Endocrine Abstracts

Background: Both overt hypothyroidism as well as subclinical hypothyroidism is frequently encountered in older individuals. It is increasingly being recognised that treatment of subclinical hypothyroidism may not be beneficial, particularly in an older person. These findings are particularly relevant at a time when treatment with thyroid hormones is increasing and more than 10–15% of people aged over 80 years are prescribed levothyroxine therapy.

Main body: The prevalence of hypothyroidism increases with age. However, the upper limit of the TSH reference range also rises with age. Furthermore, there is evidence to suggest that minor TSH elevations are not associated with important outcomes such as symptoms, impaired quality of life, cognition, cardiovascular events and mortality in older individuals. There is also evidence that treatment of mild subclinical hypothyroidism may not benefit quality of life and/or symptoms in older people. It is unknown whether treatment targets should be reset depending on the age of the patient. It is likely that some older patients with non-specific symptoms and incidental mild subclinical hypothyroidism may be treated with thyroid hormones and could potentially be harmed as a result or, at best, have no beneficial impact.

Conclusions: Evidence suggests that threshold for treating mild subclinical hypothyroidism in older people should be high. In addition, it is reasonable to aim for a higher TSH target in treated older hypothyroid patients, as their thyroid hormone requirements are lower. Therefore, it is important that age-appropriate TSH reference ranges should be considered in the diagnostic pathway of identifying hypothyroidism. Appropriately designed randomised controlled trials are required to confirm risk/benefit and cost-effectiveness of treatment of subclinical hypothyroidism in older people. Until the results of such RCTs are available to guide clinical management international guidelines should be followed that advocate a conservative policy in the management of mild subclinical hypothyroidism in older individuals.