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The Scientific World Journal
Volume 2014, Article ID 803083, 7 pages
Clinical Study

How Fast Is Recovery of Impaired Glucose Tolerance after 21-Day Bed Rest (NUC Study) in Healthy Adults?

1Department of Nutrition and Food Science-Nutrition Physiology, University of Bonn, 53115 Bonn, Germany
2Profil Neuss GmbH, 41460 Neuss, Germany
3German Aerospace Center (DLR), Institute of Aerospace Medicine, 51147 Cologne, Germany
4MLM Medical Labs GmbH, 41066 Monchengladbach, Germany
5Division of Internal Medicine, University of Trieste, 34127 Trieste, Italy

Received 8 December 2013; Accepted 30 January 2014; Published 11 March 2014

Academic Editors: K. Kiselyov and A. Pushkin

Copyright © 2014 Martina Heer et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Aim. We hypothesized that 4 days of normal daily activity after 21 days of experimental bed rest (BR) will not reverse BR induced impaired glucose tolerance. Design. Glucose tolerance of seven male, healthy, untrained test subjects (age: 27.6 (3.3) years (mean (SD)); body mass: 78.6 (6.4) kg; height: 1.81 (0.04) m; VO2 max: 39.5 (5.4) ml/kg body mass/min) was studied. They stayed twice in the metabolic ward (crossover design), 21 days in bed and 7 days before and after BR each. Oral glucose tolerance tests were applied before, on day 21 of BR, and 5 and 14 days after BR. Results. On day 21 of BR, AUC120 min of glucose concentration was increased by 28.8 (5.2)% and AUC120 min of insulin by 35.9 (10.2)% (glucose: ; insulin: ). Fourteen days after BR, AUC120 min of serum insulin concentrations returned to pre-bed-rest concentrations ( ) and AUC120 min of glucose was still higher ( ). Insulin resistance did not change, but sensitivity index was reduced during BR ( ). Conclusion. Four days of light physical workload does not compensate inactivity induced impaired glucose tolerance. An individually tailored and intensified training regime is mandatory in patients being in bed rest to get back to normal glucose metabolism in a reasonable time frame.