Hypothyroidism in Older Adults: A Concise Review of the Recent Literature

Abstract

Abstract Introduction Hypothyroidism (HypoT) is a common condition whose prevalence varies according to regional and ethnic factors, dietary iodine, gender, and age. The symptoms of HypoT are generally nonspecific, with considerable overlap with other conditions. These symptoms are not useful for diagnosing HypoT, and a thyroid function test is required for a final diagnosis. Materials and methods We aimed to provide an overview of the recent global literature on HypoT in older adults. A narrative, nonsystematic review of the international literature from a single major medical online database (PubMed) for the past 5 years was performed. The relevant literature was narrated in a concise thematic account. Results Most studies and expert opinions reiterated the benefit of replacement therapy in younger and middle-aged individuals. A good volume of literature also considered the interplay between thyroid hormones and (1) cardiovascular function and risk factors, (2) cognitive function, (3) mental health, and (4) quality of life. Most workers are cognizant of the important difference in normal ranges of thyroid-stimulating hormone (TSH) and the consequent TSH targets in older adults compared to younger age groups. Extra care is recommended for the initiation and titration of thyroid hormone replacement therapy to avoid cardiovascular and skeletal adverse effects of relative overtreatment. Conclusion While clinical benefit is evident in patients under age 65 with overt and subclinical HypoT who are treated with levothyroxine, treatment may be harmful in older adults with subclinical HypoT. The 97th percentile of TSH distribution is 7.5 mIU/L for patients over age 80. Hence, TSH goals should be individualized in older adults to achieve any possible benefit and avoid unnecessary harm.