Thyroid Hormones Are Associated with Poorer Cognition in Mild Cognitive Impairment
Open Access
- 26 August 2010
- journal article
- research article
- Published by S. Karger AG in Dementia and Geriatric Cognitive Disorders
- Vol. 30 (3), 205-211
- https://doi.org/10.1159/000319746
Abstract
Background: Alterations in interrelated endocrine axes may be related to the pathogenesis of mild cognitive impairment (MCI) and dementia. Methods: Salivary cortisol before and after a 0.5-mg dexamethasone test, and serum levels of thyroid-stimulating hormone, total thyroxine (T4), free T4, total triiodothyronine (TT3), estradiol, testosterone and insulin-like growth factor 1 were measured in 43 MCI cases and 26 healthy controls. All participants underwent a comprehensive neuropsychological test battery covering the cognitive domains of speed/attention, memory, visuospatial functions, language and executive functions. Results: The MCI group did not differ in basal levels of endocrine markers compared to controls. Among those with MCI, TT3 levels were inversely associated with cognitive performance across all domains. After stratifying MCI cases according to TT3 levels, those with relatively high TT3 levels showed impairment in memory as well as in visuospatial and executive functions. Those with TT3 levels at or below the lower boundary of the normal range performed comparably to healthy controls. Other endocrine markers were not related to cognitive performance. Conclusions: Among those with MCI, TT3 was associated with a neuropsychological profile typical of prodromal Alzheimer’s disease. While the mechanisms remain unclear, optimal levels of thyroid hormone under a compromising condition such as MCI and related neuropathology need reconsideration.Keywords
This publication has 45 references indexed in Scilit:
- Thyroid Function and the Risk of Alzheimer DiseaseThe Framingham StudyArchives of Internal Medicine, 2008
- Increased Saliva Cortisol Awakening Response in Patients with Mild Cognitive ImpairmentDementia and Geriatric Cognitive Disorders, 2007
- Thyroid function, the risk of dementia and neuropathologic changes: The Honolulu–Asia Aging StudyNeurobiology of Aging, 2007
- Patterns of Atrophy Differ Among Specific Subtypes of Mild Cognitive ImpairmentArchives of Neurology, 2007
- Thyroid Hormone Regulates Endogenous Amyloid-β Precursor Protein Gene Expression and Processing in Both In Vitro and In Vivo ModelsThyroid®, 2006
- Glucocorticoids Increase Amyloid-β and Tau Pathology in a Mouse Model of Alzheimer’s DiseaseJournal of Neuroscience, 2006
- The Goteborg MCI study: mild cognitive impairment is a heterogeneous conditionJournal of Neurology, Neurosurgery & Psychiatry, 2005
- Therapeutic actions of insulin-like growth factor I on APP/PS2 mice with severe brain amyloidosisNeurobiology of Aging, 2005
- Longitudinal study of basal cortisol levels in healthy elderly subjects: Evidence for subgroupsNeurobiology of Aging, 1996
- Estrogenic Effects on Memory in WomenaAnnals of the New York Academy of Sciences, 1994