Differences in beta-adrenergic receptor sensitivity between women and men with panic disorder.

This study was conducted on patients with panic disorder (PD) to examine the gender differences in the pathophysiology of PD by evaluating and comparing the value of CD(25)/wt, the chronotropic 25 dose of isoproterenol (CD(25)) divided by the body weight, which reflects the in vivo index of beta-adrenergic receptor sensitivity. This study included a total of 70 subjects, including 35 patients with PD (female: 13, male: 22) along with 35 healthy control subjects (female: 13, male: 22). There were significant differences in the mean value of CD(25)/wt (0.073+/-0.045 microg/kg vs. 0.032+/-0.019 microg/kg; p=0.006) and the serum epinephrine (EPI) level (77.3+/-64.1 pg/ml vs. 31.6+/-10.3 pg/ml; p=0.001) between the female panic patients and the female control subjects. However, there were no differences in either the CD(25)/wt value or the EPI level between the male panic patients and the male control subjects. These results suggest that the beta-adrenergic receptor sensitivity decreased in the female patients, but not in the male patients, which provides evidence for the possible existence of a gender difference in the pathophysiology of PD.