Job strain and vagal recovery during sleep in shift working health care professionals

Abstract

Within sample female nurses/nurse assistants in three shift work, we explored the association of job strain with heart rate variability before and during sleep. The participants (n = 95) were recruited from the Finnish Public Sector Study, from hospital wards that belonged either to the top (high job strain [HJS], n = 42) or bottom quartiles on job strain (low job strain [LJS], n = 53) as rated by Job Content Questionnaire responses. A further inclusion criterion was that participants' own job strain was at least as high (HJS group) or low (LJS group) as their ward's average estimation. Three-week field measurements included sleep diary and actigraphy to study the participants' sleep patterns and sleep–wake rhythm. A subset of three pre-selected, circadian rhythm and recovery controlled measurement days, one morning shift, one night shift and a day off, included 24-h heart rate variability (HRV) measurements. The bootstrapped HRV parameters (HR, HF, LF, LF-to-HF-ratio and RMSSD) 30 min before and during 30 min of sleep with lowest average heart rate showed no statistically significant job strain group differences. No association of exposure to stressful work environment and HRV before and during sleep was found.

• Heart rate variability
• night shift work
• nursing
• work-related stress

Acknowledgements

We thank Elise Koskenseppä for the subject recruitment, Sirkku Hopeakangas for the collection of blood samples, Nina Lapveteläinen and Riitta Velin for arranging the field measurements and Jaana Pentti, Hanna Kaisa Hyvärinen and Pertti Mutanen for statistical support.

Notes

*This manuscript is submitted for Shiftwork2013 – Special Issue of Chronobiology International.

¹In Finland, to graduate as a nurse you must complete a three and a half-year (210 ECT credits) bachelor’s degree after either high school or the nursing assistants’ degree. A nursing assistant’s degree is a 3-year course after comprehensive school.