Volume flow in the common carotid artery does not decrease postprandially

Abstract

Background and Purpose. 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/m in). 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.