Measuring lung diffusing capacity: an opportunity for improved medical surveillance and disability evaluation of coal miners.

OBJECTIVES: Spirometry is the primary lung function test utilised for medical surveillance and disability examination for coal mine dust lung disease. However, spirometry likely underestimates physiologic impairment. We sought to characterise abnormalities of single-breath diffusing capacity for carbon monoxide (DLCO) among a population of former coal miners. METHODS: Data from 3115 former coal miners evaluated at a West Virginia black lung clinic between 2006 and 2015 were retrospectively analysed to study the association between diffusion impairment (abnormally low DLCO), resting spirometry and the presence and severity of coal workers' pneumoconiosis on chest radiography. We developed ordinary least squares linear regression models to evaluate factors associated with per cent predicted DLCO (DLCOpp). RESULTS: Diffusion impairment was identified in 20.2% of subjects. Ten per cent of all miners with normal spirometry had diffusion impairment including 7.4% of never smokers. The prevalence of diffusion impairment increased with worsening radiographic category of pneumoconiosis. Mean DLCOpp decreased with increasing small opacity profusion subcategory in miners without progressive massive fibrosis. Linear regression analysis also showed significant decreases in DLCOpp with increasing small opacity profusion and presence of large opacities. CONCLUSIONS: Diffusion impairment is common among former coal miners, including among never smokers, miners without radiographic pneumoconiosis and miners with normal spirometry. These findings demonstrate the value of including DLCO testing in disability examinations of former coal miners and an important role for its use in medical surveillance of working miners to detect early chronic lung disease.

Resting diffusing capacity and severity of radiographic disease predict gas exchange abnormalities with exercise in former US coal miners.

BACKGROUND: The US Department of Labor (DOL) does not fund diffusing capacity (DLCO) or metabolic measurements from cardiopulmonary exercise testing (CPET) for coal miners' disability evaluations. Although exercise arterial blood gas testing is covered, many miners are unable to perform maximal tests, and sampling at peak exercise can be challenging. We explored the relationship between resting DLCO, radiographic disease severity, and CPET abnormalities in former US coal miners. METHODS: We analyzed data from miners evaluated between 2005 and 2015. Multivariable linear and logistic regression analyses were used to examine relationships between percent predicted (pp) forced expiratory volume in 1 s (FEV1pp), DLCOpp, VO2maxpp, A-a oxygen gradient (A-a)pp, dead space fraction (Vd/Vt), disabling oxygen tension (PO2), and radiographic findings of pneumoconiosis. RESULTS: Data from 2015 male coal miners was analyzed. Mean tenure was 28 years (SD 8.6). Thirty-twopercent had an abnormal A-a gradient (>150 pp), 20% had elevated Vd/Vt (>0.33), and 34% a VO2max < 60 pp. DLCOpp strongly predicted a disabling PO2, with an odds ratio (OR) of 2.33 [2.09-2.60], compared to 1.18 [1.08-1.29] for FEV1. Each increase in subcategory of small opacity (simple) pneumoconiosis increased the odds of a disabling PO2 by 42% [1.29-1.57], controlling for age, body mass index, pack-years of tobacco smoke exposure, and years of coal mine employment. CONCLUSIONS: DLCO is the best resting pulmonary function test predictor of CPET abnormalities. Radiographic severity of pneumoconiosis was also associated with CPET abnormalities. These findings support funding DLCO testing for impairment and suggest the term "small opacity" should replace "simple" pneumoconiosis to reflect significant associations with impairment.

[Changes of lung function and inflammatory factors in rat models of coal workers' pneumoconiosis].

Objective: To observe the changes of lung function and inflammatory factors in rat models of coal workers' pneumoconiosis at different time points. Methods: In June 2021, 96 healthy male SD rats with SPF grade were divided into 1, 3, and 6-month control group and dust staining group (coal dust group, coal silica dust group, quartz group) according to random number table method, with 8 rats in each group. After one week of adaptive feeding, a one-time non-exposed tracheal perfusion method (1 ml/ piece) was used. The dust dyeing group was given 50 g/L coal dust, coal silica mixed dust and quartz dust suspension, respectively, and the control group was given 0.9% normal saline solution. At 1, 3 and 6 months after perfusion, lung function was detected by animal lung function apparatus, then all lung tissues and alveolar lavage fluid were killed, and lung histopathological morphological changes were observed by HE staining, and the contents of interleukin (IL-1ß), IL-18, IL-4 and IL-10 in alveolar lavage fluid were detected by ELISA. One-way analysis of variance was used to compare groups. Two factors (inter-group treatment factor (4 levels) and observation time factor (3 levels) ) were used in the analysis of the effects of inter-group treatment and treatment time on related indicators. Results: HE staining results showed that coal spot appeared in the lung tissue of coal dust group, coal spot and coal silicon nodule appeared in the lung tissue of coal dust group, and silicon nodule appeared in the lung tissue of quartz group. Compared with the control group, the forced vital capacity (FVC) and forced expiratory volume at 0.2 second (FEV(0.2)) of rats in the dust staining group had interaction between the treatment and treatment time (P<0.05). With the increase of dust dyeing time, FVC and FEV(0.2) decreased significantly at 3-6 months of dust dyeing, and the maximum gas volume per minute (MVV) decreased significantly at 1-3 months of dust dyeing (P<0.05). The lowest lung function index was in quartz group, followed by coal-silica group and coal-dust group. There were statistically significant differences in the main effect and interaction effect of the pro-inflammatory factor IL-18 among all groups in treatment and treatment time (IL-18: F=70.79, 45.97, 5.90, P<0.001), and interaction existed. The highest content of inflammatory factors in alveolar lavage fluid of all dust groups was quartz group, followed by coal silica group and coal dust group. There were significant differences in the main effect and interaction effect of anti-inflammatory factors between groups and treatment time (IL-4: F=41.55, 33.01, 5.23, P<0.001, <0.001, <0.001; IL-10: F=7.46, 20.80, 2.91, P=0.002, <0.001, 0.024), and there was interaction. The highest content of anti-inflammatory factor was in quartz group, followed by coal silica group and coal dust group. Conclusion: Lung function decreased and levels of inflammatory fators increased in rat models of coal workers' pneumoconiosis, with the quartz group being the most severely damaged. Lung function is mainly impaired in thrid-six months, and the content of inflammatory factors begins to change in first-thrid months. MVV are the earliest and most obvious in lung function. IL-18 is suitable for monitoring changes in the pro-inflammatory response of coal workers' pneumoconiosis, and IL-10 is suitable for monitoring changes in anti-inflammatory response.

Respiratory traits and coal workers' pneumoconiosis: Mendelian randomisation and association analysis.

OBJECTIVES: Susceptibility loci of idiopathic pulmonary fibrosis and chronic obstructive pulmonary disease were also significantly associated with the predisposition of coal worker's pneumoconiosis (CWP) in recent studies. However, only a few genes and loci were targeted in previous studies. METHODS: To systematically evaluate the genetic associations between CWP and other respiratory traits, we reviewed the reported genome-wide association study loci of five respiratory traits and then conducted a Mendelian randomisation study and a two-stage genetic association study. RESULTS: Interestingly, we found that for each SD unit, higher lung function was associated with a 66% lower risk of CWP (OR=0.34, 95% CI: 0.15 to 0.77, p=0.010) using conventional Mendelian randomisation analysis (inverse variance weighted method). Moreover, we found susceptibility loci of interstitial lung disease (rs2609255, OR=1.29, p=1.61×10-4) and lung function (rs4651005, OR=1.39, p=1.62×10-3; rs985256, OR=0.73, p=8.24×10-4 and rs6539952, OR=1.28, p=4.32×10-4) were also significantly associated with the risk of CWP. Functional annotation showed these variants were significantly associated with the expression of FAM13A (rs2609255, p=7.4 ×10-4), ANGPTL1 (rs4651005, p=5.4 ×10-7), SPATS2L (rs985256, p=1.1 ×10-5) and RP11-463O9.9 (rs6539952, p=7.1 ×10-6) in normal lung tissues, which were related to autophagy pathway simultaneously according to enrichment analysis. CONCLUSIONS: These results provided a deeper understanding of the genetic predisposition basis of CWP.

Early radiographic pneumoconiosis is associated with impaired exercise gas exchange among coal miners with normal resting spirometry.

RATIONALE: We sought to determine if radiographic pneumoconiosis predicts abnormal gas exchange during exercise in coal mine workers with preserved resting lung function. METHODS: We analyzed data from former coal miners seen between 2006 and 2014 in a single clinic specializing in black lung evaluations. We limited the analysis to those with normal resting spirometry and an A-a gradient at peak exercise ≥10 mmHg. We used multivariable logistic regression to estimate predictors of A-a gradient widened to >150% of the reference value. We focused on chest radiographs consistent with pneumoconiosis, taking into account higher silica exposure mining activities and years underground, and adjusting for cigarette smoking, obesity, and coronary artery disease. RESULTS: Of 5507 miners, we analyzed data for 742 subjects with normal spirometry and all key clinical variables available, of whom 372 (50.1%) had radiographic evidence of pneumoconiosis. All but 21 had small opacity profusion of less than 2/1. The median A-a gradient at peak exercise was 108% of reference value (interquartile range, 81%-141%). In the multivariable analysis, radiographic pneumoconiosis was associated with increased odds of widened A-a gradient (odds ratio [OR], 2.47; 95% confidence interval [CI], 1.7-3.7). Limited to 660 subjects with normal diffusing capacity for carbon monoxide, the odds were similarly increased (OR, 3.20; 95% CI, 1.5-3.6). DISCUSSION: Among coal miners with preserved resting lung function, radiographic evidence of early pneumoconiosis more than doubled the odds of abnormal exercise physiology. Impairment in pneumoconiosis occurs in early disease and may only be evident on exercise testing.

Cross-section analysis of coal workers' pneumoconiosis and higher brachial-ankle pulse wave velocity within Kailuan study.

BACKGROUND: Brachial-ankle pulse wave velocity (baPWV) is an independent predictor of cardiovascular events and mortality. However, there is no related data on the association of baPWVwith coal workers' pneumoconiosis (CWP). We explored the baPWV in subjects withCWP and the associated risk factors. METHODS: Thiscase-control study included 1,007 male CWP cases without a history of stroke and coronary heart disease and 1,007 matched controls from the Kailuan cohort study. All of the participants underwent assessment for baPWV and traditional cardiovascular risk factors. The cumulative silica dust exposure (work history linked to a job-exposure matrix) was estimated for the CWP cases. RESULTS: Compared with the controls, the CWP cases had higher baPWV (1762.0 ± 355 cm/s vs. 1718.6 ± 354 cm/s, P = 0.006) and a higher risk of increased baPWV (defined as more than the median baPWV of the population distribution; odds ratio 1.43, 95% confidence interval 1.11-1.83) after adjusting for traditional cardiovascular risk factors. Age ≥60 years, body mass index, heart rate, and hypertension were all significantly associated with increased baPWV in the CWP cases. Compared to non-CWP subjects without hypertension, the odds ratios for increased baPWV gradually increased (P for trend, 0.001) across the CWP subjects without hypertension (odds ratio 1.20, 95%confidence interval 0.90-1.61), subjects with hypertension alone (odds ratio 2.54, 95% confidence interval 1.95-3.30), and CWP subjects with hypertension (odds ratio 3.34, 95% confidence interval 2.56-4.37). We detected a significant positive exposure-response relationship between silica dust-exposure quartiles and increased baPWV in CWP cases (P for trend < 0.001). CONCLUSIONS: For patients with CWP, increased baPWV was associated with traditional cardiovascular risk factors and long-term silica dust exposure.

Assessment of subclinical right ventricular systolic dysfunction in coal miners using myocardial isovolumic acceleration.

OBJECTIVE: Several studies have been conducted regarding the effects of coal mining on the respiratory system. However, there is a lack of data concerning potential effects of coal mining on the cardiovascular system. In this study, we aimed to evaluate the potential subclinical right and left ventricular dysfunction in coal miners. METHODS: This single-center, prospective study included a total of 102 patients. Patient and control groups consisted of 54 coal miners and 48 healthy men, respectively. All patients underwent 12-lead electrocardiography, transthoracic echocardiography, and pulmonary function test. RESULTS: As compared to control group, coal miners had significantly higher right ventricular myocardial performance index (RVMPI) (0.41 ± 0.03 vs 0.37 ± 0.02, P < .001), lower right ventricular fractional area change (RVFAC) (33.55% ± 6.70% vs 37.04 ± 9.26 P < .05), lower tricuspid annular plane systolic excursion (TAPSE) (1.54 ± 0.17 vs 1.73 ± 0.25, P < .001), lower myocardial isovolumic acceleration (IVA) (2.13 ± 0.16 vs 2.56 ± 0.36 P < .001) and decreased aortic distensibility (AD) (4.14 ± 2.18 vs 6.63 ± 3.91 P < .001). All of the echocardiographic parameters were positively correlated with exposure time to coal mine dust, except IVA. CONCLUSION: Echocardiographic parameters of both right and left ventricular dysfunction, including RVMPI, RVFAC, TAPSE, IVA, and AD, are impaired in coal miners.

Ocular findings in coal miners diagnosed with pneumoconiosis.

OBJECTIVE: Our study aimed at evaluating ocular findings and structural changes in coal mine workers who were chronically exposed to coal mine dust and diagnosed with pneumoconiosis. METHODS: Ocular findings of 161 eyes of 81 patients diagnosed with pneumoconiosis who had previously worked or are currently working in coal mines were analyzed. Forty-six coal mine workers and sex matched healthy people (n = 20) participated in the study. Workers who had early changes of pneumoconiosis were included in Group 1 (n = 17), workers diagnosed with pneumoconiosis were included in Group 2 (n = 29), and healthy subjects were included in Group 3 (n = 20). Outcome measures were the difference in peripapillary retinal nerve fiber layer (RNFL) thickness, choroidal thickness (CT), central macular thickness (CMT) and tear function tests between the groups. RESULTS: RNFL thickness values in Group 1 and 2 were lower than in Group 3, the control group, in all quadrants except the temporal quadrant. However, there was no statistically significant difference in peripapillary RNFL thickness values in any quadrants among the three groups (p > 0.05). Central subfoveal choroidal thickness and CMT measurements were thinner in Group 1 and 2 than in the control group. However, this difference among groups was not statistically significant (p > 0.05). Mean schirmer's test result was 8.8 ± 1.6 mm in group 1, 7.1 ± 1.8 mm in Group 2 and 11.5 ± 3.6 mm in the control group. Mean tear break up time (BUT) test result was 7.1 ± 1.3 seconds (sec) in Group 1, 6.5 ± 1.8 sec in Group 2 and 10.4 ± 2.9 s in the control group. The Schirmer's test and BUT test results were both statistically significantly lower in coal mine workers (Group 1 and 2) compared to the control group. Group 1 and Group 2 did not show statistically significant difference in terms of Schirmer's test and BUT test results. DISCUSSION: The association between pneumoconiosis and coal mine dust contiguity is thought to be due to the effect of coal dust by producing chronic inflammation. In addition, there are several trace elements in coal dust which are toxic to vital tissues. In this study, ocular findings suggest that systemic levels of trace elements and chronic inflammation may not reach to a level that influences ocular structures. Nonetheless, tear functions seem to be affected in coal mine workers. CONCLUSION: This study suggests that the systemic effect of coal mine dust in ocular structures is not evident. However, direct contact with coal mine and fume leads to a decrease in tear function tests.

Emphysema and Airflow Obstruction in Non-Smoking Coal Miners with Pneumoconiosis.

BACKGROUND Accumulating evidence shows that functional impairment in subjects with coal workers' pneumoconiosis (CWP) is principally due to emphysema and airflow obstruction, rather than underlying restrictive mechanisms. However, cigarette smoking has remained a major confounder. The aim of this study was to assess whether coal dust exposure was associated with emphysema and/or airflow obstruction in the absence of smoking history. MATERIAL AND METHODS The subjects evaluated for possible pneumoconiosis between 2013 and 2015 were retrospectively enrolled into this study. After excluding those with history of smoking, tuberculosis, or lung cancer, the study population was a total of 57 subjects. The emphysema severity and airflow obstruction were quantified by computed tomographic densitometry analysis and spirometry, respectively. For comparability regarding emphysema, 9 age- and sex-matched nonsmoker (n=9) control subjects without known lung disease were randomly selected from a radiology database. RESULTS Emphysema severity was significantly higher in the CWP group compared with the control group (15% vs. 4%, p<0.001). The median percent emphysema and percentage of those with FEV1/FVC <0.7 was 13% and 37% in subjects with simple CWP and 18% and 67% in subjects with complicated CWP, respectively. Percent emphysema and Perc15 (15th percentile of the attenuation curve) was correlated with FEV1/FVC (r=-0.45, r=-0.47) and FEF25-75 (r=-0.36, r=-0.56), respectively, but not with perfusion score. A linear regression analysis showed that factors associated with emphysema were FEV1/FVC (ß=-0.24, p=0.009) and large opacity (ß=-3.97, p=0.079), and factors associated with FEV1/FVC were percent emphysema (ß=-0.51, p=0.018) and tenure (ß=-0.63, p=0.044). CONCLUSIONS Our results support the observation that coal dust exposure is associated with emphysema and airflow obstruction, independent of smoking status.

Lung transplantation is increasingly common among patients with coal workers' pneumoconiosis.

BACKGROUND: The prevalence of coal workers' pneumoconiosis (CWP) in U.S. coal miners has increased, and severe presentations are increasingly common. METHODS: We describe trends in lung transplantation during 1996-2014 for recipients with a primary diagnosis of CWP or pneumoconiosis unspecified, and we summarize recipient characteristics and estimate survival. RESULTS: A total of 47 transplants were included; nearly three-quarters were performed during 2008-2014. All recipients were male, 96% were white, and the mean age was 56 years. Mean FEV1 % was 35%; mean FVC% was 53%. Mean time on a waitlist was 155 days, and 60% of transplants were bilateral. Median survival was 3.7 years. CONCLUSIONS: These transplants reflect the use of a scarce resource for an entirely preventable disease, and highlight the need for enhanced efforts to reduce coal mine dust exposures.

Small airways involvement in coal mine dust lung disease.

Inhalation of coal mine dust results in a spectrum of symptoms, dysfunction, and pathological changes in the respiratory tract that collectively have been labeled coal mine dust lung disease. Recent reports from periodic health surveillance among underground and surface coal miners in the United States have demonstrated an increasing prevalence and severity of dust diseases, and have also documented that some miners experience rapid disease progression. The coal macule is an inflammatory lesion associated with deposited dust, and occurs in the region of the most distal conducting airways and proximal respiratory bronchioles. Inflammatory changes in the small airways have long been recognized as the signature lung pathology among coal miners. Human and laboratory studies have suggested oxidant injury, and increased recruitment and activity of macrophages play important roles in dust-induced lung injury. However, the functional importance of the small airway changes was debated for many years. We reviewed published literature that documents a pervasive occurrence of both physiologic and structural abnormalities in small airways among coal miners and other workers exposed to airborne particulates. There is increasing evidence supporting an important association of abnormalities in the small peripheral airways with the development of respiratory symptoms, deficits in spirometry values, and accelerated declines in ventilatory lung function. Pathologic changes associated with mineral dust deposition in the small airways may be of particular importance in contemporary miners with rapidly progressive respiratory impairment.

[Ventilatory function in patients with silicosis or coal workers' pneumoconiosis]. / Výskyt ventilacní poruchy plic u osob se silikózou a pneumokoniózou uhlokopa.

OBJECTIVES: The aim of the study was to determine ventilatory function in a group of patients with silicosis and coal workers pneumoconisos (CWP) newly granted as occupational disease. METHODS: The authors have undertaken the analysis of all cases of occupational silicosis and CWP which were diagnosed in men in the South Moravia region. Information on ventilatory function, chest symptoms, age, working and smoking history was collected during the medical surveys, including spirometry testing and chest radiography. Diagnosis was based on history of occupational exposure to coal or silica dust, chest x-ray findings, using International Labour Office classification. RESULTS: In the years 1997-2014, 116 occupational silicosis and coal workers´ pneumoconiosis have been notified. There were diagnosed 42 cases of simple and 17 cases of complicated silicosis, 40 cases of the simple and 17 cases of complicated CWP. Duration of exposure to respiratory hazards, smoking history and prevalence of ventilatory impairment were not significantly different between these groups. The mean age of persons at diagnosing occupational disease was 61.0 (SD 11.2) years, the mean duration of exposure to respirable dust was 24.7 (SD 10.2) years. Abnormal spirometry results were detected in 51.7% of pneumoconiotics--8.6% with restrictive, 11.2% with obstructive, and 31.9 with mixed impairment. The prevalence of ventilatory function impairment was found to be significantly associated with chronic obstructive pulmonary disease and age. CONCLUSIONS: Testing of ventilatory function has an important role in the evaluation of lung disease in employees exposed to various respirable hazards. Although such testing was not useful for diagnosing silicosis or CWP, it was important for evaluating compensation amount for occupational disease in 51.7% pneumoconiotic patiens.

[The effect of pneumoconiosis observation object and coal workers' pneumoconiosis in one stage again in the dust exposure work after whole lung lavage].

OBJECTIVE: To investigate the effects of secondary dust exposure after whole-lung lavage (WLL) on the clinical symptoms, arterial blood gas parameters, and pulmonary function in subjects with pneumoconiosis and patients with stage I coal workers' pneumoconiosis (CWP). METHODS: The subjects with pneumoconiosis and patients with stage I CWP who underwent WLL in our hospital during the study period were selected. All patients were divided into postoperative dust exposure group (n = 86) and lavage control group (n = 86) according to whether they were exposed to dust after conventional operation. In addition, their workmates with similar age, history of dust exposure, and type of dust exposure were selected as non-lavage control group (n = 86). Follow-up was performed before and at one month and one year after WLL to evaluate clinical symptoms, arterial blood gas parameters, and pulmonary function. RESULTS: One month after operation, the clinical scores of the postoperative dust-exposure group and lavage control group were significantly reduced compared with their preoperative scores and the clinical score of the non-lavage control group (P < 0.01). One year after operation, the clinical scores of the postoperative dust-exposure group and lavage control group were significantly reduced compared with their preoperative scores and the clinical score of the non?lavage control group (P < 0.01), and the lavage control group had a significantly lower clinical score than the postoperative dust exposure group (P < 0.01). One month after operation, the arterial partial pressure of oxygen (PaO2) of the postoperative dust-exposure group and lavage control group were significantly higher than their preoperative values and the arterial PaO2 of the non-lavage control group (P < 0.01). One year after operation, the lavage control group had significantly higher arterial PaO2 than the postoperative dust exposure group and the arterial PaO2 of the non-lavage control group was significantly lower than its preoperative value and the arterial PaO2 of the postoperative dust exposure group and lavage control group (P < 0.05 or P < 0.01); the postoperative dust exposure group showed a significant decrease in arterial PaO2 (P < 0.01), while the lavage control group showed a significant increase in arterial PaO2 (P < 0.01). The partial pressure of carbon dioxide showed no significant differences between the three groups before and at one month and one year after operation (P > 0.05). CONCLUSION: Dust exposure should be avoided after WLL to ensure the treatment outcome.

Rapid decline in lung function in coal miners: evidence of disease in small airways.

BACKGROUND: Coal mine dust exposure can cause both pneumoconiosis and chronic airflow limitation. The contributions of various pathophysiologic mechanisms to dust-related lung function decrements remain unclear. METHODS: Clinical and physiological findings were assessed for 15 underground coal miners who had demonstrated accelerated FEV1 losses (decliners) over 6-18 years. Decliners' findings were evaluated in comparison to a group of 11 miners who had shown relatively stable lung function (referents) during the same period. RESULTS: At follow-up examination, the decliners showed significantly greater mean airway resistance (10.47 vs. 6.78 cmH2 O/L/s; P = 0.05) and more air trapping (RV/TLC = 37.5 vs. 29.1%; P < 0.01) compared to the referents. Decliners also demonstrated more evidence of small airways dysfunction and tended to have more bronchospasm than the referent group. Total lung capacity, lung compliance, diffusing capacity, and chest radiography did not differ significantly between the two groups. After cessation of mine dust exposures, the decliners' mean rate of FEV1 loss normalized. CONCLUSION: In a series of working coal miners, accelerated lung function declines were associated with air trapping and evidence of small airways dysfunction. A preventive benefit from controlling dust exposures was suggested.

[The value of terminal force of P wave in V1 lead in the diagnosis of coal-worker's pneumoconiosis with pulmonary heart disease complicated by left ventricular hypertrophy].

OBJECTIVE: To determine the value of terminal force of P wave in V1 lead (Ptf-V1) in the diagnosis of coal-workers' pneumoconiosis with pulmonary heart disease complicated by left ventricular hypertrophy. METHODS: Select the coal-worker with pneumoconiosis postmortem examination cases which were pathologically diagnosed as pulmonary heart disease complicated by left ventricular hypertrophy and can measure Ptf-V1. Select 14 cases with ECG left axis deviation, no deviation and right axis deviation. Measure and analyze the Ptf-V1 value, the thickness of left and right ventricular wall. RESULTS: There's obvious discrepancy in ventricular wall thickness mean in ECG left axis deviation, no deviation and right axis deviation groups, the discrepancy have statistical significance (F1 = 32.18, P < 0.01, F2 = 8.02, P < 0.01). The left ventricular wall is thicker in ECG left axis deviation group [(1.81 +/- 0.18) cm] than in no deviation [(1.47 +/- 0.15) cm] and right axis deviation groups [(1.39 +/- 0.10) cm], the discrepancy have statistical significance with (P < 0.01). The right ventricular wall is thicker in ECG left axis deviation group [(0.79 +/- 0.14) cm] than in no deviation group [(0.58 +/- 0.14) cm], the discrepancy have statistical significance with (P < 0.01). The right ventricular wall is thicker in ECG right axis deviation group [(0.71 +/- 0.14) cm] than in no deviation group, the discrepancy have statistical significance with (P < 0.05). ECG left axis deviation Ptf-V1 relevance ratio 85.71% is higher than in no deviation (35.70%) and right axis deviation groups (28.57%), the discrepancy have statistical significance with (P < 0.01). The Ptf-V1 absolute value is positively related with left ventricular wall thickness in ECG left axis deviation and no deviation groups (r1 = 0.92, P < 0.01, r2 = 0.93, P < 0.01). CONCLUSION: Pft-V1 absolute value is the criterion index of left ventricular morphosis and function especially left atrium loading change. ECG Ptf-V1 combined with ECG left axis deviation is valuable to the diagnosis of coal-workers with pneumoconiosis complicated by left ventricular hypertrophy.

[The value of P wave dispersion in the diagnostic of pulmonary heart disease in coal worker's pneumoconiosis].

OBJECTIVE: To determine the value of measuring P wave dispersion of ECG in the diagnosis of pulmonary heart disease in patients with coal worker's pneumoconiosis. METHODS: 50 patients with stage III and 185 patients with different stages of coal worker's pneumoconiosis were included in the study. Compare the P wave of ECG and investigate nine indexes of P-wave dispersion. RESULTS: The figure of ECG P wave dispersion was distinct, easy to measure and of high positive incidence. The positive incidence of indexes (P wave voltage > or = 0.22 mV, P wave axis > or = +80 degrees, P1 lead peak angle < or = 70 degrees, P wave elevation speed > or = 0.5 mm/s, PavL inversion, IPIV1 > or = 0.03 mms, Ta wave depressed > or = 0.05 mV, height of PV1 biphasic wave straight sharp corner > 0.07 mV) were 74.00%, 72.00%, 68.00%, 62.00%, 56.00%, 60.00%, 54.00%, 34.00% in 50 cases patients with stage III coal worker's pneumoconiosis, the discrepancy had statistical significance (P < 0.01). The above ECG P wave dispersion indexes was higher with coal worker pneumoconiosis stage, the discrepancy had statistical significance (P < 0.01). CONCLUSIONS: Adopt P wave dispersion as the index of measuring right atrial hypertrophy is beneficial to the early diagnosis of pulmonary heart disease in patients with coal worker's pneumoconiosis.

Medicare Claims Paid by the Federal Black Lung Benefits Program: US Medicare Beneficiaries, 1999 to 2016.

OBJECTIVE: To establish the burden of totally disabling respiratory impairment among coal miners, we identified the healthcare utilization and cost for Medicare claims where the Federal Black Lung Program (FBLP) was the primary payer. METHODS: We extracted FBLP claims from 1999 to 2016 institutional Medicare data along with beneficiary, comorbidity, and claim cost information. Healthcare utilization was evaluated and compared to the 2016 Medicare population. RESULTS: The FBLP was the primary payer on 75,690 claims from 19,700 beneficiaries and paid an increasing percentage of the total paid to providers annually. Claims decreased from 1999 to 2016 but cost per claim increased. Beneficiaries were hospitalized and visited the ER for respiratory and cardiovascular conditions. CONCLUSIONS: Medicare beneficiaries with FBLP primary payer claims have higher healthcare utilization and comorbidities compared with Medicare enrollees, indicative of increased financial and healthcare burden.

[Influencing factors of pulmonary dysfunction in coal worker's pneumoconiosis].

OBJECTIVE: To investigate the possible influencing factors of pulmonary dysfunction in coal worker's pneumoconiosis (CWP). METHODS: A total of 141 patients with CWP and 200 control miners with similar exposure histories but without apparent pulmonary disease or inflammation were interviewed with the detailed questionnaires (including histories of coal dust-exposure, smoking habits, alcohol consumption, protective mask uses, et al). Lung function examinations were performed at the same time. Predicted formula of lung function index were established by the local healthy residents characters and the pulmonary dysfunction was classified by the ratios between tested and predicted values. RESULTS: All parameters of lung function were significantly lower in CWP cases when compared with that of control miners and the healthy controls (P < 0.05). The main types of pulmonary dysfunction were restrictive and mixed ventilation disorders in CWP patients. The factors such as the category of CWP, the mask worn, the smoking quantity and exposure to coal mine dust were included in the unconditional logistic regression model. CONCLUSIONS: The category of CWP, the usage of mask, the smoking and long duration exposure to coal mine dust may be the main possible influencing factors of pulmonary dysfunction of CWP. Influencing factor analyses were given to inform choice of pertinence preventive measures.

Increasing Severity of Pneumoconiosis Among Younger Former US Coal Miners Working Exclusively Under Modern Dust-Control Regulations.

BACKGROUND: Coal workers' pneumoconiosis (CWP) steadily declined among US miners following dust control regulations in 1970. In 2000, severe forms of this disease reemerged among young miners, and are well described among working-but not former-miners. METHODS: Black lung benefits program (BLBP) data (2001 to 2013) were used to estimate respiratory disease burden among former miners including: (1) CWP (simple; advanced CWP, and progressive massive fibrosis [CWP/PMF]); and (2) respiratory impairment (FEV1 percent reference: mild, moderate, ≥moderately-severe). RESULTS: Among 24,686 claimants, 8.5% had advanced CWP/PMF; prevalence was highest among younger (less than or equal to 56 years: 10.8%) and older (greater than 70 years: 8.4%) miners and those who began work after versus before 1970 (8.3% vs. 4.0%). CONCLUSIONS: BLBP claims provide potentially useful data for monitoring the burden and severity of coal mine dust lung disease, and assessing efficacy of protective regulations.