Panic disorder patients had significantly lower platelet serotonin transporter function (Km 759.3 vs 1288.5 nM) than healthy controls, which independently predicted increased sympathovagal activity.
Cross-Sectional (n=75)
No
Impaired serotonin transporter function (low Km) is independently associated with increased sympathovagal activity in patients with panic disorder, suggesting a link between serotonergic dysfunction and autonomic dysregulation.
Absolute Event Rate: 759.3% vs 1288.5%
p-value: p=0.001
Many studies showed abnormal serotonin transporter (5-HTT) function and heart rate variability (HRV) in panic disorder patients. The present study investigated the relationship between HRV power spectral analysis findings and platelet serotonin uptake in panic disorder patients. Short-term HRV over 5 min and platelet serotonin transporter uptake parameters (V(max) and K(m)) were measured both in 45 patients with panic disorder and in 30 age-matched normal healthy control subjects. Low frequency power (LF) normalized unit (nu) and LF/high frequency power (HF) were significantly higher, whereas HF and HF nu were lower in the patient group than in the control group. V(max) and K(m) were all significantly lower (i.e., reflects decreased 5-HTT function) in patients with panic disorder than in normal controls. In the patient group, K(m) was negatively correlated with LF/HF and LF nu whereas no such correlations between them were found in the control group. By multivariate analysis based on multiple hierarchical linear regression, a low K(m) independently predicted an increased LF nu even after controlling for age, sex, and body mass index in the patient group. These results suggest that impaired 5-HTT function is closely related to dysregulation of autonomic nervous system in panic disorder.
Kang et al. (Fri,) conducted a cross-sectional in Panic Disorder (n=75). Panic disorder vs. Healthy controls was evaluated on Platelet serotonin uptake Michaelis-Menten constant (Km) (p=0.001). Panic disorder patients had significantly lower platelet serotonin transporter function (Km 759.3 vs 1288.5 nM) than healthy controls, which independently predicted increased sympathovagal activity.