April 1990

Thyroid Dysfunction in Adults Over Age 55 YearsA Study in an Urban US Community

Author Affiliations

From the Department of Internal Medicine (Division of Endocrinology and Metabolism), Wayne State University (Drs Bagchi and Brown) and the Metropolitan Society for Crippled Children and Adults (Dr Parish), Detroit, Mich.

Arch Intern Med. 1990;150(4):785-787. doi:10.1001/archinte.1990.00390160053012

• The prevalence of thyroid dysfunction was determined in a healthy urban population over the age of 55 years. A highly sensitive serum thyrotropin assay was used initially to screen 968 subjects. Elevated values (>6 mU/L) were found in 7.3%, while suppressed values (<0.1 mU/L) were present in 2.5% subjects. Protirelin stimulation testing demonstrated exaggerated responses in 95% of the subjects with elevated thyrotropin levels and subnormal responses in 81% of the subjects with suppressed thyrotropin levels. Thyroid dysfunction, as defined by abnormalities of both serum thyrotropin level and protirelin response, was calculated to be present in 8.9% of the population. The prevalence was greater in whites (vs blacks), in women, and in subjects older than 75 years as compared with the 55- to 64-year age group. Hypothyroidism was calculated to be present in 6.9% subjects. Despite an increased prevalence of thyroid autoantibodies in these subjects, only 8.5% of them had subnormal serum thyroxine concentrations. Hyperthyroidism was calculated to be present in 2.0% of the population, two thirds of whom were taking thyroid hormone preparations. These results suggest a significant prevalence of thyroid dysfunction in the elderly, with important sex and racial differences.

(Arch Intern Med. 1990;150:785-787)