Dobro
02.03.2007, 05:54
The beneficial effect of L-thyroxine on cardiovascular risk factors, endothelial function and quality of life in subclinical hypothyroidism: randomised, crossover trial
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Context: Subclinical hypothyroidism (SCH) is defined as raised serum thyrotropin (TSH) levels with circulating thyroid hormones within the reference range. It is uncertain whether treatment of SCH with L-thyroxine improves cardiovascular (CV) risk factors and quality of life (QoL).
Objective: To assess CV risk factors and patient-reported outcomes after treatment.
Design: Randomised double-blind crossover study of L-thyroxine and placebo.
Setting: Community-dwelling patients.
Patients: One hundred patients [mean age (SD) 53.8 (12) years, 81 females] with SCH [mean TSH 6.6 (1.3) mIU/L] without previously treated thyroid or vascular disease.
Intervention: 100 µg of L-thyroxine or placebo daily for twelve weeks each.
Measurements: Primary parameters were total cholesterol (TC) and endothelial function [brachial artery flow-mediated dilatation (FMD)], an early marker of atherosclerosis. Patient-reported outcomes were also assessed.
Results: L-thyroxine treatment reduced TC (versus placebo) from 231.6 to 220 mg/dL, p<0.001; LDL cholesterol from 142.9 to 131.3 mg/dL, p<0.05; waist-hip ratio from 0.83 to 0.81, p<0.006; and improved FMD from 4.2 to 5.9%, p<0.001. Multivariate analysis showed that increased serum free thyroxine (FT4) level was the most significant variable predicting reduction in TC or improvement in FMD. Furthermore, the symptom of tiredness improved on L-thyroxine therapy but other patient-reported outcomes were not significantly different, after correction for multiple comparisons.
Conclusion: SCH treated by L-thyroxine leads to a significant improvement in CV risk factors and symptoms of tiredness. The CV risk factor reduction is related to the increased level of achieved FT4 concentration.
[Ссылки могут видеть только зарегистрированные и активированные пользователи]
[Ссылки могут видеть только зарегистрированные и активированные пользователи]
Context: Subclinical hypothyroidism (SCH) is defined as raised serum thyrotropin (TSH) levels with circulating thyroid hormones within the reference range. It is uncertain whether treatment of SCH with L-thyroxine improves cardiovascular (CV) risk factors and quality of life (QoL).
Objective: To assess CV risk factors and patient-reported outcomes after treatment.
Design: Randomised double-blind crossover study of L-thyroxine and placebo.
Setting: Community-dwelling patients.
Patients: One hundred patients [mean age (SD) 53.8 (12) years, 81 females] with SCH [mean TSH 6.6 (1.3) mIU/L] without previously treated thyroid or vascular disease.
Intervention: 100 µg of L-thyroxine or placebo daily for twelve weeks each.
Measurements: Primary parameters were total cholesterol (TC) and endothelial function [brachial artery flow-mediated dilatation (FMD)], an early marker of atherosclerosis. Patient-reported outcomes were also assessed.
Results: L-thyroxine treatment reduced TC (versus placebo) from 231.6 to 220 mg/dL, p<0.001; LDL cholesterol from 142.9 to 131.3 mg/dL, p<0.05; waist-hip ratio from 0.83 to 0.81, p<0.006; and improved FMD from 4.2 to 5.9%, p<0.001. Multivariate analysis showed that increased serum free thyroxine (FT4) level was the most significant variable predicting reduction in TC or improvement in FMD. Furthermore, the symptom of tiredness improved on L-thyroxine therapy but other patient-reported outcomes were not significantly different, after correction for multiple comparisons.
Conclusion: SCH treated by L-thyroxine leads to a significant improvement in CV risk factors and symptoms of tiredness. The CV risk factor reduction is related to the increased level of achieved FT4 concentration.
[Ссылки могут видеть только зарегистрированные и активированные пользователи]