Objective Superior mesenteric artery (SMA) syndrome is characterized by the compression of the third segment of the duodenum between the SMA and aorta, resulting in duodenal obstruction. Because the symptoms of the syndrome are similar to those of functional dyspepsia (FD), this study aimed to examine whether or not patients with SMA syndrome were present among those diagnosed with FD. Methods Patients with an FD diagnosis underwent measurement of the angle and distance between the SMA and aorta by ultrasonography or computed tomography. Patients with an angle of ≤22° or with a distance of ≤8 mm between the SMA and aorta were diagnosed with SMA syndrome. Bacterial culture of the duodenal aspirate was also performed. Results Of the 46 FD patients, 5 (11%) met the criteria. All 5 were women with a body mass index significantly lower than the remaining 41 patients (18.7 vs. 24.0 kg/m2, p=0.003). In addition, all 5 patients had 105/mL or more bacteria in the duodenum. The symptoms of these five patients were treated through dietary and postprandial posture counselling with or without medication. Conclusion Patients with SMA syndrome were observed among underweight women diagnosed with FD. Their symptoms may be associated with bacterial overgrowth.
