Chronic Stress Reduces Alzheimer Caregiver Life by 4-8 Years

Sept. 18, 2007
(Source: Newswise.com)

Informal caregivers may find their lives are shortened by four to eight years due to the stress of caring for someone with Alzheimer’s disease, new research by the Ohio State University and National Institute on Aging reveals. The study also shows that the effects of chronic stress can be seen both at the genetic and molecular level.

These are the latest results from nearly three decades of OSU research on the links between psychological stress and a weakened immune status. Previous studies have examined medical students, newlyweds, divorced spouses, widows, widowers and long-married couples, in each case, looking for physiological effects caused by psychological stress.

OSU immunology professor Ronald Glaser and psychology professor Jan Kiecolt-Glaser worked with Nan-ping Weng and his research group from the National Institute of Aging.

While earlier research found chromosomal change in caregivers that effectively amounted to several years of additional aging among those caregivers, the researchers wanted to identify the exact cells involved in the changes, as well as the mechanisms that caused them. They focused on telomeres, areas of genetic material on the ends of a cell’s chromosomes. Over time, as a cell divides, those telomeres shorten, losing genetic instructions. An enzyme – telomerase – normally works to repair that damage to the chromosome, Glaser said.

They compared Alzheimer’s disease caregivers with non-caregivers matched for age, gender and other aspects. They analyzed blood samples from each group, looking for differences in both the telomeres and the enzyme, as well as populations of immune cells. “Caregivers showed the same kind of patterns present in the study of mothers of chronically ill kids,” Glaser said. He said the changes in these immune cells “represent the whole cell population in the body, suggesting that all the body’s cells have aged that same amount.”

The caregivers also differed dramatically with the control group on psychological surveys intended to measure depression, a clear cause of stress. “Caregivers also had fewer lymphocytes,” Glaser said, “a very important component of the immune system. They also showed a higher level of cytokines, molecules key to the inflammation response, than did the control group.”

Other experiments showed that the actual telomeres in blood cells of caregivers were shorter than those of the controls, and that the level of the telomerase repair enzyme among caregivers was also lower.

The OSU is now working on studies on how to intervene with that stress in hopes of slowing the weakening of the immune system in highly stressed people.

The findings were published in the Journal of Immunology.

from Aging Opportunities News Online