Navigation Links
Nervous System Imbalance May Cause Fatigue in Breast Cancer Survivors
Date:4/14/2011

By Maureen Salamon
HealthDay Reporter

THURSDAY, April 14 (HealthDay News) -- The persistent fatigue and exhaustion plaguing some breast cancer survivors after successful treatment stems from a tug of war between the "fight-or-flight" and "resting" parts of the autonomic nervous system, with the former working overtime and the other unable to rein it in, a new study suggests.

Researchers from Ohio State University split 109 women who had completed breast cancer treatment up to two years earlier into two groups -- those who did and didn't report long-term fatigue -- and tested their blood for a baseline level of norepinephrine, a stress hormone. Participants were then asked to give a five-minute speech and do a series of verbal math problems, both tasks aimed at increasing their stress levels.

As expected, further blood tests showed that levels of norepinephrine -- associated with the "fight-or-flight" sympathetic nervous system -- rose in both groups after the stressful experience, researchers said. However, breast cancer survivors who experienced persistent fatigue had higher levels than those who weren't chronically tired.

The study, released online in advance of publication in an upcoming print issue of the journal Psychoneuroendocrinology, was partially funded by the U.S. National Institutes of Health and the American Cancer Society.

The findings are the most recent from a 30-year-long study about the effects of stress on the human body. The researchers used earlier data from a larger ongoing study looking at whether yoga can ward off continuing fatigue in breast cancer patients.

"We're not sure if the fatigue is stress-induced. But certainly cancer is an extremely stressful life event," said study author Christopher Fagundes, a postdoctoral fellow at Ohio State University's Institute of Behavioral Medicine Research. "So those stressors might be contributing to those autonomic system changes."

The autonomic nervous system is comprised of two main parts: The sympathetic system is responsible for the short-term energized activity known as the fight-or-flight response, while the parasympathetic system conserves energy in a resting phase.

Fagundes and his colleagues found that breast cancer survivors experiencing chronic exhaustion -- which occurs in one-third of patients -- had an imbalance between the two systems, with higher activity in the sympathetic system, which prior research suggests is a signal for systemic inflammation.

This finding was pivotal, since the researchers were searching for reliable biomarkers for cancer-related fatigue. Earlier research indicated that body-wide systemic inflammation may be such a signal.

The researchers also observed that fatigued participants experienced lower heart rate variability (HRV), which has been linked to high blood pressure, heart attacks, strokes and diabetes.

While inflammation has been linked to fatigue in other forms of cancer, Fagundes' study only gathered data on breast cancer patients.

The study authors pointed out that more research is needed. "We cannot say with certainty that lower HRV or higher norepinephrine leads to great fatigue, or vice versa, a limitation of the study. It is possible that fatigued cancer survivors have [these levels] due to inactivity and deconditioning," they wrote in the report.

"Fatigue is something we've known about for quite some time but we really don't know that much about it, so I think this adds to the literature," said Lee Jones, scientific director of Duke Cancer Institute's Center for Cancer Survivorship in Durham, N.C.

"We don't see this [fatigue] as much with other cancer survivors," Jones added, noting that some breast cancer drugs may have a negative impact on long-term energy levels because they can be toxic to the heart.

Fagundes said the ongoing exhaustion in some women may be a sign of accelerated body-wide aging, causing their systems to function as if they were 20 years older than patients who weren't fatigued.

Jones noted that some of his prior research indicated a similar effect on fitness levels, with breast cancer survivors exhibiting about 30 percent lower levels of cardiovascular fitness as sedentary women of the same age. Chemotherapy is likely to blame, he said.

Both Fagundes and Jones advocated exercise as a way of mitigating cancer-related fatigue and maintaining fitness levels during and after treatment.

"Exercise is probably the best way to restore that balance," Fagundes said. "Obviously the goal is always to attenuate those negative effects."

More information

For more information about cancer-related fatigue, visit the U.S. National Cancer Institute.

SOURCES: Christopher Fagundes, Ph.D., postdoctoral fellow, Institute of Behavioral Medicine Research, Ohio State University, Columbus, Ohio; Lee Jones, Ph.D., scientific director, Duke Cancer Institute Center for Cancer Survivorship, Durham, N.C.; March 9, 2011, Psychoneuroendocrinology, online


'/>"/>
Copyright©2010 ScoutNews,LLC.
All rights reserved  

Related medicine news :

1. ATS issues statement on disorder of respiratory and autonomic nervous system regulation
2. Immune system helps transplanted stem cells navigate in central nervous system
3. Experimental Drug Aids Kids With Nervous System Tumor
4. Researchers get a grip on nervous systems receptors
5. Carolinas HealthCare System Volunteers to Join Navy Rescue Mission in Haiti
6. University of Virginia Health System Medical Laboratories Selects Sunquest's Specimen Collection Solution
7. Silverchair Learning Systems Enhances Product Expertise with New Hires
8. Centene Corporation Hosts Medical Management Systems Update in New York City
9. U.S. National Guard Connects Nationwide with Desktop Alert's Command and Control Mass Notification Systems and Common Alerting Protocol (CAP)
10. Swine Flu vaccination: voluntary system works
11. New screening system for hepatitis C
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Nervous System Imbalance May Cause Fatigue in Breast Cancer Survivors
(Date:6/25/2016)... ... June 25, 2016 , ... On Friday, June 10, ... Bronze Wellness at Work award to iHire in recognition of their exemplary accomplishments in ... the 7th annual Maryland Workplace Health & Wellness Symposium at the BWI Marriott in ...
(Date:6/24/2016)... ... ... June 19, 2016 is World Sickle Cell Observance Day. In an effort ... holistic treatments, Serenity Recovery Center of Marne, Michigan, has issued a pain ... Disease (SCD) is a disorder of the red blood cells, which can cause episodes ...
(Date:6/24/2016)... ... 24, 2016 , ... Dr. Amanda Cheng, an orthodontist ... has extensive experience with all areas of orthodontics, including robotic Suresmile technology, ... , Micro-osteoperforation is a revolutionary adjunct to orthodontic treatment. It can be used ...
(Date:6/24/2016)... ... June 24, 2016 , ... EB Medicine ... Making in Emergency Medicine conference in Ponte Vedra Beach, FL. The awards honor ... Emergency Medicine Practice and Pediatric Emergency Medicine Practice. , “With this ...
(Date:6/24/2016)... ... 24, 2016 , ... National recruitment firm Slone Partners is pleased ... and genomics experience, as Vice President of North American Capital Sales at HTG ... leading the sales team in the commercialization of the HTG EdgeSeq system and associated ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... , June 24, 2016  Global Blood ... biopharmaceutical company developing novel therapeutics for the treatment ... today announced the closing of its previously announced ... stock, at the public offering price of $18.75 ... offering were offered by GBT. GBT estimates net ...
(Date:6/24/2016)... June 24, 2016 ... announced the addition of the " Global Markets ... This report focuses ... an updated review, including its applications in various applications. ... market, which includes three main industries: pharmaceutical and biotechnology, ...
(Date:6/24/2016)... , June 24, 2016 The Academy ... of recommendations that would allow biopharmaceutical companies ... with entities that make formulary and coverage decisions, a ... "value" of new medicines. The recommendations address ... not appear on the drug label, a prohibition that ...
Breaking Medicine Technology: