Alteration of circadian time structure of blood pressure caused by night shift schedule. (1/746)

The effects of night shift schedules on circadian time structure of blood pressure were studied in seven healthy young subjects by continuous monitoring of blood pressure every 30 min for 72 h. In the control experiment, subjects were instructed to sleep at regular times with the light off at 00.00 h and the light on at 07.00 h. In the shift experiment, they were instructed to go to bed at 06.00 h and wake up at 11.00 h. The circadian rhythm of blood pressure rapidly phase delayed by 3.5 h in the second night shift day as a group phenomenon. Individual differences in changes in power spectral patterns of blood pressure were found in the night shift schedule. Ultradian rhythmicity of blood pressure was more pronounced in three subjects, whereas the circadian rhythmicity was maintained in four subjects. These findings held when the adaptation to shift work was taken into account.  (+info)

Changes in cardiorespiratory fitness, psychological wellbeing, quality of life, and vocational status following a 12 month cardiac exercise rehabilitation programme. (2/746)

OBJECTIVE: To examine and evaluate improvements in cardiorespiratory fitness, psychological wellbeing, quality of life, and vocational status in postmyocardial infarction patients during and after a comprehensive 12 month exercise rehabilitation programme. SUBJECTS: The sample population comprised 124 patients with a clinical diagnosis of myocardial infarction (122 men and two women). INTERVENTIONS: 62 patients were randomly allocated to a regular weekly aerobic training programme, three times a week for 12 months, and compared with 62 matched controls who did not receive any formal exercise training. A five year follow up questionnaire/interview was subsequently conducted on this population to determine selected vocational/lifestyle changes. RESULTS: Significant improvements in cardiorespiratory fitness (p < 0.01-0.001), psychological profiles (p < 0.05-0.001), and quality of life scores (p < 0.001) were recorded in the treatment population when compared with their matched controls. Although there were no significant differences in mortality, a larger percentage of the regular exercisers resumed full time employment and they returned to work earlier than the controls. Controls took lighter jobs, lost more time from work, and suffered more non-fatal reinfarctions (p < 0.05-0.01). CONCLUSIONS: Regularly supervised and prolonged aerobic exercise training improves cardiorespiratory fitness, psychological status, and quality of life. The trained population also had a reduction in morbidity following myocardial infarction, and significant improvement in vocational status over a five year follow up period.  (+info)

Measurement of fatigue in industries. (3/746)

Fatigue of workers is a complex phenomenon resulting from various factors in technically innovated modern industries, and it appears as a feeling of exhaustion, lowering of physiological functions, breakdown of autonomic nervous balance, and decrease in work efficiency. On the other hand industrial fatigue is caused by excessive workload, remarkable alteration in working posture and diurnal and nocturnal rhythms in daily life. Working modes in modern industries have changed from work with the whole body into that with the hands, arms, legs and/or eyes which are parts of the body, and from physical work to mental work. Visual display terminal (VDT) work is one of the most characteristic jobs in the various kinds of workplaces. A large number of fatigue tests have already been adopted, but it is still hard to draw a generalized conclusion as to the method of selecting the most appropriate test battery for a given work load. As apparatus for fatigue measurement of VDT work we have developed VRT (Visual Reaction Test) and the Portable Fatigue Meter. Furthermore, we have presented immune parameters of peripheral blood and splenic T cells for physical fatigue.  (+info)

Shift work-related problems in 16-h night shift nurses (1): Development of an automated data processing system for questionnaires, heart rate, physical activity and posture. (4/746)

To assess the shift work-related problems associated with a 16-h night shift in a two-shift system, we took the following important factors into consideration; the interaction between circadian rhythms and the longer night shift, the type of morningness and eveningness experienced, the subjective sleep feeling, the subjects' daily behavior, the effectiveness of taking a nap during the long night shift, and finally the effectiveness of using several different kinds of measuring devices. Included among the measuring devices used were a standard questionnaire, repetitive self-assessment of subjective symptoms and daily behavior at short intervals, and a continuous recording of such objective indices as physical activity and heart rate. A potential problem lies in the fact that field studies that use such measures tend to produce a mass of data, and are thus faced with the accompanying technical problem of analyzing such a large amount of data (time, effort and cost). To solve the data analysis problem, we developed an automated data processing system. Through the use of an image scanner with a paper feeder, standard paper, an optical character recognition function and common application software, we were able to analyze a mass of data continuously and automatically within a short time. Our system should prove useful for field studies that produce a large amount of data collected with several different kinds of measuring devices.  (+info)

Shift work-related problems in 16-h night shift nurses (2): Effects on subjective symptoms, physical activity, heart rate, and sleep. (5/746)

We compared the shift work-related problems between 16-h night shift and 8-h evening/night shifts among nurses in a university hospital with respect to subjective symptoms, physical activity, heart rate (HR), and sleep. The nurses of one group (n = 20) worked a 16-h night shift under a rotating two-shift system, while those of the other group (n = 20) worked an 8-h evening or night shift under a rotating three-shift system. The 16-h night shift was staffed by three or four nurses who alternately took a 2-h nap during the shift, and had at least one day off after each shift. Subjective symptoms and daily behavior were measured every 30 min by the nurses before, during, after each shift as well as during days off using a time-budget method. Also, physical activity, heart rate (HR), and posture were recorded during shifts. The results showed similar or lower levels of sleepiness, difficulty in concentration, fatigue, physical activity, and HR during the 16-h shift compared to the 8-h shifts. No differences in subjective symptoms between the two shift schedules were observed before or after the shifts or during days off. The main sleep was longer after the shifts and during days off in the 16-h shift group than in the 8-h shift group. Our results suggest that the work-related problems in 16-h night shift nurses may not be excessively greater than those in 8-h evening/night shift nurses, as long as appropriate countermeasures are taken during and after the extended shift.  (+info)

Shiftwork and myocardial infarction: a case-control study. (6/746)

OBJECTIVES: Previous studies have indicated an association between shiftwork and coronary heart disease. The increased risk could be due to job strain, which could act as a mediator of disease. There is also a possibility that interaction between shiftwork and job strain could occur that may induce or modify the development of disease. We conducted this study to explore the relation between shiftwork, job strain, and myocardial infarction. METHODS: 2006 cases with acute first time myocardial infarction were compared with 2642 controls without symptoms of myocardial infarction, and obtained from the same population that gave rise to the cases (population based case-control study). RESULTS: Myocardial infarction risk was associated with shiftwork both in men (odds ratio (OR) 1.3, 95% confidence interval (95% CI) 1.1 to 1.6) and women (OR 1.3, 95% CI 0.9 to 1.8). In the age group 45-55, the relative risk was 1.6 in men and 3.0 in women. The results cannot be explained by job strain, age, job education level, or smoking. No interaction was found between shiftwork and job strain. CONCLUSIONS: The findings indicate that shiftwork is associated with myocardial infarction in both men and women. The mechanism is unclear, but the relation cannot be explained by job strain, smoking, or job education level.  (+info)

Risk factors for neck and upper limb disorders: results from 24 years of follow up. (7/746)

OBJECTIVES: To investigate associations between different potential risk factors, related and not related to work, and disorders of the neck and upper extremities occurring up to 24 years later. METHODS: The study comprised 252 women and 232 men, Swedish citizens, 42-59 years of age and in a broad range of occupations. Information about potential risk factors was available from a former study conducted in 1969. Data on disorders of the neck, shoulder, and hand-wrist disorders were obtained retrospectively for the period 1970-93. RESULTS: Risk factors were found to differ between the sexes. Among women over-time work, high mental workload, and unsatisfactory leisure time were associated with disorders in the neck-shoulder region. Interaction was found between high mental workload and unsatisfactory leisure time. Neck symptoms earlier in life were associated with recurrent disorders. Hand and wrist disorders were associated mainly with physical demands at work. Among men blue collar work and a simultaneous presence of high mental workload and additional domestic workload predicted disorders in the neck-shoulder region. CONCLUSIONS: Factors related and not related to work were associated with disorders of the neck, shoulders, and hands and wrist up to 24 years later in life. These included factors related to working hours which previously have not been noted in this context. Interactions between risk factors both related and not related to work were commonly found.  (+info)

Out-of-hours work: the effect of setting up a general practitioner cooperative on GPs and their families. (8/746)

Since 1995 the number of general practitioner (GP) cooperatives set up to provide out-of-hours care has risen dramatically. This study demonstrates that the setting up of a cooperative in Chester is linked to an increase in the morale of the local GPs and their families.  (+info)