.

Objective: Subclinical hypothyroidism affects 5-15% of the general population, is especially prevalent in females, and may be associated with increased morbidity from cardiovascular disease, although it remains controversial. We recently reported a significant increase in the brachial-ankle pulse wave velocity (baPWV), a parameter of arterial stiffening and an independent predictor of cardiovascular events, in subclinical hypothyroidism without thyroiditis. The current study was performed to assess changes in baPWV in female subclinical hypothyroidism with autoimmune chronic thyroiditis (Hashimoto's disease) after restoration of normal thyroid function. Methods: In a randomized placebo-controlled study, 95 female subclinical hypothyroid patients were monitored for changes in baPWV before and after levothyroxine (L-T 4 ) replacement therapy. Changes in baPWV were also measured in 42 age-matched normal female subjects. Results: The baseline baPWV values in patients with subclinical hypothyroidism were significantly higher than in normal subjects. With attainment of euthyroidism, baPWV showed a significant decrease from 1776.7G86.0 to 1674.3G79.2 cm/s (PZ0.006) in patients treated with L-T 4 , but the changes in baPWV and TSH were not correlated. The change in baPWV was significantly and negatively correlated with age and baseline pulse pressure, but multiple regression analysis revealed that these parameters failed to be associated with the change in baPWV. Conclusions: Sustained normalization of thyroid function during L-T 4 replacement therapy significantly decreases baPWV in female subclinical hypothyroid patients with autoimmune chronic thyroiditis, suggesting the improvement of arterial stiffening and, consequently, possible prevention of cardiovascular disease.

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ITA-PSV may assist in the prediction of early GD relapse after ATD withdrawal.

Objective: This study examined whether levothyroxine (L-T 4 ) replacement might affect serum markers of endothelium injury, including von Willebrand factor (vWF), factor VIII activity and thrombomodulin (TM), during normalization of increased intima-media thickness (IMT) in the common carotid artery (CCA) in hypothyroid patients after L-T 4 replacement therapy. Patients and methods: Thirty-three hypothyroid patients were examined for vWF, factor VIII, TM and CCA IMT before and after 1 year of normalization of thyroid function by L-T 4 replacement. CCA IMT was measured from digitized still images taken during scanning by high-resolution ultrasonography as an indicator of early atherosclerosis. Results: Serum factor VIII and vWF increased significantly during 1 year of normalization of thyroid function (from 122.7^9.4 to 151.3^18.8% (P , 0.05) and from 109.9^9.6 to 135.2^12.4% (P , 0.005) respectively), although these values all fell within the respective normal range. Serum TM, in contrast, did not change appreciably in response to L-T 4 treatment, moving from 2.57^0.15 to 2.74^0.18 ng/ml (P ¼ 0.086). During 1 year of a euthyroid state, all patients showed a significant decrease in CCA IMT (P , 0.0001). Change in serum vWF, but not in factor VIII or TM, showed a positive correlation with that of CCA IMT during L-T 4 replacement therapy. Furthermore, the change in serum vWF was significantly and independently associated with change in CCA IMT (r ¼ 0.490, P ¼ 0.0038).Conclusions: The present study demonstrated that the improvement of CCA IMT during L-T 4 treatment might have the potential to attenuate an elevation of vWF and to attenuate vascular injury by the cardiovascular effects of thyroid hormone in hypothyroid patients. 150 125-131 European Journal of Endocrinology

Hypothyroidism is associated with increased morbidity from cardiovascular disease, and an increase in serum osteoprotegerin (OPG) has recently been reported to be associated with the severity of coronary heart disease and cardiovascular mortality. The present study was designed to examine whether hypothyroidism causes an increase in serum OPG, and to determine whether levothyroxine (L-T4) replacement therapy might suppress serum OPG levels in hypothyroid patients. Fifty-three hypothyroid patients with chronic thyroiditis and age-and sex-matched normal control subjects were examined for the levels of serum OPG and plasma von Willebrand factor (vWF), a vascular injury marker. Thirty-seven of the hypothyroid patients were further monitored for changes in these markers during 1 year in a euthyroid state induced by L-T4 replacement therapy. Baseline OPG was significantly higher in hypothyroid patients than in normal controls (4.51^0.50 vs 3.72^0.23 pmol/l (mean^S.E.); P ¼ 0.0182). In multivariate analysis, baseline OPG was significantly associated with baseline levels of TSH (r ¼ 0.280, P ¼ 0.0162) and vWF (r ¼ 0.626, P , 0.0001). During one year of L-T4 replacement therapy, hypothyroid patients showed a significant decrease in OPG levels from 4.35^0.51 to 3.48^0.26 pmol/l (P ¼ 0.0166), a level comparable to normal controls. The change in serum OPG levels during L-T4 replacement therapy was significantly and independently associated in a negative fashion with baseline vWF (r ¼ 2 0.503, P ¼ 0.0014). This study suggested that the severity of hypothyroidism and vascular injury might have important independent roles in increasing the serum OPG level in hypothyroid patients. Furthermore, it was demonstrated that a sustained euthyroid state might have the potential to decrease the serum OPG level in hypothyroid patients and that the degree of vascular injury in the hypothyroid state is independently associated with a decrease in serum OPG during a 1-year normalization of thyroid function.

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