Associations of plasma leptin to clinical manifestations in reproductive aged female patients with panic disorder

Preclinical studies suggest the implication of the adipocyte hormone leptin in anxiety and fear processes. We explored for potential differences regarding plasma leptin, cortisol and the ratio leptin/Body Mass Index (BMI) between 27 medication-free female patients with Panic Disorder (PD) and 42 age-matched female controls, and for potential associations between plasma leptin and psychometric evaluations including number of panic attacks during last week, Clinical Global Impression-Severity of Illness (CGI-S) and Symptoms Checklist-90-Revised (SCL-90-R). Cortisol levels showed no differences between patients and controls, or correlations to leptin or to any clinical features. Both groups demonstrated a strong positive correlation between leptin and BMI and similar leptin and leptin/BMI, despite patients' lower BMI. However, patients -but not controls- demonstrated significant negative correlations of leptin to the 'somatization', 'anxiety', and 'phobic anxiety' SCL-90-R subscales. Moreover, there was a significant negative correlation of leptin and of leptin/BMI ratio to the number of panic attacks during last week, while higher CGI-S was associated with lower leptin/BMI ratio. Our results, limited to PD female patients, suggest that lower leptin serum levels are significantly associated with greater severity of psychopathological manifestations, including number of panic attacks, symptoms of somatization, anxiety and phobic anxiety and overall clinical presentation.