Endocrine Abstracts

Background: Most recent cross sectional and longitudinal studies have failed to find an association between cognitive dysfunction and subclinical hypothyroidism. A recent paper from our country however suggested a significant association.

Objectives: This study was undertaken to determine the prevelance of cognitive impairement among educated, elderly Indian patients (>60 years) with and without subclinical hypothyroidism.

Materials and methods: This study was conducted on educated, elderly patients admitted to the in-patient department of Christian Medical College, Ludhiana. One hundred patients with subclinical hypothyroidism an equal number of controls with normal thyroid functions were interviewed after taking informed consent. Subclinical hypothyroidism was defined as serum TSH level more than 4.0 mIU/L with serum fT3 and fT4 in the normal reference range. Cognitive function was assessed by Hindi/English Mini mental status examination (MMSE) and clock drawing test (CDT).

Results: The cases (n=100) had a mean age of 68.2 years, were 59% males and had a mean body mass index of 25.5 kg/m² compared to controls (n=100) who had a mean age of 69.9 years (P-0.09), were 64% male (P-0.5) and had a mean BMI of 25.3 kg/m².All other baseline variables including co-morbidities, family history of dementia, head injury, smoking, alcohol use, fruit and vegetable intake, daily newspaper reading, education and exercise regularity were comparable in both groups. The cases had mean MMSE of 26.1 and controls of 25.9 (P-0.68) respectively The cases had mean CDT of 2.19 and controls 2.18 (P-0.95).

Conclusions: There is no difference in cognitive function in elderly with subclinical hypothyroidism in comparison with elderly population having normal thyroid function.

Keywords: Subclinical, Hypothyroidism, Biochemical, Cognitive functions, Elderly