Age Effects on Cognitive and Physiological Parameters in Familial Caregivers of Alzheimer's Disease Patients

Abstract

ObjectivesOlder familial caregivers of Alzheimer’s disease patients are subjected to stress-related cognitive and psychophysiological dysfunctions that may affect their quality of life and ability to provide care. Younger caregivers have never been properly evaluated. We hypothesized that they would show qualitatively similar cognitive and psychophysiological alterations to those of older caregivers.MethodThe cognitive measures of 17 young (31–58 years) and 18 old (63–84 years) caregivers and of 17 young (37–57 years) and 18 old (62–84 years) non-caregiver controls were evaluated together with their salivary cortisol and dehydroepiandrosterone (DHEA) levels, as measured by radioimmunoassays and ELISA assays of brain-derived neurotrophic factor (BDNF) in serum.ResultsAlthough younger caregivers had milder impairments in memory and executive functions than older caregivers, their performances fell to the same or lower levels as those of the healthy older controls. Decreases in DHEA and BDNF levels were correlated with the cognitive dysfunctions observed in the older and younger caregivers, respectively. Cortisol at 10PM increased in both caregiver groups.DiscussionYounger caregivers were prone to cognitive impairments similar to older caregivers, although the degree and the neuropsychological correlates of the cognitive dysfunctions were somewhat different between the two groups. This work has implications for caregiver and care-recipient health and for research on the neurobiology of stress-related cognitive dysfunctions.

Mental health in familial caregivers of Alzheimer’s disease patients: are the effects of chronic stress on cognition inevitable?

“…Compromise of caregiver's mental health was also indicated by the results of prefrontal and temporal lobe-dependent tasks. Executive function (inhibitory response capacity), attention, working memory and declarative memory were impaired, corroborating previous results from ours (Corrêa et al, 2015a(Corrêa et al, , 2016Palma et al,2011) and other research groups (see Allen et al, 2017 for a review). Higher nadir cortisol/DHEA ratios and lower BDNF levels accompanied these cognitive dysfunctions.…”

“…The caregiver's impairment in these cognitive domains are well established (Allen et al, 2017) and an association with alterations on cortisol/DHEA ratios and BDNF levels has been shown by ours (Corrêa et al, 2015a(Corrêa et al, , 2016 and other research groups (Vedhara et al, 2002).…”

“…These characteristics are common among familial caregivers (Roth, Fredman, & Haley, 2015;Vitaliano et al, 2011) and can be explained by the physical and emotional overburden, this last caused mainly by the affective connection between the caregiver and the patient (Dassel et al, 2017). The caregiver's chronic stress was further confirmed by their higher cortisol/ DHEA ratio, which was previously shown to be a physiological marker of chronic stress in caregivers of demented patients (Corrêa 2015b(Corrêa , 2016Vedhara et al, 2002) and other conditions (Kamin & Kertes, 2017).…”

“…Blood was collected from each volunteer via venipuncture into an anticoagulant-free vacuum tube. The clotted blood samples were then centrifuged at 4000 rpm for 10 minutes, and the serum was kept frozen at -80 C until further analysis (Corrêa et al, 2016). The serum BDNF analysis was performed using an ELISA kit following the manufacturer's instructions (Millipore, USA).…”

Depression, quality of life and cortisol: a cross-sectional study of caregivers of patients with Alzheimer’s disease

“…This evidence underscores the fact that the HPA axis does not have a standard relationship with exhaustive experiences and associated feelings of individuals. Taking into account past work 10,40,48,57,58 , these findings present a broader discussion, in terms of evidence, of cortisol responsiveness to caregiver health and possible co-influencers, such as the age and the impact of the CDR evolution of these individuals.…”