Disability does not necessarily follow disease in living to old age

Researchers from Boston Medical Center's (BMC) New England Centenarian Study report that for a substantial proportion of their centenarian subjects, avoiding age-related diseases (i.e. stroke, cardiovascular disease, diabetes) may not be the key to their longevity; rather, the avoidance of disability may be a key feature in their exceptional survival.

These findings appear in the February 11th issue of Archives of Internal Medicine.

The researchers examined the health histories of 739 centenarians and found about one third of the subjects had age-related diseases for 15 or more years (age of onset prior to the age of 85). “We expected to find that nearly all centenarians have to compress the time they are sick towards the very end of their lives, otherwise how could they get to such old age"” asked senior author, Thomas Perls, MD, MPH, director, of BMC's New England Centenarian Study and associate professor of medicine at Boston University School of Medicine. “One factor enabling the survival of these sick centenarians-to-be appears to be a delay or compression of their disability,” he added.

Seventy two percent of the male centenarians and 34 percent of the female centenarians in this “survivors-of-disease” group (centenarians who developed age-related diseases prior to age 85) scored in the independent range on the Barthel Activities of Daily Living Index at the age of 97 or older. According to the researchers, for a significant proportion of people surviving to extreme old age, compression of disability, rather than morbidity is a key feature of their ability to live such long lives.

“The ramifications of our findings are that among older people, morbidity and disability do not always go hand in hand,” said lead author Dellara Terry, MD, MPH, co-director of the New England Centenarian Study and assistant professor of medicine at Boston University School of Medicine. “Eventually being able to understand the underlying mechanisms for delaying disability in the presence of important age related diseases could lead to better prognostication and perhaps even therapies,” she added.

The researchers also found that though far fewer in number, male centenarians tend to have significantly better cognition and physical function than their female counterparts. One possible explanation for this may be that women are more resilient compared to men when it comes to aging. Thus, for a man to live to 100 or older, he must be in truly fantastic shape as close to the end of his life, whereas, the women can better handle living with age-related illnesses.