Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan.
Division of Geriatric and Palliative Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan.
Endocr Pract. 2024 Nov;30(11):1113-1118. doi: 10.1016/j.eprac.2024.07.013. Epub 2024 Aug 5.
As the population of older adults in the United States continues to rise, understanding modifiable risk factors that contribute to cognitive decline and dementia becomes increasingly important. This narrative review summarizes existing literature on the association between thyroid function in the euthyroid range, hypothyroidism and hyperthyroidism, and cognitive outcomes in older adults.
A comprehensive literature search of the PubMed and Ovid/Medline databases was conducted. Randomized controlled trials, systematic reviews, meta-analyses, and observational studies published in English between January 2000 and December 2023 were included.
Overall, existing studies yielded conflicting results, failing to delineate a concrete relationship between thyroid function and cognitive outcomes and/or dementia in older adults. There may be a possible association between higher thyroid stimulating hormone in the reference range and lower risk of incident dementia, which may be more pronounced in women. Majority of studies elucidated a possible association between low thyroid stimulating hormone and incident dementia, with suggestion that duration of hyperthyroidism may contribute to increasing dementia risk. Even though evidence on the association of hypothyroidism and cognitive decline are disparate, current data do not support treatment of subclinical hypothyroidism to improve cognitive outcomes in older adults.
Despite numerous studies, there is no conclusive evidence that supports a direct relationship between hyperthyroidism or hypothyroidism and cognitive decline. Study limitations include heterogeneity in study designs, measurement methodologies, and cognitive assessment tools. Future research is needed to better delineate whether an association exists and whether treatment of thyroid dysfunction ameliorates cognitive impairment.
随着美国老年人口的持续增长，了解导致认知能力下降和痴呆的可改变风险因素变得越来越重要。本综述总结了现有关于甲状腺功能在正常范围内、甲状腺功能减退症和甲状腺功能亢进症与老年人认知结局之间关联的文献。
对 PubMed 和 Ovid/Medline 数据库进行了全面的文献检索。纳入了 2000 年 1 月至 2023 年 12 月期间以英文发表的随机对照试验、系统评价、荟萃分析和观察性研究。
总体而言，现有研究结果存在差异，未能明确界定甲状腺功能与老年人认知结局和/或痴呆之间的具体关系。在参考范围内，较高的促甲状腺激素与较低的痴呆发病风险之间可能存在关联，而这种关联在女性中更为明显。大多数研究阐明了低促甲状腺激素与痴呆发病之间可能存在关联，提示甲状腺功能亢进症的持续时间可能会增加痴呆的风险。尽管关于甲状腺功能减退症与认知能力下降的关联的证据存在差异，但目前的数据并不支持治疗亚临床甲状腺功能减退症以改善老年人的认知结局。
尽管进行了多项研究，但没有确凿的证据表明甲状腺功能亢进症或甲状腺功能减退症与认知能力下降之间存在直接关系。研究局限性包括研究设计、测量方法和认知评估工具的异质性。需要进一步的研究来更好地阐明是否存在关联，以及治疗甲状腺功能障碍是否能改善认知障碍。
