Pasqualetti Giuseppe, Caraccio Nadia, Dell Agnello Umberto, Monzani Fabio
Geriatrics Unit, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy; Via Roma 67, 56 126-Pisa; Italy.
Recent Pat Endocr Metab Immune Drug Discov. 2016;10(1):4-10. doi: 10.2174/1872214810666160701110509.
Over the last decades an increasing body of evidence suggested a possible relationship between thyroid hormone (TH) and the ageing process, and several efforts have been made to determine the actual role of TH dynamic during human life. It is still unclear whether the serum level shift of Thyroid Stimulating Hormone toward higher value, observed during ageing, is a normal adaptive response associated with senescence or an actual mild thyroid dysfunction. A growing body of evidence supports the hypothesis of a reset of the hypothalamus-pituitary-thyroid axis in order to contrast the catabolic status of the ageing process. On the other hand, several meta-analyses showed a direct link between subclinical hypothyroidism (sHT) and cardiovascular events (both ischemic heart disease and stroke), although mainly in individuals younger than 65 years. Similarly, a recent meta-analysis documented consistent data on a positive relationship between sHT and cognitive impairment, but only in individuals younger than 75 years.
The available data suggest a complex relationship between mild thyroid failure and the ageing process as well as the development and progression of several cardiovascular and neurological diseases. In this paper, we reviewed the scientific English literature on sHT and the ageing process focusing on experimental evidences related to cognitive impairment and dementia. Moreover, we focused on new patents of treatments potentially able to improve the care of sHT patients, especially in the elderly, where treatment drawbacks may have negative impact on the long term outcome.
在过去几十年中，越来越多的证据表明甲状腺激素（TH）与衰老过程之间可能存在关联，并且人们已经做出了多项努力来确定TH动态变化在人类生命过程中的实际作用。目前仍不清楚在衰老过程中观察到的促甲状腺激素血清水平向更高值的转变，是与衰老相关的正常适应性反应，还是实际存在的轻度甲状腺功能障碍。越来越多的证据支持下丘脑 - 垂体 - 甲状腺轴重置的假说，以便对抗衰老过程中的分解代谢状态。另一方面，多项荟萃分析表明亚临床甲状腺功能减退（sHT）与心血管事件（包括缺血性心脏病和中风）之间存在直接联系，不过主要是在65岁以下的个体中。同样，最近的一项荟萃分析记录了关于sHT与认知障碍之间存在正相关的一致数据，但仅在75岁以下的个体中。
现有数据表明轻度甲状腺功能减退与衰老过程以及几种心血管和神经疾病的发生和发展之间存在复杂关系。在本文中，我们回顾了关于sHT与衰老过程的科学英文文献，重点关注与认知障碍和痴呆相关的实验证据。此外，我们关注了可能改善sHT患者护理的新治疗专利，特别是在老年人中，因为治疗缺陷可能对长期预后产生负面影响。
