title: Rapid and reversible alterations in thyroid function tests in dehydrated patients.
abstract: Dehydration commonly leads to hypovolemia and hemoconcentration. Changes in thyroid hormone-binding proteins secondary to hemoconcentration profoundly affect total serum thyroid hormone concentrations. The authors sought to determine the acute effects of mild to moderate dehydration on thyroid hormone levels/thyroid function tests and its reversibility upon rehydration. Total thyroxine, total triiodothyronine, free thyroxine, and the free-thyroxine index decreased significantly after hydration, in parallel with the decrease in extra cellular fluid volume status markers. Triiodothyronine-resin uptake increased after hydration. Thyrotropin levels decreased by 8% after hydration. Hypovolemia leads to simultaneous alterations in extracellular fluid volume markers and thyroid hormone serum concentrations that reverse rapidly upon rehydration. This constitutes, by itself, a distinct and new clinical entity.
authors.affiliation: Instituto de Cardiología Avanzada y Medicina, Centro Médico Teknon, C/Vilana 12, Barcelona 08022, Spain. juanybarra@hotmail.com
authors.forename: Juan
authors.initials: J
authors.lastname: Ybarra
authors.forename: Sandra
authors.initials: S
authors.lastname: Fernandez
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001774:Blood Chemical Analysis; D003681:Dehydration / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000451:nursing*; D004638:Emergency Treatment; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D013960:Thyroid Function Tests; D013963:Thyroid Hormones / Q000097:blood*
chemical_list: D013963:Thyroid Hormones