In Vivo beta-Adrenergic Receptor Responsiveness: Ethnic Differences in the Relationship with Symptoms of Depression and Fatigue

作者：Euteneuer Frank^*; Ziegler Michael G; Mills Paul J; Rief Winfried; Dimsdale Joel E

来源：International Journal of Behavioral Medicine, 2014, 21(5): 843-850.

DOI：10.1007/s12529-013-9359-1

• beta-adrenergic receptor
• African Americans
• Caucasian Americans
• Depression
• Fatigue

Depressive symptoms and fatigue frequently overlap in clinical samples and the general population. The link of depressive symptoms and fatigue with increased risk of cardiovascular disease has been partly explained by shared biological mechanisms including sympathetic overactivity. Prolonged sympathetic overactivity downregulates the responsiveness of the beta-adrenergic receptor (beta-AR), a receptor that mediates several end-organ sympathetic responses.
The authors studied whether depression and fatigue are related to reduced beta-AR responsiveness within the human body (in vivo) in an ethnically diverse sample of African and Caucasian Americans.
The chronotropic(25) dose (CD25) was used to determine in vivo beta-AR responsiveness in 93 healthy participants. Psychometric measures included the Center of Epidemiological Studies-Depression Scale and the Multidimensional Fatigue Symptom Inventory.
Hierarchical regression analyses (adjusted for age, gender, body mass index, blood pressure, smoking, and ethnicity) revealed that mental fatigue was significantly related to reduced beta-AR responsiveness (i.e., higher CD25 values) in the whole sample. Moderation analyses indicated significant ethnicity x depression/fatigue interactions. Depressive symptoms, total fatigue, emotional fatigue, mental fatigue, and physical fatigue were related to reduced beta-AR responsiveness in Caucasian American but not in African Americans.
Our findings suggest that symptoms of depression and fatigue are related to decreased in vivo beta-AR responsiveness in Caucasian Americans. The lack of this association in African Americans highlights the importance for considering ethnicity as a potential moderator in research focusing on associations between psychological variables and cardiovascular function.

• 出版日期2014-10