Macedo Silva Sofia, Carvalho Alexandra, Lopes-Pereira Maria, Fernandes Vera
Unidade de Saúde Familiar Esposende Norte. Esposende. Portugal.
Serviço de Endocrinologia. Hospital de Braga. Braga. Portugal.
Acta Med Port. 2018 Dec 28;31(12):766-773. doi: 10.20344/amp.10991.
Subclinical hypothyroidism, defined as an increase of thyroid stimulating hormone levels with normal levels of thyroid hormones, could have a multiorgan impact. There seem to be differences in the elderly (over 65 years of age) which indicate that there should be a different approach in terms of diagnosis and the treatment.
Electronic database search and narrative bibliographical review.
Different case studies showing the multiorgan consequences of subclinical hypothyroidism suggest that, in the elderly, there is a minor impact or even a lack of repercussion, especially in those over 80 - 85 years old. Additionally, there is evidence indicating that the levels of thyroid stimulating hormone rise with the age of the patient. The standard treatment, in the beginning, is a low dose of levothyroxine when the levels of thyroid stimulating hormone are over 10.0 mIU/L, when there are noticeable symptoms or positive anti-thyroid antibodies. However, the treatment is not consensual when the levels of thyroid stimulating hormone are between 4.5 and 10.0 mIU/L, in such a way that the TRUST study concluded that no benefits have outcome from treating these patients.
The non-definition of the reference range and the age gap are the key factors that contribute the most to biased results. However, there is consensus regarding non-treatment of mild thyroid dysfunctions (4.5 - 7.0 mIU/L) in the elderly, particularly above 80 years of age. Nevertheless, for positive anti-thyroid antibodies, suggestive ultrasound changes or iatrogenic side effects, the reference level should be 4.5 mIU/L.
The general impact of subclinical hypothyroidism is different in elderly people, meaning that an individualized therapeutic approach and long-term monitoring is the appropriate strategy.
亚临床甲状腺功能减退症定义为甲状腺激素水平正常但促甲状腺激素水平升高，可能对多器官产生影响。老年人（65岁以上）似乎存在差异，这表明在诊断和治疗方面应有不同的方法。
电子数据库检索和叙述性文献综述。
不同的病例研究显示了亚临床甲状腺功能减退症的多器官后果，表明在老年人中，影响较小甚至没有影响，尤其是80 - 85岁以上的老人。此外，有证据表明促甲状腺激素水平随患者年龄增长而升高。初始标准治疗是当促甲状腺激素水平超过10.0 mIU/L、出现明显症状或抗甲状腺抗体呈阳性时，给予低剂量左甲状腺素。然而，当促甲状腺激素水平在4.5至10.0 mIU/L之间时，治疗尚无共识，因此TRUST研究得出结论，治疗这些患者没有益处。
参考范围的不明确和年龄差距是导致结果有偏差的最关键因素。然而，对于老年人轻度甲状腺功能障碍（4.5 - 7.0 mIU/L），尤其是80岁以上者不进行治疗已达成共识。不过，对于抗甲状腺抗体呈阳性、超声有提示性改变或有医源性副作用的情况，参考水平应为4.5 mIU/L。
亚临床甲状腺功能减退症对老年人的总体影响不同，这意味着个体化治疗方法和长期监测是合适的策略。
