New View Of Link Between Aging, Atherosclerosis
DURHAM, N.C. - The exceptions have always fascinated Duke University Medical Center cardiologist Pascal Goldschmidt, M.D. In the case of atherosclerosis, these exceptions, specifically how some people's bodies can repair arterial damage better than others, might hold a key to a new way of looking at the link between aging and the disease process in general.
He cites as examples those individuals who smoke all their lives but do not get cardiovascular disease, or those who have always eaten an unhealthy diet but still make it to old age with clear arteries.
Goldschmidt, chairman of the department of medicine, and fellow cardiologist Eric Peterson, M.D., Duke Clinical Research Institute, believe that medicine has spent so much time investigating the risk factors for disease that they have neglected to appreciate the other half of the equation, the body's innate ability to protect and repair itself.
"It is this relationship between the body's ability to keep up with the cumulative damage it suffers over time that could be the key to who gets sick and who stays healthy into old age," Goldschmidt explained. "We believe that the key resides in the bone marrow, which produces cells that can repair damage to the body, and it is not until this restorative ability is exhausted or overwhelmed that the disease process takes its toll."
The researchers published their theory on the online "Science of Aging Knowledge Environment" (SAGE KE), (http://sageke.sciencemag.org/), a joint effort of the journal Science and its publisher, the American Association for the Advancement of Science (AAAS).
Said Peterson, "Age has always been considered a risk factor for heart disease, but we haven't really understood why. Why do some of us age faster than others? Why aren't the effects of aging consistent from individual to individual? It may have to do with the delicate balance between physical insults of daily life and the ability to repair them.
"On one side of the equation are the factors that damage blood vessels, like smoking, hypertension or high cholesterol," Peterson continued. "On the other side is the ability to repair that damage -- people who can repair with a high degree of success can withstand more damage and live longer."
Earlier this year (Circulation, July 29, 2003), Duke researchers discovered that a major outcome of aging is an unexpected failure of the bone marrow to produce progenitor cells needed to repair and rejuvenate arteries exposed to a genetically induced risk of high blood pressure in the mouse. Stem cells are immature cells produced in the bone marrow that have the potential to mature into a variety of different cells. The researchers demonstrated that an age-related loss of these particular stem cells