Hormone therapy no benefit for subclinical hypothyroidism

20 May 2019

Thyroid hormones should no longer be offered to patients with a moderately underactive thyroid gland, according to new guidelines published in collaboration with The University of Queensland.

UQ School of Clinical Medicine researcher Professor Mieke van Driel said thyroid hormones should not be offered to adults who present with mild symptoms.

“Current guidelines generally recommend to treat patients with symptoms of hypothyroidism accompanied by high levels of thyroid stimulating hormone (>10 mIU/L),” Professor van Driel said.

“However, there was uncertainty about a large group of patients with moderately high thyroid-stimulating hormone levels (4 to 10 mIU/L); a condition referred to as subclinical hypothyroidism.

“The available evidence from 21 clinical trials with over 2000 participants shows that almost all adults with subclinical hypothyroidism will gain no benefit from treatment with thyroid hormones.”

Thyroid hormones are among the most frequently prescribed medicines and are used as a substitute for underactive thyroids.

Symptoms of hypothyroidism range from fatigue to dry skin, constipation, cold sensitivity, muscle soreness, anxiety and depression.

“We make a strong recommendation against prescribing thyroid hormones for almost all adults with subclinical hypothyroidism,” she said.

“Treatment does not improve symptoms, quality of life, nor cardiovascular outcomes and mortality in this group of patients.

 “While prescribing hormone treatment has become routine practice, we see no benefit from treatment on fatigue, low mood, weight gain or any other outcomes that were tested.

“These treatments may be doing more harm than good for patients who must take pills and commit to attending lifelong check-ups.

“We also acknowledge the financial burden, and although we only looked at direct costs to patients, thyroid hormones cannot be a cost-effective treatment.”

The recommendation does not apply to women who are trying to become pregnant or patients with particularly high thyroid stimulating hormone levels.

It may also not apply to patients with severe symptoms or some aged under 30.

This research is published in the British Medical Journal (DOI: https://doi.org/10.1136/bmj.l2006).

Media: Professor Mieke van Driel, m.vandriel@uq.edu.au; Faculty of Medicine Communications, med.media@uq.edu.au, +61 7 3365 5118, +61 436 368 746.