Low vagal activity as mediating mechanism for the relationship between personality factors and gastric symptoms in functional dyspepsia.

Low vagal tone may represent a mediating mechanism for relationships between personality and symptoms of functional dyspepsia (FD) through a mechanism of antral hypomotility. Twenty-one patients with FD and seventeen healthy controls completed a series of personality tests before vagal and sympathetic activity, antral motility, and abdominal symptoms were assessed in response to a laboratory task. Functional dyspepsia patients had lower scores on vagal tone (p = .054) and motility index (p = .011) in addition to the expected higher scores on epigastric discomfort (p = .002). Psychological factors explained a substantial amount of the variance in vagal activity, antral motility, and reported symptoms. Symptoms were predicted by trait anxiety (STAI-TR), depression (BDI), and neuroticism (EPQ-N). Poor vagal tone was related to neuroticism (EPQ-N). Poor motility was best explained by task-related state dysphoria (SACL-STR).