The log TSH-free T4 relationship in a community-based cohort is nonlinear and is influenced by age, smoking and thyroid peroxidase antibody status

摘要

BackgroundThe TSH-T4 relationship was thought to be inverse log-linear, but recent cross-sectional studies of selected populations report a complex, nonlinear relationship. The TSH-T4 relationship has not been evaluated in an unselected, community-based cohort, and there are limited data regarding clinical factors which affect it.