Department of General Internal Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
Departments of Medicine and Epidemiology & Biostatistics, University of California, San Francisco, CA, USA.
Clin Endocrinol (Oxf). 2017 Nov;87(5):617-626. doi: 10.1111/cen.13458. Epub 2017 Sep 14.
Data on the association between subclinical thyroid dysfunction and dementia are limited and conflicting. We aimed to determine whether subclinical thyroid dysfunction was associated with dementia and cognitive decline.
Population-based prospective cohort study.
Adults aged 70-79 years with measured thyroid function, but no dementia at baseline, and Modified Mini-Mental State (3MS) at baseline and follow-up.
Primary outcome was incident-adjudicated dementia, based on 3MS, hospital records and dementia drugs. Secondary outcome was change in 3MS. Models were adjusted for age, sex, race, education and baseline 3MS, and then further for cardiovascular risk factors.
Among 2558 adults, 85% were euthyroid (TSH 0.45-4.49mIU/L), 2% had subclinical hyperthyroidism with mildly decreased TSH (TSH 0.10-0.44 mIU/L), 1% subclinical hyperthyroidism with suppressed TSH (TSH < 0.10 mIU/L with normal free thyroxine [FT4]) and 12% subclinical hypothyroidism (TSH 4.50-19.99 mIU/L with normal FT4). Over 9 years, 22% developed dementia. Compared to euthyroidism, risk of dementia was higher in participants with subclinical hyperthyroidism with suppressed TSH (HR 2.38, 95% CI = 1.13;5.04), while we found no significant association in those with mildly decreased TSH (HR 0.79, 95% CI = 0.45;1.38) or with subclinical hypothyroidism (HR 0.91, 95% CI = 0.70;1.19). Participants with subclinical hyperthyroidism with suppressed TSH had a larger decline in 3MS (-3.89, 95% CI = -7.62; -0.15).
Among older adults, subclinical hyperthyroidism with a TSH < 0.10 mIU/L was associated with a higher risk of dementia and a larger cognitive decline, while subclinical hyperthyroidism with mildly decreased TSH or subclinical hypothyroidism were not.
关于亚临床甲状腺功能障碍与痴呆的关系，现有数据有限且相互矛盾。本研究旨在确定亚临床甲状腺功能障碍是否与痴呆和认知能力下降有关。
基于人群的前瞻性队列研究。
年龄在 70-79 岁之间，基线时甲状腺功能已测量但无痴呆，且基线和随访时均接受了改良的迷你精神状态量表（3MS）测试。
主要结局为根据 3MS、医院记录和痴呆药物确定的新发确诊痴呆。次要结局为 3MS 的变化。模型根据年龄、性别、种族、教育程度和基线 3MS 进行了调整，然后进一步根据心血管危险因素进行了调整。
在 2558 名成年人中，85%为甲状腺功能正常（TSH 0.45-4.49mIU/L），2%患有轻度 TSH 降低的亚临床甲状腺功能亢进（TSH 0.10-0.44mIU/L），1%患有 TSH 抑制的亚临床甲状腺功能亢进（TSH<0.10mIU/L 且游离甲状腺素[FT4]正常），12%患有亚临床甲状腺功能减退（TSH 4.50-19.99mIU/L 且 FT4 正常）。9 年内，22%的参与者发展为痴呆。与甲状腺功能正常相比，TSH 抑制的亚临床甲状腺功能亢进患者的痴呆风险更高（HR 2.38，95%CI=1.13；5.04），而 TSH 轻度降低的患者（HR 0.79，95%CI=0.45；1.38）或亚临床甲状腺功能减退的患者（HR 0.91，95%CI=0.70；1.19）并无显著关联。TSH<0.10mIU/L 的亚临床甲状腺功能亢进患者的 3MS 下降幅度更大（-3.89，95%CI=-7.62；-0.15）。
在老年人中，TSH<0.10mIU/L 的亚临床甲状腺功能亢进与痴呆风险增加和认知能力下降幅度更大相关，而 TSH 轻度降低的亚临床甲状腺功能亢进或亚临床甲状腺功能减退则不然。
