Relationships between psychosocial stress, cortisol, apolipoprotein є4, beta-amyloid, hippocampal volumes and Alzheimer's disease in a sample of South African older adults

Includes bibliographical references.Many factors contribute to age-related changes in cognitive functioning. There is no single defined profile of factors that is clearly associated with the presence, or rate of progression, of cognitive changes in older adults. Stress, both psychosocial and physiological, may play a role. Aims: The general aim of this study was to explore the relationships between cognitive functioning and cognitive decline, on the one hand, and psychosocial and physiological stress, as well as a range of sociodemographic, psychosocial and physiological factors, on the other, in older adults with a range of cognitive function including healthy and impaired. Methods: Both cross-sectional (Study 1) and longitudinal (Study 2) designs addressed these aims. Study 1 examined the contribution of stress and sociodemographic, psychosocial, and physiological factors to cognition. Participants were 69 cognitively healthy older adults and 65 possible or probable Alzheimer’s disease (AD) patients. They were all over the age of 60 and resided in the greater Cape Town metropolitan region of South Africa. Cognitive functioning was assessed using a battery of neuropsychological tests. Salivary cortisol levels, apolipoprotein E (APOE) genotype, and plasma beta-amyloid levels were determined at baseline