TY - JOUR
T1 - Thyroid hormones
T2 - Positive relationships with cognition in healthy, euthyroid older men
AU - Prinz, Patricia N.
AU - Scanlan, James M.
AU - Vitaliano, Peter P.
AU - Moe, Karen E.
AU - Borson, Soo
AU - Toivola, Bert
AU - Merriam, George R.
AU - Larsen, Lawrence H.
AU - Reed, H. Lester
PY - 1999/3
Y1 - 1999/3
N2 - Background. Although the association of clinical hypothyroidism with cognitive deficits is well known, the cognitive effects of thyroid hormones in euthyroid subjects are less studied and understood. The purpose of this study was to examine thyroid-cognition relationships in healthy, euthyroid older men. Methods. We examined healthy men (N = 44, mean age = 72), excluding clinically hypothyroid/hyperthyroid or diabetic/hyperglycemic subjects and those with dementia, depression, CNS medications, or recent illness. Plasma samples obtained across a 24-hour period were pooled, then assayed for total thyroxine (TT4), total triiodothyronine (TT3), and T3 resin uptake. Free thyroxine index (FT4I) was calculated. A broad cognitive battery (including the Wechsler Adult Intelligence Scale-Revised [WAIS-R], the Dementia Rating Scale [DRS], and the Rivermead Behavioral Profile [PROFILE]) was administered to all subjects. Results. Regression analyses controlling age and education showed TT4 and FT4I to have significant positive relationships with measures of overall cognition; TT4 accounted for 8% to 12% of the variance in omnibus cognitive measures such as WAIS Performance, WAIS Verbal score, and GLOBAL cognitive scores. Conclusions. Our findings suggest that within 'normal' range of variation in plasma thyroid hormones, TT4 but not T3 positively associates with general cognition in healthy elderly men.
AB - Background. Although the association of clinical hypothyroidism with cognitive deficits is well known, the cognitive effects of thyroid hormones in euthyroid subjects are less studied and understood. The purpose of this study was to examine thyroid-cognition relationships in healthy, euthyroid older men. Methods. We examined healthy men (N = 44, mean age = 72), excluding clinically hypothyroid/hyperthyroid or diabetic/hyperglycemic subjects and those with dementia, depression, CNS medications, or recent illness. Plasma samples obtained across a 24-hour period were pooled, then assayed for total thyroxine (TT4), total triiodothyronine (TT3), and T3 resin uptake. Free thyroxine index (FT4I) was calculated. A broad cognitive battery (including the Wechsler Adult Intelligence Scale-Revised [WAIS-R], the Dementia Rating Scale [DRS], and the Rivermead Behavioral Profile [PROFILE]) was administered to all subjects. Results. Regression analyses controlling age and education showed TT4 and FT4I to have significant positive relationships with measures of overall cognition; TT4 accounted for 8% to 12% of the variance in omnibus cognitive measures such as WAIS Performance, WAIS Verbal score, and GLOBAL cognitive scores. Conclusions. Our findings suggest that within 'normal' range of variation in plasma thyroid hormones, TT4 but not T3 positively associates with general cognition in healthy elderly men.
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U2 - 10.1093/gerona/54.3.M111
DO - 10.1093/gerona/54.3.M111
M3 - Article
C2 - 10191837
AN - SCOPUS:0033035838
SN - 1079-5006
VL - 54
SP - M111-M116
JO - Journals of Gerontology - Series A Biological Sciences and Medical Sciences
JF - Journals of Gerontology - Series A Biological Sciences and Medical Sciences
IS - 3
ER -