Blood tests for diseases: Scientists say a massive new analysis of blood chemistry could eventually make it possible to spot the early signs of major diseases more than a decade before symptoms appear, using just a small pinprick of blood.
The work builds on what researchers describe as the world’s largest study of key substances circulating in the bloodstream. As part of the project, UK Biobank has measured levels of nearly 250 different proteins, sugars, fats and other molecules in blood samples collected from half a million volunteers across the UK.
These detailed “metabolic profiles” give a snapshot of how each person’s body is functioning at a given point in time. When researchers match this information with medical records and death data, they can begin to see patterns that predict who is more likely to go on to develop conditions such as diabetes, heart disease, cancer and dementia.
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“It’s going to be a real gamechanger for our work,” said Dr Joy Edwards-Hicks from the University of Edinburgh, who studies how changes in blood metabolites affect the immune system. She believes more accurate predictive tests will help shift healthcare towards preventing illness, not just treating it once it appears.
“It fits with the model of prevention that we are moving towards, to be able to send off a little pinprick blood sample and get an idea of your health,” she said. “If we have early predictors of disease, we can tell someone in their 40s that their biomarkers are not looking good for their age and advise on changes they could make.”
To build the new dataset, UK Biobank worked with Finnish company Nightingale Health to quantify hundreds of metabolites in stored blood samples. These include sugars, amino acids, different types of fats, hormone precursors and waste products such as urea. These molecules are produced and used as the body digests food and medicines, generates energy, repairs tissues and supports normal organ function.
When an organ begins to fail, the metabolic pattern can shift in recognisable ways. A struggling liver can lead to raised ammonia levels. Impaired kidneys may cause urea and creatinine to rise. Muscle breakdown can show up as elevated lactate. In many cancers, glucose usage increases as tumours grow.
Importantly, metabolic profiles are shaped not only by a person’s genes but also by their lifestyle and environment. Diet, exercise, pollution, stress and other factors all leave a chemical fingerprint in the blood.
“These metabolic profiles capture all of the genetic predisposition and the downstream consequences of that, as well as the environmental exposures, so it gives us a snapshot of a person’s physiological state,” said Dr Julian Mutz of King’s College London. “It’s also highly dynamic, whereas genetics, for example, is fixed.”