Anxiety is one of the most common and debilitating mental health disorders, and is related to changes in interoception (perception of bodily states). While anxiety is more prevalent in women than men, gender differences in interoception-anxiety associations are often overlooked. Here we examined gender-specific relationships between anxiety and interoception in the breathing domain, utilising multicentre data pooled from four study sites (N=175; 51% female). State anxiety scores were quantified via the Spielberger State-Trait Anxiety Inventory, and interoceptive measurements via an inspiratory load detection task. From this task, breathing-related interoceptive dimensions of sensitivity, decision bias, metacognitive bias (confidence in interoceptive decisions), and metacognitive insight (congruency between performance and confidence) were quantified. Regression analyses revealed a significant negative relationship between state anxiety and metacognitive bias (=-0.28; p=0.01) and insight (=-0.09; 95% Highest Density Interval [HDI] in a hierarchical Bayesian regression=[-0.18,-0.004]) across the whole sample, while anxiety did not relate to interoceptive sensitivity nor decision bias. No mean effects of gender were observed for any interoceptive variables, however, the relationship between anxiety and metacognitive insight into breathing perception was driven by women (women: =-0.18; HDI=[-0.31,-0.05]; men: =0.02; HDI=[-0.12,0.15]) with a significant interaction effect ( difference=-0.20; HDI=[-0.37, -0.01]). In summary, anxiety was associated with decreased metacognitive bias across all participants, while decreased interoceptive insight was only associated with anxiety in women but not men. Therefore, treatment programs focusing on interoceptive metacognitive bias may be useful for all anxiety patients, while interoceptive insight might represent a specific treatment target for women with anxiety.
