Korean J Occup Environ Med.  2001 Jun;13(2):180-189.

Influence of Shiftwork Duration on Blood Pressure and Heart Rate Variability in Short Rotating 8-hour Shiftworkers

• Ha MN
• Kim JY
• Park JS
• Chung HK

Abstract

OBJECTIVES
This study was performed to investigate the chronic health effect of shiftwork on cardiovascular system.
METHODS
We checked blood pressure(BP) and heart rate variability(HRV) at every shift on 134 male workers whose shift type was 8-hour and short rotating of 3 days shift interval. As confoundings, job stress was measured by Karasek's JCQ 49 items questionnaire and circardian type was assessed by morningness-eveningness questionnaire. Smoking and alcohol drinking habit, marital status and past medical history were also acquired. We used the method of repeated measured data analysis with mixed model to show the association between shiftwork duration and BP or HRV.
RESULTS
Average age of workers was 29 years olds(range 25~44). Among them, 77.9 % were current smokers, 50 % were the passive type of job strain in Karasek's model. Mean shiftwork duration was 5.21 years(range 5.4 months~10 years). In circadian type, no one was definitely morning type or definitely evening type. In multivariate analyses adjusted by age, job strain, shift, circadian rhythm and smoking, blood pressure were showed significantly increasing trends according to shiftwork duration in both systolic and diastolic(p<0.05). Heart rate variability were also showed significantly decreasing trends according to shiftwork duration in both parasympathetic and sympathetic functions(p<0.05).
CONCLUSIONS
The results of this studs suggests the chronic negative health effect of shiftwork on cardiovascular system.

Keyword

Shiftwork; Chronic health effect; Blood pressure; Heart rate variability

MeSH Terms

Alcohol Drinking
Blood Pressure*
Cardiovascular System
Circadian Rhythm
Heart Rate*
Heart*
Humans
Male
Marital Status
Multivariate Analysis
Questionnaires
Smoke
Smoking
Statistics as Topic
Smoke