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Randomized Controlled Trial
. 2018 Aug;12(4):1150-1159.
doi: 10.1007/s11682-017-9777-9.

Investigating the impact of overnight fasting on intrinsic functional connectivity: a double-blind fMRI study

Stelios Orfanos  1   2 , Timur Toygar  3   4 , Mark Berthold-Losleben  3   5 , Natalya Chechko  3   5 , Annette Durst  3   5 , Zacharias G Laoutidis  3   6 , Sebastian Vocke  3   5 , Caren Weidenfeld  3   5 , Frank Schneider  3   5 , Wolfram Karges  7 , Christian F Beckmann  8   9 , Ute Habel  3   5 , Nils Kohn  3   8
Affiliations
Randomized Controlled Trial

Investigating the impact of overnight fasting on intrinsic functional connectivity: a double-blind fMRI study

Stelios Orfanos et al. Brain Imaging Behav. 2018 Aug.

Abstract

The human brain depends mainly on glucose supply from circulating blood as an energy substrate for its metabolism. Most of the energy produced by glucose catabolism in the brain is used to support intrinsic communication purposes in the absence of goal-directed activity. This intrinsic brain function can be detected with fMRI as synchronized fluctuations of the BOLD signal forming functional networks. Here, we report results from a double-blind, placebo controlled, cross-over study addressing changes in intrinsic brain activity in the context of very low, yet physiological, blood glucose levels after overnight fasting. Comparison of four major resting state networks in a fasting state and a state of elevated blood glucose levels after glucagon infusion revealed altered patterns of functional connectivity only in a small region of the posterior default mode network, while the rest of the networks appeared unaffected. Furthermore, low blood glucose was associated with changes in the right frontoparietal network after cognitive effort. Our results suggest that fasting has only limited impact on intrinsic brain activity, while a detrimental impact on a network related to attention is only observable following cognitive effort, which is in line with ego depletion and its reliance on glucose.

Keywords: Blood glucose; Default mode; ICA; Resting-state; Strength model; fMRI.

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Conflict of interest statement

Funding

This work was funded by the Faculty of Medicine, RWTH Aachen University (START program 138/09) and by the German Research Foundation (DFG, IRTG 1328, International Research Training Group). UH is supported by a grant from the IZKF Aachen (Interdisciplinary Center for Clinical Research within the faculty of Medicine at the RWTH Aachen University, N4-4).

Conflict of interest

All authors declare that they have no conflict of interest.

Informed consent

Informed consent was obtained from all individual participants included in the study.

Figures

Fig. 1
Fig. 1
BGL under EC are displayed in red, BGLs in FC in blue. BGL were sampled approximately every 15 min. t0 refers to the time just before fMRI measurements began. t4 refers to the time just after fMRI measurements were completed. Blood glucose levels represent mean values. ***: p < 0.001. Graphic taken with permission from (Chechko et al. 2014)
Fig. 2
Fig. 2
Differences between EC and FC in the DMN displayed in the upper part of the figure; differences between R1 and R2 in FC in the right frontoparietal network in the lower part of the figure. Results are superimposed on a standard brain (MNI 152). Areas shown were stronger connected to the rest of the network in EC compared to FC (upper part) and during R1 compared to R2 (lower part). Both contrasts are TFCE corrected at p < 0.05
See this image and copyright information in PMC

References

    1. Aiello M, Salvatore E, Cachia A, Pappatà S, Cavaliere C, Prinster A, Nicolai E, Salvatore M, Baron JC, Quarantelli M. Relationship between simultaneously acquired resting-state regional cerebral glucose metabolism and functional MRI: a PET/MR hybrid scanner study. NeuroImage. 2015;113:111–121. doi: 10.1016/j.neuroimage.2015.03.017. - DOI - PubMed
    1. Anderson AW, Heptulla RA, Driesen N, Flanagan D, Goldberg PA, Jones TW, Rife F, Sarofin H, Tamborlane W, Sherwin R, Gore JC. Effects of hypoglycemia on human brain activation measured with fMRI. Magnetic Resonance Imaging. 2006;24:693–697. doi: 10.1016/j.mri.2006.03.013. - DOI - PubMed
    1. Authier, F., & Desbuquois, B. (2008). Glucagon receptors. Cellular and Molecular Life Sciences. - PMC - PubMed
    1. Baumeister RF, Vohs KD, Tice DM. The strength model of self-control. Current Directions in Psychological Science. 2007;16:351–355. doi: 10.1111/j.1467-8721.2007.00534.x. - DOI
    1. Beckmann CF, Smith SM. Probabilistic independent component analysis for functional magnetic resonance imaging. IEEE Transactions on Medical Imaging. 2004;23:137–152. doi: 10.1109/TMI.2003.822821. - DOI - PubMed

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