SUBCLINICAL THYROID-DISEASE IN THE ELDERLY

The development of sensitive assays for thyrotropin (TSH) has led to t he discovery that many older patients have abnormal TSH levels without other alterations in serum thyroid hormone levels, conditions termed subclinical hypothyroidism (isolated elevation of TSH levels);Ind subc linical hyperthyroidism (isolated suppression of TSH levels). Subclini cal hypothyroidism occurs in 5% to 10% of elderly subjects, and is esp ecially prevalent in elderly women. Subclinical hyperthyroidism is les s common, affecting less than 2% of the elderly population. The causes of subclinical thyroid disease in the elderly are similar to those of thyroid disease in the general population, although medications and i odine-containing compounds may Flay an increased role. Potential risks of subclinical hypothyroidism in the elderly include progression to o vert hypothyroidism, cardiovascular effects, hyperlipidemia, and neuro logical and neuropsychiatric effects. Potential risks of subclinical h yperthyroidism in the elderly include progression to overt hyperthyroi dism, cardiovascular effects (especially atrial fibrillation), and ost eoporosis. Decisions to treat elderly subjects with subclinical thyroi d disease should be based on a careful assessment of these risks in th e individual patient.