Effects of thyroxine replacement on endothelial function and carotid artery intima-media thickness in female patients with mild subclinical hypothyroidism
Clinics
;
66(8): 1321-1328, 2011. tab
Artigo
em Inglês
| LILACS
| ID: lil-598370
ABSTRACT
BACKGROUND:
Previous studies have suggested an association between subclinical hypothyroidism and coronary artery disease that could be related to changes in serum lipids or endothelial dysfunction.METHODS:
Thirty-two female subclinical hypothyroidism patients were randomly assigned to 12 months of L-thyroxine replacement or no treatment. Endothelial function was measured by the flow-mediated vasodilatation of the brachial artery, as well as mean carotid artery intima-media thickness, and lipid profiles were studied at baseline and after 12 months of follow-up.RESULTS:
The mean ( ± SD) serum thyroid-stimulating hormone levels in the L-thyroxine replacement and control groups were 6.09±1.32 and 6.27 ± 1.39 μUI/ml, respectively. No relationship between carotid artery intima-media thickness or brachial flow-mediated vasodilatation and free T4 and serum thyroid-stimulating hormone was found. The median L-T4 dose was 44.23 ± 18.13 μg/day. After 12 months, there was a significant decrease in the flow-mediated vasodilatation in the subclinical hypothyroidism control group (before 17.33 ± 7.88 to after 13.1 ±4.75 percent, p =0.03), but there were no significant differences in flow-mediated vasodilatation in the L-thyroxine treated group (before 16.81 ± 7.0 to after 18.52 ± 7.44 percent, p = 0.39). We did not find any significant change in mean carotid intimamedia thickness after 12 months of L-thyroxine treatment.CONCLUSION:
Replacement therapy prevents a decline in flow-mediated vasodilatation with continuation of the subclinical hypothyroidism state. Large prospective multicenter placebo-controlled trials are necessaryto investigate endothelial physiology further in subclinical hypothyroidism patients and to define the role of L-thyroxine therapy in improving endothelial function in these patients.
Texto completo:
DisponíveL
Índice:
LILACS (Américas)
Assunto principal:
Tiroxina
/
Tireotropina
/
Terapia de Reposição Hormonal
/
Espessura Intima-Media Carotídea
/
Hipotireoidismo
Tipo de estudo:
Ensaio Clínico Controlado
/
Estudo observacional
/
Estudo prognóstico
/
Fatores de risco
Limite:
Adulto
/
Feminino
/
Humanos
/
Masculino
Idioma:
Inglês
Revista:
Clinics
Assunto da revista:
Medicina
Ano de publicação:
2011
Tipo de documento:
Artigo
País de afiliação:
Brasil
Instituição/País de afiliação:
Centro de Estudos e Pesquisas da Mulher/BR
/
Universidade Federal do Rio de Janeiro/BR
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