Investigating the influence of shift work rosters on stress measured as cortisol in hair during the SARS-CoV-2 pandemic

The COVID-19 pandemic has increased the workload and has affected physical and mental health of many employees. Hair cortisol concentration (HCC) has proven useful as a marker for retrospective assessment of stress in epidemiological studies and was measured here in non-healthcare night-shift workers with standard shifts (8-h shifts) and extended shifts (12-h shifts) before and during the first wave of the COVID-19 pandemic in Germany. Results showed a twofold increase in HCC among shift workers during the first wave of the COVID-19 pandemic compared with previous measurements. Subjectively reported measures of psychosomatic stress were not found to be reliable predictors of HCC. No statistically significant HCC differences were found between rosters. Working 12-h shifts does not appear to be an additional stressor in the already demanding COVID-19 pandemic.