The identification of new biomarkers for the early detection of increased risk of mortality remains an unmet need. There has been significant progress in establishing the epidemiology of novel blood biomarkers for all-cause and cause-specific mortality, such as serum neurofilament light chain,
1,2 N-terminal pro-brain natriuretic peptide,
3 retinol,
4 alpha tocopherol,
5 and beta carotene.
6 Despite this progress, simple, inexpensive, and reliable indicators are still essential for predicting mortality in clinical practice. At present, routine laboratory tests are widely used in primary care and hospitals, and further use of routine clinical biomarkers is expected. For example, several new biomarkers, such as the prognostic nutritional index, ratio of neutrophil to lymphocyte, and ratio of platelet to lymphocyte, were derived from routine laboratory tests. These simple integrated biomarkers showed significant associations with all-cause and cause-specific mortality in the general population.
7-9 Therefore, there is still substantial interest in the use of routine biomarkers to identify persons who are at risk for mortality.