Lower-but-normal serum TSH level is associated with the development or progression of cognitive impairment including mild cognitive impairment and dementia in elderly: A result from Korean Longitudinal Study on Health and Aging (KLoSHA)
|Abstract | Context:
The association between subclinical hyperthyroidism and the risk of dementia has been validated in several studies. However, the effect of thyroid function within reference range on the risk of cognitive dysfunction including mild cognitive impairment (MCI) and dementia is still unclear. Objective: Our aim was to investigate the association between thyroid function and the risk of MCI and dementia in euthyroid elderly subjects. Design, setting, and participants: We conducted a population-based prospective study as a part of the Korean Longitudinal Study on Health and Aging (KLoSHA). 313 participants who were euthyroid and non-demented at baseline and completed cognitive function tests at 5-year-follow-up evaluation (mean age, 72.5 ± 6.9 yrs) were analyzed in the present study.