What time does your body think it is?

Some of us are night owls who just can’t seem to become morning people… We all have different internal body clocks – our circadian clocks – and these control many physiological processes such as our sleep-wake cycles and digestive activities.

Now, researchers have developed a quick and easy way to estimate your internal body time, which could help optimize drug delivery and food intake for your personalized medical treatment.

Called ‘chronotherapy,’ drug delivery based on body time maximizes drug potency while minimizing toxicity. Timing a course of chemotherapy to the internal body time of cancer patients, for example, can improve treatment efficacy and reduce side effects. It can also help time-restricted diets reduce the risk of weight gain and metabolic diseases.

“Usually personalized medicine is focusing on genetic differences, but there are also temporal differences [among patients],” says study researcher Hiroki Ueda of RIKEN Center for Developmental Biology. “That will be the next step in personalized medicine.”

1. They measured the abundance over 50 blood metabolites, such as hormones and amino acids, those byproducts from biological activity.
2. They did this for several healthy people over 1.5 days.
3. Then, they developed a ‘molecular timetable’ using the circadian oscillations of the metabolites.
4. This reference metabolite timetable allowed them to accurately detect an individual’s body time with only 2 blood samples drawn 12 hours apart. (Current methods require hourly sampling, along with constant tracking of melatonin levels.)

Pictured: In the conventional method, a single indicator monitored over a few days detects internal body time. In the molecular timetable method, multiple metabolic flowers are simultaneously measured at a few time points, reducing efforts in sampling.

The study was published in Proceedings of the National Academy of Sciences yesterday.

[Via ScienceNOW]

Image: T. Kasukawa & M. Sugimoto et al., PNAS