Factors Linking Interoception and Sleep Across the Adult Lifespan.

Sleep patterns change with age, and interoception-a multifaceted concept referring to the perception of internal body sensations-may be one of the underlying mechanisms of these changes. The insula cortex, a key region for both interoception and sleep, might be a shared neural link. In this study, we examined the role of the insula in linking multiple interoceptive constructs with objectively measured sleep. We also investigated how interoception relates to sleep quality across the adult lifespan at different levels of anxiety. We measured interoceptive accuracy (the objective ability to detect internal signals), interoceptive sensibility (the self-perceived ability to detect these signals), insular volume (using structural MRI), objectively assessed sleep quality (via actigraphy), and trait anxiety in 70 participants aged 18-79. The results indicated that both interoceptive constructs were associated with poorer sleep quality across age, particularly in individuals with higher anxiety levels. We also found that greater insula volume was associated with a stronger subjective belief in one's interoceptive abilities (interoceptive sensibility). Although there was no direct link between insula volume and sleep quality, insula integrity may indirectly influence sleep quality through its association with interoceptive sensibility. These findings highlight the negative relationship between interoception and sleep quality across the adult lifespan. Sleep interventions using mindfulness- or interoception-focused strategies should be implemented with caution, particularly for anxious individuals or those with heightened interoceptive sensibility. Further research should include poor sleepers and individuals with a wide range of health conditions for better understanding.