Alterations in Rev-ERBα/BMAL1 ratio and glycated hemoglobin in rotating shift workers: the EuRhythDia study

Objective To detect premature gluco-metabolic defects among night shift workers with disturbances in circadian rhythms. Design and methods We performed a hypothesis-generating, cross-sectional analysis of anthropometric, metabolic, lipid, and inflammation parameters, comparing active (a-NSW, n = 111) and former (f-NSW, n = 98) rotating night shift workers with diurnal workers (controls, n = 69). All participants were hospital nurses. We also evaluated the Pittsburgh Sleep Quality Index (PSQI) and assessed expression of transcription factors REV-ERB alpha and BMAL1 in peripheral blood mononuclear cells (PBMCs), as indicators of the molecular clock. Results Both a-NSW and f-NSW participants had significantly higher glycated hemoglobin (HbA1c) and white blood cell counts (WBC) (p < 0.001 for both), PSQI global score (p = 0.001) and diastolic blood pressure levels (p = 0.024) compared with controls. Expression of REV-ERB alpha/BMAL1 RNA in PBMC was significantly higher in a-NSW (p = 0.05) than in f-NSW or control participants. Multivariate regression analysis showed that working status and PSQI were independent determinants of higher HbA1c levels (p < 0.001). Conclusions We demonstrated that young, healthy night shift workers show subclinical abnormalities in HbA1c and changes in peripheral clock gene expression.

Automated summary

The study found subclinical abnormalities in premature gluco-metabolic defects and changes in peripheral clock gene expression among night shift workers. The Pittsburgh Sleep Quality Index and working status were identified as independent determinants of higher HbA1c levels.