The new test it time-based; it can reveal whether it feels like 6 a.m. inside a person’s body and yet it’s 8 a.m. outside. Given that medical research now suggests that certain medications are best taken at certain times of the day – and this varies with different people – this insight could enable medics to appropriately dose medicines for maximum effectiveness based on a person’s circadian rhythm.
A circadian rhythm is an approximate twenty-four hour cycle in the physiological processes of living beings. Circadian rhythms are endogenously generated, although they can be modulated by external cues such as sunlight and temperature. It is this internal factor that can lead to misalignment.
There is a complexity with people, in that with some people their internal clocks are in alignment with the external environment; whereas with other people there is a mismatch. The new test seeks to understand the reason for misalignment. Misalignment is believed to be connected with conditions like heart disease and diabetes, and possibly also to neurodegenerative diseases.
The new blood test has been devised by Northwestern Medicine scientists. The test is called the ‘TimeSignature’, with the analysis based on two blood samples. Analysis of these reveals a person’s ‘body time’ as opposed to the ‘real time’.
Alternative test that seek to measure time differences between the body’s clock and the outside have been developed. However, these tests rely on multiple samples taken across many time points, a practice that renders such tests meaningless as a diagnostic tool.
The test measures 40 different gene expression markers in the blood. Analyzing the genetic information provide cues about circadian misalignment and diabetes, obesity, depression, heart disease and asthma.
With the new test analysis is undertaken through an algorithm. Northwestern aim to make the software freely available to other researchers, with the aim of using a wider pool of data to help to drive personalized medicine initiatives.
According to lead researcher, Dr. Rosemary Braun: “This is a much more precise and sophisticated measurement than identifying whether you are a morning lark or an night owl. We can assess a person’s biological clock to within 1.5 hours.”
The new research has been published in the science journal PNAS. The paper is titled “Universal method for robust detection of circadian state from gene expression.”
