Free triiodothyronine/free thyroxine ratio rather than thyrotropin is more associated with metabolic parameters in healthy euthyroid adult subjects.
So Young ParkSe Eun ParkSang Won JungHyun Seok JinIe Byung ParkSong Vogue AhnSihoon LeePublished in: Clinical endocrinology (2017)
Thyrotropin levels were positively associated with FT3/FT4 ratio within the euthyroid range. The higher FT3/FT4 ratio is associated with increased risk of metabolic syndrome parameters and insulin resistance. FT3/FT4 ratio has a better predictive power for metabolic syndrome than TSH.