Serum Thyrotropin and Triiodothyronine Levels in Levothyroxine-Treated Patients.
Matthew D EttlesonWesley H PrietoPedro S T RussoJose de SaWen WanNeda LaiteerapongRui M B MacielAntonio Carlos BiancoPublished in: The Journal of clinical endocrinology and metabolism (2022)
In LT4-treated patients, the relationships between serum FT4 vs TSH and FT4 vs T3 across a range of FT4 levels are disproportionate. As a result, dose changes in LT4 that robustly modify serum FT4 and TSH values may only minimally affect serum T3 levels and result in no significant clinical benefit.