Volume flow in the common carotid artery does not decrease postprandially.
OBJECTIVE
A commonplace explanation for postprandial fatigue is the assumption of the redistribution of perfusion from the cerebral to the mesenterial territory. However, this assumption has never been scientifically proven.


METHODS
Because approximately 70% of the blood flow in the common carotid artery (CCA) is directed to the internal carotid artery, this vessel can be seen as a major brain-supplying artery. Flow volume in the CCA can be measured by color M-mode duplex sonography. The authors investigated the flow volume rate in 20 healthy volunteers before and after the intake of a high-energy meal. Heart rate, blood pressure, and expiratory CO2 were also measured at both times.


RESULTS
There was a significant (P = .001) increase in right, left, and net CCA flow volume postprandially (right: from 362.0 [interquartile range 315.5-410.5] to 401.5 [322.1-486.4] mL/min; left: from 384.5 [345.5-439.0] to 414.5 [357.9-527.7] mL/min; net: from 756.0 [683.0-822.5] to 832.4 [713.7-967.26] mL/min). This increase was paralleled by a statistically significant increase in heart rate from 66 (58-70) to 76 (63-84) bpm, but without substantial correlation (r = 0.28) with the volume flow changes. There was no correlation with any other tested parameter.


CONCLUSIONS
The authors conclude that the assumption of global brain hypoperfusion in the postprandial state cannot serve as an explanation for postprandial fatigue.
Department of Neurology, Johannes Gutenberg-University/University of Mainz, Langenbeckstrasse 1, D-55101 Mainz, Germany. eicke@neurologie.klinik.unimainz.de
Bernhard Martin
BM
Eicke
Elisabeth
E
Seidel
Frank
F
Krummenauer
D000328:Adult; D001783:Blood Flow Velocity; D001921:Brain / Q000098:blood supply; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging* / Q000502:physiology; D005221:Fatigue; D005260:Female; D006801:Humans; D008297:Male; D019518:Postprandial Period; D018616:Ultrasonography, Doppler, Duplex