Meng W
Abteilung für Endokrinologie und Stoffwechselkrankheiten, Ernst-Moritz-Arndt-Universität Greifswald.
Z Arztl Fortbild (Jena). 1996 Feb;90(1):43-9.
In the majority of cases, the symptoms of hypothyroidism develop slowly and as a result, they often are not recognized or misjudged for a long time. The complete picture is a late diagnosis. Especially in older patients, the symptoms are quite frequently assigned to the aging process. The most important form is the primary hypothyroidism often caused by auto-immune thyroiditis. The presence of a hypothyroidism should be considered more often and a TSH examination should be run. Normal TSH levels exclude a primary hypothyroidism. Increased TSH levels in conjunction with lowered T4 levels prove the diagnosis. If a secondary form is suspected, complete pituitary diagnostics are mandatory. The substitution therapy is carried out with a medium dosage of levothyroxine, 2.0 micrograms/kg body weight per day. The appropriate dosage should be established slowly using small initial dosages. This is especially important in older patients and in those suffering from coronary disorders. For younger patients and those with a shorter history, a more immediate adjustment is possible. During gravidity, the hormone requirement increasing by 40% must be taken into consideration. The therapeutic effect is shown by the clinic as well as by the TSH level. Overdosage will lead to a reversible appearance of thyreoitoxicosis factitia and require re-adjustment of the dosage. A physiological dosage does not have negative consequences on the bone metabolism. Transitory corrections are possible although a continuous substitution is necessary most of the time. Regular checks must be made as the therapy may be discontinued in 40% of the cases. In case of subclinical hypothyroidism, an indication for treatment does not exist in all patients. However, treatment is indicated if there is a high risk for developing a permanent form of hypothyroidism or if additional findings exist possibly linked to subclinical hypothyroidism. This would make a hormone substitution necessary. In case of doubt, a probatory therapy can be initiated and discontinued after 6-12 months when there is no therapeutic effect.
在大多数情况下，甲状腺功能减退的症状发展缓慢，因此，它们常常在很长一段时间内未被识别或被误诊。完整的病情往往是晚期诊断。特别是在老年患者中，这些症状常常被归因于衰老过程。最重要的形式是原发性甲状腺功能减退，通常由自身免疫性甲状腺炎引起。应更频繁地考虑甲状腺功能减退的存在，并进行促甲状腺激素（TSH）检查。TSH水平正常可排除原发性甲状腺功能减退。TSH水平升高且甲状腺素（T4）水平降低可证实诊断。如果怀疑是继发性形式，则必须进行完整的垂体诊断。替代疗法采用中等剂量的左甲状腺素进行，每天2.0微克/千克体重。应使用小剂量开始缓慢确定合适的剂量。这在老年患者和患有冠状动脉疾病的患者中尤为重要。对于年轻患者和病史较短的患者，可以更快地进行调整。在妊娠期间，必须考虑激素需求量增加40%的情况。临床症状以及TSH水平可显示治疗效果。用药过量会导致人为甲状腺毒症的可逆表现，需要重新调整剂量。生理剂量对骨代谢没有负面影响。虽然大多数时候需要持续替代，但也可能进行临时调整。必须定期检查，因为40%的病例可能需要停止治疗。对于亚临床甲状腺功能减退，并非所有患者都有治疗指征。然而，如果发展为永久性甲状腺功能减退的风险很高，或者存在可能与亚临床甲状腺功能减退相关的其他发现，则表明需要治疗。这将使激素替代成为必要。如有疑问，可以开始试验性治疗，在6至12个月后如果没有治疗效果则停药。
