The Fascinating Science Behind the ‘Death Test’
New research shows that a blood test could potentially tell you if you are at risk of dying in the next few years. The aim is not to be a harbinger of doom but create an early warning test the likes of which could potentially revolutionize medicine.
The study behind this research, published in the scientific journal PLOS Medicine, saw Finnish and Estonian researchers identify four chemicals and the specific levels of those chemicals that appear to be present in the body when death is relatively near.
This study, the first of its kind, purports to give us a glimpse of the so-called biomarkers, a molecule found in blood, body fluids or tissues of the body, that can flag up something abnormal, for instance the precursors of cancer or cardiovascular disease, or even more exotic causes of death.
The study is being treated as a serious potential advancement, albeit in the very early stages, because of the number of test subjects that were involved and the strong results the researchers were able to obtain. Here’s more about the so-called “death test.”
How Did Scientists Develop the “Death Test?”
Researchers compiled data from 9,482 blood samples collected from Estonians aged between 18 and 101. These samples were then put through a scan that employs nuclear magnetic resonance spectroscopy (NMR spectroscopy). An NMR spectroscopy is most commonly used to investigate the properties of organic compounds, to understand their composition and discover their properties. By using this technique, the scientists were able to identify 106 biomarkers that were common among the entire sample.
Over a follow up period of five years, 508 members of the sample unfortunately died. The researchers then dug deeper to evaluate the biomarkers and the levels of those biomarkers present in both groups, the living and the now deceased, looking for the things that those who died shared that those who were still living either didn’t have or didn’t have in the same quantities.
In this way, the researchers were able to find that four biomarkers were unusually common among the group of subjects who died and far less common in the rest of the sample that lived. These biomarkers were albumin, alpha-1-acid glycoprotein, citrate and lipoprotein particles.
The researchers then used a further statistical analysis to check for other things that might have contributed to an individuals’ death, like age, weight, substance use/abuse and pre-existing conditions like diabetes or cancer. They found that the link between the four biomarkers and risk of death within five years remained the same even by introducing those factors as controls.
Wanting to see just how far they could take this, the researchers then devised what they called a biomarker score. If someone had all four biomarkers they scored the highest amount, two led to a score of 50%, and none gave them a score of zero. The biomarker scores provided strong predictors for those at short-term risk of dying. In fact, those who had a top biomarker score were almost 19 times more likely to die than those in the bottom 20%.
The researchers again attempted to control for pre-existing conditions like diabetes and cancer and so removed all those in the sample whom they knew to have medical problems. The biomarker tests in this so-called validation group of seemingly perfectly healthy people also demonstrated similar predictive strengths.
‘What is especially interesting is that these biomarkers reflect the risk for dying from very different types of diseases such as heart disease or cancer. They seem to be signs of a general frailty in the body,” researcher Johannes Kettunen, of the Institute for Molecular Medicine in Finland, is quoted as saying about the result.
Why Could the Death Test be Important?
This study had several limitations, and we have to qualify what the study does and doesn’t show.
Putting aside the technical limitations of NMR spectroscopy and the fact that the study groups were both from northern European areas, both of which could be explored in future studies, the first very important thing to note is that the study doesn’t prove a connection between the biomarkers and death. That is to say there’s no evidence these biomarkers necessarily predict death, there’s just a reasonably strong correlation. The study also gives us no insight into what triggers an accumulation of these biomarkers or why they might predict death.
Unfortunately, the research can’t at this time give us a way to intervene to stop the increased chance of death these four biomarkers seem to predict, either. Yet, this is where the study is important. The observations the researchers were able to gather about the possible predictive power of the biomarkers opens up new and exciting avenues of research for future investigation.
For instance, there may be other biomarkers this test couldn’t find due to its limitations. If found, those additional biomarkers would increase the predictive power of the biomarker test and allow for greater accuracy. Researchers might find, for instance, that certain combinations of biomarkers predict specific, potentially fatal, diseases like cancers, but the initial research suggests that these biomarkers are general indicators of the body knowing something is wrong rather than being disease-specific — whether probing deeper can allow for greater nuance remains to be seen.
As is apparent, the blood “death test” is still a long way away from being a market-ready product, but ultimately the hope is it could be used to help doctors identify rising levels of biomarkers as part of a routine medical even before someone has any symptoms. In effect, before they even feel ill. Then, patients could be given what would likely be less aggressive forms of life saving medicine, like chemotherapy, to prevent a fatal disease manifesting.
So, while a number of mainstream media sites are asking the question “Would you take the death test?” it’s fairly obvious the question should be, “Why wouldn’t you?”
Photo credit: Thinkstock.