Does body posture affect the parameters of a cutaneous electrogastrogram?

In a study aimed to test the effect of body position on the parameters derived from surface electrogastrograms, 17 healthy volunteers (2M, 15F; median age 22.5 years) attended in random order two examination sessions held on separate days. A 30-min recording of the interdigestive gastric myoelectrical activity (GMA) was followed by a 90-min postprandial recording after intake of a 394 kcal mixed solid-liquid test meal. For the first examination the subject was examined in a recumbent position, whereas for the second examination a sitting position was maintained. The dominant frequency and relative time occupied by normogastria was negligibly affected by the posture of the subject during GMA recording. However, a decrease in the dominant power (DP) of the gastric slow waves was observed during both the interdigestive and the postprandial recording period in a sitting position compared to a recumbent position. Consequently, the fed to fasted state DP ratio remained unaffected by body posture during GMA recording. The results indicate that by carefully observing procedural guidelines, good quality electrogastrograms can be obtained with a sitting subject, enabling the provision of comparable parameters to those achieved from standard examination in a recumbent position.