Abstract

Background: Altered circadian rhythm for sleep-wakeful cycle is seen in shift work, leading to sleep deprivation which may affect the cardiac autonomic nervous system (ANS). In the past two decades, a significant relationship has been established between impaired ANS activity and cardiovascular mortality. This effect is not addressed in workers working in both shifts.

Aims and Objectives: This study aims to assess sleep quality and heart rate variability (HRV) before and after day and night shift work.

Materials and Methods: A total of 140 healthy male workers aged between 24 years and 45 years working in alternate weekday and night shift at least for more than 2 years in automobile factory. Procedure: Before and after both day and night shifts sleep quality were noted by Pittsburgh Sleep Quality Index along with HRV parameters such as mean RR interval (mRRI) and low-frequency power/high-frequency power (LF/HF).

Results: Global score was statistically increased with reduced mRRI and increased LF/HF after night shift.

Conclusion: Reduced sleep quality and HRV may reflect sympathetic excitation and further leading to increased risk for cardiovascular diseases among the shift workers.

Key words: Shift Work; Sleep Quality; Pittsburgh Sleep Quality Index; Heart Rate Variability; Sympathoexcitation