This new preprint paper shows that all the thyroid parameters decline in very old agre with implications for cognitive ability. I would say that a lower TSH would extend to lowerFT4/3 because the pituitary is not responding as sensitively to the lower levels. However this begs the question as to whether a small dose of T4 should be given to raise FT4/3 a little, even if TSH becomes suppressed. The dreaded Pearce is part of the group
Thyroid
Ahead of Print Free Access
Changes in Serum Thyroid Function Predict Cognitive Decline in the Very Old: Longitudinal Findings from the Newcastle 85+ Study
Earn H. Gan, Carol Jagger, Mohammad E. Yadegarfar, Rachel Duncan, and Simon H. Pearce
Published Online:2 Jul 2021doi.org/10.1089/thy.2020.0596