Universität zu Köln

Hoffmeister, Torben, Schwenke, Dirk, Krug, Oliver, Wachsmuth, Nadine, Geyer, Hans, Thevis, Mario, Byrnes, William C. and Schmidt, Walter F. J. (2018). Effects of 3 Weeks of Oral Low-Dose Cobalt on Hemoglobin Mass and Aerobic Performance. Front. Physiol., 9. LAUSANNE: FRONTIERS MEDIA SA. ISSN 1664-042X

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Abstract

Introduction: Cobalt ions (Co2+) stabilize HIFa and increase endogenous erythropoietin (EPO) production creating the possibility that Co2+ supplements (CoSupp) may be used as performance enhancing substances. The aim of this study was to determine the effects of a small oral dosage of CoSupp on hemoglobin mass (Hbmass) and performance with the objective of providing the basis for establishing upper threshold limits of urine [Co2+] to detect CoSupp misuse in sport. Methods: Twenty-four male subjects participated in a double-blind placebo-controlled study. Sixteen received an oral dose of 5mg of ionized Co2+ per day for 3 weeks, and eight served as controls. Blood and urine samples were taken before the study, during the study and up to 3 weeks after CoSupp. Hbmass was determined by the CO-rebreathing method at regular time intervals, and VO2max was determined before and after the CoSupp administration period. Results: In the Co2+ group, Hbmass increased by 2.0 +/- 2.1% (p < 0.001) while all the other analyzed hematological parameters did not show signi fi cant interactions of time and treatment. Hemoglobin concentration ([Hb]) and hematocrit (Hct) tended to increase (p = 0.16, p = 0.1) and also [EPO] showed a similar trend (baseline: 9.5 +/- 3.0, after 2 weeks: 12.4 +/- 5.2 mU/ml). While mean VO2max did not change, there was a trend for a positive relationship between changes in Hbmass and changes in VO2max immediately after CoSupp (r = 0.40, p = 0.11). Urine [Co2+] increased from 0.4 +/- 0.3 to 471.4 +/- 384.1 ng/ml (p < 0.01) and remained signi fi cantly elevated until 2 weeks after cessation. Conclusion: An oral Co2+ dosage of 5 mg/day for 3 weeks effectively increases Hbmass with a tendency to increase hemoglobin concentration ([Hb]) and hematocrit (Hct). Because urine Co2+ concentration remains increased for 2 weeks after cessation, upper limit threshold values for monitoring CoSupp can be established.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Hoffmeister, Torben UNSPECIFIED UNSPECIFIED UNSPECIFIED Schwenke, Dirk UNSPECIFIED UNSPECIFIED UNSPECIFIED Krug, Oliver UNSPECIFIED UNSPECIFIED UNSPECIFIED Wachsmuth, Nadine UNSPECIFIED UNSPECIFIED UNSPECIFIED Geyer, Hans UNSPECIFIED UNSPECIFIED UNSPECIFIED Thevis, Mario UNSPECIFIED UNSPECIFIED UNSPECIFIED Byrnes, William C. UNSPECIFIED UNSPECIFIED UNSPECIFIED Schmidt, Walter F. J. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-172672
DOI:	10.3389/fphys.2018.01289
Journal or Publication Title:	Front. Physiol.
Volume:	9
Date:	2018
Publisher:	FRONTIERS MEDIA SA
Place of Publication:	LAUSANNE
ISSN:	1664-042X
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language CO-REBREATHING METHOD; BLOOD-CONCENTRATIONS; VOLUNTEERS; CHLORIDE; SAMPLES; IMPACT Multiple languages Physiology Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/17267