Short rest between shifts and risk of hypertension in hospital workers

Objectives: Shift work is related to hypertension and other cardiovascular diseases, and short shift intervals of less than 11 h (quick returns) are reported to be related to health problems, including sleep disturbance and fatigue. However, its cardiovascular effect has rarely been examined. The purpose of this study was to investigate the relationship between quick returns, consecutive night shifts, and risk of hypertension in hospital workers. Methods: Data collected from a medical examination of 1372 nonhypertensive shift workers in a hospital were retrospectively followed up. Demographic factors (sex and age), lifestyle habits (smoking, alcohol use, exercise, and obesity), and work-related factors (working hours, shift work experience, consecutive night shifts, and quick returns status) were included in the analyses. Multivariate Cox proportional-hazard models were conducted to estimate hazard ratio and 95% confidence interval (CI). Results: The findings showed that quick returns was related to an increased risk of hypertension (hazard ratio, 95% CI: 1.88, 1.00-3.54), whereas consecutive night shifts were not. However, the risk of hypertension was significantly higher in workers with quick returns and 2-3 days of consecutive night shifts (3.33, 1.18-9.39) and those with quick returns and at least 4 days of consecutive night shifts (3.79, 1.22-11.76), compared with the reference group. Conclusion: The findings of this study indicate that short shift intervals and consecutive night shifts are related to an increased risk of hypertension in shift-working hospital workers.