Researchers have developed a new simple blood test that can tell the time in your body which might be very different from the time showing on the clock on the wall. The study was published in the Proceedings of the National Academy of Sciences.

Previously, measurements this precise could only be achieved through a costly and laborious process of taking samples every hour over a span of multiple hours. The new test, called TimeSignature, requires only two blood draws.

This is a much more precise and sophisticated measurement than identifying whether you are a morning lark or a night owl. We can assess a person’s biological clock to within 1.5 hours. Various groups have tried to get at an internal circadian time from a blood test, but nothing has been as accurate or as easy to use as TimeSignature.

In Sync, Out Of Sync

Processes in nearly every tissue and organ system in the body are orchestrated by an internal biological clock, which directs circadian rhythm, such as the sleep-wake cycle. Some individuals’ internal clocks are in sync with external time, but others are out of sync and considered misaligned.

The new test will for the first time offer researchers the opportunity to easily examine the impact of misaligned circadian clocks in a range of diseases, including heart disease, diabetes, and Alzheimer’s disease.

When the blood test becomes clinically available, it also will provide doctors with a measurement of an individual’s internal biological clock to guide medication dosing at the most effective time for his or her body.

Physiological Time

The software and algorithm are available for free to other researchers so they can assess physiological time in a person’s body. Northwestern has filed for a patent on the blood test. This is an integral part of personalized medicine. So many drugs have optimal times for dosing.

Knowing what time it is in your body is critical to getting the most effective benefits. The best time for you to take the blood pressure drug or the chemotherapy or radiation may be different from somebody else.

Time Is Everything

The scientists then developed a machine-learning method that they used to train a computer to predict the time of day based on patterns in these gene expression measurements. Out of about 20,000 genes researchers measured, these 40 emerged with the strongest signal.

Circadian Rhythm

Timing is everything, they know if you have disruption of your internal clock, it can predispose you to a range of diseases. Virtually every tissue and organ system are governed by circadian rhythm.

Preclinical research by scientist Joe Bass, chief of endocrinology, metabolism, and molecular medicine previously identified a link between circadian misalignment and diabetes, obesity, depression, heart disease, and asthma.

Circadian Rhythm

Circadian timing is a modifiable risk factor for improving cognitive health, but if we can’t measure it, it’s difficult to know if we’ve made the right diagnosis.