Thyroid dysfunction in adults over age 55 years. A study in an urban US community

Arch Intern Med. 1990 Apr;150(4):785-7.


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 (greater than 6 mU/L) were found in 7.3%, while suppressed values (less than 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Female
  • Humans
  • Hyperthyroidism / epidemiology*
  • Hypothyroidism / epidemiology*
  • Immunoradiometric Assay
  • Incidence
  • Male
  • Michigan / epidemiology
  • Middle Aged
  • Prevalence
  • Thyrotropin / blood
  • Thyrotropin-Releasing Hormone
  • Urban Population


  • Thyrotropin-Releasing Hormone
  • Thyrotropin