Long-term night shift work leads to changes in the expression of circadian rhythm genes in women and weakens their systemic coordination, according to a study published in the journal Frontiers in Endocrinology, as reported by infohub.kz.
The cross-sectional study involved 93 female healthcare workers aged 37 to 66. The volunteers were divided into two groups: 47 worked exclusively day shifts, while 46 had regular night work experience, with 57% of them having worked more than 1,000 night shifts over their careers.
The authors analyzed fasting morning blood samples using RT-PCR to assess the expression levels of the CLOCK, TEF, PER1, PER3, and YY1 genes. The analysis showed that women working nights had significantly lower expression levels of CLOCK, TEF, PER1, and YY1 compared to their day-shift colleagues. The only gene without significant changes in level was PER3, but connections within its network also underwent transformation.
The researchers found that TEF and YY1 gene indicators decreased most strongly with longer night work experience and a higher total number of shifts. Additionally, night workers showed weakened overall systemic coordination among circadian regulatory genes.
The scientists emphasize that these results require further longitudinal studies to understand whether these changes are reversible and how exactly they affect long-term health risks.