Lower morning to evening cortisol ratio is associated with cognitive impairment in men but not women: An analysis of 733 older subjects of the cross-sectional KORA-Age study

Diurnal Cortisol Slope Mediates the Association Between Affect and Memory Retrieval in Older Adults With Mild Cognitive Impairment: A Path-Analytical Study

“…Despite the use of concurrent measures at baseline, these findings appear to support a causal direction from affect to neuroendocrine functioning. In line with previous findings among cognitively healthy older adults (Gerritsen et al, 2011;Stawski et al, 2011;Johar et al, 2015), flattened diurnal cortisol slopes were linked with diminished memory retrieval and worsening daily functioning. In this study, better emotional well-being in the older adults with MCI appears to predict better functioning 12 months later by maintaining the diurnal cortisol slope and memory retrieval.…”

Cognitive ability across the life course and cortisol levels in older age

“…These results appear more consistent with previous work supporting the opposite relationship, between higher cortisol levels and higher cognitive ability, or reduced cognitive decline (Patel & Finch, 2002;Geerlings et al, 2005), or those relating cognitive decline to blunted diurnal cortisol responses (Johar et al, 2015). The few significant associations between childhood IQ and higher older-age cortisol were also contrary to our expectation, based on previous evidence of a longitudinal association between higher earlier cognitive ability and lower later cortisol levels (Franz et al, 2011), and instead also suggest a positive relationship between cortisol and cognition.…”

“…In another recent study of 4,244 older people, Geerlings et al (2015) found that, while higher evening cortisol levels were associated with smaller total brain volume and poorer cognitive functioning, higher morning levels were associated with greater white matter volume, faster processing speed and executive functioning. Other recent studies suggest that dysregulation of diurnal cortisol secretion (Johar et al, 2015), reduced variability in levels (Dijckmans et al, 2017) or blunted cortisol responses to stress (Almela et al, 2014) may be more important than overall elevation of levels in mediating cognitive ageing. Additionally, Franz et al (2011) observed that lower early-adulthood cognitive ability predicted higher later-adulthood cortisol levels (in salivary samples taken over three days), rather than the other way around, which may indicate a different mechanistic relationship between cortisol and cognition across the life course.…”

Early-Life Adversity and Dysregulation of Adult Diurnal Cortisol Rhythm

“…Pioneering work by Dallman and colleagues (1994) in rats and Rosmond and colleagues (1998) in humans established the importance of a robust diurnal cortisol dynamic range to the self-regulatory ability of the HPA axis, and its role in preventing the development of abdominal obesity and metabolic abnormalities. As predicted by their work, flatter cortisol trajectories over the waking day have been linked cross-sectionally to atherosclerosis (Toledo-Corral et al, 2013) and to poor cognitive functioning (Fiocco, Wan, Weekes, Pim, & Lupien, 2006;Johar et al, 2015). Experiments by Liston and colleagues (2013) in mouse models provide the neurological underpinning for the latter observations: They show that the diurnal cortisol peak is critical for postsynaptic dendritic spine formation in the brain cortex and promotes learning, and that the cortisol nightly trough is needed to stabilize the newly formed spines and promotes retention.…”