Effects of lifestyle factors on concentrations of salivary cortisol in healthy individuals.

OBJECTIVE: Salivary cortisol is widely used in occupational health research. However, many ordinary daily activities can influence the concentrations of cortisol and the interpretation of field studies. The aim of the present study was to evaluate the effect of lifestyle factors on salivary cortisol in everyday settings. MATERIAL AND METHODS: Healthy employees participated in one or more sub-studies on the effect of eating a vegetable salad versus protein-rich mid-day meal (n = 40), drinking coffee and smoking (n = 12), drinking alcohol (n = 32), awakening at different times (n = 29) and exercising (n = 21). Cortisol in saliva was measured by radioimmunoassay (RIA). RESULTS: When eating a mid-day meal, salivary cortisol was increased by 10 % (CI -1 % to 24 %) 1 h after eating compared to before eating in the case of both types of meal. Salivary cortisol increased by 80 % (CI 9 % to 199 %) after exercising compared to before exercise. The relative awakening response was approximately 100 % when using an alarm clock on both work-days and days off. However, the awakening response was 39 % (CI 10 % to 75 %) on a day off with spontaneous awakening. No effects of alcohol, coffee or smoking were observed. DISCUSSION: In field studies, the biological variation in salivary cortisol may be reduced by restricting physical exercise and in collecting pre-meal samples. However, the protein content of food and moderate consumption of alcohol had no effect on concentrations of cortisol. Differences in relative awakening responses on work-days and days off are related to time and mode of awakening.

Physiological restitution after night-call duty in anaesthesiologists: impact on metabolic factors.

BACKGROUND: Several studies have shown impaired mental well-being and performance in physicians work on call, but knowledge of the physiological effects is scarce. The aims of the present study were to investigate if there was a metabolic stress response in the restitutional phase after night-call duty, indicating potential negative health effects, and determine whether there were differences between physician specialities. METHODS: Anaesthesiologists (n = 19) were compared with paediatricians/ear, nose and throat (ENT) surgeons (n = 18). On an ordinary workday, 1 and 3 days after work on night call, blood samples were taken for analysis of glucose, thyroid-stimulating hormone (TSH), free thyroxine, testosterone, insulin growth factor-1 (IGF-1), high- and low-density lipoprotein cholesterol (HDL and LDL), triglycerids (TG) and insulin. Saliva cortisol was sampled on an ordinary working day, a day including 16-h night call, the third day following, and for anaesthesiologists also on a day off work. RESULTS: TSH differed significantly between days in both groups, with a 26% lower level 1 day after on-call duty (P < 0.001). A 48% cortisol rise in the morning preceding night duty was found for paediatricians/ENT surgeons (P < 0.01). CONCLUSION: The significant dip in TSH level 24 h after night-call duty indicates a metabolic effect of working on night call and should be studied further. However, the levels were within the normal range and the overall results do not imply any serious metabolic changes and only minor differences were seen between specialist groups.

Personality, mental distress, and subjective health complaints among persons with environmental annoyance.

The aim of this study was to assess possible early determinants of idiopathic environmental intolerance (IEI), contributing to an integrated model for the development of IEI. Questionnaires concerning personality traits, current mental distress, subjective health complaints, work load and satisfaction, and options for recovery, were given to 84 persons from the general population attributing annoyance to (i) chemicals/smells (smell-annoyed (SA) n= 29); (ii) electrical equipment (electrically annoyed (EA) n= 16); and (iii) both smells and electricity (generally annoyed (GA) n= 39), but otherwise healthy and in active work. Compared to referents (n= 54), the EA and GA groups showed strongly elevated scores on 5/6 scales within the trait anxiety/neuroticism personality dimension, while the SA group had a slight elevation on only one anxiety scale. Current mental distress and subjective health complaints scores were generally elevated in the EA and GA groups, but only partially in the SA group. Higher proportions of the EA, GA, and SA groups reported low satisfaction with their work situation, including more frequent fatigue after work and a higher, and often unfulfilled, need for recovery. The findings suggest that trait anxiety is prominent already at prodromal stages of IEI, possibly indicating that trait anxiety facilitates the acquisition of attribution of health complaints to environmental factors.

Psychological distress and coping in women married to men with a diagnosis of solvent-induced chronic toxic encephalopathy.

BACKGROUND: Solvent-induced chronic toxic encephalopathy (TE) is a slowly developing brain disorder associated with both a direct effect on the nervous system and as indirect experienced psychological distress. It can presumably also imply negative influence on the subject's social surroundings. METHODS: Seventeen women married to men diagnosed with TE (WTE) and 51 referent women of the same age married to healthy husbands were examined. Symptoms, social network and coping style were measured by questionnaires. RESULTS: The WTE reported slightly more psychological distress and fewer social contacts than did the referents. The WTE did not report affected stress management. Retired women in the WTE group accounted for most of the deviances from the referents. CONCLUSIONS: The conclusion is that becoming a WTE does not necessarily imply more psychological distress, social isolation or poorer stress management capability if they continue with their work and social activities.

Prevalence of annoyance attributed to electrical equipment and smells in a Swedish population, and relationship with subjective health and daily functioning.

BACKGROUND: Self-reported annoyance from electrical equipment has been in evidence since the mid-1980s, and the first reports of illness from everyday chemicals arose in the 1960s. However, the extent of the problem has not yet been fully established. AIMS: The aim of this study was to estimate the prevalence of annoyance related to electrical and chemical factors in a Swedish general population, and to assess possible relationships with subjective health and daily functioning. METHODS: In total, 13,604 subjects, representative of the population of Scania, Sweden, answered a survey containing five questions regarding annoyance from five environmental factors: fluorescent tube lighting, visual display units, other electrical equipment, air that smells of chemicals, and other smells. The survey also obtained data on self-reported health (SRH-7), mental well-being [General Health Questionnaire (GHQ)-12], work situation and daily functioning. RESULTS: Almost one-third of the respondents reported annoyance from at least one environmental factor. Annoyance was more frequent among women, subjects of working age and immigrants. Subjects who reported environmental annoyance scored higher on GHQ-12 and lower on SRH-7, indicating impaired subjective physical and mental well-being. They were also more likely to report deteriorated daily functioning. CONCLUSIONS: Annoyance related to electrical and/or chemical factors was common in a Swedish population. Subjects reporting environmental annoyance rated their overall health significantly poorer than the general population. The association with subjective health and functional capacity increased with severity of annoyance, which suggests that there is some connection between environmental annoyance, well-being and functional capacity.

Self-assessed and directly measured occupational physical activities--influence of musculoskeletal complaints, age and gender.

This study compares questionnaire assessed physical activity with direct technical measurements among cleaners and office workers, stratified regarding age, gender and self-reported neck/shoulder complaints. During two full working days number of steps was recorded by a pedometer, sitting/standing positions by a posimeter and heart rate by a Sport-Tester. In addition the subjects kept a work task diary for 10 days. There were high intra-individual variations in exposure between the days. Subjects with complaints rated their exposure higher than those without, although they in fact showed lower direct measured exposure. This may imply underestimation of exposure-effect relationships. Rate of perceived exertion showed low correlation with heart rate ratio within the two occupational groups, but high, 0.64 when the two groups were combined. Age and complaints explained 31% of the variance for the cleaners.

Questionnaire-based mechanical exposure indices for large population studies--reliability, internal consistency and predictive validity.

OBJECTIVES: This study attempts to construct valid indices for mechanical exposure of the shoulder-neck region with relation to the development of shoulder-neck pain in a 1-year perspective study of a general population. METHODS: A comprehensive questionnaire was presented to 14 556 subjects aged 45 or 65 years and repeated after 12 months. Twenty-four questions concerning positions, movements, and manual materials handling were registered on a 3-point impact scale. Musculoskeletal problems were reported on a slightly modified version of the Standardized Nordic Questionnaire for the Analysis of Musculoskeletal Symptoms. Test-retest stability after 2 weeks was calculated for 232 consecutive participants. Based on mechanistic theories, 4 exposure indices were formed. Another 5 constructs were obtained by factor analysis. RESULTS: All the indices showed good test-retest stability, and 5 of them had very good internal consistency. Due to overlaps between the indices, 2 indices stood out as having unique properties. One of them concerned mainly postures and the other dealt primarily with measured lifting. However, the latter was not related to the shoulder-neck pain outcome when adjusted for the posture index. The posture index showed an exposure-effect relationship with the outcome. The job titles implied a large degree of exposure misclassification. CONCLUSIONS: The posture index is recommended as a mechanical exposure index for analyses of interaction with other possible determinants of shoulder-neck pain (ie, psychosocial factors). The use of such an index instead of job titles in large population studies will reduce the risk of misclassification.

Influence of personality traits on neuropsychological test performance in toxic encephalopathy cases and healthy referent subjects.

The relationship between personality traits and cognitive performance was studied in two groups: men with symptoms and neuropsychological test results compatible with toxic encephalopathy (TE) and demographically similar healthy men (N=57 per group). Personality traits were assessed with the Karolinska Scales of Personality (KSP). The neuropsychological examination included 13 tests covering various functional domains. The TE group displayed elevated scores on all three KSP anxiety scales as well as an elevated impulsiveness score. Furthermore, the TE group had a lower score on the socialization scale than did the referent group. Different relationships between personality dispositions and cognitive functioning emerged in the two groups. Within the referent group the highest correlations were observed between KSP anxiety and socialization scale scores and reaction times measures. This pattern did not appear in the TE group; instead, divergent and a few weak relationships emerged. These relationships involved correlations between the KSP monotony avoidance score and some motor speed scores. By dividing the referent group into low anxiety and high anxiety subgroups on the basis of the multi-component anxiety scale score, it was shown that the test scores in the high anxiety subgroup mostly were indistinguishable from the scores in the TE group. In contrast, the low anxiety group had higher test scores than the TE group in 8 of the 13 tests. In conclusion, the expected relationship between anxiety and cognitive vigilance is absent in TE cases. This indicates that the neuropsychological performance decrement in TE cases is not primarily related to elevated mental distress, but is probably dominated by the effects of organic brain impairment. Thus, in TE cases low neuropsychological test scores should not be regarded as a consequence of emotional symptoms. Furthermore, personality traits may be considered as potential confounders even if traditional matching by demographic criteria has been successfully implemented.

Euroquest: the validity of a new symptom questionnaire.

The new questionnaire Euroquest was designed to study effects from exposure to organic solvents, and it covers the most commonly reported symptoms associated with long-term solvent exposure. Its convergence and criterion validity were evaluated by means of comparison with the two well-established generic symptom questionnaires Symptom Checklist (SCL-90) and General Health Questionnaire (GHQ-30). Men with long-term exposure to organic solvents and symptoms common in toxic encephalopathy (TE) classified as TE type 2A (n=29) or 2B (n=28) according to their neuropsychological test performance, and a comparable group of non-exposed healthy referents (N=57), were included. The six Euroquest factors obtained by a factor analysis were labeled: 'emotional lability' 'cognitive disturbances' 'peripheral neurology' 'sleepiness' 'fatigue' and 'sleep disturbances'. These factors correlated well with most SCL-90 scales and with the GHQ-30 total score in the combined TE groups. The combined TE groups were correctly classified to a similar degree by the Euroquest factors 'cognitive disturbances' and 'peripheral neurology' (TE 82.5% and referents 93%) and the SCL-90 scales 'somatization, 'interpersonal sensitivity', 'obsessive-compulsive symptoms' and 'hostility' (TE 84.2% and referents 93.0%), but not as well by GHQ-30 (TE 61.4% and referents 79%). In comparison with the separate TE groups most referents, and a considerably higher percentage of 2B than 2A subjects, could be correctly classified with both Euroquest and SCL-90. With GHQ-30, only a few 2A cases and fewer than half of the 2B cases were correctly classified. In conclusion, the Euroquest factors converged with both SCL-90 scales and GHQ-30 score. With both the Euroquest and SCL-90 questionnaires a similar percentage of the TE subjects were discriminated from the referents, most conspicuously regarding TE 2B subjects, who had an objectified cognitive dysfunction. In a choice between Euroquest and SCL-90, the Euroquest may have the advantage of higher face validity, for TE subjects.

A comparison of neuropsychological tests for the assessment of chronic toxic encephalopathy.

BACKGROUND: From the viewpoint of the clinical neuropsychologist, it is not evident if the detection of solvent induced toxic encephalopathy (TE) could be optimized by a modification of the traditional test batteries, adding tests covering new dimensions or monitoring further functional domains. METHODS: To clarify this issue, TE patients were re-examined with (a) the tests traditionally used in screening for TE and (b) some tests hitherto less utilized within neurotoxicology, involving complex attention and frontal lobe functioning. RESULTS: The results do not indicate that tests of the latter category would be more sensitive to TE than the tests traditionally used. Using an optimized core battery, compiled of tests from both categories, the sensitivity and specificity levels reached a maximum of around 0.7 when using as criterion the reproduction of a subnormal test profile (TE type 2B). CONCLUSIONS: A combination of several traditional and a few newer tests is suggested to optimize the detection of TE. Repeated assessments over time are also recommended.

Psychological test performance during experimental challenge to toluene and n-butyl acetate in cases of solvent-induced toxic encephalopathy.

OBJECTIVES: This study determined whether performance in neurobehavioral tests deteriorates during subjectively annoying chemical challenge below known neurotoxic thresholds among persons with toxic encephalopathy with subjective hypersensitivity to chemicals. METHODS: Subjects with symptoms and previous neuropsychological test results compatible with toxic encephalopathy (TE) of either type 2A (N=12) or 2B (N=12) and unexposed referents (N=12) were challenged in an exposure chamber. In a counterbalanced design, the subjects were exposed on 2 occasions to increasing air concentrations of n-butyl acetate and toluene at levels well below the thresholds for neurotoxic effects. Attention and motor speed tests were given (i) in room air outside the chamber before the challenge, (ii) in room air inside the chamber before the exposure, (iii) at 12 ppm (44 or 56 mg/m3), and (iv) at 48 ppm (at 180 or 228 mg/m3). RESULTS: For both substances the TE groups showed a slight increase (deterioration) in the simple reaction-time task during chemical exposure, but not in the complex reaction-time task or in the digit symbol test of the Wechsler Adult Intelligence Scale. Contrary to reference subjects, the TE subjects did not show any improvement or learning effect in the digit symbol test over the chamber phases. n-Butyl acetate tended to affect cognitive functioning more obviously than toluene did. Suggestion or expectancy effects were not observed in any group in the clean-air baseline conditions. CONCLUSIONS: The results do not support the notion that men with subjective hypersensitivity to chemicals would be more affected than healthy men regarding cognitive functioning during annoying solvent exposure below thresholds for acute neurotoxic effects.

Stress management in men with solvent-induced chronic toxic encephalopathy.

Stress management was studied in male patients with solvent-induced chronic toxic encephalopathy (TE) of types 2A (TE 2A, n = 31) and 2B (TE 2B, n = 26). The patients were compared with a healthy reference group (n = 57). Self-reported symptoms (90-item Symptoms Checklist [SCL-90]), sense of coherence, coping strategies, and level of mastery were measured. As expected, both TE groups reported highly deviating symptoms on most SCL-90 scales. The TE 2B patients, who had objectified cognitive dysfunction, reported more use of passive, less situationally adequate coping strategies; a weaker sense of coherence; and a lower degree of mastery. In contrast, the TE 2A cases showed only minor deviations from the reference group in these respects. The results suggest that having a strong sense of coherence, a sense of mastery, and flexible resources for stress management could be dependent on intact brain functions.

Suprathreshold intensity and annoyance reactions in experimental challenge to toluene and n-butyl acetate among subjects with long-term solvent exposure.

OBJECTIVES: This study explores reactions to low-level chemical challenge, aiming at the development of test procedures for assessing individual sensitivity to smells and chemicals. METHODS: Subjects with symptoms and neuropsychological test results compatible with toxic encephalopathy type 2A (TE-2A) and 2B (TE-2B) and unexposed referents (N=12 in each group) were challenged in an exposure chamber. Toluene exposure was started at 11 mg/m3, and it followed a geometric progression scale with a ratio of 2, until reaching 180 mg/m3. In a counterbalanced design, the subjects were similarly exposed to n-butyl acetate starting at a concentration of 14 mg/m3 and increasing to 228 mg/m3. At each exposure level, smell intensity was measured on a 7-step category scale. Mucous membrane irritation and annoyance reactions were rated on visual analogue scales. RESULTS: Both TE groups showed high sensitivity to the low-level solvent challenge, which provoked immediate annoyance and fatigue reactions. In particular the TE-2B group related smell intensity to various annoyance dimensions during exposure to n-butyl acetate, a pattern not observed during toluene exposure. The reference group clearly separated smell intensity and annoyance reactions in both exposure conditions. CONCLUSIONS: The reaction of the TE cases suggests that chemical sensitivity can be distinguished from normal annoyance reactions by the inability to differentiate between smell intensity and an experience of irritation from mucous membranes in air concentrations well below the trigeminal irritation threshold level. Fatigue coreactivity in challenges to single substances below the neurotoxic level may also be important.

Long-term follow-up of psychological distress, social functioning, and coping style in treated and untreated patients with solvent-induced chronic toxic encephalopathy.

Patients with organic solvent-induced toxic encephalopathy (TE) (n = 13) were followed up seven years after the application of an intervention program. They were also compared with untreated TE patients diagnosed at the same time (n = 26) and with unexposed referents (n = 39). Psychological distress, social function, and coping ability and style were measured with the Symptom Checklist-90, Interview Schedule of Social Interaction, and Sense of Coherence and Strategies to Handle Stress questionnaires. Both TE groups had unchanged function in neuropsychological tests. Members of the treated group had improved their social functioning and reduced their mental stress but were not any better than the untreated patients. Compared with referents, the TE patients continued to live with increased psychological distress and used predominantly emotionally focused strategies to cope with their problems. This can be a cause for concern in family life and can also make gainful work impossible.

A seven-year follow-up study of lung function and methacholine responsiveness in sensitized and non-sensitized workers handling laboratory animals.

Lung function, studied with spirometry, nitrogen washout technique, and methacholine responsiveness, was prospectively investigated in a seven-year follow-up study of 35 laboratory animal workers (19 women and 16 men) of whom 11 were skin prick test (SPT) positive to laboratory animal allergens; five had asthma and six had rhinitis symptoms. During the follow-up, 82% of the SPT positive subjects had stopped animal work, compared with 29% of the SPT-negative subjects. In baseline spirometry, there was no decrement in the lung volumes or differences between SPT-positive and SPT-negative subjects. At follow-up, no difference was found in vital capacity (VC), forced expiratory volume during one second (FEV1), or residual volume (RV), but the volume of trapped gas (VTG), which is assumed to measure small airways, had increased with a median of 11 mL (P = 0.03). Subjects sensitized to laboratory animals had a minor increase in methacholine responsiveness in FEV1 at follow-up (P = 0.03). The VTG responsiveness was already increased in the first examination (P = 0.035) and remained so at follow-up. Furthermore, the FEV1 responsiveness could predict a subsequent decline in baseline VC and FEV1. In conclusion, our results support the hypothesis that airway responsiveness in immunoglobulin E-mediated allergy might start in small airways and subsequently affect large airways.

Chronic toxic encephalopathy: social consequences and experiences from a rehabilitation program.

This study evaluates a rehabilitation program designed to address the social function issues of patients with solvent-induced chronic toxic encephalopathy (TE) and their families. Fourteen newly diagnosed men and their spouses participated in group sessions. The patients were given cognitive training, and crisis intervention measures were implemented. Their spouses were given information about the disease and had an opportunity to talk about their emotions and the disease's impact on the family's functioning. Interviews after the program showed that patients and their spouses were experiencing less psychological distress and increased social activity and had begun reestablishing contacts with friends. Their psychiatric symptoms, measured during a structured interview by a nurse, decreased significantly immediately after the treatment period but increased again after 6 months. Only a long-term follow-up study comparing the experiences of these patients with those of untreated TE patients can determine whether improvement can be sustained over the long term.

Solvent-induced toxic encephalopathy: electrophysiological data in relation to neuropsychological findings.

Male subjects with type 2A (n = 12) and 2B (n = 12) solvent-induced toxic encephalopathy and a reference group of healthy men (n = 12) without previous solvent exposure were studied using quantitative EEG and event-related potentials from an odd-ball and a dual-task paradigm. Subjects with toxic encephalopathy of types 2A and 2B showed markedly lower P300 amplitudes than did controls in both paradigms. In the relatively complex dual-task setting, subjects with 2A and 2B showed lower signal detection than did controls.

Human leukocyte antigens in occupational allergy: a possible protective effect of HLA-B16 in laboratory animal allergy.

Human leukocyte antigens (HLA-A, -B, -C, and -DR loci) and possible associations with occupational allergy to laboratory animals and atopy indicators were studied in laboratory animal workers with airway symptoms (n = 92) and in those who were symptom free (n = 27), as well as in a population reference group of blood donors in good health (n = 123). The laboratory animal workers, but not the population reference group, were allergologically examined with skin prick testing to common environmental and animal allergens together with measurement of total serum IgE levels. Seven HLA antigens, i.e., HLA-A9, -B5, -B12, -B16, -DR4, -DR5, and -Drw6, suggested possible associations with symptoms and/or atopy indicators. When correcting the p-values for the number of studied antigens, only the HLA-B16 differences remained statistically significant. HLA-B16 was elevated in symptom-free subjects compared to the population reference group and in subjects with serum IgE < 10 kU/L. Subjects with serum IgE > 100 kU/L and sensitized against environmental and/or laboratory animals, including LAA asthmatics, lacked HLA-B16. It is suggested that HLA-B16 or an immunosuppressive gene linked to HLA-B16 reduce the risk of producing IgE antibodies against animal protein allergens. However, our a priori hypothesis of a possible risk associated with HLA B15-DR4 could not be confirmed.

Cancer incidence and mortality of patients with suspected solvent-related disorders.

OBJECTIVE: The aim of this study was to study the incidence of cancer and deaths from cancer and other diseases among patients referred to the 11 clinics of occupational medicine in Sweden between 1967 and 1987 for examination because of exposure to organic solvents. METHODS: The cohort comprised 5791 persons, 5283 men and 508 women. Information about cancer incidence and causes of death was collected from the Cancer Register of the National Board of Health and Welfare and the National Death Register of Statistics Sweden, respectively. The expected values were calculated from the national death rates and incidence rates of cancer. RESULTS: The overall mortality rate was close to expected, but the mortality rate was decreased for diseases of the circulatory system [standardized mortality ratio (SMR) 0.7, 95% confidence limit (95% CI) 0.5-0.9] and increased for suicide (SMR 2.0, 95% CI 1.2-3.2). The total cancer incidence was slightly elevated [standardized incidence ratio (SIR) 1.2, 95% CI 0.99-1.4], and some specific cancer sites showed an increased incidence, although the lower confidence limits surpassed one. Malignancies of the lymphohematopoietic system and cancer of the uterine cervix had an increased risk (SIR 1.9, 95% CI 1.2-3.2, and SIR 3.7, 95% CI 2.2-6.2, respectively). Patients with presumerably high solvent exposure had an SIR of 1.4 for all malignancies (95% CI 0.9-2.1) and those with presumerably low exposure had an SIR of 1.1 (95% CI 0.9-1.4). CONCLUSIONS: The study showed an increased risk for malignancies of the hematopoietic system and the uterine cervix among patients originally examined with regard to solvent-induced disorders. There was also an increased risk of suicide and a decreased risk of death from diseases of the circulatory system. There was no increased risk for deaths from mental or neurological disorders.

Upper airway irritation and small airways hyperreactivity due to exposure to potassium aluminium tetrafluoride flux: an extended case report.

OBJECTIVES: 22 workers, exposed to potassium aluminium tetrafluoride used as flux for soldering aluminium, were studied as clinical outpatients for symptoms of irritation of the nose, eye, skin, and airways. METHODS: 16 volunteered for spirometry with methacholine provocation test including a test for small airways function by volume of trapped gas (VTG). RESULTS: Median (range) latency time before respiratory symptoms developed was 6 (1-60) months. Symptoms of airways irritation diminished in all subjects after flux exposure ended. The FEV1 was within the normal range in 16 of 17 subjects before the methacholine provocation test. The FEV1 decreased by > or = 20% in two out of 16 subjects after the 0.1% methacholine provocation. Four out of the 17 subjects had a high VTG before methacholine provocation. After inhalation of 0.1% methacholine eight out of 16 subjects (50%) had an abnormal increase of VTG indicating hyperreactivity in small airways. DISCUSSION: Potassium aluminium tetrafluoride flux seems to induce an increase of bronchial reactivity in small airways. A setting of an occupational standard for potassium aluminium tetrafluoride is proposed.