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Changes in endothelium‐dependent arterial dilation before and after subtotal thyroidectomy in subjects with hyperthyroidism
Author(s) -
Guangda Xiang,
Hongyan Cao,
Xianmei Zeng
Publication year - 2004
Publication title -
clinical endocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 147
eISSN - 1365-2265
pISSN - 0300-0664
DOI - 10.1111/j.1365-2265.2004.02112.x
Subject(s) - medicine , euthyroid , cardiology , thyroidectomy , endocrinology , blood flow , blood pressure , stage (stratigraphy) , hemodynamics , artery , thyroid , paleontology , biology
Summary objective This case–control study was carried out to assess the alteration of endothelium‐dependent arterial dilation before and after subtotal thyroidectomy in subjects with hyperthyroidism. patients and methods The study subjects included 12 patients with hyperthyroidism and 39 apparently healthy individuals. We performed a subtotal thyroidectomy on the hyperthyroid patients. The endothelium‐dependent arterial dilation was determined with a high‐resolution ultrasound method in each patient at the hyperthyroid stage before treatment (stage H), the euthyroid stage induced immediately before surgery (stage E), and the transient hypothyroid stage 1 or 2 months after surgery (stage L). results The flow‐mediated arterial dilation decreased significantly from H to E and from E to L ( P < 0·001). As compared with H, baseline blood flow decreased markedly at stages E and L ( P < 0·001). The flow‐mediated arterial dilation and baseline blood flow in the control subjects were very close to those at stage E of the hyperthyroid patients. The absolute change in the flow‐mediated arterial dilation showed significant negative correlation with the changes in TSH ( r =−0·86, P < 0·001), lipoprotein (a) [Lp(a)] ( r =−0·77, P < 0·001) and low density lipoprotein (LDL) ( r =−0·79, P < 0·001), and significant positive correlation with changes in fT3 ( r =+0·88, P < 0·001). The absolute change in the baseline blood flow showed significant positive correlation with the change in fT3 ( r =+0·85, P < 0·001) and significant negative correlation with the change in TSH ( r =−0·63, P < 0·01). conclusion The endothelium‐dependent arterial dilation increases significantly in untreated hyperthyroid patients, and decreases markedly after a subtotal thyroidectomy. Therefore, we conclude that the endothelium is more responsive to reactive hyperaemia in the hyperthyroid than the euthyroid state.