Analysis of autonomic function in patients with functional dyspepsia using real-time wearable devices and smartphone applications.

Autonomic dysfunction is involved in functional dyspepsia (FD) however, the details have not been elucidated. The aim is to clarify the relationship among autonomic nervous system (ANS) activity, life events, and abdominal symptoms by real-time recordings. This is a prospective multicenter study including 9 patients with FD and 23 healthy controls (HC). The ANS activity was recorded for 24 ‍h using a T-shirt-type wearable device. Life events and abdominal symptoms were simultaneously recorded with ANS activity by smartphone application software. We defined low-frequency/high-frequency (LF/HF) and HF as activity indicators of the sympathetic and parasympathetic nerves, respectively. The number of abnormal LF/HF and HF in patients with FD was significantly higher than that in HC. The number of abnormal LF/HF and HF signals was significantly positively correlated with dyspeptic symptoms. The number of abnormal LF/HF signals was significantly negatively correlated with quality of life (QOL). During the symptomatic period, the HF levels were elevated in the HC group. In contrast, HF significantly decreased in patients with FD, which may imply parasympathetic nervous system dysfunction. In conclusion, patients with FD have abnormal ANS activity, which is associated with symptoms and lower QOL, and they exhibit parasympathetic nervous system dysfunction during symptomatic period.