2026-10-11T13:45:29Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34022472 2026-09-29T09:55:47Z category_7 portal_147 item_type_3 month_year_09_2026

Supplemental Material for: The transient pubertal free thyroxine dip should not be misinterpreted as central hypothyroidism: a case series figshare admin karger (2628495) Mark R. Garrelfs (25136362) Jacquelien J. Hillebrand (25136363) Annemieke C. Heijboer (495806) Christiaan F. Mooij (345130) A.S. Paul van Trotsenburg (25136366) Nitash Zwaveling-Soonawala (5043473) Medicine Medicine <p dir="ltr">Introduction: During puberty, free thyroxine (fT4) concentrations transiently decreasewith a nadir around Tanner stage 3. Due to the interindividual variation in timing of pubertal onset, this transient fT4 dip occurs at different ages and becomes less apparentwithin an age-specific reference interval (RI).This may result in fT4 concentrations temporarily falling below the lower limit of the RI when age-specific instead of Tanner stage-specific RIs are used. As thyroid stimulating hormone (TSH) levels usually remain within the age-specific RI, the resulting biochemical profile resembles central hypothyroidism and frequently triggers extensive, butoften unnecessary diagnostic work-ups. </p><p dir="ltr">Case Presentation: We present twocases of asymptomatic adolescents withlow fT4 concentrations in combination witha normal TSH, in whom central hypothyroidism was initially suspected but subsequently excluded. In all cases, fT4 concentrations normalized later in puberty without intervention. </p><p dir="ltr">Conclusion: This phenomenonlikely reflects increased peripheral conversion of T4 to triiodothyronine (T3) under the influence of growth hormone and sex steroids. Awareness of this physiological phenomenon is essential to avoid misdiagnosis, overtreatment, and undue psychological stress. Our findings highlight the need for Tanner stage–specific fT4 RIs to guide thyroid function interpretation in adolescents.</p> 2026-09-29T09:55:47Z Dataset Dataset 10.6084/m9.figshare.34022472.v1 https://figshare.com/articles/dataset/Supplemental_Material_for_The_transient_pubertal_free_thyroxine_dip_should_not_be_misinterpreted_as_central_hypothyroidism_a_case_series/34022472 CC BY 4.0