Scientists from Kiel and Odense/Denmark are currently jointly researching the influence that working shifts, the quality of sleep and nutrition has on metabolic disorders and gene activity. The Department of Human Biology in the Zoological Institute at Kiel University, the Institute of Human Genetics at the University Medical Center Schleswig-Holstein, Campus Kiel and the University of Southern Denmark in Odense are participating in the new project: “Sleep, work and their consequences for human metabolic disorders”. The researchers are receiving support amounting to EUR 730,000 over a period of three years from the European Union as part of the INTERREG 4A South Denmark-Schleswig-K.E.R.N. programme, using funds from the European Regional Development Fund. The long-term objective of this study is to develop preventative measures in order to reduce the risk of metabolic and sleep disorders developing in future.
People who work shifts are not able to comply with the natural sleep/wake rhythm based on the cycle of day and night. Their internal body clock becomes unbalanced. The consequences of this can be a variety of metabolic disorders which, on a long-term basis, can be accompanied by a range of illnesses, psychological disorders and even the inability to work. In order to be able to investigate the extent of the changes to the human body and its cells which result from shift work, pairs of twins from Denmark are being examined using molecular-biological methods. From each pair, one twin works shifts. According to the Kiel human geneticist, Dr. Ole Ammerpohl, “The advantage of examining identical twins is that both are practically genetically alike and the effects of lifestyle can be identified more easily. That is why it is essential to work together with the national Danish twins register, which has been analysing twins with regard to medical and professional aspects for many years.”
The effects of working shifts may well be far more fundamental than previously assumed. They may have a direct impact on our genetic make-up and the genes contained within this material. “Gene activity is controlled by small switches on the DNA, known as DNA methylation”, explains Ammerpohl. “This DNA methylation adjusts to suit changes in environmental conditions and can even be passed on to subsequent generations.”
Alongside shift work itself, nutritional and sleeping patterns also aid the development of metabolic disorders. Therefore the project does not only include DNA methylation and genetic variations, it also covers the twins’ nutritional behaviour, the quality of sleep obtained as well as hormone and blood counts (blood sugar, blood lipids, etc.). For example, whether the levels of the stress-hormone “cortisol” change in people as a result of working shifts is being tested. All the features mentioned above are placed in relation to each other at the university in Odense and evaluated using special mathematical models.
Right up until a few generations ago, people got up at daybreak and went to bed when it got dark. “In order to adjust to this, our bodies have evolved over centuries to develop a sophisticated system of transmitters which control the sleep-wake cycle and enable the body to regenerate sufficiently”, explains Professor Manuela Dittmar from Kiel University. However, over the last few decades our lifestyles have changed drastically. Working hours are no longer based on how long the day lasts. “More and more people are required to work shifts. The consequences for those affected include a higher incidence of typical civilisation diseases right up to burn-out syndrome and early disability”, according to Dittmar.
Source: Christian-Albrechts-Universitaet zu Kiel, AlphaGalileo Foundation.