Neuroendocrine and immunological correlates of chronic stress in 'strictly healthy' populations.
BACKGROUND
Chronic stress has been associated with detrimental or maladaptive neuroendocrine and immunological changes.


OBJECTIVE
We assessed the neuroendocrine and immunological correlates of a realistic chronic stress experienced by strictly healthy caregivers of Alzheimer's disease patients and age-matched controls.


METHODS
We screened 330 caregivers and 206 non-caregivers according to the 'strictly healthy' conditions established by the SENIEUR protocol. Forty-one strictly healthy caregivers (60.56 +/- 16.56 years) and 33 non-stressed controls (60.27 +/- 14.11 years) were selected for this study. Salivary cortisol and dehydroepiandrosterone sulfate (DHEAS) were assessed at multiple points by radioimmunoassay. Peripheral T cell proliferation and cellular sensitivity to glucocorticoids (corticosterone and dexamethasone, DEX) were evaluated by colorimetric assays. We also examined the hypothalamic-pituitary-adrenal (HPA) axis response to the administration of a low-dose DEX in vivo.


RESULTS
The caregivers were significantly more stressed, anxious and depressed than non-caregivers (all p < 0.0001), in contrast to similar cortisol levels. Caregivers had reduced DHEAS levels (-32%, p < 0.0001), an increased cortisol/DHEAS ratio (39.7%, p < 0.0001) and impaired HPA axis response to DEX intake. Caregivers had a higher T cell proliferation (p < 0.0001) and increased sensitivity to glucocorticoids in vitro (p < 0.01) as compared to non-stressed controls.


CONCLUSIONS
Our results suggest that the maintenance of health in chronically stressed populations may be associated with both protective and detrimental neuroendocrine and immunological changes.
Jeckel
Cristina M Moriguchi
CM
Laboratory of Cellular and Molecular Immunology, Instituto de Pesquisas Biomédicas and Faculdade de Biociências, Porto Alegre, RS 90610-000, Brazil.
Lopes
Rodrigo P
RP
Berleze
Maria Cristina
MC
Luz
Clarice
C
Feix
Leandro
L
Argimon
Irani Iracema de Lima
II
Stein
Lilian M
LM
Bauer
Moisés E
ME
D000368:Aged; D000544:Alzheimer Disease / Q000451:nursing / Q000523:psychology; D001008:Anxiety Disorders / Q000453:epidemiology / Q000276:immunology / Q000503:physiopathology; D017028:Caregivers / Q000523:psychology*; D002452:Cell Count; D049109:Cell Proliferation / Q000187:drug effects; D015331:Cohort Studies; D015897:Comorbidity; D003687:Dehydroepiandrosterone / Q000378:metabolism; D003866:Depressive Disorder / Q000453:epidemiology / Q000276:immunology / Q000503:physiopathology; D005260:Female; D005938:Glucocorticoids / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects / Q000276:immunology / Q000503:physiopathology; D007107:Immune System / Q000276:immunology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009490:Neurosecretory Systems / Q000276:immunology* / Q000503:physiopathology; D013315:Stress, Psychological / Q000453:epidemiology* / Q000276:immunology* / Q000503:physiopathology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology
D005938:Glucocorticoids; D003687:Dehydroepiandrosterone; D006854:Hydrocortisone