TSH − Physiologie, Funktionsstörungen und Einflussfaktoren auf die Referenzwerte

Zusammenfassung

Die Bestimmung des TSH-Spiegels ist die wichtigste Methode zur Untersuchung der Schilddrüsen-Homöostase. Wir sind daran gewöhnt, dass ein erhöhter TSH-Spiegel für eine Hypothyreose spricht und ein erniedrigter TSH-Spiegel für eine Überversorgung mit Schilddrüsenhormonen. Trotz der inversen Beziehung zwischen FT4- und Thyreotropin-Konzentration gilt dies jedoch nicht immer. Auffällige TSH-Werte oder eine Diskordanz zwischen Klinik und Laboruntersuchung erfordern daher weitere Analysen, insbesondere die Bestimmung freier Schilddrüsenhormone.

Die Übersicht erläutert Physiologie und Funktionsstörungen von TSH sowie mögliche Faktoren, die die Laborergebnisse beeinflussen. Es werden Hinweise zu den Referenzbereichen gegeben, aus denen therapeutische Konsequenzen abgeleitet werden können.

Abstract

Determination of TSH levels is the most important method for diagnostic evaluation of thyroid homeostasis. By virtue of the inverse correlation of FT4 and thyrotropin levels a single TSH determination is sufficient for screening purposes. In cases of suspicious TSH levels or discordance among clinical presentation and laboratory results additional investigations are necessary, first of all determination of free thyroid hormones.

The overview explains the physiology and dysfunctions of TSH as well as possible factors, which influence the laboratory results. Therapeutic consequences can be derived from the reference ranges which are presented.

Schlüsselwörter

TSH - Thyroxin - Schilddrüsenerkrankungen - Diagnostik - Homöostase

Keywords

TSH - thyroxin - thyroid diseases - diagnostic strategy - homeostasis

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