Yale scientists develop measure to calculate biological age with greater accuracy.
It could be just the thing for those who need a nudge to start ticking items off their bucket list; scientists have developed a blood test that reveals how long a person has left to live.
The test draws on nine biomarkers found in the blood that can be used to calculate the biological age of a person’s body – that is, how old it seems from the way it functions, as opposed to how long it has been out of the womb.
Researchers at Yale University in Connecticut found that the test was a more accurate predictor of life expectancy than a person’s chronological age or any of the biomarkers individually.
Morgan Levine, a pathologist at Yale, said the test could be used to identify people who are ageing faster than normal, meaning they are at greater risk than expected of disease and an early death.
“We showed that even among people who have no diseases, who are presumably healthy, we can still pick up differences in life expectancy. It’s capturing something preclinical, before any diseases present themselves,” she said.
“It’s picking up how old you look physiologically. Maybe you’re 65 years old but physiologically you look more like a 70 year old, so your mortality risk is more like that of a 70 year old.”
The test does more than reveal who is ageing well and who is not. With the results in hand, doctors can see what is contributing most to a person’s rate of ageing and suggest lifestyle changes that might reduce it.
“The biggest advantage of this is now being able to say someone’s at high risk, and that they should come in regularly so you can make sure they’re not developing this or that disease. It’ll show you how can you reduce their risk because you can plug all the numbers in and see how the risk drops if they bring their glucose down, for example,” Levine said.
To create the test, the scientists looked at 42 different clinical measures, such as white blood cell count, glucose and albumin levels, that were recorded for people who took part in two large studies as part of the US National Health and Nutrition Examination Surveys (NHANES). The studies gathered people’s medical and lifestyle details and were linked to death records.
The scientists used information from 10,000 people in the first study, which ran from 1988 to 1994, to identify clinical measures that most strongly predicted life expectancy. From this work, the scientists developed a combined test based on nine biomarkers which they validated in 11,000 people who had taken part in the second study, which ran from 1999 to 2010.
The test calculates what the scientists call a ‘phenotypic age’, which reflects the biological rather than chronological age of a person’s body. If a person’s phenotypic age is greater than their chronological age, they are ageing faster than average, and vice versa.
Read the entire story by Ian Sampler in The Guardian Weekly.