Effects of Self-compassion on Diurnal Cortisol Pattern via Positive Affect in Colorectal Cancer Survivors

Objectives Colorectal cancer survivors are at risks of emotional distress and dysregulated diurnal cortisol rhythms. Dispositional self-compassion has been linked with better psychological adjustment and greater positive affect. This study evaluated the associations between self-compassion and the diurnal cortisol pattern, and the role of positive affect and emotional distress in mediating this association, in cancer patients. Methods This longitudinal study recruited 127 Chinese colorectal cancer survivors, who completed assessments for self-compassion, positive affect, emotional distress, and naturalistic salivary cortisol at baseline. The participants completed follow-up assessments for affect and emotional distress after 2 months (time 2) and the diurnal cortisol pattern after 8 months (time 3). Bootstrapped mediation analysis analyzed the direct and indirect effects of self-compassion on the diurnal cortisol pattern via positive affect and emotional distress. Results A structural equation model with latent factors of self-compassion, self-criticism, and emotional distress provided an adequate fit to the data. The direct effects of self-compassion and self-criticism on the diurnal cortisol pattern were not significant (p = 0.11–0.50). Positive affect, but not emotional distress, at time 2 significantly predicted steeper diurnal cortisol slopes at time 3 (β = − 0.22, SE = 0.08, p < 0.01). Self-compassion and self-criticism showed significant negative and positive indirect effects on time 3 diurnal cortisol slopes via time 2 positive affect, respectively. Conclusions Our findings support indirect linkages between self-compassion and steeper diurnal cortisol slopes via positive affect. Positive affect may mediate temporal relationships between self-compassion and neuroendocrine functioning in colorectal cancer survivors.

Chronobiological Factors Related to Sleep and Neuropsychiatric Symptoms in Persons Living With Dementia

Circadian rhythm disturbances (CRD) are commonly seen in people living with dementia. A clear understanding of the role of CRD in dementia etiology will be beneficial by exploring the exogenous factors (externally influence the duration of sleep hours, such as light/dark cycles) and endogenous factors (internal biological rhythm, such as diurnal cortisol pattern). This symposium will apply a chronobiological approach to study exogenous and endogenous factors that influence circadian rhythm and their effects on sleep and neuropsychiatric symptoms in persons living with dementia (PLWD). Four paper presentations will use secondary data analysis of data from the Healthy Patterns Clinical Trial (NCT03682185), a randomized controlled trial of a home-based activity intervention designed to improve circadian rhythm disorders in PLWD. We will first describe the circadian rhythm pattern reflected by endogenous factors (salivary cortisol), then examine salivary cortisol (endogenous) and white light intensity (exogenous) and on subjective sleep and neuropsychiatric symptoms (including depression) in PLWD, respectively. In session 1, we will present cortisol diurnal rhythm pattern in PLWD using a cross-sectional design. In session 2, we will discuss the relationship between salivary cortisol indicators and depressive symptoms. In session 3, we focus on the association between diurnal cortisol slope and neuropsychiatric symptoms using the baseline data. In session 4, we describe the association between evening white light exposure and subjective sleep. The discussant will describe how these findings build on our understanding the nature of circadian rhythm disturbance in dementia and inform future research and treatment approaches.

Salivary Cortisol Patterns in People Living With Dementia

Salivary cortisol has a well-documented circadian pattern in older adults. Yet, the pattern of salivary cortisol in persons living with dementia (PLWD) due to circadian rhythm disturbances is unknown. This study examined diurnal salivary cortisol patterns in 176 PLWD (mean age 73.6±8.8, 33.3% male, clinical dementia rating &gt;=0.5) by collecting saliva at waking (AM1), 30 minutes after waking (AM2) and bedtime (PM) over two consecutive days. Cortisol awakening response (CAR) was calculated as the change between AM2 and AM1 cortisol levels. The mean baseline salivary cortisol levels (ug/dl) were 0.35 (SD:0.3) at AM1, 0.40 (SD:0.39) at AM2, and 0.19 (SD:0.4) at PM. On average, cortisol levels decreased from morning to evening, with 58% exhibiting a positive CAR (mean 0.05; SD:0.34). There were no significant associations between cortisol levels with age, sex, obesity, and comorbidities. The findings demonstrated that diurnal cortisol rhythms are maintained in PLWD with a flattened CAR.

Relationships Between Salivary Cortisol Slope and Neuropsychiatric Symptoms in Persons Living With Dementia

While a flatter diurnal cortisol slope has been related to poor health outcomes in healthy populations, little is known about this relationship in persons living with dementia (PLWD). The purpose of this study was to examine the association between diurnalcortisol slope and neuropsychiatric symptoms in PLWD. Secondary data analysis was conducted using baseline data from the Healthy Patterns Study (N=168). Diurnal cortisol slope was calculated using the difference between changes in salivary cortisol from 30 minutes after awakening to bedtime. Spearman rho coefficients were used. Flatter cortisol slope was associated with the presence of symptoms of agitation (r=-0.191, p=0.013) and disinhibition (r=-0.168, p=0.03). Steeper cortisol slope was related to a more severe level of anxiety symptoms (r=0.36, p=0.009) and higher frequency of insomnia (r=0.292, p=0.011). We found that cortisol slope was associated with neuropsychiatric symptoms in PLWD. Future research is needed to examine the mechanisms underlying the relationships.

Experiences of adversity in childhood and adolescence and cortisol in late adolescence

Early life adversity influences the diurnal cortisol rhythm, yet the relative influence of different characteristics of adversity remains unknown. In this study, we examine how developmental timing (childhood vs. adolescence), severity (major vs. minor), and domain of early life adversity relate to diurnal cortisol rhythms in late adolescence. We assessed adversity retrospectively in early adulthood in a subsample of 236 participants from a longitudinal study of a diverse community sample of suburban adolescents oversampled for high neuroticism. We used multilevel modeling to assess associations between our adversity measures and the diurnal cortisol rhythm (waking and bedtime cortisol, awakening response, slope, and average cortisol). Major childhood adversities were associated with flatter daily slope, and minor adolescent adversities were associated with greater average daily cortisol. Examining domains of childhood adversities, major neglect and sexual abuse were associated with flatter slope and lower waking cortisol, with sexual abuse also associated with higher cortisol awakening response. Major physical abuse was associated with higher waking cortisol. Among adolescent adversities domains, minor neglect, emotional abuse, and witnessing violence were associated with greater average cortisol. These results suggest severity, developmental timing, and domain of adversity influence the association of early life adversity with stress response system functioning.