The use of saliva steroids (cortisol and DHEA-s) as biomarkers of changing stress levels in people with dementia and their caregivers: A pilot study

The rationale was to explore the efficacy/sensitivity of using morning and evening cortisol levels as biomarkers for stress reduction in persons with dementia (PWDs) and their family caregivers (FCGs) participating in a music intervention program. Thirty-two PWD and their FGC were recruited to an 8-week, home-based music intervention program. Daily home-based collection of saliva samples took place at bedtime and upon awakening. Cortisol was analyzed in the morning and evening saliva samples and DHEA-s in the morning samples. Trends over 40 workdays (15–40 observations per subject) were assessed using linear regression analysis. Twenty-three PWD (72% of invited, 16 men and 7 women, age 69–93) and 24 caregivers (75%, 8 men and 16 women, age 37–90) completed the intervention for at least 6 weeks and were included in the analysis. One-fourth of the PWD and FCG had decreasing evening cortisol, accompanied by decreasing morning cortisol levels. In one-fourth of the participants the ratio between cortisol and DHEA-S in the morning samples was improved, indicating improved balance between energy mobilization and regeneration. Several participants showed no significant endocrine change. There was a statistically significant (two-sided test) correlation within the PWD-caregiver dyads in evening cortisol trend and a statistically significant decrease (two-sided test) in the morning-evening cortisol slope for the FCG group. Reduction in stress, as measured by evening cortisol, was observed in a substantial number of the participants. Recording endocrine stress is helpful for the unbiased assessment of the intervention.

POTENTIAL MECHANISMS OF CANCER PREVENTION BY WEIGHT CONTROL

Weight control via dietary caloric restriction and/or physical activity has been demonstrated in animal models for cancer prevention. However, the underlying mechanisms are not fully understood. Body weight loss due to negative energy balance significantly reduces some metabolic growth factors and endocrinal hormones such as IGF-1, leptin, and adiponectin, but enhances glucocorticoids, that may be associated with anti-cancer mechanisms. In this review, we summarized the recent studies related to weight control and growth factors. The potential molecular targets focused on those growth factors- and hormones-dependent cellular signaling pathways are further discussed. It appears that multiple factors and multiple signaling cascades, especially for Ras-MAPK-proliferation and PI3K-Akt-anti-apoptosis, could be involved in response to weight change by dietary calorie restriction and/or exercise training. Considering prevalence of obesity or overweight that becomes apparent over the world, understanding the underlying mechanisms among weight control, endocrine change and cancer risk is critically important. Future studies using "-omics" technologies will be warrant for a broader and deeper mechanistic information regarding cancer prevention by weight control.