Longevity in Older Adults Based on Cholesterol, Physical Capabilities

The life expectancy of older adults is based more on their capabilities rather and less on a specific diagnosis, Duke Health researchers say.

Factors such as  ability to grocery shop, whether and how often they smoked, and the amount of certain cholesterol particles present in their blood can help predict how likely an individual over 70 years old will live two, five, or 10 years into the future, researchers at Duke Health have found.

"This study was designed to determine the proximal causes of longevity—the factors that portend whether someone is likely to live two or more years or 10 more years," researcher Virginia Byers Kraus, MD, PhD, said in a statement. "Properly applied, these measures could help determine the benefits and burdens of screening tests and treatments for older people."

Along with her colleagues from Duke University School of Medicine, Kraus began their study with examining a cache of 1,500 blood samples of older adults, which had been used in a study in the 1980s. The participants were at least 71 years old at the time, and with the samples having been drawn during a time where statins weren't widely used, there was no worry of them providing skewed results.

Those same participants had been followed for years after the fact, filling out questionnaires about their health history and habits, which provided a helpful resource for the university's current study.

With the leadership of researchers from the University of Minnesota, the Duke Health team was able to identify a core set of 17 predictive variables that could impact longevity.

The leading factor for longevity for all older individuals— those who lived two, five, and 10 years after having their blood drawn—was physical function. The longevity of those who lived two years after having their blood drawn was associated with having high quantity of small high-density lipoprotein (HDL) cholesterol particles in their blood.

"This was especially surprising. We hypothesize that these very small HDL particles are the size that is best at scavenging and clearing endotoxin, a potent inflammation-causing molecule from gut microbes, from the circulation," Kraus explained.

For those who lived five years after having their blood drawn, being on the younger side of participants and cognitive function were predictive of their longevity. In the group that lived 10 years after having their blood drawn, the individual's smoking history was the best predictor of their longevity, with non-smokers faring best.

"These measures clarify and enrich our understanding of mechanisms underlying longevity and could point to appropriate tests and potential interventions," Kraus said.

The next stage of their research, Kraus said, would be to use analytical tools to improve the predictivity and identify potential targets for therapies.