A blood appearance can give doctors a lot of information about their patients' health. Even the biological risk of dying in the coming years could be read on the basis of this body fluid, as researchers now report. They identified 14 blood biomarkers that should do just that. For example, predictions based on these biomarkers can assist physicians and patients in making treatment decisions. However, such a blood test is still far from being used in practice.
"One is as old as it feels," says the well-known proverb – and there is indeed a true core to this statement. Because it does not always reveal the date of birth, how fit and physically young the man is. Especially in older people, the calendar age usually says little about the state of health or life expectancy. In this respect, biological indicators are far more meaningful than looking at numbers: for example, blood pressure, body mass index (BMI), but also products of the breakdown of blood metabolism. But can such biomarkers predict reliably how many people will survive the years to come? And if so, with what?
14 blood biomarkers
These questions are now addressed to Joris Deelen of the Max Planck Institute for the Biology of Aging in Cologne and his colleagues. For their study, the researchers analyzed the metabolic data from the blood of 44,168 subjects who participated in long-term scientific research and were initially between 18 and 109 years old. 5,512 people involved died during the study period. Would a link be discovered between the remaining life span and certain substances in the blood? In fact, the evaluations showed that a set of 14 biomarkers appeared to be associated with the mortality of the subjects – including amino acids, lipid levels and inflammatory parameters.
As scientists indicate, based on these indicators and gender, it is surprisingly easy to predict the likelihood that a person will die within the next five to ten years. This has to do with the biological risk of death – death from an infection by a fatal infectious disease or a car accident cannot be predicted that way, of course. Interesting about the results: Predictions based on this metabolic profile appear to be more accurate than previously available indicators. This applies to both men and women and to age groups. According to Deelen and his team, the biomarkers now identified could in the future be, among other things, appropriate for risk assessment in the context of therapeutic decisions. For example, is the elderly too fragile for invasive surgery? Should a still very old patient be treated or is palliative treatment only?
However, there is still a long way to go before blood tests can help doctors and patients make decisions in these situations, as Florian Kronenberg of the University of Innsbruck points out: But before any clinical application, it is imperative that further studies be conducted in a controlled manner to evaluate the pros and cons of prediction. "Algorithms that allow physicians to predict the predictive power of data should also be tested for blood use.
The inevitable question is the ethical consequences of such a test: “How do we prevent association with a statistically analyzed high-risk biomarker group that leads to patient discrimination? And who shares this risk and its importance with the individual patient? "It can be daunting if the algorithm decides therapies," says Kronenberg. "But even today, decisions are always made in medicine, mostly based on relatively little data." better biomarkers could make medical forecasts more accurate in the future, though never 100% accurate.
Source: Joris Deelen (Max Planck Institute for the Biology of Aging, Cologne) et al., Nature Communications, doi: 10.1038 / s41467-019-11311-9