Cross-sectional observations of thyroid function in geriatric Mexican outpatients with and without dementia.

UNLABELLED: This work was aimed at determining and comparing the frequency of abnormal levels of thyroid stimulating hormone (TSH) in geriatric outpatients with and without dementia. This cross-sectional study enrolled patients, aged 60 years and older with or without dementia (established on the basis of DSM-IV-R), from geriatric outpatient unit with third level of medical care. Comparisons were between 33 (34%) patients without dementia versus 26 (58%) with dementia; both among 142 (24%) randomly selected sample (RSS) from unit's register; and the 101 (89%) in the memory-clinic case series (MCCS) of dementia were contrasted with the former. MEASUREMENTS: TSH, total/free thyroxine, mini-mental-state examination (MMSE), geriatric depression scale (GDS), Hachinski ischemic-score (HIS), and clinical data from the patients' charts. In the above order, high TSH was found in 9 (27.3%, confidence interval (CI)=12.1-42.5%), 6 (23.1%, CI=6.9-46.5%), and 30 (29.7%, CI=20.8-38.6%), respectively. Low-normal free thyroxine levels accompanied 76% of individuals with elevated TSH; in contrast of Gaussian distribution of free thyroxine in those with TSH in normal range. In conclusion, the high frequency found of hypothyroidism in patients with and without dementia warrants further studies. Treatment is only being recommended for patients with below range thyroxin levels; while treatment of subclinical hypothyroidism in the presence of cognitive decline will be addressed in the forthcoming studies.