August 20, 2019

expert reaction to study looking at mortality associated biomarkers in the blood

Research, published in Nature Communications, reports on biomarkers in the blood that may be able to help predict mortality risk.

Prof Kevin McConway, Emeritus Professor of Applied Statistics, The Open University, said:

“This is a solid and interesting piece of research. But it doesn’t go beyond investigating the plausibility of setting up a system for predicting risk of death, based on this type of data. It doesn’t claim to do more than that, and makes clear that there’s some way to go, in terms of further research and analysis, until a risk prediction tool that’s useable in clinical work with patients might emerge. One reason that these results can’t be used directly in clinical work is that the bioindicators involved weren’t measured on the same scale in the 12 cohorts (groups) of individuals that were studied. Instead, within each cohort the measurements were scaled in a way that depends on the pattern of values of the bioindicator in that cohort, and those scalings aren’t the same across the cohorts. The researchers make that clear, and it’s a reasonable thing to do in investigating the feasibility of using this kind of data, but it’s no good for clinical use where patients don’t belong to a specific cohort in the same way. Also, there’s some evidence that, for some of the biomarkers, the relationship between biomarker level and mortality differs from one cohort to another.

“There do seem to be some potential advantages in using metabolomic data like this in place of the biomarkers currently used, but to develop a clinically useable tool might require looking at some different indicators (because some aspects of the choice of indicators in a study like this are inevitably slightly arbitrary, and because different platforms for measuring such biomarkers provide different data), and further development will certainly require investigation of measurement scales for the biomarkers that don’t have such different definitions in different patient groups.”

Dr Amanda Heslegrave, Researcher, UK Dementia Research Institute, UCL, said:

“Biomarkers give us important insight into what’s happening in health and in disease, which is why we’re studying them in the context of dementia. In this new study, a number of the markers are validated and implicated in long term mortality and the authors suggest that more could be, which would be a worthwhile exercise. The large numbers in the study are good and also the fact that they have a large number for outcome – in this case mortality – makes the data more viable. However, it is limited by the fact that being only European data it may not apply to other ethnic groups without further studies.

“Whilst this study shows that this type of profiling can be useful, they do point out importantly that it would need further work to develop a score at the individual level that would be useful in real life situations. We’d need to see: validation to ensure repeatability in different labs, production of reference samples to test this on an ongoing basis, work to make the individual score possible, validation in other cohorts and validation of all components of the panel. So, it’s an exciting step, but it’s not ready yet.”

‘A metabolic profile of all-cause mortality risk identified in an observational study of 44,168 individuals’ by Deelen et al. was published in Nature Communications at 16:00 UK time on Tuesday 20^th August 2019. 

DOI: 10.1038/s41467-019-11311-9

Declared interests

Prof Kevin McConway: “Prof McConway is a member of the SMC Advisory Committee, but his quote above is in his capacity as a professional statistician.”

Dr Amanda Heslegrave: “No conflicts of interest.”