Recent evidence sets therapeutic targets for levothyroxine-treated patients with primary hypothyroidism based on risk of death

Since the introduction of sensitive assays for serum thyroid-stimulating hormone (TSH) clinicians have advised hypothyroid patients to adjust dose levothyroxine (L-T4) in order achieve a normal TSH. A minority are dissatisfied with this treatment strategy and experience symptoms. Some indirect evidence suggests that TSH may not necessarily reflect euthyroidism at tissue level treated L-T4. Increasingly demand higher doses L-T4 or liothyronine (L-T3) animal thyroid extract, often purchased online, titrate against symptoms, although ample combination (L-T4 L-T3) is no more effective than alone. Community surveys show up 53% any time outside range. The recommendation by guidelines upper limit range should be exceeded supported robust generally accepted patients. However, until recently lower optimal replacement has been controversial. New obtained two independent large population studies over past years shown mortality increased when exceeds reduced reference It estimated implementation policy normalising will reduce risk death 28.3 million people USA Europe