Anxiety and Beta Adrenergic Receptor Function

Woo, Geum Seok; Yu, Bum Hee

Abstract

OBJECTIVE
There have been many studies to show the close relationship between anxiety and beta-adrenergic receptor function in patients with anxiety disorder. This study examined the relationship between anxiety levels and beta-adrenergic receptor function in a normal population.
METHODS
Subjects for this study were 18 men and 28 women from 20 to 40 years of age whose body mass index was between 17.525 and 26.145. All of them were healthy subjects who had no previous history of medical or psychiatric illnesses. We measured the Korean versions of Spielberger State-Trait Anxiety Inventory and Beck Depression Inventory, and a self-report form of physical fitness level. We also measured the Chronotrophic 25 Dose (CD 25) of isoproterenol, previously developed to assess in vivo beta-adrenergic receptor sensitivity.
RESULTS
The mean of CD 25 was 2.5 (+/-1.2)microgram, and there was a significant difference in the mean of CD 25 between men and women (t (17)= -3.73, p=0.0009). This gender difference in beta-adrenergic receptor sensitivity might be accounted for by different means of body mass index between men and women. The correlations between CD 25 and state anxiety levels (r=-0.3966, p=0.0064) and between CD 25 and trait anxiety levels (r=-0.3918, p=0.0071) were both statistically significant. The CD 25 was also positively correlated with age (r=0.4827, p=0.0007) and body mass index (r=0.3517, p=0.0166).
CONCLUSION
The sensitivity of beta-adrenergic receptors increased as anxiety levels became higher in a normal population. Thus, the relationship between anxiety and beta-adrenergic function in healthy subjects seemed to be different from that in patients with anxiety disorder. This result suggests that we need a new hypothetical model in order to explain how anxiety affects beta-adrenergic receptors in both healthy subjects and patients with anxiety disorder.