Twenty-four hour ambulatory antroduodenal manometry in normal subjects (co-operative study)

Circadian antroduodenal motor activity was studied in 40 normal subjects by means of a portable recording system consisting of a computerized data log ger and a probe with microtransducers. The quantitative and qualitative cha racteristics of contraction events during the interdigestive and digestive periods, as well as during the awake and asleep periods, were analysed. The composition and timing of meals and night recumbence were standardized. In spite of the high interindividual variability in motor parameters, signifi cant differences in the characteristics of interdigestive and digestive per iods between waking and sleep states were found. This paper confirms the ex istence of a circadian variation in antroduodenal motor activity and provid es reference values from a large series of normal subjects that can be used for statistical comparisons with those obtained from patients recorded wit h the same method.