The aim of this work was the analysis of blood and urine samples of shift working nurses. The obtained profiles of metabolomics and hormone will be used to identify biomarkers affecting the health of nurses. To verify changes of biomarker samples metabolomics and hormone profiles of nurses without shift work were gathered as comparison.
In this field study to determine indicators of stress through shift work, a total of 100 women of the BG Klinikum Bergmannsheil were examined in several day shifts. 75 subjects were examined for two consecutive working days during day shift and three consecutive working days during night shift. A comparison group of 25 women working only day shift completed the study protocol during two working days. Subjects were instructed to collect saliva samples at fixed times during the consecutive day study period. Furthermore, each participant donated spontaneous urine samples. In the saliva samples, the melatonin levels as the most important marker signal of circadian rhythm, as well as the levels of other relevant hormones cortisol and 17β-estradiol, were assessed. The metabolome was analyzed based on urine samples. Important individual factors were collected through interviews. The chronotype was determined during the first interview by means of the Munich Chronotype questionnaire for shiftworkers and subdivided into early, intermediate and late type. During the examination blocks, individual light exposure and sleeping behavior were further recorded. Light in different spectral regions (including blue light in the frequency range around 460 nm) was recorded every 10 seconds during the study days with shoulder-mounted instruments (LightWatcherTM).
Shift work and hormones:
The results obtained here describe for the first time the 24-h blue light exposure on working days with day and night shifts. The results indicate that not only the shift work, but also other factors influence the blue light exposure and thus together form the blue light day profile.
With regard to the "light-at-night" hypothesis, a marginal association between the nocturnal blue light exposure and the height of the melatonin peak in the first night shift can be observed.
Studies on the influence of shift work on cortisol awakening and the role of the chronotype were carried out for female shift workers. A significantly lower cortisol awakening response was observed for all shift workers in the night shift compared to the day shift.
A flattened cortisol awakening reaction was observed with night shift for both early, intermediate and late chronotypes. To what extent differences between shiftworkers and the control group can be seen is still being analyzed.
Shift work and metabolites:
No significant differences were observed in the day shifts metabolite profiles, when comparing nurses that are only working day shift and those that also work in night shift.
Comparing the metabolite profiles between day shift and night shift (within the night shift group), significant differences were observed for 34% of the used measured metabolites. Especially, in nurses with early chronotype, we observed that acylcarnitines altered significantly between day and night shifts, which indicate a strong impairment of the fatty acid oxidation due to the circadian disturbance. Furthermore, it can be seen that early and late chronotypes in the present study appear to be exposed to increased cellular stress during the night shift, whereas intermediate chronotypes are better able to cope with night shift activity.
Rabstein, S.; Burek, K.; Lehnert, M.; Beine, A.; Vetter, C.; Harth, V., Putzke, S.; Kantermann, T.; Walther, J.; Wang-Sattler, R.; Pallapies, D.; Brüning, T.; Behrens, T.: Differences in twenty-four-hour profiles of blue-light exposure between day and night shifts in female medical staff.
Sci. Total Environ. 653 (2019) pp. 1025-1033.
Hertel, J.; Rotter, M.; Frenzel, S.; Zacharias, H. U.; Krumsiek, J.; Rathkolb, B.; Hrabe de Angelis, M.; Rabstein, S.; Pallapies, D.; Brüning, T.; Grabe, H. J.; Wang-Sattler, R.: Dilution correction for dynamically influenced urinary analyte data.
Anal. Chim. Acta. 1032 (2018) pp. 18-31.
Rotter, M.; Brandmaier, S.; Covic, M.; Burek, K.; Hertel, J.; Troll, M.; Bader, E.; Adam, J.; Prehn, C.; Rathkolb, B.; Hrabe de Angelis, M.; Grabe, H.J.; Daniel, H.; Kantermann, T.; Harth, V.; Illig, T.; Pallapies, D.; Behrens, T.; Brüning, T.; Adamski, J.; Lickert, H.; Rabstein, S.; Wang-Sattler, R.:Night Shift Work Affects Urine Metabolite Profiles of Nurses with Early Chronotype. Metabolites 8 (2018) No. 3: p. 45.
Lehnert, M.; Beine, A.; Burek, K.; Putzke, S.; Schlösser, S.; Pallapies, D.; Brüning, T.; Behrens, T.; Rabstein, S.: Vitamin D supply in shift working nurses.
Chronobiol Int. 35 (2018) No. 5, p. 724-729.
Rotter, M.; Brandmaier, S.; Prehn, C.; Adam, J.; Rabstein, S.; Gawrych, K.; Brüning, T.; Illig, T.; Lickert, H.; Adamski, J.; Wang-Sattler, R.: Stability of targeted metabolite profiles of urine samples under different storage conditions.
Metabolomics 13 (2017) No. 1