Risk of gastric cancer in pneumoconiotic coal miners and the effect of respiratory impairment

OBJECTIVES: This study was carried out to investigate the mortality patterns in a group of 3790 coal miners. The study population had abnormal chest x ray films at a routine medical examination that was performed in the 1950s. METHODS: The total group of 3790 coal miners were followed up for mortality up to 1 January 1992. Causes of death, determined and coded at time of death, were traced with help from the Central Bureau of Statistics. RESULTS: Total mortality in this group of coal miners with abnormal chest x ray films was significantly higher than expected (SMR 127.1, 95% CI 122.5-131.6), mainly a reflection of the increase in mortality from non-malignant respiratory disease (SMR 411.0, 95% CI 382.3-441.3). Mortality from gastric cancer was also significantly increased (SMR 147.5, 95% CI 122.3-176.3). This risk of mortality from gastric cancer was confined to workers with no pneumoconiosis or only a mild form. Despite the strong relation to duration of employment and pneumoconiosis the group of workers with more severe manifestations of pneumoconiosis did not experience an excess in mortality from gastric cancer. CONCLUSION: This study confirms the earlier reported risk of gastric cancer in coal miners. Also it confirms the hypothesis that this risk of gastric cancer is limited to workers with a mild degree of pneumoconiosis or none. In workers with severe forms of pneumoconiosis the pulmonary clearance system is impaired in such a way that the inhaled coal dust does not reach the digestive tract.     

Inter-organ leptin exchange in humans

To assess whether the evolution to pneumoconiosis may be suspected in coal miners, we conducted a 4-yr longitudinal study of 80 dust-exposed miners with chest X-ray findings classified 0/1 or 1/0 according to the International Labor Organization (ILO) classification (exposed to coal mine dust, suspected of pneumoconiosis [ES group]) and two control groups having normal X-rays. The first of these latter two groups included 80 miners with similar exposure to that of the first group (exposure with normal X-rays [EN]), whereas the second group consisted of markedly less exposed miners (no exposure with normal X-rays [NN]). The protocol comprised a questionnaire on respiratory symptoms and smoking, assessment of cumulative coal-mine-dust exposure, X-rays, computed tomographic (CT) scans, and lung-function tests. The study was conducted in 1990 and 1994 by the same medical team. At the end of the follow-up, 24 members of the ES group had worsened X-ray findings, and 10 of them had X-ray findings classified as 1/1 or greater. In the EN and NN groups, six and one subjects, respectively, had worsened X-ray findings. At the first examination, subjects who developed pneumoconiosis had significantly lower values for FEV1/FVC ratio, maximum midexpiratory flow (MMEF), and maximal forced expiratory flow at 25% of vital capacity (FEF25%), and higher CT-scan micronodule scores. This latter score and FEF25% were significantly associated with the evolution to pneumoconiosis in the ES group, and scanner micronodule score and MMEF were significantly associated with this in all three groups combined. Worsening findings on X-ray and change to pneumoconiosis must be controlled in coal miners. The findings in this study offer the possibility of identifying miners who especially need follow-up and monitoring.     

Respiratory status of surface coal miners in the United States

The United States Public Health Service examined 1,438 surface coal miners to determine the prevalence of coal worker's pneumoconiosis (CWP), chronic bronchitis, and ventilatory impairment among them. Four percent (fifty-nine individuals) showed some roentgenographic evidence of pneumoconiosis, but only seven miners had films interpreted as CWP of category 2 or greater (according to the UICC/Cincinnati classification system). Moreover, most of the affected miners had worked in underground coal mines for prolonged periods. Significant decrements in pulmonary function to increasing exposure to surface mine dust were demonstrated only in the forced vital capacity of smokers. Increased prevalence of chronic bronchitis with increasing exposure was found in all smoking categories. However, significant airway obstruction was an uncommon finding (6.6%) in nonsmoking miners. Employment in surface mining was not likely to cause either the development of CWP or clinically significant respiratory impairment.     

Mortality among coal miners with pneumoconiosis in Poland

A mortality cohort study was carried out on 7,065 coal miners with pneumoconiosis first diagnosed during the years of 1970-85. The cohort was selected from among subjects entered into the National Register of Occupational Diseases and followed up through to the end of 1991. The general male population of Poland was considered as a reference group. The PYRS-3 programme was used to identify, by means of standardized mortality ratios (SMRs), total and selected cause-specific mortality. An analysis revealed significantly elevated total mortality (SMR = 105; 95% confidence interval (CI): 100-110) in the whole cohort of coal miners. The risk of selected cause-specific mortality was significantly enhanced due to diseases of the respiratory system among which pneumoconiosis predominated (SMR = 383; 95% CI: 345-424). While mortality from all diseases of the circulatory system (SmR = 89; CI: 82-96), arterial hypertension (SMR = 63; 95% CI: 38-98), cerebrovascular diseases (SMR = 79; 95% CI: 62-99), atherosclerosis (SMR = 79; 95% CI: 66-93), and injury in poisoning (SMR = 50; 95% CI: 38-64) was significantly lower. The risk of death from malignant neoplasm of lung in the whole study population as well as in individual groups and categories of coal miners with pneumoconiosis, which varied in the risk of pneumoconiosis and the level of exposure to ionizing radiation, was not increased.     

Reliability of reported occupational history information for US coal miners, 1969-1977

For estimating reliable exposure-response relations it is necessary that random variation in both the response and the exposure variables be sufficiently small. Variability in cumulative exposures can arise from uncertainties in self-reported work histories from interviews. In most epidemiologic surveys, the information gathered from questionnaires is used without knowing the validity or reproducibility of these data. This paper investigates the reliability of occupational histories reported by the same individuals on two occasions separated by 9 years in the US National Study of Coal Workers' Pneumoconiosis and its implications on the exposure-response relation for simple coal workers' pneumoconiosis. For 480 coal miners, from whom occupational histories were obtained twice (in 1969-1971 and 1977-1981), the reliability (intraclass correlation coefficient) of the cumulative exposures generated from each work history was 87%. Logistic model fitting of simple coal workers' pneumoconiosis prevalence to the cumulative coal dust exposure produced almost identical results. After accounting for intersurvey variability in the occupational histories, the authors found that the exposure-response coefficients estimated from information reported at the surveys were attenuated by 12%. In epidemiologic studies, knowledge of the reproducibility of self-reported occupational history information is important to ascertain whether the true exposure effect is underestimated.     

Carcinoma of the lung in patients with pneumoconiosis

From 614 patients with notified pneumoconiosis who died in 1964-1992 on necropsy carcinoma of the lungs was found in 87, i.e. 14.1% (in 48 it was the cause of death). The incidence in individual years did not differ significantly; on evaluation in relation to the diagnosis of pneumoconiosis an insignificantly more frequent incidence was found in complicated pneumoconiosis of miners. On evaluation by work places miners in black coal mines and workers in quarries were affected more frequently, the difference being at the borderline of statistical significance. As to the histological aspect, most frequently squamous cell carcinoma was involved, the site was most frequently in both upper lobes. The carcinoma was seven times associated with silicotic lesions, with anthracofibrotic lesions six times (a total of 14.9%). In lifetime carcinoma was detected in 55 of the patients who died, i.e. in 63.2%. As to aetiopathogenetic influences, the relationship with smoking is significant. The aetiopathogenesis of carcinoma of the lungs in patients with pneumoconiosis is most probably not uniform-the influence of smoking is beyond doubt, the carcinogenic effect of silica should be considered in patients with carcinoma in the scar. With regard to the repeatedly proved more frequent incidence of carcinoma of the lungs in patients with pneumoconiosis, frequent check-ups of patients with pneumoconiosis focused on possible detection of lung cancer are essential.     

Improved immunoturbidimetric method for rheumatoid factor testing

The performance of two immunoturbidimetric modifications for rheumatoid factor (RF) testing, which differ with respect to the means of complement inactivation (heat treatment and inactivation with polyvinyl sulphonate), were compared in serum samples from 87 patients with rheumatoid arthritis (RA) and from 403 healthy subjects. IgM-rheumatoid factor titres were also measured with an enzyme linked immunosorbent assay (ELISA). Both immunoturbidimetric tests gave positive reactions (rheumatoid factor > or = 20 IU/ml) in 74 out of the 87 (85%) RA sera. In cases with high RF concentrations the results after chemical inactivation tended to be slightly higher compared with heat inactivation. In healthy subjects rheumatoid factor was detected in 19/403 (4.7%) sera using heat inactivation and in 22/403 (5.5%) sera with chemical inactivation of complement. Interrun coefficient of variation in the chemical inactivation assay was 4.4%; with the heat inactivation method it was 8.1%. In the ELISA, a marginally better correlation was noted in the results obtained using chemical inactivation. Inactivation of complement by means of polyvinyl sulphonate offers the advantage of easier test performance and better reproducibility, and the results may reflect more accurately true rheumatoid factor concentrations.     

Epidemiological and clinical aspects relating to the variability of rheumatoid arthritis

OBJECTIVE: To review epidemiological studies dealing with the temporal and geographic variability in the occurrence of rheumatoid arthritis (RA) and clinical studies that address the variability of severity and manifestations among populations. METHODS: An extensive search of the literature, including a Medline search, was completed. Studies addressing the origin, history, and trends in the occurrence of RA were reviewed first. Next, studies of the prevalence and incidence of RA in different populations were reviewed, and occurrence rates compared. Standardization was attempted by tabulating adult prevalence rates of studies using equivalent sets of criteria. Studies comparing RA patients from two populations were sought next. Finally, studies dealing with explanations of the presumed variability were reviewed. RESULTS: Temporal variability is indicated by paleopathological evidence that RA has existed in the New World since 4000 BC, whereas there is no evidence that it occurred in Europe before the 17th century, or in Africa before the 20th century. Epidemiological studies show a possible trend of decreasing incidence of RA in the United States and Western Europe, whereas reports from Africa note a rising incidence. In white populations of Europe and America, prevalence is approximately 1%, and incidence is 0.03%. Significantly higher rates are found in some North American Indians, and significantly lower rates in some Asian and African populations, even when the different population structures are taken into account. In the latter populations, different patterns of occurrence from those observed in whites emerge, such as greater female preponderance and a much younger peak age at onset. Direct standardized comparisons of two diverse populations of RA patients showed some differences in expression, severity, or manifestations of RA between populations. CONCLUSION: The occurrence and manifestations of RA are temporally and geographically variable.     

Helplessness and depression in rheumatoid arthritis.

Found that scores on a measure of helplessness mediated the relationship between severe, disabling rheumatoid arthritis (RA) and depression in 106 RA patients (aged 23–81 yrs). This association was independent of a previously demonstrated correlation between cognitive distortion and depression in RA patients. However, the association between disease severity and depression was mediated by Ss' views of their ability to control or cope with their disease. Both helplessness and cognitive distortion may be important factors in the development and treatment of depression among RA patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Importance of reactive oxygen species in rheumatoid arthritis

Free radical oxidation--peroxidation products, superoxide dismutase (SOD) activity--and nonproteic thiols were measured in blood from 10 normal subjects and 10 patients with rheumatoid arthritis (RA). Peroxidation products and SOD activity have been found significantly elevated, while blood nonproteic thiols have been found significantly lower in RA patients, as compared to normal controls. Also, plasmatic concentration of ceruloplasmin has been found significantly higher in RA patients than in controls.     

Effect of social deprivation on disease severity and outcome in patients with rheumatoid arthritis

OBJECTIVE: Social deprivation is now recognised to have an important impact on morbidity and mortality. This study sought to ascertain the effect of deprivation, if any, on disease severity, functional disability, and outcome in rheumatoid patients in Glasgow. METHODS: 814 patients with rheumatoid arthritis (RA) were assessed for clinical, functional, and laboratory indices of disease activity. Deprivation categories for individual patients were determined using the Carstairs index. Five year follow up is available for 440 patients. RESULTS: The study population of RA patients live largely in the most deprived areas. Patients from deprived areas have significantly poorer function at outset and at five years as defined by the Health Assessment Questionnaire (HAQ) score. This is not attributable to differences in disease duration in patients from the most deprived regions or compliance with treatment. Furthermore, these patients do not achieve over five years the initial functional level of those living in the most advantaged localities. CONCLUSION: RA patients from deprived areas have poorer function, which is associated with greater need--medical, social, and paramedical. Strategies and resources for healthcare need to be adjusted according to this variation.     

Differential relationships between stress and disease activity for immunologically distinct subgroups of people with rheumatoid arthritis.

Immunologically distinct subgroups of patients with rheumatoid arthritis (RA)--those with the autoantibody rheumatoid factor (seropositive RA) and those without (seronegative RA) were compared on a variety of clinical and self-report measures in a consecutive series of women with disease of 7 yrs or less duration. The groups were comparable on clinical, pain, functional, and psychosocial variables. However, the seronegative RA group reported elevated levels of pre-onset negative life event stress. Postonset life event stress and disease activity were significantly correlated for the seronegative RA group, but not for the seropositive RA group. Results suggest that stress factors may be more important in the etiology and maintenance of seronegative RA and that the seronegative RA group may possibly derive particular benefit from psychological techniques to enhance stress management skills. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

HLA-DRB1 genes and disease severity in rheumatoid arthritis. The MIRA Trial Group. Minocycline in Rheumatoid Arthritis

OBJECTIVE: To examine the effect of alleles encoding the "shared"/"rheumatoid" epitope on rheumatoid arthritis (RA) disease severity in patients who participated in the minocycline in RA (MIRA) trial. METHODS: Of 205 patients with a week-48 visit, blood was available for typing of HLA-DRB1 and HLA-DQB1 in 174 (85%) and successfully completed in 169 (82%). Baseline erosions were used to assess disease severity and new erosions at the last visit served as a proxy for progression. RESULTS: At baseline, there was no association between the presence of erosive disease or rheumatoid factor status and the dose of rheumatoid epitope (homozygous, heterozygous, none) or the specific alleles identified. At the final visit, a gradient was observed for the 3 allelic subgroups (and their gene doses) in the occurrence of new erosions among the Caucasian placebo-treated, but not the minocycline-treated, patients. A treatment group/HLA-DR4 epitope interaction was demonstrated in multivariate analyses. Approximately two-thirds of African-American patients did not have the rheumatoid epitope. CONCLUSION: HLA-DRB1 oligotyping may be useful in predicting the progression of disease in some Caucasian patients. Our study corroborates the infrequency of the epitope among African-American patients with RA.     

Osteoporosis in rheumatoid arthritis

Patients with rheumatoid arthritis (RA) develop both periarticular and generalized osteoporosis. Periarticular osteopenia in appendicular bones occurs early in the course of RA and is one of the earliest radiological signs of RA. An uncoupled state in bone resorption-formation linkage, contributes to the development of periarticular osteopenia and it might be mediated through an increased productions of cytokines and prostaglandins by synovium and bone marrow. Accordingly, early suppression of rheumatoid synovitis is necessary for the prevention of periarticular osteopenia. Generalized osteoporosis is also common in RA and leads to increased risk of fractures. Generalized osteoporosis considered to be multifactorial and factors contributing to lumbar osteoporosis might be different from those to loss of appendicular bones, such as femur and radius. Corticosteroids and menopausal state are important risk factors for lumbar osteoporosis. Rheumatoid activity and reduced physical activity are also important determinants. According to the previous studies, however, the influence of functional impairment is more prominent in the femoral BMD compared to spinal BMD. In addition to control of RA and maintenance of physical activity, hormone replacement therapy (HRT) and bisphosphonate are possible agents for the treatment of osteoporosis in RA patients, especially postmenopausal women.     

Muscle strength in rheumatoid elbow: quantitative measurement and comparison to Larsen's X-ray grade

Accurate assessment of elbow function is important to determine the total ability of the arm. The purpose of this study was to clarify the relationship between isometric muscle strength of the elbows of patients with rheumatoid arthritis (RA) and Larsen's X-ray evaluation. Fifty-six elbows of 45 RA patients aged 47 to 77 years (mean age, 63 years) were tested. Muscle strength was measured with an isometric torque-cell dynamometer. Test-retest reliability of the dynamometer was proven by measuring 12 elbows of 6 healthy young men. In RA patients, elbow flexion and extension strength decreased in proportion to increases in the severity of Larsen's grades from Grade 1 to 4. However, Grade 5 elbows had greater muscle strength than those in Grade 4. Forearm pronation and supination strength also decreased in proportion to increases in the severity of Larsen's grades from Grade 1 to 5. This quantitative study made it clear that the muscle strength of RA patients' elbows almost completely correlates to X-ray finding according to the grade of Larsen's evaluation based on X-rays. With regard to muscle strength of postoperative elbows, both flexion strength and supination strength after total elbow replacement (TER) were about two times greater than before TER, and after synovectomy it was as great as those in non-operative RA patients of Grade 2.     

Factors predicting outcome of rheumatoid arthritis: results of a followup study

OBJECTIVE: To determine prognostic factors in rheumatoid arthritis (RA). METHODS: One hundred thirty-two women with definite RA were followed yearly from an early phase of the disease (symptoms < 5 years) for a mean duration of 6 years. The prognostic value of the first available clinical and laboratory variables and assessments of functional ability was related to several outcome measures (physician's opinion of disease severity, disease activity, radiological abnormalities, functional ability and number of prescribed 2nd-line drugs) by single predictor analysis and by logistic regression. RESULTS: The variables most predictive for one or more of the outcome measures were number of swollen joints, Ritchie score, health assessment questionnaire score, radiographical abnormalities, positive IgM rheumatoid factor (RF), positive IgG-RF, HLA-DR4, and an elevated percentage serum agalactosyl IgG. The accuracy of predicting outcome was calculated from several combinations of these variables, and varied between 70 and 80%. The accuracy based on a combination of the commonly available variables (number of swollen joints, IgM-RF and the erosion score), closely approximated the maximal accuracy that could be achieved. CONCLUSION: The outcome of RA can be predicted by a combination of variables that are commonly available in the clinical setting.     

HLA-DM polymorphisms in patients with rheumatoid arthritis

OBJECTIVE: To investigate the contribution of HLA-DMA and DMB genes, which play a crucial role in the HLA class II restricted antigen presentation pathway, in susceptibility to rheumatoid arthritis (RA). METHODS: The distribution of DMA and DMB alleles was examined in patients with RA and in healthy subjects by oligotyping of PCR amplified genomic DNA with sequence specific oligonucleotide probes. RESULTS: There were no significant differences in the prevalence of DMA and DMB alleles in patients with RA as compared to healthy controls. In addition, no significant differences in frequencies of DMA and DMB alleles were observed in RA susceptibility epitope positive RA patients and controls. CONCLUSION: DMA and DMB genes do not appear to play a role in susceptibility to RA.