Estimation of sleep recovery in shift working long-haul truck drivers – A heart rate variability based study
Pradhapan, Paruthi (2013)
2013
Master's Degree Programme in Biomedical Engineering
Tieto- ja sähkötekniikan tiedekunta - Faculty of Computing and Electrical Engineering
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Hyväksymispäivämäärä
2013-12-04
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tty-201312191513
https://urn.fi/URN:NBN:fi:tty-201312191513
Tiivistelmä
Prolonged work hours, shortened and irregular sleep patterns often leads to inadequate recovery in shift workers resulting in increased sleepiness or fatigue during the day. Heart rate and heart rate variability (HRV) have been often used in occupational health studies to examine sleep quality and recovery. The aim of the current study was to determine the factors affecting the recovery process in shift working long-haul truck drivers and to as-sess the impact different shifts have on the drivers’ sleep health.
Of the recruited volunteers, data collected from 38 volunteers (Age: 38.46 ± 10.89 years) satisfied the inclusion criteria for this study. Driver demographics and background questionnaires were obtained prior to measurements. R-R intervals and actigraphy data were collected for three intensive measurement days (non-night shift, night shift and lei-sure day) and subjective measures of sleep quality, recorded on the sleep-diary, were used for the analyses. Several time- and frequency-domain HRV indices were calculated in 10-minute segments and averaged on an hourly basis and for the entire duration of sleep. All tests for statistical significance was conducted on a within-subject basis.
Comparison of HRV indices over the entire sleep duration recorded on different in-tensive measurement days revealed no significant differences except for LF/HF ratio (Lei-sure day vs. Night shift, p <0.05). Sleep duration and efficiency were significantly lower on duty days. Regression analyses indicated VLF power was strong predictor of recovery and 31% of the outcome was influenced by explanatory factors. SDNN (r = 0.555, ad-justed r2 = 0.248, F(9, 92) = 5.166, p <0.001), RMSSD (r = 0.414, adjusted r2 = 0.131, F(9.92) = 4.229, p <0.05) and HF power (r = 0.460, adjusted r2 = 0.165, F(9.92) = 4.526, p <0.001) were significantly associated with age and sleep duration. Short-term variabil-ity indices, RMSSD and HF power, were moderately influenced by diurnal variations.
The results suggest that despite the fact that shift type does not have any direct con-sequences on sleep recovery, the odd work hours and irregular sleep schedules pose an indirect effect. The truncated sleep length, especially seen after night shift work, have been significantly associated with the impaired recovery and is contributed to by other short-term (diurnal variations) and long-term (ageing) factors. These results provide a basis for planning shift schedules such that direct or indirect manifestations of shift type-related influence on recovery are mitigated.
Of the recruited volunteers, data collected from 38 volunteers (Age: 38.46 ± 10.89 years) satisfied the inclusion criteria for this study. Driver demographics and background questionnaires were obtained prior to measurements. R-R intervals and actigraphy data were collected for three intensive measurement days (non-night shift, night shift and lei-sure day) and subjective measures of sleep quality, recorded on the sleep-diary, were used for the analyses. Several time- and frequency-domain HRV indices were calculated in 10-minute segments and averaged on an hourly basis and for the entire duration of sleep. All tests for statistical significance was conducted on a within-subject basis.
Comparison of HRV indices over the entire sleep duration recorded on different in-tensive measurement days revealed no significant differences except for LF/HF ratio (Lei-sure day vs. Night shift, p <0.05). Sleep duration and efficiency were significantly lower on duty days. Regression analyses indicated VLF power was strong predictor of recovery and 31% of the outcome was influenced by explanatory factors. SDNN (r = 0.555, ad-justed r2 = 0.248, F(9, 92) = 5.166, p <0.001), RMSSD (r = 0.414, adjusted r2 = 0.131, F(9.92) = 4.229, p <0.05) and HF power (r = 0.460, adjusted r2 = 0.165, F(9.92) = 4.526, p <0.001) were significantly associated with age and sleep duration. Short-term variabil-ity indices, RMSSD and HF power, were moderately influenced by diurnal variations.
The results suggest that despite the fact that shift type does not have any direct con-sequences on sleep recovery, the odd work hours and irregular sleep schedules pose an indirect effect. The truncated sleep length, especially seen after night shift work, have been significantly associated with the impaired recovery and is contributed to by other short-term (diurnal variations) and long-term (ageing) factors. These results provide a basis for planning shift schedules such that direct or indirect manifestations of shift type-related influence on recovery are mitigated.