title: Thyroid function and neuropsychological status in older adults.
abstract: Overt thyroid dysfunction is recognized as a risk factor for neuropsychological deficits in aging populations, yet evidence for how changes in levels of circulatory thyroid hormones impact specific neuropsychological domains is limited. Here we report cross-sectional associations between serum thyroid hormone concentrations and several neuropsychological function domains among men and women aged 55-74years. We administered neuropsychological tests to assess memory, learning, executive function, measures of attention, visuospatial function, affective state, and motor function. Multivariable linear regression analyses were performed adjusting for age, sex, education, and cigarette smoking. Effects were reported as differences in test scores per one interquartile range (IQR) increase in hormone concentration. Higher total thyroxine (T4) and free thyroxine (fT4) were associated with improved visuospatial function, as measured by Block Design Subtest total scores; associated increments per IQR differences in T4 and fT4 were 15% and 19%, respectively (false discovery rate q-values <0.05). We also detected statistical interactions between age and fT4 for effects in tasks of memory and learning. Concurrent increases in age and fT4 were associated with deficits in memory and learning as measured by California Verbal Learning Test subtests (10% and 16% deficits in t-score and short delay free recall score, respectively). Our findings suggest that changes in thyroid hormones may have important implications for neuropsychological function in aging populations. Further large-scale studies with comprehensive thyroid function and neuropsychological outcome assessments are warranted to confirm these results.
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, University at Albany, State University of New York, One University Place, Rensselaer, NY 12144, United States.
authors.forename: Srishti
authors.initials: S
authors.lastname: Shrestha
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, University at Albany, State University of New York, One University Place, Rensselaer, NY 12144, United States; Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, One University Place, Rensselaer, NY 12144, United States.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Bloom
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, University at Albany, State University of New York, One University Place, Rensselaer, NY 12144, United States.
authors.forename: Recai
authors.initials: R
authors.lastname: Yucel
authors.affiliation: Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, One University Place, Rensselaer, NY 12144, United States; Division of Environmental Health Sciences, Wadsworth Center, New York State Department of Health, Empire State Plaza, P.O. Box 509, Albany, NY 12201, United States.
authors.forename: Richard F
authors.initials: RF
authors.lastname: Seegal
authors.affiliation: Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, P.O. Box 509, Albany, NY 12201, United States; Department of Biomedical Sciences, School of Public Health, University at Albany, State University of New York, One University Place, Rensselaer, NY 12144, United States.
authors.forename: Robert
authors.initials: R
authors.lastname: Rej
authors.affiliation: Department of Psychology, University at Albany, State University of New York, Albany, NY 12222, United States.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: McCaffrey
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, University at Albany, State University of New York, One University Place, Rensselaer, NY 12144, United States; Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, One University Place, Rensselaer, NY 12144, United States. Electronic address: efitzgerald@albany.edu.
authors.forename: Edward F
authors.initials: EF
authors.lastname: Fitzgerald
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology*; D001288:Attention / Q000502:physiology; D003071:Cognition / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D013963:Thyroid Hormones / Q000097:blood*; D014796:Visual Perception / Q000502:physiology
chemical_list: D013963:Thyroid Hormones
keywords: Neuropsychological status; Older adults; Thyroid function