Sleep disturbance, norepinephrine, and D-dimer are all related in elderly caregivers of people with Alzheimer disease.
OBJECTIVE
Caregiving for a relative with Alzheimer disease has been associated with sympathoadrenal medullary arousal and morbidity and mortality. In this study, we examined if sleep disturbance of elderly caregivers was associated with physiologic markers of cardiovascular risk, including plasma norepinephrine, epinephrine, and the hemostasis marker D-dimer.


METHODS
Cross-sectional.


METHODS
Community-based sample of elderly caregivers of spouses with Alzheimer disease assessed within their homes.


METHODS
A sample of 40 elderly spousal caregivers of patients with Alzheimer disease.


RESULTS
Participants underwent in-home full-night polysomnography and had plasma assayed for norepinephrine and epinephrine. Using multiple regression analyses and controlling for a number of cardiovascular risk factors (e.g., age, sex, blood pressure, body mass index), increased wake after sleep onset was positively associated with norepinephrine levels (beta = .35; t = 2.45, df = 32, p = .020) and plasma D-dimer (beta = .31; t = 2.18, df = 29, p = .038). Further, plasma norepinephrine was significantly associated with D-dimer (beta = .34; t = 2.11, df = 29, p = .044). Additional analyses indicated that norepinephrine accounted for 28% of the relationship between wake after sleep onset and D-dimer. No association was observed between sleep variables and epinephrine.


CONCLUSIONS
These findings provide preliminary evidence that sleep disturbance may contribute to morbidity in caregivers through sympathoadrenal medullary arousal and downstream physiologic effects such as altering the hemostasis environment.
Mausbach
Brent T
BT
Department of Psychiatry, University of California, San Diego, CA 92093-0682, USA. bmausbach@ucsd.edu
Ancoli-Israel
Sonia
S
von Känel
Roland
R
Patterson
Thomas L
TL
Aschbacher
Kirstin
K
Mills
Paul J
PJ
Ziegler
Michael G
MG
Dimsdale
Joel E
JE
Calleran
Susan
S
Grant
Igor
I
D000368:Aged; D000544:Alzheimer Disease; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000378:metabolism; D017028:Caregivers / Q000706:statistics & numerical data*; D002395:Catecholamines / Q000378:metabolism; D003430:Cross-Sectional Studies; D004837:Epinephrine / Q000097:blood; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism*; D006801:Humans; D008297:Male; D009638:Norepinephrine / Q000097:blood*; D017286:Polysomnography; D012307:Risk Factors; D012891:Sleep Apnea Syndromes / Q000175:diagnosis / Q000453:epidemiology / Q000378:metabolism; D012893:Sleep Wake Disorders / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology*
D002395:Catecholamines; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D; D009638:Norepinephrine; D004837:Epinephrine