Day or night person Individual biorhythm measurable by blood test

Blood test allows you to read the internal clock

Our internal clock determines the individual biological rhythm and has far-reaching influence on bodily functions. With a new blood test, scientists are now able to objectively determine the status of a patient's internal clock for the first time. This could also lead to improved therapeutic success, since, for example, the time of taking the medication can be adjusted to this.

The individual biological rhythm causes daily fluctuations in the various body functions, which can also influence the success of therapeutic measures. However, an objective determination of the patient's internal clock has not been possible so far. Here is the new blood test remedy. The international research team led by Professor dr. Achim Kramer from the Institute of Medical Immunology at the Charité has identified certain biomarkers in the blood that make it possible to read the internal clock. Their findings were published in the journal "The Journal of Clinical Investigation".

Our internal clock has a significant influence on body functions and can also influence the effect of medication. Scientists have now developed a blood test that allows them to read the internal clock. (Image: contrastwerkstatt / fotolia.com)

Daily variations in body functions

The distinction between larks and owls describes the difference between people who are more active early in the day and go to bed earlier, as well as people who tend to be late risers and stay awake in the evening or at night. This is controlled by our internal clock. It requires individual variations of the functions of the human body during the day. As a result, "depending on the internal clock, for example, medications have different effects - depending on the time they are taken," explain the experts at the Charité.

Different effects of the drugs

Thus, the effect of the medication may vary from person to person, depending on whether his internal clock tends to late type or early type, so whether the person is more of an owl or a lark, the researchers report. An exact determination of the individual biological rhythm would therefore have great advantages for the therapy. With the aid of so-called chronotherapy, medicines as a whole could be used more effectively and more tolerably than before, explain the experts.

Biomarkers show the status of the biorhythm

The international research team led by Prof. dr. In the current study, Kramer first determined the activity of all 20,000 genes in a specific group of blood cells in several subjects throughout the day, according to the Berlin Charité. With the help of special computer algorithms, they were able to determine twelve genes from these datasets that reliably indicate the inner time. They identified biomarkers in the blood that are characteristic of the individual's indoor life. In this case, the biomarkers of a single blood sample can still distinguish a delayed type from an early type, if the person is awakened against their biological rhythm early in the morning by an alarm clock, reports the Charité on.

Chronotherapy rarely used

So far chronotherapy has rarely been used, taking into account the time of day because of a lack of internal diagnosis, reports Prof. Kramer. However, the expert was convinced that chronotherapy is often superior to conventional therapy. "We think that this first objective in-home test will help to make the time of day in therapy and diagnosis much more important," emphasizes the study leader.

Optimization of the treatment

In clinical follow-up studies, scientists are now planning a review of the effectiveness of personalized chronotherapy. For this purpose, the therapy will be tailored to the individual indoor time of the patients, explain the experts. If the time window is known in which a drug is particularly effective, the effect of the treatment can be optimized and at the same time the risk of side effects can be reduced, the researchers continue. (Fp)