Models of cognitive functions with respect to selected parameters of functional state of the thyroid gland in post-menopausal women

Introduction: The objective of the study was the development of models of cognitive functions in a group of post-menopausal women, according to the concentration of the selected laboratory parameters evaluating the functional state of the thyroid gland.

Material and methods: The study was conducted during 2012-2014, and covered women aged 50-65 years, minimum two years after the last menstruation, without chronic diseases, cancerous diseases, mental disorders, addiction to drugs or alcohol, and who did not use hormone replacement therapy. At the stage of qualification, a brief MoCA test was performed; 383 women were qualified for the study. Blood was collected for the determination of such parameters as: TSH, TT4, fT4, anti-TPO, anti-Tg, and AB-TSHR. Assessment of cognitive functions was performed using the diagnostic instrument Central Nervous System - Vital Signs (CNS-VS) (Polish version). The results were statistically analysed.

Results: The mean age of the women in the study was 56.4 ± 3.4; the mean TSH was 1.91 ± 1.35 mU/L, fT4 14.76 ± 2.34 pmol/L, and TT4 99.12 ± 16.98 nmol/L. Mean values were: 64.74 IU/L for anti-TPO, 100.69 IU/L for anti-Tg, and 1.40 IU/L for AB-TSHR. The examined women obtained the neurocognitive index (NCI) on the level of 84.4 scores, on average. The lowest results were obtained in tests assessing cognitive flexibility (mean 78.64 scores), processing speed (mean 79.25 scores), and executive functions (mean 79.75 scores). In the tests evaluating complex attention, the mean values were 82.24 scores, psychomotor speed - mean 83.42 scores, and reaction time - mean 86.87 scores. The women examined obtained the best results in tests assessing memory (mean 90.15 scores), including verbal (mean 91.22 scores), and visual (mean 93.37 scores). The NCI and cognitive function models were assessed from the aspect of thyroid gland examinations in post-menopausal women. Based on the analyses performed, the following conclusions were drawn: The developed models of cognitive functions indicate a considerable effect of TSH, fT4, AB-TSHR, and anti-TPO, as well as TT4 and anti-Tg, on the level of cognitive functions after menopause in the group examined. The conducted study suggests the need for examination of the functional state of the thyroid gland in post-menopausal women who show cognitive function disorders.