title: Simvastatin improves endothelial function in patents with subclinical hypothyroidism.
abstract: Patients with subclinical hypothyroidism (SCH) have impaired endothelial function probably related to dyslipidemia. The present study compares the effects of simvastatin versus levothyroxine (LT-4) treatment on lipid profile and endothelial function in patients with SCH. Fifty-nine patients with newly diagnosed SCH were enrolled. Patients were randomized into 3 groups to receive no treatment (n = 19), LT-4 (n = 20), or simvastatin (n = 20). We measured endothelium-dependent vasodilation (EDV) and endothelium-independent vasodilation (EIV) at baseline and after 8 months. Serum total cholesterol, triglycerides and LDL-cholesterol were significantly lower following simvastatin. EDV increased significantly in simvastatin treatment group (7.5% +/- 3.3% vs 14.0% +/- 4.5% (P < 0.01). The improvement of EDV correlated with the percent decrease of LDL-cholesterol (rho = 0.68, P < 0.01). Although LT-4 therapy caused a trend towards an increase in EDV compared to baseline, statistical significance was not achieved. EIV remained unchanged in all three groups. Simvastatin but not LT-4 treatment significantly improves EDV of the brachial artery and dyslipidemia in patients with SCH. Improvement in brachial artery endothelial function may be related in part to a hypolipidemic effect of simvastatin treatment.
authors: Department of Cardiology, Haydarpasa Numune Training and Research Hospital, Istanbul, Turkey. drduman@excite.com
authors: Dursun
authors: D
authors: Duman
authors: Sinan
authors: S
authors: Sahin
authors: Kenan
authors: K
authors: Esertas
authors: Refik
authors: R
authors: Demirtunc
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D002784:Cholesterol / Q000097:blood*; D050171:Dyslipidemias / Q000097:blood / Q000150:complications / Q000188:drug therapy; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D007037:Hypothyroidism / Q000097:blood / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D011446:Prospective Studies; D019821:Simvastatin / Q000494:pharmacology* / Q000627:therapeutic use; D013974:Thyroxine / Q000494:pharmacology* / Q000627:therapeutic use; D014280:Triglycerides / Q000097:blood; D014664:Vasodilation / Q000187:drug effects
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D014280:Triglycerides; D002784:Cholesterol; D019821:Simvastatin; D013974:Thyroxine