Preliminary Study on the Effect of a Night Shift on Blood Pressure and Clock Gene Expression

Abstract

Night shift work has been found to be associated with a higher risk of cardiovascular and cerebrovascular disease. One of the underlying mechanisms seems to be that shift work promotes hypertension, but results have been variable. This cross-sectional study was carried out in a group of internists with the aim of performing a paired analysis of 24 h blood pressure in the same physicians working a day shift and then a night shift, and a paired analysis of clock gene expression after a night of rest and a night of work. Each participant wore an ambulatory blood pressure monitor (ABPM) twice. The first time was for a 24 h period that included a 12 h day shift (08.00–20.00) and a night of rest. The second time was for a 30 h period that included a day of rest, a night shift (20.00–08.00), and a subsequent period of rest (08.00–14.00). Subjects underwent fasting blood sampling twice: after the night of rest and after the night shift. Night shift work significantly increased night systolic blood pressure (SBP), night diastolic blood pressure (DBP), and heart rate (HR) and decreased their respective nocturnal decline. Clock gene expression increased after the night shift. There was a direct association between night blood pressure and clock gene expression. Night shifts lead to an increase in blood pressure, non-dipping status, and circadian rhythm misalignment. Blood pressure is associated with clock genes and circadian rhythm misalignement.

Mediation Mendelian randomisation study on the effects of shift work on coronary heart disease and traditional risk factors via gut microbiota

“…Approximately 19–25% of workers in most countries engage in JSW, especially night shifts [ 1 – 3 ]. Such jobs are among the most common external factors underlying disorganised circadian rhythms, which endogenously regulate behavioural and physiological activities over a 24-hour cycle and are crucial for maintaining health [ 4 ].…”

The Effect of Night Shift on Blood Pressure in Healthcare Workers

“…16 There is substantial evidence that disruptions caused by night-shift work in the circadian system lead to misalignment between the circadian system and the external light-dark cycle, as well as internal desynchronization within the circadian system. 17 Toffoli et al 18 demonstrated that night shifts enhance clock gene expression the following morning, indicative of circadian misalignment, with an independent link observed between night-time blood pressure and Period Circadian Regulator 2-3 (PER2-3) gene expression. Additionally, there is a study that demonstrates the correlation between reverse dipper status and electrocardiographic changes in newly diagnosed hypertensive patients.…”

Associations between long-term night shift work and incidence of chronic obstructive pulmonary disease: a prospective cohort study of 277,059 UK Biobank participants

“…Therefore, lower melatonin levels caused by disruption of circadian rhythm may be an important pathway that contributes to the observed associations. Additionally, circadian disruption induced by night shifts can disrupt the normal expression of clock gene expression, such as BMAL, CLOCK, PER1, PER2, and PER3 [46]. The oscillation and dysregulated expression of these clock gene expression have been reported to play a role in COPD pathogenesis, including chronic inflammation and imbalanced autophagy level [47].…”