FOR EMBARGOED RELEASE
Friday, March 24
Contact: Amy Stone
Phone: (414) 918-3156
The impact of stress and aging on fighting diseases,
from the Society of Behavioral Medicine
SAN FRANCISCO - The body's decreasing ability to handle stress as people age may have a profound effect on a person's ability to fight disease progression, affecting their health and mortality, according to new research presented today at the Society of Behavioral Medicine Annual Meeting and Scientific Sessions.
Researchers from Stanford University are exploring the Hypothalamic-Pituitary-Adrenal Axis (HPA), stress and aging, as they relate to autonomic physiology, genetics, brain imaging and psychotherapy in four groups: people with breast cancer or cognitive decline, people at risk for cardiovascular disease, and Alzheimer's caregivers. The research is funded by a program project grant from the National Institute on Aging and the National Cancer Institute.
Janine Giese-Davis, PhD, and colleagues examined whether there are common mechanisms linking accelerated cancer and cardiac death. Metastatic breast cancer patients (MBC) experience major stress, and their biologic stress reactions may affect both quality of life and mortality. Depression has been found to be associated with increased mortality among both cancer and heart disease patients.
For one study, Giese-Davis used a modified Trier Social Stress Test to evaluate how depression affects psychophysiological and HPA function. Non-depressed (45) and depressed (47) MBC patients participated. The baseline review found that the increase in cortisol upon waking was flatter in the depressed group, who also showed a lower positive affect and less respiratory sinus arrhythmia, a measure of vagal activity, a component of the autonomic nervous system that counters sympathetic arousal and provides a 'calming influence' on the heart.. In response to the stress test, depressed patients showed greater negative affect and reduced high-frequency heart rate variability, which is a risk factor for cardiovascular disease.
In other research, C. Barr Taylor, MD, and colleagues sought to determine whether treatment of depression would alter abnormal cardiovascular risk factors as well as pyschophysiological and cortisol responses to stress and daytime cortisol slopes. The study evaluated 48 depressed men and women, age 55 and older, with elevated cardiovascular risk factors but no cardiovascular disease.
Before and after treatment, patients underwent a psychological stress test while heart rate, blood pressure, respiratory and heart rate variability were measured. There were no significant differences between treatment and control groups on any of the atypical risk factors, or on daytime cortisol slopes or reactivity of cortisol to psychological stress.
A third study reviewed the impact of cortisol on age-related neurocognitive and brain function. In a sample of 162 community-dwelling older adults, mean age 72.1, Ruth O'Hara, PhD, and colleagues investigated the relationship of waking cortisol, daytime cortisol and psychosocial stress to cognitive and brain function. Age was not associated with greater impairment of HPA function in this sample. However, older adults with increased waking cortisol showed poorer cognitive performance on measures of memory, and had reduced volume of brain regions associated with memory function. This effect was exacerbated in individuals who already are at an increased genetic risk for the development of cognitive decline and dementia. Together these studies demonstrate ways in which abererant hormonal stress-respose systems can mediate relationships among age, depression, cognition and poor health.
###
