School of Medicine, Patras University, Patras, Greece.
Red Cross Hospital, Athens, Greece.
Trends Cardiovasc Med. 2020 Feb;30(2):57-69. doi: 10.1016/j.tcm.2019.02.011. Epub 2019 Mar 5.
Subclinical thyroid dysfunction (STD), presenting as subclinical hypothyroidism (SHypo) or subclinical hyperthyroidism (SHyper), defined as abnormal serum thyrotropin (TSH) and normal free thyroid hormones, is associated with increased cardiovascular (CV) risk and mortality. Depending on the degree of such dysfunction, atherosclerosis, coronary artery disease, heart failure and cardiac arrhythmias, predominantly atrial fibrillation, characterize both disorders and increase CV and total mortality compared to euthyroid persons. There are some differences in the mechanisms involved in the increased CV risk incurred by each type of STD, with more traditional CV risk factors clustered in SHypo than in SHyper, while the role of the TSH or its absence thereof, together with the respective, even subtle, changes incurred in thyroid hormone concentrations, seem to adversely influence the CV system in both types of STD. There is evidence that treatment of STD confers potential benefits by reducing CV events, however, no consensus has been reached due to lack of randomized controlled studies. Nevertheless, due to accumulating evidence from observational studies, many authorities agree that individuals with severe SHypo (TSH > 10 mIU/L) or grade 2 SHyper (TSH < 0.1 mIU/L) should receive treatment, mostly for the increased risk of CV morbidity and mortality. The evidence reviewed herein should alert and help the clinician to wake up to these two potentially alarming conditions of STD as they may confer serious CV complications, while their treatment appears quite beneficial.
亚临床甲状腺功能障碍（STD）表现为亚临床甲状腺功能减退症（SHypo）或亚临床甲状腺功能亢进症（SHyper），定义为血清促甲状腺激素（TSH）异常和游离甲状腺激素正常，与心血管（CV）风险增加和死亡率升高有关。根据这种功能障碍的程度，动脉粥样硬化、冠状动脉疾病、心力衰竭和心律失常，主要是心房颤动，这两种疾病都有特征，并与甲状腺功能正常的人相比，增加了 CV 和总死亡率。每种类型的 STD 导致 CV 风险增加的机制存在一些差异，SHypo 比 SHyper 中更聚集了更多传统的 CV 危险因素，而 TSH 或其缺乏以及各自的、甚至是微妙的甲状腺激素浓度变化似乎都对两种类型的 STD 的 CV 系统产生不利影响。有证据表明，治疗 STD 通过减少 CV 事件带来潜在益处，然而，由于缺乏随机对照研究，尚未达成共识。尽管如此，由于观察性研究的积累证据，许多权威机构都认为严重 SHypo（TSH>10mIU/L）或 2 级 SHyper（TSH<0.1mIU/L）的患者应该接受治疗，主要是因为 CV 发病率和死亡率增加的风险。本文综述的证据应该引起并帮助临床医生警惕这两种潜在的 STD 情况，因为它们可能导致严重的 CV 并发症，而它们的治疗似乎非常有益。
