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Thyroid replacement = placebo for symptom resolution in subclinical hypothyroidism
Clinical Question
Does l-thyroxine treatment affect thyroid symptoms and tiredness in older patients with subclinical hypothyroidism?
Bottom line
Ahh, the placebo effect. Sometimes bad for researchers, sometimes good for patients. Treatment for a year with either placebo or titrated doses of levothyroxine produces a similar, clinically relevant benefit in patients with tiredness or high hypothyroidism scores. The results could be a placebo effect or natural history. Recent guidelines do not recommend treating patients with vague symptoms [LINKTO: 210827]. 1b-
Reference
Study design: Randomized controlled trial (double-blinded)
Funding: Government
Setting: Outpatient (any)
Synopsis
The researchers enrolled 638 persons aged 65 years or older with persistent subclinical hypothyroidism, meaning they had a thyroid stimulating hormone (TSH) level of 4.60 to 19.9 mIU/L and normal free thyroxine (free T4), independent of symptoms. The subjects were randomized, allocation concealment unknown, to receive levothyroxine or placebo for one year. Doses were titrated to normal TSH levels (or faux-titrated in the case of placebo). This analysis focused on the 132 subjects (20.7%) who had hypothyroidism scores (more than 30 out of a possible 100) or high tiredness scores (more than 40 out of a possible 100). Using a 9-point change as a minimum clinically relevant effect for both measures, both treatment (12.3 points) and placebo (10.4 points) reduced symptoms similarly, and also affected tiredness similarly (average decrease 8.9 for treatment and 10.9 for placebo).
Reviewer
Allen F. Shaughnessy, PharmD, MMedEd
Professor of Family Medicine
Tufts University
Boston, MA
Comments
Retired
Retired