COLUMBUS, Ohio The persistent fatigue that plagues one out of every three breast cancer survivors may be caused by one part of the autonomic nervous system running in overdrive, while the other part fails to slow it down.
That imbalance of a natural system in the body appears linked to the tiredness and exhaustion that can burden cancer patients as much as a decade after their successful treatment.
The effect is so great, researchers say, that it may be a sign of accelerated aging in fatigued patients, causing them to seem as much as 20 years older compared with patients who aren't fatigued.
Those new research findings, just reported in the journal Psychoneuroendocrinology, are the latest from a three-decade-long study of the impact that stress can have on the human body.
Christopher Fagundes, a postdoctoral fellow at Ohio State University's Institute of Behavioral Medicine Research (IBMR), and Janice Kiecolt-Glaser, a professor of psychiatry and psychology and a member of the IBMR, drew early data from a larger ongoing study testing whether yoga can combat continuing fatigue in breast cancer patients.
They were looking for a new biomarker, a signal that could point to the initial cause of this fatigue. Their target was the autonomic nervous system, that part of the body that controls unconscious activities like breathing, heartbeat, digestion and such, which earlier research had indicated might play a role.
The autonomic nervous system has two main parts the sympathetic and the parasympathetic. The former is responsible for what has become known as the fight-or-flight response, a triggering of short-term, energized activity. The latter deals with opposite situations. It is the resting phase, best recognized by the sleepiness that may follow eating a big meal.
While the sympathetic system is an energy hog, the parasympathetic conserves energy, and the two should remain in balance in healthy
|Contact: Janice Kiecolt-Glaser|
Ohio State University