The Relationship Between Heart Rate Variability and Interoception in Anorexia Nervosa Spectrum Disorders.

OBJECTIVE: Restrictive eating disorders are characterized by abnormalities in both HRV and interoception, yet the extent to which transient physiological changes are related to interoceptive sensibility in this population remains unclear. The present study examines the association between HRV and interoceptive sensibility among individuals with anorexia nervosa and atypical anorexia (i.e., Anorexia Nervosa Spectrum Disorders) in real-time using a combination of biosensor and ecological momentary assessment data. METHOD: Seventy-five adults with Anorexia Nervosa Spectrum Disorders and current or lifetime suicidality completed 21 days of ecological momentary assessment while wearing a sensor band that passively collected HRV data. Multilevel models examined the association between HRV and interoceptive sensibility at the within- and between-person levels. RESULTS: HRV was positively associated with interoceptive sensibility at the between-person level, such that individuals with higher HRV demonstrated greater interoceptive sensibility. However, temporary changes in HRV (i.e., deviations from one's average) were not associated with corresponding changes in interoceptive sensibility. DISCUSSION: Within Anorexia Nervosa Spectrum Disorders with co-occurring suicidality, alterations in autonomic function are accompanied by differences in interoceptive sensibility at the trait, but not state, level. Both heightened HRV and irregularities in interoceptive sensibility may arise as a consequence of prolonged caloric restriction. Physiological processes distinct from HRV may be responsible for driving momentary fluctuations in interoceptive sensibility in this population. Further research is needed to continue parsing potential differences in physiological processes across specific diagnoses and illness stage.