Test may some day predict five-year risk of death
(CNN) — Will you be alive five years from now? New research suggests it might be possible to predict if you’ll die from a medical condition in the next half-decade.
How, you ask? With a simple blood test.
According to a recent study published in the journal PLOS Medicine, if your blood registers high levels of four “biomarkers,” biological molecules found in your blood, body fluids, or tissues, you are at a substantially higher risk of dying in the next five years.
Researchers from Finland and Estonia followed more than 17,000 people between the ages of 18 and 103 to determine causes of death, tracking them in what is called a prospective cohort study. The researchers first looked at more than 100 components of blood taken from the Estonian group. They found that high levels of four different molecules (naturally present in everyone’s blood) — albumin, alpha-1-acid glycoprotein, citrate and very low-density lipoprotein particles — predicted imminent death.
In the Estonian group, for instance, 288 people who died during the five-year study period tested in the top 20% for presence of these four molecules, while only 15 people died who tested in the bottom 20%. The researchers found that those who were tested in Finland faced similar risks when these biomarkers were elevated. These predictors remained unchanged even after researchers factored out both genetic predispositions and lifestyle choices such as age, weight, tobacco and alcohol use, cholesterol levels and pre-existing illness.
While all of the four biomarkers were associated with frailty and onset of illness, only one, alpha-1-acid glycoprotein, had previously been associated with deaths from all causes, mainly for the elderly. No individual biomarker currently exists to test an individual of any age if they are at risk of ill health in general. The discovery of this combination of four biomarkers suggests the possibility of eventually creating such a test.
But a lot of work remains to be done. Researchers now have to figure out why these biomarkers are linked and how a test like this could be helpful for doctors and patients. According to Dr. Johannes Kettunen, one of the lead authors of the study, a general test for risk of dying may become an important means of identifying high-risk asymptomatic people so that they can be referred for more specific screening procedures.
“If we can identify people who appear healthy, but actually are at high risk for developing severe disease, then we may – in the future – be able to act to cure their looming disease state,” Kettunen argues. “This could eventually open a window for prolonged prevention, and hopefully extend the life span.”
Critics say a general test for mortality like this may cause as many problems as it solves. Dr. Daniel Callahan, a biomedical ethicist and former president of the Hastings Center, an independent bioethics research institute, says this type of screening would likely catch the attention of patients and doctors alike. But it could also be a source of a lot of anxiety, particularly if the condition the test indicates cannot be reversed or treated.
“I could see lots of problems at the clinical level to explain to the patients what to do with something like this.” Callahan says.
It could raise issues surrounding insurance coverage.
Given these concerns, Kettunen predicts that this kind of test will only be accessible to the public once treatments for those who are at high risk are available.
“If we can uncover the mechanisms and come up with some effective treatment strategies, then I believe they could be part of patient screening — in a similar fashion as blood cholesterol is now used,” he said.
So don’t obsess too much over your annual blood tests just yet; more research is needed.