title: Decrease of serum S100B during an oral glucose tolerance test correlates inversely with the insulin response.
abstract: Increased S100B serum levels have been considered as a marker of glial pathology, brain damage, and blood-brain-barrier impairment. However, S100B expression has also been detected outside the nervous system, suggesting that altered S100B serum levels may not exclusively reflect brain-specific pathologies. Notably, S100B secretion in adipocytes seems to be down-regulated by insulin, and up-regulated by stress and fasting. Therefore, we assumed that dynamic changes of S100B could be observed by challenging healthy subjects with an oral glucose tolerance test (OGTT). OGTT was performed in 17 healthy adult test persons (9 male and 8 female). Apart from S100B, glucose, free fatty acids, insulin, C-peptide, and cortisol were determined in all samples after an overnight fast (0 h), as well as 1h and 2h after ingestion of 75 g glucose. Mean S100B concentrations decreased about 20% during the first hour after glucose ingestion (P<0.001). This decrease of S100B levels was not related to the declining morning peak of cortisol. However, the decrease of serum-S100B 1h after glucose ingestion correlated inversely with the respective changes of serum-insulin (r = -0.484, P=0.049) and serum-C-peptide (r = -0.570, P = 0.017). Our study suggests an inverse correlation between insulin secretion and S100B release after a standardized OGTT. Additional experiments, including the administration of insulin and the measurement of other food intake-related factors are important to ascertain an insulin-regulated S100B release in vivo. To improve comparability between clinical studies assessing conditions with rather mild changes of serum S100B, blood should be taken in a more standardized way (e.g., after fasting overnight).
authors.affiliation: Department of Psychiatry, University of Magdeburg, Magdeburg, Germany; Center for Behavioral Brain Sciences, Magdeburg, Germany. Electronic address: johann.steiner@med.ovgu.de.
authors.forename: Johann
authors.initials: J
authors.lastname: Steiner
authors.affiliation: Department of Psychiatry, University of Magdeburg, Magdeburg, Germany.
authors.forename: Hans-Gert
authors.initials: HG
authors.lastname: Bernstein
authors.affiliation: Department of Psychiatry, University of Magdeburg, Magdeburg, Germany; Center for Behavioral Brain Sciences, Magdeburg, Germany.
authors.forename: Kolja
authors.initials: K
authors.lastname: Schiltz
authors.affiliation: Department of Psychiatry, University of Magdeburg, Magdeburg, Germany.
authors.forename: Thekla
authors.initials: T
authors.lastname: Haase
authors.affiliation: Department of Psychiatry, University of Magdeburg, Magdeburg, Germany.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Meyer-Lotz
authors.affiliation: Department of Psychiatry, University of Magdeburg, Magdeburg, Germany.
authors.forename: Henrik
authors.initials: H
authors.lastname: Dobrowolny
authors.affiliation: Department of Psychiatry, University of Magdeburg, Magdeburg, Germany.
authors.forename: Ulf J
authors.initials: UJ
authors.lastname: Müller
authors.affiliation: Department of Psychiatry, University of Magdeburg, Magdeburg, Germany; Planck Institute of Psychiatry, Munich, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Martins-de-Souza
authors.affiliation: Institute of Clinical Chemistry and Pathobiochemistry, University of Magdeburg, Magdeburg, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Borucki
authors.affiliation: Max-Planck-Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Day Clinic of Cognitive Neurology, University of Leipzig, Leipzig, Germany.
authors.forename: Matthias L
authors.initials: ML
authors.lastname: Schroeter
authors.affiliation: Institute of Clinical Chemistry and Pathobiochemistry, University of Magdeburg, Magdeburg, Germany.
authors.forename: Berend
authors.initials: B
authors.lastname: Isermann
authors.affiliation: Department of Psychiatry, University of Magdeburg, Magdeburg, Germany; Center for Behavioral Brain Sciences, Magdeburg, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Bogerts
authors.affiliation: Institute of Clinical Chemistry and Pathobiochemistry, University of Magdeburg, Magdeburg, Germany; Institute of Clinical Chemistry and Laboratory Medicine, Dessau Hospital, Dessau, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Westphal
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood*; D008297:Male; D064568:S100 Calcium Binding Protein beta Subunit / Q000097:blood*
chemical_list: D001786:Blood Glucose; D007328:Insulin; D064568:S100 Calcium Binding Protein beta Subunit; C579160:S100B protein, human
keywords: Adipocytes; Astrocytes; Hepatocytes; Insulin; Oligodendrocytes; Oral glucose tolerance; S100B