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P3‐152: Cognitive decline as a quadratic function of free tri‐iodothyronine levels in Alzheimer's disease
Author(s) -
Leyhe Thomas,
Frank Jeanette,
Fallgatter Andreas,
Müssig Karsten,
Saur Ralf
Publication year - 2012
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2012.05.1372
Subject(s) - cognitive decline , medicine , cognition , dementia , free thyroxine , endocrinology , thyroid stimulating hormone , triiodothyronine , disease , psychology , thyroid function , hormone , psychiatry
Background: Both hypoand hyperthyroidism appear to be risk factors for the development of Alzheimer’s disease. We hypothesized that the levels of thyroid stimulating hormone (TSH), free triiodothyronine (T3), and free thyroxine (T4) may influence the rate of cognitive decline of patients with this illness. Methods: In 70 patients with Alzheimer’s dementia (AD), the rate of cognitive decline was correlated with the levels of TSH, free T3 and free T4. Rate of cognitive decline in the patients with AD was assessed by the difference of theMMSE score at onset of cognitive decline (estimated as 30) and the MMSE score at the time point of the measurement of TSH, free T3 and free T4 divided by the time of disease duration (month since onset of cognitive decline). Onset of cognitive deterioration was obtained by inquiry of the patients or their relatives.Results:A quadratic correlation between the rate of cognitive decline and the levels of free T3 was found in the AD patients (P< 0.01), but not between the rate of cognitive decline and the levels of TSH or free T4 (both P > 0.2). Conclusions: The results of the present study suggest a more rapid cognitive decline in AD patients with both high and low free T3 levels. This could be due to a propagation of amyloid-pathology or vascular risk factors by low concentration of T3 in the brain or conversely increased neuronal stress by high concentration of T3 in the brain. Our data suggest a close monitoring of thyroid function in patients with Alzheimer’s disease.