Objectives: The pathophysiology of dyspeptic symptoms is complex. The aim of this study was to evaluate the association of gastric emptying (GE), gastric accommodation (GA), and respiratory sinus arrhythmia (RSA, to assess vagal dysfunction) in a large cohort with functional gastroduodenal symptoms.
Methods: We reviewed demographic, clinical features, and results of gastric motor and vagal function studies of 1,287 patients (74.0% females, mean age 43.1±15.4 years) who had undergone both single photon emission computed tomography GA and scintigraphic GE. Accommodation was based on postprandial to fasting gastric volume ratio (VR). Electrocardiograms were available and analyzed for RSA in 300 patients.
Results: There were 29.8% patients with normal GE and GA, 21.9% with abnormal GA only, 27.1% with abnormal GE only, and 21.1% with abnormal GA and GE. There were numerical differences in GA among patients with normal, accelerated, and delayed GE (P=0.062, by χ2). Increased GA (VR >3.85) was more prevalent in patients with delayed GE compared to accelerated GE (14.0% vs. 6.8%, P=0.004). Decreased VRs (median 2.9) were observed with accelerated GE compared to normal GE (median 3.1, P<0.05). Nausea and vomiting were more prevalent (in contrast to the less prevalent bloating) in patients with delayed compared to accelerated or normal GE (all P<0.05). In patients with diminished RSA, there was higher prevalence of reduced GA (41.5%) compared to those with preserved RSA (29.2%, P=0.031). Multivariable analysis showed associations of the main abdominal symptoms with gender, body mass index, gastric emptying, diabetes, and prior abdominal surgery.
Conclusions: Patients with symptoms of functional gastroduodenal disorders may have one or more gastric motor dysfunctions and reduced RSA; among the patients with abnormal gastric motor functions, vomiting suggests delayed GE, whereas reduced RSA is associated with reduced GA.