Relation between thyroid and cardiac functions and the geriatric rating scale.

To assess the effects of thyroid hormone and cardiac function on senile dementia, relations between serum thyroid hormone concentrations, hemodynamic parameters and dementia rating scale scores were studied in 83 subjects aged 70 and over. Age and serum-free T3 concentrations had a significantly negative correlation in all subjects and in subjects without dementia, but not when analysed only in dementia subjects. Regarding the genesis of dementia, serum free T3 concentrations and cardiac index were both significantly lower in cerebrovascular dementia than in those without dementia. Moreover, subjects with cerebrovascular dementia showed significantly lower serum free T3 concentrations and cardiac index than those with senile dementia of Alzheimer's type in all age groups. These findings suggest that cognitive function is closely related to serum free T3 and cardiac function in subjects with cerebrovascular dementia and that serum free T3 concentrations may be a good indicator, reflecting health and cognitive status.