2 - (IOP 35) Relative Contributions of Gastrointestinal-specific Hypervigilance and Anxiety in Explaining Eating Disorder Symptoms

Gastrointestinal (GI) disturbances and eating disorder symptoms commonly co-occur and may maintain one another. Hypervigilance and anxiety about GI symptoms, in particular, may motivate eating disorder behaviors in an effort to avoid GI symptoms. The widely used Visceral Sensitivity Index (VSI), a one-factor assessment of lower GI-specific anxiety, catastrophizing, and avoidance behaviors, is positively associated with eating disorder symptoms. Unlike the unidimensional model put forth by the VSI, the Fear-Avoidance Model of Pain distinguishes between attentional processes (e.g., hypervigilance) and cognitive features (e.g., catastrophizing, anxiety) as contributors to the development and maintenance of pain avoidance behaviors. We examined whether differentiating between GI-specific hypervigilance and anxiety had incremental validity in understanding eating disorder behaviors. We hypothesized that GI-specific anxiety would be more strongly associated with purging and restricting than GI-specific hypervigilance. Further, we hypothesized that distinguishing between GI-specific anxiety and hypervigilance would have incremental validity over using the unidimensional VSI . Participants were 382 undergraduate students (83.5% female, 87.4% white) with elevated eating pathology. Of the sample, 81% had elevated shape and weight-oriented eating pathology and 19% had elevated avoidant/restrictive food intake disorder symptoms. Participants completed questionnaires assessing the Esophageal Hypervigilance and Anxiety Scale modified to assess the entire GI tract, the VSI, and the Eating Pathology Symptoms Inventory. Hypotheses were pre-registered and tested using relative weights analysis. Relative weights analysis creates orthogonal predictor variables to isolate the unique variance explained by each variable. The raw relative weights were small for hypervigilance (.008 for purging and restricting) and anxiety (.032 for purging; .027 for restricting). GI-specific anxiety was more strongly associated with purging than GI-specific hypervigilance (95% CI [.001, .071]). GI-specific anxiety (95% CI [.003, .070]), but not GI-specific hypervigilance (95% CI [-.009, .018]), demonstrated incremental validity over the VSI in explaining purging. In predicting restriction, the relative weight of GI-specific anxiety did not differ from that of GI-specific hypervigilance (95% CI [-.001, .052]). Further, neither variable provided incremental validity over the VSI in predicting restriction (GI-specific anxiety 95% CI [-.005, .037]; GI-specific hypervigilance 95% CI [-.015, .014]). Given the relative importance of GI-specific anxiety in explaining purging, adapting existing interventions to prioritize targeting GI-related worry and catastrophic thinking may be valuable in reducing purging. Future research assessing purging may wish to distinguish between GI-specific anxiety and hypervigilance, while the VSI may be a more useful assessment for restricting.