The Aging Thyroid

• In an unselected population of elderly (over age 60 years) men and women (the original cohort of the Framingham Study), the prevalence of thyroid deficiency, evidenced by a clearly elevated serum thyrotropin (TSH) level (>10 μU/mL), was 4.4%. Women had thyroid deficiency (5.9%) more often than men (2.3%). Of those with clearly elevated serum TSH levels, only 39% had low serum thyroxine (T₄) levels; the remainder had serum T₄levels in the lower half of the normal range. Others (5.9%) had a slightly elevated serum TSH level (5 to 10 μU/mL); their status was not clear, but more (12.7%) had low T₄levels than expected. The level of serum T₄was not a sensitive measure of thyroid deficiency nor was routine examination by a physician, even when the patient's background contained a clue to a possible thyroid problem. An elevated serum TSH level was a sensitive marker of thyroid deficiency in the elderly and was often the only way to detect it. Further studies are needed to determine the relationship of thyroid deficiency to cognitive and cardiovascular function in older persons. (Arch Intern Med1985;145:1386-1388)