Publication in Annals of Internal Medicine

19.05.2020 - Does L-thyroxine help older adults with subclinical hypothyroidism and hypothyroid symptoms? New results published in Annals of Internal Medicine.

In this secondary analysis of the large, randomized TRUST trial (Thyroid hormone Replacement for Untreated older adults with Subclinical hypothyroidism Trial), we showed that L-thyroxine, compared to placebo, does not improve hypothyroid symptoms or tiredness in older adults with subclinical hypothyroidism and high burden of symptoms.

Subclinical hypothyroidism (SCH) is a common condition in older people, and it is often treated with L-thyroxine, which is one of the most commonly prescribed drug in the US and Europe.
The large randomized trial of older adults with SCH (TRUST trial) and a systematic review and meta-analysis of all randomized controlled trials found no improvement in symptoms with L-thyroxine therapy, compared to placebo. However, it remained unclear whether a subset of patients with SCH who have greater symptoms might still benefit from treatment. Therefore, our study focused on those with high symptom burden before treatment.

In our study symptoms improved, but similarly in the L-thyroxine and placebo groups. This may be due to the natural history of SCH, the placebo effect or regression to the mean, and may explain why many patients are convinced that L-thyroxine is beneficial.
Our study results do not support routine L-thyroxine treatment for older adults with SCH, including those with high symptom burden. Treating physicians should reconsider prescribing/offering L-thyroxine to older adults with SCH, even those with symptoms, because there is no clear evidence for its benefit in treating SCH to date.