After a long battle with reviewers and editors we've got our latest paper accepted by Endocrine Connections. I summarise the conclusions. The paper will be published online in the next 7 days.
The findings of the present study have several clinical implications. Firstly, they recognize
thyroid hormone conversion efficiency, as defined by the calculated global deiodinase
activity or more simply the T3-T4 ratio, is an important determinant of L-T4 dose
requirements and the biochemical response to treatment. Secondly, in view of a T4-related
FT3-TSH disjoint FT3 measurement should be adopted as an additional treatment target.
Thirdly, in cases where an FT3-FT4 dissociation becomes increasingly apparent following
dose escalation of L-T4 an alternate treatment modality, possibly T3/T4 combination
therapy, should be considered, but further randomized controlled trials are required to assess the benefit versus risk in this particular group.
By global deiodinase we mean the total deiodinase activity in the body, whether directly acting in the thyroid gland itself or anywhere else in the body. By FT3-TSH disjoint we mean a change in the relation between FT3 and TSH in treated people as compared with normal health.