Circadian variation of heart rate variability among welders (original) (raw)
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Changes in heart rate variability during working and non-working nights
2011
The aim of this study was to compare levels and patterns of heart rate variability during working night shifts and the same period of non-working nights. Eight nurses from the Surgical Department of Zadar Hospital, aged 25-33, participated in this study. The study included continuous recordings of cardiac activity during 10 hours of night-shift working (9.00 pm – 7.00 am) and during the equivalent non-working night periods. As expected, the analyses showed differences in the levels of cardiac activity between working and nonworking nights. Non-working nights were characterised by longer R-R intervals, higher variability indices and greater parasympathetic effects on cardiac activity, while their patterns of changes and spectral compositions were rather similar to those obtained during working nights. The obtained results showed the supremacy of the circadian pattern of changes, i.e. parasympathetic prevalence, during both working and non-working nights. Parasympathetic prevalence du...
Circadian heart rate variability rhythm in shift workers
Journal of Electrocardiology, 1997
The objective of this study was to assess the influence of day-night cycle and sleep-awake period on the circadian pattern of heart rate variability (HRV). Twelve male oil refinery security shift workers, aged 39 _+ 7 years, 'were studied with 24-hour Holter monitor recordings during morning and :night work periods. Hourly HRV parameters in the time and frequency domains were evaluated. For both shifts, all HRV parameters during awake or work periods were found not to be statistically different. In both day and night work shifts, the very low frequency and high-frequency components of HRV and the proportion of differences in successive R-R intervals greater than 50 ms increased during the sleep period, while the low frequency/high frequency ratio decreased. The low-frequency component in absolute units and the SD of the R-R interval did not show any variation in either shifts for the different periods. These results suggest that the circadian pattern of HRV seems to be predominantly related to sleep (supine) and wakefulness (standing) and remains independent of night-day cycle. Key words: circadian rhythm, heart rate variability, shift workers, autonomic nervous system.
The aim of this study was to compare levels and patterns of heart rate variability during working night shifts and the same period of non-working nights. Eight nurses from the Surgical Department of Zadar Hospital, aged 25-33, participated in this study. The study included continuous recordings of cardiac activity during 10 hours of night-shift working (9.00 pm – 7.00 am) and during the equivalent non-working night periods. As expected, the analyses showed differences in the levels of cardiac activity between working and non-working nights. Non-working nights were characterised by longer R-R intervals, higher variability indices and greater parasympathetic effects on cardiac activity, while their patterns of changes and spectral compositions were rather similar to those obtained during working nights. The obtained results showed the supremacy of the circadian pattern of changes, i.e. parasympathetic prevalence, during both working and non-working nights. Parasympathetic prevalence d...
Romanian Journal of Occupational Medicine, 2019
In many large cohort studies, the night shift constitutes a risk factor for developing cardiovascular disease and diabetes in workers. Current screening tests for people working in night shift include fasting glycaemia and electrocardiography. In fact, there are few studies focused on the description of the electrocardiographic changes after the night shift. This article describes the protocol of the “ECG modifications induced by the disturbance of the circadian rhythm in night-shift workers (ECGNoct)” study, which was initiated by the National Institute for Infectious Diseases “Prof. Dr. Matei Balș”. Nurses represent the target population. The protocol includes a full medical and occupational history, lifestyle habits (smoking, alcohol, nutrition), anthropometric and blood pressure measurements, blood tests (fasting glycemia, total cholesterol, triglycerides and high density lipoprotein cholesterol) and electrocardiogram recording. For nurses working in (night) shifts, we will reco...
The influence of day and night work on the circadian variations of cardiovascular performance
European Journal of Applied Physiology and Occupational Physiology, 1982
Circadian variations of the pre-ejection period, Q-T interval, heart rate and oral temperature at rest and in day and night shift work were investigated. At rest, pronounced circadian variation was found in heart rate, pre-ejection period and Q-T interval. The ratio between Q-T interval and heart rate also shows a distinct circadian variation. When working, the rest rhythms of the variables were obscured. The physiological implications for shift work are discussed.
Clinical Nursing Studies, 2015
Introduction: Shift work is one of the most serious occupational risk factors for health problems such as cardiovascular diseases. Furthermore, shift work disturbs sleep and alertness and impairs recovery from work, especially if the time between work shifts is insufficient. The aim of this study was to evaluate if a reduced number of short intervals (i.e., less than 11 hours) between work-shifts would result in better recovery indicated by sleep time heart rate variability reflecting the psychophysiological recovery. Methods: Participants were 39 female shift-working nurses with the mean age of 45 years. The study design was a prospective within-subject study with a one year follow-up. The 24-hour heart rate variability recordings supplemented with questionnaires were performed twice. First, while working in the old shift schedule with frequent short intervals between work shifts, and again after one year of a working schedule with a reduced number of short intervals between work shifts. Statistical analyses were conducted using liner mixed models. Results: The comparison between the initial shift system and the schedule with the reduced number of short intervals between work shifts caused an increase in heart rate variability parameters reflecting mainly parasympathetic activation of the autonomic nervous system (i.e., RMSSD, HF power and HF power in normalized units) (p < .001). Conclusions: In conclusion, our results suggest that reducing the number of short intervals between work shifts is an effective way to enhance the physiological recovery during the sleep. This study demonstrated that the recovery of autonomic nervous system from shift work can be promoted by implementation of ergonomic recommendations.
Circadian Rhythms in Heart Rate Measures
For many shift workers in 24/7 societies, working schedules and social influences off the job conflict with their sleep-wake cycle (SWC). In order to ensure sustained wakefulness and high performance during work time as well as to support worker's long-term health, it's important to forecast their SWC by individualized bio-mathematical models. This way, potential conflicts of work duty with physiological rhythms can be predicted and managed in advance. Such individualized adaptation of models require objective markers in order to determine model parameters such as circadian and ultradian phase length of an individual's SWC. We analyzed long-term ECG recordings and investigated the suitability of heart rate measures as circadian and ultradian markers.
Circadian variation and influence of risk factors on heart rate variability in healthy subjects
The American Journal of Cardiology, 1991
Quantification of variations in instantaneous heart rate (HR) can be used to evaluate cardiac autonomic function. A 24-hour standard deviation of all normal RR intervals less than 50 ms in survivors of myocardial infarction has been shown to be an independent marker of adverse prognosis. Twenty-four-hour HR variability in 140 healthy subjects aged 40 to 77 years was determined as (1) standard deviation, and (2) percentage of successive RR interval differences greater than 6%--an index of parasympathetic activity. The 24-hour standard deviation varied between 68 and 261 ms (median 139). Range for index of parasympathetic activity was 0.1 to 29.6% (median 4.4). Twenty percent of the interindividual variation in HR variability was explained by impact of risk factors. Standard deviation was uninfluenced by age, whereas parasympathetic activity decreased by increasing age. High physical training level was independently associated with significantly higher standard deviation (and parasympathetic activity) values during both day and night. Hourly figures of standard deviation decreased during the night, whereas parasympathetic activity increased and peaked early morning. Standard deviation values as low as those reported in high-risk patients were not observed, but comparable low values for, and lack of diurnal variation in, parasympathetic activity were seen in healthy subjects also. In conclusion, risk factors and, in particular, the physical training level have impact on 24-hour HR variability in healthy subjects. This may prove valuable for modification of cardiac autonomic activity in patients.
Effects of prolonged working hours on heart rate variability in internal medicine physicians
Scientific Reports
Prior studies have utilized heart rate variability (HRV) as the assessment tools for psychological and physiological stress during 24-h shift. However, data regarding effects of prolonged working hours > 24 h on HRV are limited. We aimed to compare between pre- and post-call HRV among physicians who worked 24 plus 8 h. The study included 60 physicians in the internal medicine training. All subjects underwent Holter ECG monitoring for HRV assessment. We compared between HRV of an 8-h regular workday (8am to 4 pm) before on-call duty (pre-call HRV) and an 8-h workday after 24-h on-call duty (post-call HRV). The mean age was 26 ± 2.5 years. Mean total sleep time during on-call duty was 238.9 ± 88.3 min. In overall population, the time-domain and frequency-domain HRV parameters were not different between pre- and post-call day. However, the physicians reported their sleep time in the 1st quartile (< 180 min) had significant increase in SDNN, pNN50, high frequency (HF), and decreas...