Depression Impacts Stress System, Fight Or Flight Response, Can Lead To Heart Disease

Main Category: Depression
Also Included In: Heart Disease
Article Date: 30 Nov 2011 - 0:00 PST

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Depression may have more far-reaching consequences than previously believed. Recent data suggests that individuals who suffer from a mood disorder could be twice as likely to have a heart attack compared to individuals who are not depressed.

This process has been poorly understood - until now. A new study led by Concordia University has found that depressed individuals have a slower recovery time after exercise compared to those who are non-depressed.

These findings suggest that a dysfunctional biological stress system is at play among depressed individuals. Published in the journal Psychophysiology, the research warns of the importance of testing for cardiovascular disease among people suffering from major depression.

"There have been two competing theories as to why depression is linked to cardiovascular disease," says first author Jennifer Gordon, who is a PhD candidate at McGill University. "Depressed people may have poorer health behaviors, which may in turn lead to heart problems. The other possibility is physiological: a problem with the stress system known as the fight or flight response. Our study was the first to examine the role of a dysfunctional fight or flight response in depression in a large population."

Heart rate recovery is a powerful diagnostic tool

A total of 886 participants, who were on average 60 years old, took part in the study conducted by Concordia in association with the Montreal Heart Institute, McGill University, the Hôpital Sacré-Coeur de Montréal, the Université du Québec à Montréal and the University of Calgary.

Approximately 5 per cent of participants were diagnosed with a major depressive disorder. All individuals were asked to undergo a stress test after which their heart rate and blood pressure were recorded. Recovery heart rates and blood pressure levels were compared between depressed and non-depressed individuals.

"We found that it took longer for the heart rate of depressed individuals to return to normal," says senior author, Simon Bacon, a professor in the Concordia University Department of Exercise Science and a researcher at the Montreal Heart Institute. "Heart rate recovery from exercise is one way to measure the fight or flight stress response. The delayed ability to establish a normal heart rate in the depressed individuals indicates a dysfunctional stress response. We believe that this dysfunction, can contribute to their increased risk for heart disease."

"The take-home message of this study is that health care professionals should not only address the mental disorder, but also the potential for heart disease in patients who are suffering from major depression," adds Bacon. "Both of these health issues should be treated to minimize risk of severe consequences."

Article adapted by Medical News Today from original press release. Click 'references' tab above for source.
Visit our depression section for the latest news on this subject. Partners in research: This work was supported by the Heart and Stroke Foundation of Quebec, the Canadian Institutes of Health Research, the Canadian Hypertension Society and le Fonds de la recherche en santé du Québec.
Concordia University Please use one of the following formats to cite this article in your essay, paper or report:

MLA

Concordia University. "Depression Impacts Stress System, Fight Or Flight Response, Can Lead To Heart Disease." Medical News Today. MediLexicon, Intl., 30 Nov. 2011. Web.
9 Dec. 2011. APA

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View the original article here

Is Oxidative Stress Less Harmful Than Suspected?

Main Category: Heart Disease
Also Included In: Neurology / Neuroscience;  Cancer / Oncology
Article Date: 06 Dec 2011 - 3:00 PST

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Arterial calcification and coronary heart disease, neurodegenerative diseases such as Parkinson's and Alzheimer's, cancer and even the aging process itself are suspected to be partially caused or accelerated by oxidative stress. Oxidative stress arises in tissues when there is an excess of what are called reactive oxygen species (ROS). "However, up to now, nobody was able to directly observe oxidative changes in a living organism and certainly not how they are connected with disease processes," said Associate Professor (PD) Dr. Tobias Dick of DKFZ. "There were only fairly unspecific or indirect methods of detecting which oxidative processes are really taking place in an organism."

For the first time, Tobias Dick and his co-workers have been able to observe these processes in a living animal. Jointly with Dr. Aurelio Teleman (also of DKFZ), they introduced genes for biosensors into the genetic material of fruit flies. These biosensors are specific for various oxidants and indicate the oxidative status of each cell by emitting a light signal - in realtime, in the whole organism and across the entire life span.

In the fly larvae, the investigators already discovered that oxidants are produced at very differing levels in different tissue types. Thus, blood cells produce considerably more oxidants in their energy plants, the mitochondria, than, for example, intestinal or muscle cells. In addition, the larvae's behavior is reflected in the production of oxidants in individual tissues: The researchers were able to distinguish whether the larvae were eating or moving by the oxidative status of the fat tissue.

Up to now, many scientists have assumed that the aging process is associated with a general increase in oxidants throughout the body. However, this was not confirmed by the observations made by the investigators across the entire life span of the adult animals. They were surprised that almost the only age-dependent increase in oxidants was found in the fly's intestine. Moreover, when comparing flies with different life spans, they found out that the accumulation of oxidants in intestinal tissue even accelerated with a longer life span. The group thus found no evidence supporting the frequently voiced assumption that an organism's life span is limited by the production of harmful oxidants.

Even though comprehensive studies have failed to provide proof until the present day, antioxidants are often advertised as a protection against oxidative stress and, thus, health-promoting. Dick and colleagues fed their flies with N-acetyl cysteine (NAC), a substance which is attributed an antioxidant effect and which some scientists consider suitable for protecting the body against presumably dangerous oxidants. Interestingly, no evidence of a decrease in oxidants was found in the NAC-fed flies. On the contrary, the researchers were surprised to find that NAC prompted the energy plants of various tissues to significantly increase oxidant production.

"Many things we observed in the flies with the help of the biosensors came as a surprise to us. It seems that many findings obtained in isolated cells cannot simply be transferred to the situation in a living organism," said Tobias Dick, summarizing their findings. "The example of NAC also shows that we are currently not able to predictably influence oxidative processes in a living organism by pharmacology," he adds. "Of course, we cannot simply transfer these findings from fly to man. Our next goal is to use the biosensors to observe oxidative processes in mammals, especially in inflammatory reactions and in the development of tumors."

Article adapted by Medical News Today from original press release. Click 'references' tab above for source.
Visit our heart disease section for the latest news on this subject. Simone C. Albrecht, Ana Gomes Barata, Jörg Großhans, Aurelio A. Teleman and Tobias P. Dick: In vivo mapping of hydrogen peroxide and oxidized glutathione reveals chemical and regional specificity of redox homeostasis. Cell Metabolism 2011, DOI:10.1016/j.cmet.2011.10.010.
Legend: Yellow light signals emitted by the biosensor indicate oxidant production in the tissue of a migrating fly larva.
Source: Tobias Dick, German Cancer Research Center
Helmholtz Association of German Research Centres Please use one of the following formats to cite this article in your essay, paper or report:

MLA

Helmholtz Association of German Research Centres. "Is Oxidative Stress Less Harmful Than Suspected?." Medical News Today. MediLexicon, Intl., 6 Dec. 2011. Web.
9 Dec. 2011. APA

Please note: If no author information is provided, the source is cited instead.

posted by Brian on 6 Dec 2011 at 1:54 pm

Well articulated and cogent article. Much appreciated. Always had the feeling that anti-oxidants and ROS are being overplayed. Technically, they are necessary signalling molecules in the cell, so their influence cannot always be deleterious!

| post followup | alert a moderator |

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All opinions are moderated before being included (to stop spam)

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View the original article here

Depression Impacts Stress System, Fight Or Flight Response, Can Lead To Heart Disease

Main Category: Depression
Also Included In: Heart Disease
Article Date: 30 Nov 2011 - 0:00 PST

email to a friend   printer friendly   opinions  

Depression may have more far-reaching consequences than previously believed. Recent data suggests that individuals who suffer from a mood disorder could be twice as likely to have a heart attack compared to individuals who are not depressed.

This process has been poorly understood - until now. A new study led by Concordia University has found that depressed individuals have a slower recovery time after exercise compared to those who are non-depressed.

These findings suggest that a dysfunctional biological stress system is at play among depressed individuals. Published in the journal Psychophysiology, the research warns of the importance of testing for cardiovascular disease among people suffering from major depression.

"There have been two competing theories as to why depression is linked to cardiovascular disease," says first author Jennifer Gordon, who is a PhD candidate at McGill University. "Depressed people may have poorer health behaviors, which may in turn lead to heart problems. The other possibility is physiological: a problem with the stress system known as the fight or flight response. Our study was the first to examine the role of a dysfunctional fight or flight response in depression in a large population."

Heart rate recovery is a powerful diagnostic tool

A total of 886 participants, who were on average 60 years old, took part in the study conducted by Concordia in association with the Montreal Heart Institute, McGill University, the Hôpital Sacré-Coeur de Montréal, the Université du Québec à Montréal and the University of Calgary.

Approximately 5 per cent of participants were diagnosed with a major depressive disorder. All individuals were asked to undergo a stress test after which their heart rate and blood pressure were recorded. Recovery heart rates and blood pressure levels were compared between depressed and non-depressed individuals.

"We found that it took longer for the heart rate of depressed individuals to return to normal," says senior author, Simon Bacon, a professor in the Concordia University Department of Exercise Science and a researcher at the Montreal Heart Institute. "Heart rate recovery from exercise is one way to measure the fight or flight stress response. The delayed ability to establish a normal heart rate in the depressed individuals indicates a dysfunctional stress response. We believe that this dysfunction, can contribute to their increased risk for heart disease."

"The take-home message of this study is that health care professionals should not only address the mental disorder, but also the potential for heart disease in patients who are suffering from major depression," adds Bacon. "Both of these health issues should be treated to minimize risk of severe consequences."

Article adapted by Medical News Today from original press release. Click 'references' tab above for source.
Visit our depression section for the latest news on this subject. Partners in research: This work was supported by the Heart and Stroke Foundation of Quebec, the Canadian Institutes of Health Research, the Canadian Hypertension Society and le Fonds de la recherche en santé du Québec.
Concordia University Please use one of the following formats to cite this article in your essay, paper or report:

MLA

Concordia University. "Depression Impacts Stress System, Fight Or Flight Response, Can Lead To Heart Disease." Medical News Today. MediLexicon, Intl., 30 Nov. 2011. Web.
8 Dec. 2011. APA

Please note: If no author information is provided, the source is cited instead.

Please note that we publish your name, but we do not publish your email address. It is only used to let you know when your message is published. We do not use it for any other purpose. Please see our privacy policy for more information.

If you write about specific medications or operations, please do not name health care professionals by name.

All opinions are moderated before being included (to stop spam)

Contact Our News Editors

For any corrections of factual information, or to contact the editors please use our feedback form.

Please send any medical news or health news press releases to:

Note: Any medical information published on this website is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional. For more information, please read our terms and conditions.

View the original article here

Is Oxidative Stress Less Harmful Than Suspected?

Main Category: Heart Disease
Also Included In: Neurology / Neuroscience;  Cancer / Oncology
Article Date: 06 Dec 2011 - 3:00 PST

email to a friend   printer friendly   opinions  

Arterial calcification and coronary heart disease, neurodegenerative diseases such as Parkinson's and Alzheimer's, cancer and even the aging process itself are suspected to be partially caused or accelerated by oxidative stress. Oxidative stress arises in tissues when there is an excess of what are called reactive oxygen species (ROS). "However, up to now, nobody was able to directly observe oxidative changes in a living organism and certainly not how they are connected with disease processes," said Associate Professor (PD) Dr. Tobias Dick of DKFZ. "There were only fairly unspecific or indirect methods of detecting which oxidative processes are really taking place in an organism."

For the first time, Tobias Dick and his co-workers have been able to observe these processes in a living animal. Jointly with Dr. Aurelio Teleman (also of DKFZ), they introduced genes for biosensors into the genetic material of fruit flies. These biosensors are specific for various oxidants and indicate the oxidative status of each cell by emitting a light signal - in realtime, in the whole organism and across the entire life span.

In the fly larvae, the investigators already discovered that oxidants are produced at very differing levels in different tissue types. Thus, blood cells produce considerably more oxidants in their energy plants, the mitochondria, than, for example, intestinal or muscle cells. In addition, the larvae's behavior is reflected in the production of oxidants in individual tissues: The researchers were able to distinguish whether the larvae were eating or moving by the oxidative status of the fat tissue.

Up to now, many scientists have assumed that the aging process is associated with a general increase in oxidants throughout the body. However, this was not confirmed by the observations made by the investigators across the entire life span of the adult animals. They were surprised that almost the only age-dependent increase in oxidants was found in the fly's intestine. Moreover, when comparing flies with different life spans, they found out that the accumulation of oxidants in intestinal tissue even accelerated with a longer life span. The group thus found no evidence supporting the frequently voiced assumption that an organism's life span is limited by the production of harmful oxidants.

Even though comprehensive studies have failed to provide proof until the present day, antioxidants are often advertised as a protection against oxidative stress and, thus, health-promoting. Dick and colleagues fed their flies with N-acetyl cysteine (NAC), a substance which is attributed an antioxidant effect and which some scientists consider suitable for protecting the body against presumably dangerous oxidants. Interestingly, no evidence of a decrease in oxidants was found in the NAC-fed flies. On the contrary, the researchers were surprised to find that NAC prompted the energy plants of various tissues to significantly increase oxidant production.

"Many things we observed in the flies with the help of the biosensors came as a surprise to us. It seems that many findings obtained in isolated cells cannot simply be transferred to the situation in a living organism," said Tobias Dick, summarizing their findings. "The example of NAC also shows that we are currently not able to predictably influence oxidative processes in a living organism by pharmacology," he adds. "Of course, we cannot simply transfer these findings from fly to man. Our next goal is to use the biosensors to observe oxidative processes in mammals, especially in inflammatory reactions and in the development of tumors."

Article adapted by Medical News Today from original press release. Click 'references' tab above for source.
Visit our heart disease section for the latest news on this subject. Simone C. Albrecht, Ana Gomes Barata, Jörg Großhans, Aurelio A. Teleman and Tobias P. Dick: In vivo mapping of hydrogen peroxide and oxidized glutathione reveals chemical and regional specificity of redox homeostasis. Cell Metabolism 2011, DOI:10.1016/j.cmet.2011.10.010.
Legend: Yellow light signals emitted by the biosensor indicate oxidant production in the tissue of a migrating fly larva.
Source: Tobias Dick, German Cancer Research Center
Helmholtz Association of German Research Centres Please use one of the following formats to cite this article in your essay, paper or report:

MLA

Helmholtz Association of German Research Centres. "Is Oxidative Stress Less Harmful Than Suspected?." Medical News Today. MediLexicon, Intl., 6 Dec. 2011. Web.
8 Dec. 2011. APA

Please note: If no author information is provided, the source is cited instead.

posted by Brian on 6 Dec 2011 at 1:54 pm

Well articulated and cogent article. Much appreciated. Always had the feeling that anti-oxidants and ROS are being overplayed. Technically, they are necessary signalling molecules in the cell, so their influence cannot always be deleterious!

| post followup | alert a moderator |

Please note that we publish your name, but we do not publish your email address. It is only used to let you know when your message is published. We do not use it for any other purpose. Please see our privacy policy for more information.

If you write about specific medications or operations, please do not name health care professionals by name.

All opinions are moderated before being included (to stop spam)

Contact Our News Editors

For any corrections of factual information, or to contact the editors please use our feedback form.

Please send any medical news or health news press releases to:

Note: Any medical information published on this website is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional. For more information, please read our terms and conditions.

View the original article here