Can Caregiver Stress Cause Early Death?

February 6, 2018 | by the National Care Planning Council

A 2003 study of caregivers by a research team at Ohio State University has proven the off-repeated adage "stress can kill you" is true. The focus of the investigation was the effect the stress of caregiving had on caregivers. The team, led by Dr. Janice Kiecolt-Glaser, reports on a 6-year study of elderly people caring for spouses with Alzheimer's Disease. The study not only found a significant deterioration in the health of caregivers when compared to a similar group of non-caregivers but also found the caregivers had a 63% higher death rate than the control group.

The demands on a caregiver result in a great deal of stress. It is often observed in aging publications that stress can induce illness and depression. The resulting poor health can further decrease the effectiveness of the caregiver and in some cases, as proven by the study mentioned above, even cause premature death.

Stress can be defined as a physiological reaction to a threat. The greater the threat -- the greater the level of stress. A threat is a real or perceived action against our person. Threats may include the anticipated possibility of death or injury but may also include challenges to our self-esteem, social standing or relationships to others or a threat may simply be a potential or real disruption of our established routines. What is stressful to one person may not be to another. For example, bumper-to-bumper traffic might be stressful to the woman executive who is late for an important meeting but to the delivery man who has no deadline and is being paid by the hour, it may be a welcome respite to relax and listen to the radio.

Stress produces real physical changes. The fears in our mind, both real and imagined, cause the hypothalamus and pituitary glands, deep in our brain, to initiate a cascade of hormones and immune system proteins that temporarily alter our physical body. This is a normal human physiological response inherent to the human body when a threat is perceived--real or not. It is often called the "fight-or-flight response" or the "stress response". The purpose is to give us clearer thought and increased strength as well as to activate the immune system to deal with potential injury and to repair potential wounds. When the perceived threat is removed, assuming no damage is done, the body returns to normal.

The team of researchers at Ohio State University Medical Center led by Doctor Glaser found a chemical marker in the blood that shows a significant increase under chronic stress and is linked to an impaired immune system response in aging adults. With the caregivers, the team found a four-fold increase in an immune system protein -- interleukin 6 (IL-6) -- as compared to an identically matched control group of non-caregivers. Only the stress of caregiving correlated to the marked increase of IL-6 in the caregiver group. All other factors, including age, were not significant to the outcome. Even the younger caregivers saw an increase in IL-6. The study also found that the caregivers had a 63% higher death rate than the control group. About 70% of the caregivers died before the end of the study and had to be replaced by new subjects. Another surprising result was that high levels of IL-6 continued even three years after the caregiving stopped. Dr. Glaser proposes the prolonged stress may have triggered a permanent abnormality of the immune system.

IL-6 is only one cytokine--an immune system mediator protein--in a cascade of endocrine hormones and cytokines that are released when the brain signals a person is threatened with harm, injury, undue mental or physical stress or death. The hormones prepare the body to react quickly by increasing heart rate, making muscles more reactive, stimulating thought, altering sugar metabolism and producing many more changes that result in the "rush" people experience when they think they may be harmed.

The cytokine release is mediated by IL-6, which takes the role of directing the immune system to gear up to prevent infection, promote wound healing and repair organs and muscles from any injury that may result from the imminent danger. The release of cytokines such as IL-1, IL-6, IL-8, TNF and other proteins such as CRP (C reactive protein) also promote development of inflammation, which is essential for blood cells to home in on injury or infection. In addition, these chemicals promote development of various types of immune system blood cells in bone marrow. This response to harm -- either real or perceived -- is an important and beneficial life-saving activity of a normally functioning body.

The problem is if this response is initiated over and over again, frequently, and over a long period; it can have a dangerous effect on the body. This constant initiation of the stress response is common among caregivers -- especially those caring for loved ones with dementia. Providing supervision or physical assistance many hours a week and over a period of years turns out to be extremely stressful. This type of stress is often unrelenting, occurring day after day and week after week. And the long term effects of this type of stress are more pronounced in middle-aged and older people who are precisely the group most likely offering long term care to loved ones.

In most younger people, when the threat lessens or disappears, the body reacts fairly quickly to shut down the stress response and return things to normal. But numerous studies have shown, as people age, the chemical cascade from stress lingers. Over a period of time, this constant chemical stimulus impairs the immune system and results in early aging, development of debilitating disease and early death. In this altered state, the body maintains high, potentially harmful levels of IL-6. The body does not return to normal without intervention.

Prolonged high levels of IL-6 and the accompanying hormones and cytokines have been linked to: cardiovascular disease, type II diabetes, frequent viral infections, intestinal problems, stomach and colon disorders, osteoporosis, periodontal disease, various cancers and auto immune disorders such as lupus, rheumatoid arthritis and multiple sclerosis. Alzheimer's, dementia, nerve damage and mental problems are also linked to high IL-6. Wounds heal slower, vaccinations are less likely to take and recovery from infectious disease is impaired. People who have depression also have high levels of IL-6. Depression in caregivers is about 8 times higher than the non-cargiving population.

This debilitating response to chronic stress is not unique to humans. Animals are affected as well. A 2004 PBS Scientific American Frontiers Special entitled "Worried Sick", explored the effect of chronic stress on animals. Observations in the field and experiments on animals exposed to chronic stress, uncovered the same phenomenon of debilitating disease and early death found in humans. Blood tests on the affected animals confirmed high levels of IL-6. The work of Dr. Janice Kiecolt-Glaser's team was also followed in the Special.

The information above should provide a compelling reason to eliminate or reduce the stress of caregiving.