Sex Differences in the Relationship between Perceived Stress and Cognitive Trajectories

Sex differences in amyloid PET in a large, real-world sample from the Imaging Dementia-Evidence for Amyloid Scanning (IDEAS) Study

INTRODUCTION

We examined sex effects on amyloid positron emission tomography (PET) in a large cohort of patients evaluated for cognitive complaints in a "real-world" specialty setting.

METHODS

We analyzed 10,361 amyloid PET scans (51% females) from the Imaging Dementia-Evidence for Amyloid Scanning Study. Amyloid positivity was defined by either local visual read or central PET processing and quantification (≥ 24.4 Centiloids). Sex differences were examined using multilinear regression and logistic regression adjusted for age, comorbidities, and other demographic and clinical covariates.

RESULTS

Females had higher rates of positive amyloid PET visual reads (63% vs. 59%, P < 0.001) and higher Centiloids (CLs; median 48.7 vs. 36.8, p < 0.001). On logistic regression, females had higher odds ratios (ORs) for positive amyloid PET (visual read OR 1.20, 95% confidence interval [CI]: 1.11-1.31; CL threshold-based OR 1.37, 95% CI: 1.26-1.49; both p < 0.001).

DISCUSSION

Females with cognitive impairment showed higher amyloid PET positivity and greater amyloid burden. Further research is needed to explore mechanisms and treatment implications.

HIGHLIGHTS

Females exhibited higher rates of amyloid positron emission tomography (PET) positivity and higher amyloid burden than males. These sex effects were found in patients with both mild cognitive impairment (MCI) and dementia. Females also had higher rates of dementia and amnestic MCI, while males had higher rates of non-amnestic MCI and more cholinesterase inhibitor use.

Neonatal maternal separation causes depressive-like behavior and potentiates memory impairment induced by amyloid-β oligomers in adult mice

BACKGROUND

Alzheimer's disease (AD) is characterized by memory decline and mood alterations. A growing body of evidence implicates stress and other social determinants of health as potential contributors to the progressive cerebral alterations that culminate in AD. In the current study, we investigated the impact of neonatal maternal separation (MS) on the susceptibility of male and female mice to AD-associated memory impairments and depressive-like behavior in adulthood, and on brain levels of pro-inflammatory cytokines and neurotransmitters.

METHODOLOGY

Male and female Swiss mice were exposed to MS for 180 min daily from post-natal day 1 to 10. Seventy days post-MS, mice received an intracerebroventricular infusion of amyloid-β oligomers (AβOs), and memory and mood were evaluated. Levels of TNF-α, IL-1β, serotonin, dopamine, and related metabolites were determined in the cortex and hippocampus.

RESULTS

Previous exposure to MS alone did not cause memory impairments in adult mice. Interestingly, however, MS increased the susceptibility of adult male mice to memory impairment and depressive-like behavior induced by AβOs, and potentiated the inhibitory impact of AβOs on memory in adult females. Females were more susceptible to depressive-like behavior caused by a low dose of AβOs, regardless of MS. No changes in IL-1β were found. A decrease in TNF-α was selectively found in females exposed to MS that received an infusion of 1 pmol AβOs. MS led to an increase in serotonin (5-HT) in the hippocampus of male mice, without influencing the levels of the serotonin metabolite, 5-HIAA. Changes in serotonin turnover were predominantly observed in the cortex of female mice. No changes in dopamine or its metabolites were induced by MS or AβOs in male or female mice.

CONCLUSIONS

Neonatal MS enhances the susceptibility of adult mice to AD-associated cognitive deficits and depressive-like behavior in a sex-specific manner. This suggests that early life stress may play a role in the development of AD.

Circulating Stress Hormones, Brain Health, and Cognition in Healthy Older Adults: Cross-Sectional Findings and Sex Differences in Age-Well

Background

Increased stress is a proposed risk factor for Alzheimer's disease (AD). We examined cross-sectional associations between circulating stress biomarkers and multimodal measures of brain health and cognition susceptible to AD in older adults and sex-specific subgroups.

Methods

Baseline data from 132 cognitively unimpaired participants without depression (age, mean ± SD = 74.0 ± 4.0 years, women: n = 80) in the Age-Well trial (NCT02977819) were included. Stress hormone levels were measured in overnight fasting blood serum (cortisol, dehydroepiandrosterone sulfate) and blood plasma (epinephrine, norepinephrine) samples. AD-sensitive measures of brain health, including glucose metabolism (n = 89), cerebral perfusion, gray matter volume, amyloid deposition in a priori regions of interest, and cognitive markers were evaluated. Models were adjusted for age, sex, education, trait anxiety, and depressive symptoms.

Results

Higher epinephrine levels were associated (false discovery rate-corrected p < .05) with lower glucose metabolism in the anterior cingulate cortex (β = -0.26, p = .008), posterior cingulate cortex (β = -0.32, p = .006), and precuneus (β = -0.27, p = .021) and lower perfusion in the posterior cingulate cortex (β = -0.23, p = .013). Interactions between stress hormones and sex showed (false discovery rate-corrected p < .05) that in women only, higher epinephrine was associated with larger anterior cingulate cortex volume (interaction: β = 0.32, p = .016), whereas in men only, higher cortisol was associated with lower episodic memory performance (interaction: β = 0.98, p = .012).

Conclusions

The current study demonstrates the involvement of circulating stress hormones, particularly epinephrine and cortisol, in greater resilience or vulnerability of brain health and cognitive indicators of susceptibility to AD in older adults. The identification of sex-specific patterns in these associations may inform the development of more effective and tailored interventions.

Applying the Research Domain Criteria to Rodent Studies of Sex Differences in Chronic Stress Susceptibility

Women have a 2-fold increased rate of stress-associated psychiatric disorders such as depression and anxiety, but the mechanisms that underlie this increased susceptibility remain incompletely understood. Historically, female subjects were excluded from preclinical studies and clinical trials. Additionally, chronic stress paradigms used to study psychiatric pathology in animal models were developed for use in males. However, recent changes in National Institutes of Health policy encourage inclusion of female subjects, and considerable work has been performed in recent years to understand biological sex differences that may underlie differences in susceptibility to chronic stress-associated psychiatric conditions. Here, we review the utility as well as current challenges of using the framework of the National Institute of Mental Health's Research Domain Criteria as a transdiagnostic approach to study sex differences in rodent models of chronic stress including recent progress in the study of sex differences in the neurobehavioral domains of negative valence, positive valence, cognition, social processes, and arousal.

Sex Differences in Basal Cortisol Levels Across Body Fluid Compartments in a Cross-sectional Study of Healthy Adults

Context

Many studies have moved toward saliva and peripheral blood sampling for studying cortisol, even in relation to disorders of the brain. However, the degree to which peripheral cortisol reflects central cortisol levels has yet to be comprehensively described. Data describing the effect that biological characteristics such as age and sex have on cortisol levels across compartments is also limited.

Objective

To assess the relationships of cortisol levels across cerebrospinal fluid (CSF), saliva, and plasma (total and free) compartments and describe the effects of age and sex on these relationships.

Design

Multisite cross-sectional observation study.

Setting

Samples collected in academic outpatient settings in 2001-2004.

Patients or Other Participants

Healthy community volunteers (n = 157) of both sexes, aged 20-85 years.

Interventions

None.

Main Outcome Measures

This study was a secondary analysis of data collected from a previously published study.

Results

CSF cortisol correlated more strongly with plasma (r = 0.49, P < .0001) than with saliva cortisol levels. Sex but not age was a significant modifier of these relationships. CSF cortisol levels trended higher with older age in men (R2 = 0.31, P < .001) but not women. Age-related cortisol binding globulin trends differed by sex but did not correlate with sex differences in cortisol levels in any compartment.

Conclusion

Variability in the correlations between central and peripheral cortisol discourages the use of peripheral cortisol as a direct surrogate for central cortisol measures. Further investigation of how mechanistic drivers interact with biological factors such as sex will be necessary to fully understand the dynamics of cortisol regulation across fluid compartments.

Risk Factors for Rapid Cognitive Decline in Amyloid-Negative Individuals Without Cognitive Impairment or With Early-Stage Cognitive Loss in Screening Tests

PURPOSE

Although rapid cognitive decline (RCD) is an important unfavorable prognostic factor, not much is known about it, especially in amyloid-negative individuals. The purpose of this study was to investigate risk factors for RCD in amyloid-negative individuals.

PATIENTS AND METHODS

We retrospectively enrolled 741 individuals who were either cognitively unimpaired or had early-stage cognitive ability loss and who underwent 18 F-florbetaben (FBB) (n = 402) or 18 F-flutemetamol (FMM) (n = 339) PET/CT. Based on visual and semiquantitative (SUV ratio [SUVR]-based) analysis, the following amyloid-negative groups were established: visual-negative FBB (n = 232), visual-negative FMM (n = 161), SUVR-negative FBB (n = 104), and SUVR-negative FMM (n = 101). Univariable and multivariable logistic regression analyses were performed for RCD using 5 SUVRs, 5 cortical thicknesses, and 5 neuropsychological domains and clinico-demographic factors.

RESULTS

In the amyloid-negative groups, a decline in language function was commonly identified as a significant risk factor for RCD ( P = 0.0044 in the visual-negative FBB group, P = 0.0487 in the visual-negative FMM group, P = 0.0031 in the SUVR-negative FBB group, and P = 0.0030 in the SUVR-negative FMM group). In addition, declines in frontal/executive function, frontal SUVR, and parietal SUVR; a longer duration of education; and mild cognitive decline in the amyloid-negative groups were also significant risk factors for RCD.

CONCLUSIONS

Even in amyloid-negative individuals without cognitive impairment or with early-stage cognitive ability loss, those with decreased language and frontal/executive functions on neuropsychological testing are at risk of progression to RCD.

Associations of dietary patterns and perceived stress with memory deficits in patients with heart failure

This study aimed to examine the relationships between dietary patterns and perceived stress with memory deficits in 291 patients with heart failure aged 45-85 years. A total of 142 (48.8%) patients reported memory deficit. Three dietary patterns were identified by K-means clustering: nut-fruit-dairy, meat-processed, and traditional (high intake of cereals) diets. Compared to the traditional diet, the nut-fruit-dairy diet and meat-processed diet were associated with lower levels of deficits in short-term memory, delayed memory, and overall memory. What's more, perceived stress was positively associated with deficits in short-term memory and overall memory, but the association was only found in patients adhering to the traditional diet using stratified analyses. Our findings suggest that adhering to a healthy diet may be conducive to improving deficits in short-term memory, delayed memory, and overall memory, while also buffering the adverse association between perceived stress and deficits in short-term memory and overall memory.

Examining a Healthy Lifestyle as a Moderator of the Relationship between Psychological Distress and Cognitive Decline among Older Adults in the NuAge Study

INTRODUCTION

The objective of this study was to examine whether a healthy lifestyle composite score of social engagement, physical activity, and Mediterranean diet adherence moderates the association between psychological distress and global cognitive decline among cognitively healthy older adults (67+ years of age at baseline).

METHODS

A total of 1,272 cognitively intact older adults (Mage = 74.1 ± 4.1 years, 51.9% female) in the Quebec Longitudinal Study on Nutrition and Successful Aging (NuAge) completed a series of self-reported questionnaires to measure psychological distress and lifestyle behaviors, and the Modified Mini-Mental Examination (3MS) to assess cognitive performance at baseline and annually over 3 years.

RESULTS

Controlling for sociodemographic and health-related characteristics, greater psychological distress was associated with steeper cognitive decline over time among males (B = -0.07, 95% CI: [-0.12, -0.02]), but not females (B = 0.008, 95% CI: [0.03, 0.04]). Although a healthy lifestyle composite score did not statistically significantly moderate the distress-cognition relationship (B = -0.005, 95% CI: [-0.02, 0.01]), there was an association between higher psychological distress and greater cognitive decline at low levels of social engagement (B = -0.05, 95% CI: [-0.09, -0.006]), but not at high levels of social engagement (B = 0.02, 95% CI: [-0.03, 0.07]).

CONCLUSION

This study suggests that the potentially harmful impact of stress on cognitive function may be malleable through specific healthy lifestyle behaviors and emphasizes the importance of taking a sex-based approach to cognitive aging research.