Time of medical tests impacts results

The time of day and sleep deprivation have a significant effect on your metabolism, says a new research.

The finding could be crucial when looking at the best time of day to test for diseases such as cancer and heart disease, and for administering medicines effectively.

"Our results show that if we want to develop a diagnostic test for a disease, it is imperative to take the time of day when taking blood samples into account, since this has a significant effect on metabolism," said professor Debra Skene from the University of Surrey in Britain.

"This is also the key for administering medicines and determining when they will be at their most effective.

"Of course, this will have to be considered on a case-by-case basis, since many people such as shift workers will have a different sleep/wake cycle and timings will need to be adapted to their body clocks," Skene added.

The researchers investigated the links between sleep deprivation, body clock disruption and metabolism and discovered a clear variation in metabolism according to the time of day.

Healthy male volunteers were put in an environment where light, sleep, meals and posture were controlled.

Researchers collected blood samples every two hours to show how metabolic biomarkers change during the day.

The results showed that metabolic processes are significantly increased during sleep deprivation.

The study appeared in the journal Proceedings of the National Academy of Sciences.