Vulnerable caregivers of Alzheimer disease patients have a deficit in beta 2-adrenergic receptor sensitivity and density.
OBJECTIVE
The chronic stress of caregiving may lead to sympathetic nervous system activation and immune suppression. beta(2)-adrenergic receptors are expressed on all immune cells and contribute to the stress-induced loss of immune-cell function. The authors examined the effects of being a spousal caregiver of a patient with Alzheimer disease (AD) on the lymphocyte beta(2)-adrenergic receptor.


METHODS
One hundred and six women and men, spousal caregivers and non-caregivers, participated (mean age: 71.5 years). Caregivers were classified as either vulnerable or non-vulnerable on the basis of the amount of care required by the patient relative to the amount of respite the caregiver received during the previous 6 months. beta(2)-adrenergic receptor sensitivity (cyclic-AMP response to isoproterenol stimulation) and density (radioligand binding) were determined by use of whole lymphocytes.


RESULTS
Vulnerable caregivers had reduced beta(2)-adrenergic receptor sensitivity and density when compared with their non-vulnerable counterparts or with non-caregivers.


CONCLUSIONS
The findings indicate that for more vulnerable caregivers, the stress of caregiving leads to a loss of lymphocyte beta(2)-adrenergic receptors. This finding may be relevant to previous observations of clinically-relevant reduced immunity in highly stressed caregivers of AD patients.
Mills
Paul J
PJ
Department of Psychiatry, University of California San Diego, 92103-0804, USA. pmills@ucsd.edu
Adler
Karen A
KA
Dimsdale
Joel E
JE
Perez
Christy J
CJ
Ziegler
Michael G
MG
Ancoli-Israel
Sonia
S
Patterson
Thomas L
TL
Grant
Igor
I
D000368:Aged; D000544:Alzheimer Disease; D001008:Anxiety Disorders / Q000378:metabolism / Q000523:psychology; D001665:Binding Sites; D017028:Caregivers / Q000523:psychology*; D002452:Cell Count; D017281:Cost of Illness; D000242:Cyclic AMP / Q000378:metabolism; D003866:Depressive Disorder / Q000378:metabolism / Q000523:psychology; D005260:Female; D006801:Humans; D007545:Isoproterenol / Q000494:pharmacology; D008214:Lymphocytes / Q000378:metabolism; D008297:Male; D018343:Receptors, Adrenergic, beta-2 / Q000378:metabolism*; D012680:Sensitivity and Specificity; D013315:Stress, Psychological / Q000378:metabolism* / Q000523:psychology*; D013566:Sympathomimetics / Q000494:pharmacology; D035862:Vulnerable Populations / Q000706:statistics & numerical data*
D018343:Receptors, Adrenergic, beta-2; D013566:Sympathomimetics; D000242:Cyclic AMP; D007545:Isoproterenol