(PS5-52) Examining differences in momentary assessment of interoceptive sensibility across diagnosis and remission status in anorexia nervosa spectrum disorder

Abstract Text: Interoception, or the act of sensing and interpreting information from within the body, is impaired in individuals with eating disorders (EDs). Specifically, lower BMI is associated with more pronounced interoceptive impairments. However, no research has examined whether interoceptive sensibility varies based on the presence of specific ED behaviors (e.g., restriction vs. binge-eating/purging) or ED remission status (i.e., active vs. partial remission). Therefore, this study investigates interoceptive sensibility in individuals with AN spectrum disorder (ANSD) who primarily engage in restriction versus those who engage in binge/purge (BP) behaviors, while also examining differences between those with a current diagnosis and those in partial remission. Participants (77.3% White, 71.6% female, average age 28.2 years) with ANSD- restricting subtype (ANSD-R; n = 25), ANSD-R in partial remission (PR) (n = 14), ANSD-BP subtype (n = 4), and ANSD-BP PR (n = 10) completed ecological momentary assessment (EMA) measures of interoception five times per day for 21 days (total assessments=105). Items assessed interoception (e.g., body trust, connectedness) and scores ranged from 0 (“not at all”) to 100 (“extremely”). Multilevel modeling was used to examine differences in average levels of interoception, as well as the rate of change, based on diagnostic subtype, remission status, and their interaction. Analyses controlled for length of illness. A null model was compared to a full model that included random intercepts and slopes. The model examining differences on the EMA item “I trust my body sensations” was the only model in which the full model was significantly different than the null (p <.001). Individuals with the restricting subtype demonstrated significantly lower levels of body trust (as compared to the BP subtype; estimate = -22.96; p = 0.02), as did individuals in PR (as compared to active diagnosis; estimate = -29.33; p = 0.02). The interaction between the subtype and status was significant (estimate = 30.00; p = 0.04), such that for those with a current diagnosis, the restricting subtype is associated with lower levels of body trust than the BP subtype. However, for those with a PR diagnosis, the BP subtype is associated with lower levels of body trust than the restricting subtype. There were no significant effects of subtype or remission status on the rate of change of body trust over the course of the study. Individuals engaging in restrictive behaviors and those in PR from ANSD demonstrate lower average levels of body trust compared to individuals who engage in BP behaviors and have an active diagnosis, respectively. However, the significant interaction suggests a more nuanced relationship. Results highlight a potentially important relationship between restrictive eating and low body trust in the ill state, as well as a relationship between BP and low body trust as symptoms improve. Factors associated with partial remission status, such as undesired weight gain or difficulty accessing hunger cues, may decrease body trust, though future research is needed. Interventions targeting body trust may be beneficial for individuals who engage in restriction and/or those in PR from ANSD.