Influence of Night Shift Work on Psychologic State and Cardiovascular and Neuroendocrine Responses in Healthy Nurses

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Author(s)

    • MUNAKATA Masanori
    • Division of Hypertension and Cardiology, Tohoku University Graduate School of Medicine
    • ICHII Satoko
    • Department of Behavioral Science, Tohoku University Graduate School of Medicine
    • NUNOKAWA Tohru
    • Division of Hypertension and Cardiology, Tohoku University Graduate School of Medicine
    • SAITO Yuki
    • Department of Behavioral Science, Tohoku University Graduate School of Medicine
    • ITO Nobuhiko
    • Division of Hypertension and Cardiology, Tohoku University Graduate School of Medicine
    • FUKUDO Shin
    • Department of Behavioral Science, Tohoku University Graduate School of Medicine
    • YOSHINAGA Kaoru
    • Division of Hypertension and Cardiology, Tohoku University Graduate School of Medicine

Abstract

Night shift work has often been associated with increasing degree and frequency of various psychologic complaints. The study examined whether psychologic states after night work are related to adaptive alterations of the cardiovascular and neuroendocrine systems. We studied 18 healthy nurses (age 29±2 years) engaged in a modified rapid shift rotation system (day work, 8:15-17:15; evening work, 16:00-22:00; night work, 21:30-8:30). Blood pressure, heart rate, RR interval variability (L/H and HF power spectrum for sympathetic and vagal activities), and physical activity were measured using a multibiomedical recorder for 24h from the start of work during the night and day shifts. Plasma ACTH and cortisol concentrations were measured at the end of each shift and at 8:30 AM on a day of rest. Each subject’s psychologic state was assessed using a validated questionnaire. Among the parameters measured, scores for confusion, depression, anger-hostility, fatigue and tension-anxiety were highest, and scores for vigor lowest, after a night shift. Systolic blood pressure and heart rate during work were lower during night shift than during day shift (119±2 vs. 123±1mmHg, <I>p</I><0.05 and 75±1 vs. 84±2bpm, <I>p</I><0.001, respectively). Both parameters were lower still (<I>p</I><0.005 and <I>p</I><0.05) when measured outside of the hospital under waking conditions following a night shift than following a day shift, even though the levels of physical activity were similar. The HF power spectrum of RR interval variability was greater not only during work (24.2±2.1 vs. 18.5±1.8ms, <I>p</I><0.005) but also during the awake period (29.1±2.5 vs. 24.4±2.6ms, <I>p</I><0.005) after the night shift compared with the day shift. Plasma ACTH and cortisol concentrations were lower after night work than in the day of rest(7.3±1.2 vs. 11.5±2.3pg/ml, <I>p</I><0.1 and 11.1±1.1 vs. 14.4±1.1mg/dl, <I>p</I><0.05). Systolic and diastolic blood pressures during night shift work and the subsequent awake period correlated positively with scores for vigor and negatively with scores for confusion (<I>p</I><0.05). Plasma ACTH and cortisol concentrations did not correlate with any psychologic scores. We conclude that psychologic disturbances after night work were associated with altered cardiovascular and endocrine responses in healthy nurses. Some of the psychologic complaints may be attributable to lower waking blood pressure. (Hypertens Res 2001; 24: 25-31)

Journal

  • Hypertension Research

    Hypertension Research 24(1), 25-31, 2001-01-01

    The Japanese Society of Hypertension

References:  26

Cited by:  3

Codes

  • NII Article ID (NAID)
    10008741907
  • NII NACSIS-CAT ID (NCID)
    AA10847079
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    09169636
  • Data Source
    CJP  CJPref  J-STAGE 
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