Zytokine, metabolisches Syndrom und Ernährung

Zusammenfassung

Fettgewebe ist nicht nur ein passiver Energiespeicher, sondern ein aktives Gewebe, das zahlreiche Signalsubstanzen sezerniert. Hierzu zählen auch Zytokine wie IL-6, das als unabhängiger Risikofaktor für Diabetes beschrieben wurde. In der Zellkultur konnte tatsächlich auch ein kausaler Zusammenhang zwischen IL-6 und Insulinresistenz beobachtet werden. Die IL-6-Spiegel im Blut zeigten sich korreliert mit dem Anteil gesättigter Fettsäuren in der Nahrung. Der Effekt von gesättigten Fettsäuren auf die Insulinresistenz könnte daher teilweise durch IL-6 vermittelt sein. Interventionen mit unterschiedlichen Fettsäurezusammensetzungen der Nahrung sollten dann zu unterschiedlichen IL-6-Werten führen. Diese Studien sind aktuell allerdings noch uneinheitlich und schwierig zusammenfassend zu interpretieren. Auch verschlechterte eine niedrig dosierte IL-6-Gabe beim Menschen nicht die Insulinsensitivität und bei der Beurteilung von Studien, die den Zusammenhang zwischen IL-6 und Insulinsensitivität untersuchten, muss die Korrelation zwischen IL-6 und Übergewicht berücksichtigt werden. Weitere Studien sind daher notwendig zur Untersuchung des IL-6-Effektes beim Menschen und zur Beantwortung der Frage, in welchem Umfang Nahrungsfette Zytokine beeinflussen und inwieweit sich hierdurch ein zusätzlicher Effekt auf das individuelle Risiko erreichen ließe.

Abstract

Adipose tissue is not just a storage for energy but is actively secreting a large amount of signalling substances. Amongst them are cytokines like IL-6. IL-6 was shown to independently predict diabetes risk in humans and cell culture experiments could indeed describe a causal relationship between IL-6 and insulin sensitivity. IL-6 levels in human blood were described correlated to the intake of saturated fatty acids. IL-6 might therefore be a mediator of the impact of saturated fatty acids on insulin resistance. Intervention studies testing different fatty acid compositions are therefore supposed to yield different IL-6 levels. However, their results are so far unequal and difficult to interprete which does not allow to draw a final conlcusion. Additionally, low dose administration of IL-6 to humans failed to deteriorate insulin sensitivity and correlation analyses between IL-6 and insulin resistance must be interpreted with caution due to the tight relationship between IL-6 and obesity. Therefore, further studies are necessary to define IL-6 effects in humans and to address the question whether dietary fatty acids alter cytokines and whether this might further effect individual risk.

Schlüsselwörter

Ernährung - Fettgewebe - metabolisches Syndrom - Zytokine

Key words

nutrition - adipose tissue - metabolic syndrome - cytokines

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