Biomedical subjects

Anders Knutsson

Publications and source records attributed to Anders Knutsson.

15 recordsLinked to original sources

PubMed2005

Effort-reward imbalance, sleep disturbances and fatigue.

OBJECTIVES: The objective of this study was to investigate the validity of the effort-reward imbalance (ERI) model in relation to disturbed sleep and fatigue. METHODS: The study population derived from a subset of the WOLF (WOrk, Lipids, Fibrinogen) cohort study of cardiovascular risk in a working population who replied to the ERI-questionnaire comprising 789 men and 214 women. Cox regression analysis was used to calculate the prevalence ratio (PR) for sleep disorders and fatigue in relation to the components of ERI. RESULTS: As sleep disturbances and fatigue, based on literature, were defined to be represented by the uppermost quintile, 14% of the men and 23% of the women were affected by sleep disturbances while 14 and 26%, respectively, were affected by fatigue. Higher levels of exposure for the ERI components were associated with increased prevalence of sleep disturbances and fatigue. For men, the strongest association was seen between high overcommitment and fatigue (PR 5.77, 95% confidence interval 2.89-11.5). For women, high effort and sleep disturbances (PR 4.04, CI 1.53-10.7), high effort/reward ratio and sleep disturbances (PR 4.13, CI 1.62-10.5), and between low reward and fatigue (PR 4.36, CI 1.79-10.6) yielded the most obvious associations. CONCLUSIONS: The present study adds sleep disturbances and fatigue to the list of adverse consequences of effort-reward imbalance.

Adolescent↗

PubMed2005

Electroencephalography and subjective ratings of sleep deprivation.

BACKGROUND AND PURPOSE: Sleep-related vehicle accidents account for many injuries and fatalities each year on monotonous motorways and roads. To effectively prevent such incidents requires greater knowledge of the mechanisms and development of the effects of sleep deprivation. Ten volunteers participated in a laboratory study aimed to analyze the way changes in wakefulness were described in terms of EEG changes and subjective ratings. PATIENTS AND METHODS: For each subject, the study consisted of four testing sessions that varied in length on different days: one session each of 60, 90, and 120 min when sleep-deprived, and one session of 120 min when rested. Changes in wakefulness were analyzed using electroencephalographic recordings and ratings on two different scales, the Karolinska Sleepiness Scale (KSS) and the Category-Ratio Scale (CR-10). RESULTS: The results indicate quite conclusively that significant changes in the perception of sleepiness occur during the first 60-90 min of sedentary, monotonous work. Beyond this time period, subjective and physiological changes remained constant throughout the rest of the 120-min period. CONCLUSION: In general, the subjective rating scales highly and significantly correlated with theta activity in both tired and rested states and with alpha activity in the rested state. Similar results were seen using both subjective rating scales.

Adult↗

PubMed2005

Psychosocial factors, gender, and sleep.

Low social support may contribute to poor sleep, more so than adverse aspects of demand and control and more so for women than men. This study on 1,179 working individuals, 623 women and 556 men, from the Multinational Monitoring of Trends and Determinants in Cardiovascular Disease (MONICA) study investigated the association between sleep and psychosocial factors. Chi-square analyses investigated the associations among sleep and demand, control, social networks, and emotional support. A logit log-linear model analyzed interactions. More women reported poorer sleep when perceiving adverse psychosocial factors. Interactive effects were found between adverse scores on demand, control, and emotional support. A multivariate partial least square analysis showed that poorer health, pain, and adverse aspects of emotional support and social networks contributed significantly to the pattern of poor sleep.

Adult↗

PubMed2005

Vessel size estimation in peripheral artery interventions: are angiographic measurements reliable?

PURPOSE: To describe and evaluate a new technique for angiographic measurement of arterial diameters and to make a comparison with other common techniques. MATERIAL AND METHODS: The Angiometer has a radiopaque metal body with six cylindrical segments of varying diameter. Arterial diameter is estimated by visually relating the vessel to these segments. The measurements (method A) were compared: to measuring in relation to a ruler on the table-top by means of compasses (B), to an automated measurement technique (quantitative angiography) utilizing calibration to a catheter of known diameter (C), and to a computer-based distance measurement using the ruler on the table-top as reference (D). Twenty-five patients were studied. Each method was used twice by each of two independent observers. A phantom with four drilled holes, filled with contrast agent, was also studied. RESULTS: The coefficient of variation was highest for method C and lowest for method A. Correlations between readings were highest for method A and lowest for method C. Mean diameter values were highest for method A and lowest for methods B and D. In the phantom experiments, sizes were overestimated by between 5% and 9% with method A, and underestimated by between 4% and 27% with the other methods. CONCLUSION: In terms of reproducibility and accuracy, the proposed method compares favorably with alternative methods.

Angiography↗

PubMed2005

Total mortality and cause-specific mortality of Swedish shift- and dayworkers in the pulp and paper industry in 1952-2001.

OBJECTIVES: The study investigated the relationship between shiftwork and mortality, both total mortality and cause-specific mortality from coronary heart disease (CHD), stroke, and diabetes. Methods The cohort consisted of 2354 shiftworkers and 3088 dayworkers in two pulp and paper manufacturing plants. The mortality of the cohort was monitored from 1 January 1952 to 31 December 2001 by linkage to the national Cause of Death Register. Groups of workers defined by different durations of shiftwork exposure were compared with dayworkers by calculating standardized relative rates (SRR). RESULTS: Death due to any cause (total mortality) was not higher among the shiftworkers than among the dayworkers [SRR 1.02, 95% confidence interval (95% CI) 0.93-1.11]. A longer duration of shiftwork was associated with an increased risk of CHD, and shiftworkers with >30 years of shiftwork had the highest risk of CHD (SRR 1.24, 95% CI 1.04-1.49) Diabetes was more common as the number of shift years of exposure increased [b(linear coefficient) = 4.14 x 10(-5), 95% CI 2.46 x 10(-5) -5.81 x 10(-5)]. Compared with dayworkers, shiftworkers had a greater risk of death due to stroke (SRR 1.56, 95% CI 0.98-2.51). CONCLUSIONS: In the present study, no general increase in mortality was observed among shiftworkers when they were compared with dayworkers. However, the results demonstrate an increased mortality from CHD among shiftworkers with a long duration of shiftwork exposure. Mortality due to diabetes also increased as the number of shift years and mortality due to ischemic stroke in shiftworkers increased.

Adolescent↗

PubMed2004

Job strain and plasminogen activator inhibitor-1: results from the Swedish WOLF study.

OBJECTIVES: To investigate the association between job strain and elevated levels of plasminogen activator inhibitor-1. METHODS: A cross-sectional study was carried out, comprising 1,954 actively working men and women between the ages of 19-64 years. Data were collected by questionnaire, clinical examination and blood samples. RESULTS: Elevated plasminogen activator inhibitor-1 levels were more commonly noted in women exposed to job strain than in unexposed women (odds ratio 1.33; 95% confidence interval 1.06-1.65). This association remained after we had adjusted for factors related to behaviour and general health, but became close to 1 after we had adjusted for factors related to the metabolic syndrome. For men, no association between job strain and elevated levels of plasminogen activator inhibitor-1 was observed (odds ratio 0.94; 95% confidence interval 0.71-1.26). CONCLUSIONS: Women exposed to job strain were more inclined to respond with increased plasminogen activator inhibitor-1 than men. In this first study on the association between job strain and plasminogen activator inhibitor-1 in both men and women, we observed such a relationship among women but not among men. The data support the notion that job strain might affect the risk of coronary heart disease by influencing an important cardiovascular system: the metabolic syndrome.

Adult↗

PubMed2004

Sickness absence and early retirement at two workplaces--effects of organisational intervention in Sweden.

This study sought to compare sickness absence and early retirement at two workplaces in Sweden before and after they had received financial support from the Working Life Fund and implemented vocational rehabilitation activities. Two paper and pulp manufacturing plants were compared and a cohort study was set up. The cohort included everyone born in 1934 or later who was employed in December 1988 (918 employees at Plant A and 1543 at Plant B). For 10 years (1989-98), sick leave and disability pensions were monitored. The periods before and after the intervention (1989-93 and 1994-98, respectively) were compared. Cumulative incidence was calculated for short-, long-term and very long-term sick leave, company pension and early retirement. There was no difference between the plants in terms of the three different outcomes when sick leave was measured before and after the intervention. Sick leave in Period 1 was strongly correlated with an elevated risk of sick leave in Period 2. The cumulative incidence of short-term sick leave decreased from 0.92 (95% CI, 0.91-0.93) in Period 1 to 0.79 (95% CI, 0.77-0.80) in Period 2. For employees in the upper age groups, relative risk for long-term and very long-term sick leave was elevated in both periods. The incidence of early retirement and company pension differed between the companies. We conclude that the size of financial investments in rehabilitation programmes has no significant impact on sickness absence or disability pension, based on a comparison between two paper and pulp manufacturing plants in Sweden during the early 1990s.

Adult↗

PubMed2004

Shift workers' mortality scrutinized.

The objective of this article is to reappraise previous published data on the mortality of male shift workers from Taylor and Pocock (1972). Mortality rate ratios were calculated for shift workers, ex-shift workers, and for shift workers plus ex-shift workers, respectively, compared to day workers using the Mantel-Haenszel method. The overall risk for current and former shift workers was 1.05 (95% Confidence Interval: 0.95-1.16). For ex-shift workers the mortality was increased compared to day workers (1.24, 95% Confidence Interval: 1.03-1.51). In the age specific analyses increased mortality was observed in shift workers compared with day workers in the age group of 45-54 yrs (Relative Risk: 1.47, 95% Confidence Interval: 1.12-1.93). We suggest that shift work is associated with increased mortality risk.

Adult↗

PubMed2004

Methodological aspects of shift-work research.

A major issue in shift-work research is to understand the possible ways in which shift work can impact performance and health. Nearly all body functions, from those of the cellular level to those of the entire body, are circadian rhythmic. Disturbances of these rhythms as well as the social consequences of odd work hours are of importance for the health and well-being of shift workers. This article reviews a number of common methodological issues which are of relevance to epidemiological studies in this area of research. It discusses conceptual problems regarding the use of the term "shift work," and it underscores the need to develop models that explain the mechanisms of disease in shift workers.

Circadian Rhythm↗

PubMed2003

Leisure time, occupational and household physical activity, and risk factors for cardiovascular disease in working men and women: the WOLF study.

AIMS: The aim of the present study was to examine the association of leisure time, occupational and household physical activity, as well as a combination of these (total activity), with four major risk factors for cardiovascular disease. METHODS: Cross-sectional data from the Work, Lipids and Fibrinogen (WOLF) study were used. The study population consisted of 10413 employed persons from two regions in Sweden, 7168 men and 3245 women, aged 19 to 70 years. RESULTS: The adjusted prevalence ratio (PR) of having low high density lipoprotein (HDL) cholesterol levels was 0.54 (95% confidence interval (C.I.) 0.46-0.65) for men and 0.55 (95% C.I. 0.41-0.73) for women who were involved in leisure time physical activity on a regular basis compared with persons with a more sedentary lifestyle. The adjusted PR of having elevated plasma fibrinogen was also significantly lower among those with regular leisure time physical activity. Occupational and household physical activity showed different associations among men and women. Women with high self-perceived household physical activity had an adjusted PR of 1.33 (95% C.I. 1.05-1.68) of having low HDL cholesterol levels. Total activity showed strong beneficial associations with several cardiovascular risk factors. Overweight persons seemed to have relatively more benefit from their physical activity with regard to cardiovascular risk factors than leaner persons. Smokers did not have as strong relative decrease in plasma fibrinogen with increasing activity level as non-smokers. CONCLUSION: Leisure time, as well as total physical activity, was associated inversely with cardiovascular risk factors, particularly HDL cholesterol, in both men and women.

Adult↗

PubMed2003

Health disorders of shift workers.

The effects of shift work on physiological function through disruption of circadian rhythms are well described. However, shift work can also be associated with specific pathological disorders. This article reviews the evidence for a relationship between specific medical disorders and working at night or on shift systems. The strongest evidence exists for an association with peptic ulcer disease, coronary heart disease and compromised pregnancy outcome.

Cardiovascular Diseases↗

PubMed2003

Screening for high-risk and elevated alcohol consumption in day and shift workers by use of the AUDIT and CDT.

BACKGROUND: Alcohol consumption levels and drinking patterns have been reported to vary between day and shift workers, although the results have been conflicting. Previous results indicate that questions about alcohol habits may be asked in the workplace. However, no studies have evaluated the Alcohol Use Disorders Identification Test (AUDIT) or the alcohol biomarker carbohydrate-deficient transferrin (CDT) in serum for this purpose. AIM: To investigate, in conjunction with routine health examinations, whether there is any difference between permanent day and shift workers in high-risk alcohol consumption, according to the AUDIT and CDT. Gamma-glutamyl transferase (GGT) in serum was included mainly as a comparison test. METHODS: The employees who attended for a regular health examination during the study period were offered voluntary alcohol screening with the AUDIT and CDT. RESULTS: Altogether, 990 employees (day, two-shift, and three-shift workers) participated in the study, 194 (20%) of whom screened positive with the AUDIT and/or CDT. There were no significant differences in the screening results between day and shift workers, whereas significantly fewer of the two-shift workers (odds ratio=0.5, 95% confidence interval=0.3-0.9) screened positive with CDT. CONCLUSIONS: The present findings on employees who attended for regular health examinations suggest that shift workers did not show a higher level of risky alcohol consumption than day workers, according to the results with the AUDIT, CDT and GGT. On the contrary, the two-shift workers appeared to drink significantly less.

Adult↗

PubMed2002

A descriptive study of women injured by hand-arm vibration.

The aim of this study was to describe the symptoms and the prognosis of vibration injuries in women. The investigation was based on a study of 374 women who had reported an injury due to hand-arm vibration to the Social Insurance Office or had received financial compensation from the Swedish Labor Market Insurance scheme during 1988-1997. Information on, for example, self-rated health symptoms and vibration exposure was collected by means of a questionnaire. On average, the first symptoms started after 7 yr of exposure and the first visit to a doctor took place after 11 yr. Neurological symptoms developed after a shorter period of exposure compared to vascular symptoms, 6.8 and 9.2 yr, respectively. The prevalence of numbness at the time of reporting the injury was 91% and the prevalence of white fingers was reported by 54%. The occupational group with the highest prevalence of vibration injuries was dental technicians. Two thirds of the women had stopped using vibrating machines in their work. Among the women who suffered from white fingers when they reported the injury, 50% declared impairment or no improvement of the symptoms. One woman in five was retired and the same number of women had retrained due to the occupational injury.

Adult↗

PubMed2002

Postprandial responses of glucose, insulin and triglycerides: influence of the timing of meal intake during night work.

The objective was to study the postprandial responses of glucose, insulin and triglycerides to meal intake at different clock times during night work. Eleven night shift working nurses participated. Identical test meals were ingested at 19:30, 23:30 and 03:30, and contained 440 kcal/1,860 kJ of energy (33 E% fat, 51 E% carbohydrate, 16 E% protein). The food intake was standardized three days before the first test meal. Blood samples were drawn just before the test meals were ingested and thereafter at 30, 60, 90, 120, 180 and 240 minutes. The postprandial responses were estimated as the total area under the curve (AUC) and significance testing was done using repeated measures ANOVA. The highest insulin level was found after meal intake at 23:30, and the lowest after meal intake 03:30. The glucose response showed the same pattern. The insulin response to food intake in night working nurses is more pronounced in the night compared with morning and evening. The results would have implications for metabolic and cardiovascular disorders in night workers.

Adult↗

PubMed2002

Job strain and major risk factors for coronary heart disease among employed males and females in a Swedish study on work, lipids and fibrinogen.

OBJECTIVES: The aim of this study was to analyze the relationship of job strain (high psychological job demands and low decision latitude) to hypertension, serum lipids, and plasmafibrinogen. METHODS: The study population consisted of employed persons between the ages of 15 and 64 years in the counties of Stockholm, Västernorrland, and Jämtland, Sweden. The data collection was carried out during 1992-1998. A total of 10,382 subjects participated in a medical examination and completed a questionnaire. RESULTS: No strong associations were found between job strain and plasma fibrinogen. The males reporting job strain had lower levels of total cholesterol and high-density lipoprotein cholesterol than the other males. Similar tendencies were found for the females. The females, but not the males, with job strain had an increased prevalence of hypertension when compared with the subjects with relaxed psychosocial work characteristics. In the subgroups of younger males and females an adverse association between job strain and the ratio between low-density and high-density lipoprotein cholesterol was noted. CONCLUSIONS: The results do not support the hypothesis that job strain has an adverse impact on serum total cholesterol and plasma fibrinogen levels. They suggest that an increased risk of coronary heart disease in association with job strain, if causal, is mediated by other factors, possibly partly by hypertension and low levels of high-density lipoprotein cholesterol.

Adolescent↗