Thyroid hormone treatment for the elderly
Thyroid hormone has multiple pleiotropic effects on physiological systems, including the vascular tree, heart, skeletal muscle and brain. Hormone replacement has the potential to give multi-system benefits to older people with mild thyroid hormone deficiency. Small studies have reported reduced atherosclerosis and improved cardiac function with thyroxine replacement, but no large clinical trials have been performed. To address this, the EU-funded TRUST project performed a multicentre clinical trial to assess the impact of thyroxine treatment on older adults with persisting subclinical hypothyroidism. Partners were particularly interested to see how hormone replacement may improve health-related quality of life, prevent cardiovascular disease, while improving muscle function and cognition. The TRUST team screened over 2 640 subjects with biochemical evidence of subclinical hypothyroidism for possible participation in the trial. A total of 737 adults aged over 65 years with persisting subclinical hypothyroidism were finally included in the study and randomised to receive placebo or thyroxine treatment. In the course of one year, patients treated with hormone replacement exhibited no changes in hypothyroid symptom scores or tiredness scores. No beneficial effects were seen on secondary outcome measures either, indicating that thyroxine intervention does not provide any benefits to older people with subclinical hypothyroidism and should not be routinely prescribed to this cohort. Taken together, the findings of the study address current variations in guidelines and clinical management of subclinical hypothyroidism in older people, providing solid evidence on the indications for screening and treatment. The TRUST project attracted considerable media attention and the generated biobank will be exploited for future investigations into the biochemical causes of ageing. Importantly, it established a strong European network of complementary research expertise on subclinical hypothyroidism in older people.
Keywords
Thyroid hormone, subclinical hypothyroidism, clinical trial, thyroxine, TRUST
