Psychosocial stress moderates the relationship of cancer history with natural killer cell activity

Abstract

Data suggest that both cancer history and psychosocial stress may be associated with reductions in natural killer cell activity (NKA). Therefore, we tested whether individual differences in cancer history, chronic/perceived stress, and their interactions would be associated with decreased levels of NKA. We tested these hypotheses in 80 spouse caregivers of victims of Alzheimer's Disease (AD) (persons known to report high levels of psychosocial stress) and in 85 age- and sex-matched spouses of non-demented controls. Participants were assessed at study entry (Time 1) and 15-18 months later (Time 2). Individuals with cancer histories (N = 43) had not been treated with immune altering medications within the last year. At both Times 1 and 2, cross-sectional main effects were weak or absent for cancer history, perceived stress (e.g. high hassles, low uplifts), and caregiver status; however, interactions occurred between cancer history and perceived stress, such that persons with cancer histories and high hassles/low uplifts had the lowest NKA values (p < .05). These results occurred even after controlling for age, gender, beta-blocker use, hormone replacement therapy, alcohol, and exercise. At Time 1, an interaction also occurred between caregiver status and cancer history--caregivers with cancer histories had lower NKA than did controls with cancer histories and caregivers/controls without cancer histories (p < .05). At Time 2, this interaction only showed a trend (p < .08), primarily because caregivers with cancer histories experienced increases in NKA (p < .05) from Time 1 to Time 2, whereas in the other three groups NKA did not change. Importantly, in caregivers with cancer histories, high perceived stress at Time 1 predicted low NKA at Time 2 (p < .05). This research suggests that the combinations of biological vulnerabilities and chronic/perceived stress may have interactive effects resulting in reduced NKA.

Neighborhood Characteristics Moderate Effects of Caregiving on Glucose Functioning

“…For example, the work of Vitaliano (4) has shown that caregivers who report higher levels of anger/ hostility have significantly higher levels of glucose, as compared with noncaregivers and caregivers with low levels of anger/hostility. Similarly, the role of caregiving has been shown to interact significantly with existing co-morbidities to predict the following health outcomes: metabolic syndrome (5), natural killer cell activity (6), and blood pressure reactivity (7). On the basis of these findings the current research was undertaken to test the hypothesis that negative neighborhood characteristics would increase the impact of caregiving on biological indicators of physical health.…”

Effects of sleep and sleep deprivation on blood cell count and hemostasis parameters in healthy humans

“…Sleep is a homeostatic process, an active and periodic biological state that is crucial to physical and mental health and modulated by specific neurotransmitters [4]. It is a common belief that SD increases susceptibility to many diseases [5][6][7], including cardiovascular disease [8][9][10]. Historically, SD was used as a scientific tool to understand the function of sleep.…”

Caregiving for Children With Developmental Disabilities Is Associated With a Poor Antibody Response to Influenza Vaccination

“…In humans, the effects of chronic stress on immunity have been studied by comparing caregivers who provide care to sick or disabled relatives with broadly matched controls (1)(2)(3)(4)(5)(6) and the antibody response to vaccination is regarded as a useful model for the studying the effects of stress in this context (7)(8)(9). Older spousal caregivers of dementia patients have been found to show a relatively poor antibody response to both influenza and pneumococcal vaccinations (5,10,11), implying a reduced capacity to fight viral and bacterial infections.…”