Analysis Of Characteristics Of Impaired Lung Function And Related Factors Leading To Chronic Obstructive Pulmonary Disease In Patients With Stage Ⅰ And Ⅱ Coal Workers’ Pneumoconiosis

Pneumoconiosis,mainly characterized by diffuse fibrosis of lung tissue,is caused by long-term inhalation of occupational mineral dust and retention in the lungs during occupational activities.At present,pneumoconiosis’ diagnosis in China mainly relies on imaging examination combined with dust exposure history,clinical manifestations and occupational survey data.However,respiratory physiology abnormalities have been reported less frequently in coal miners who lack radiographic evidence of pneumoconiosis or show only mild radiographic abnormalities.In addition to imaging examinations,pulmonary function tests play a key role in the screening of occupational diseases during the working life,as well as are the main method for evaluating and identifying the disease progression and working ability of patients with pneumoconiosis.Due to this,this study focuses on the following areas:(1)To explore the incidence and injury characteristics of impaired lung function in patients with stage I and II coal workers’ pneumoconiosis(CWP);(2)The prevalence of COPD varies significantly between populations,but is less studied in occupational cohorts.This study explores the prevalence and influencing factors of CWP combined with COPD,and analyzes the results of pulmonary function indicators and other relevant examinations in patients with CWP and COPD.Part Ⅰ Analysis of lung function characteristics of 228 patients with coal workers’ pneumoconiosis: a cross-sectional studyObjective:To explore the impaired lung function of coal workers’ pneumoconiosis patients of different ages,dust collection years,types of work,and pneumoconiosis stages.Methods:A total of 228 patients with stage I and II CWP who participated in the examination of the Key Laboratory of Pneumoconiosis of the National Health Commission in the First Hospital of Shanxi Medical University were chosen from August 2021 to December2021,and general data were recorded,and pulmonary function were examined.Results:1.A total of 228 male coal workers with CWP were included,with 181 cases(79.4%)in stage I and 47 cases(20.6%)in stage II.Among them,57 cases(25.0%)had pulmonary ventilation dysfunction.Compared with stage I CWP,the proportion of pulmonary ventilation dysfunction was higher in stage II(63.8% vs.14.9%),and the difference was statistically significant(p < 0.05).According to the types of ventilation dysfunction,there were 41 cases(18.0%)of obstructive ventilation dysfunction,4 cases(1.7%)of restrictive ventilation dysfunction,7 cases(3.1%)of mixed ventilation dysfunction,5 cases(2.2%)of nonspecific ventilatory dysfunction.There was no statistically significant difference in the distribution of ventilation dysfunction types among patients of different ages,dust exposure durations,occupational types,and stages of pneumoconiosis(p > 0.05).According to the severity of ventilation dysfunction,there were 44 cases(19.3%)of mild dysfunction,8 cases(3.5%)of moderate dysfunction,and5 cases(2.2%)of moderate to severe dysfunction or higher.Compared with stage I CWP,the proportion of moderate to severe pulmonary ventilation dysfunction was higher in stage II CWP(36.7% vs.7.4%),and the difference was statistically significant(p < 0.05).2.There were 43 cases(18.9%)with decreased pulmonary diffusion function,and the proportion of patients with decreased diffusion function was higher in stage II patients compared to stage I patients(36.2% vs.14.4%),with a statistically significant difference(p < 0.05).According to the severity of diffusion function decline,there were34 cases(14.9%)with mild decline and 9 cases(3.9%)with moderate to severe decline.Compared with CWP patients younger than 60 years old,the proportion of moderate to severe diffusion function decline was higher in patients aged 60 years and older(36.4%vs.4.8%),and the difference was statistically significant(p < 0.05).3.Among the 228 coal workers with CWP,93 cases(40.7%)had small airway dysfunction.Compared with CWP patients younger than 60 years old,patients aged 60 years and older had lower MMEF%pred(62.4±24.2 vs.69.4±23.4)and MEF25%pred[46.0(35.5,61.9)vs.57.9(38.1,69.4)],with statistically significant differences(p < 0.05).Compared with stage I CWP patients,stage II patients had lower MMEF%pred(52.5±25.6 vs.70.5±21.8),MEF50%pred(60.5±30.0 vs.78.1±23.0),and MEF25%pred[35.7(26.1,56.4)vs.57.9(41.3,67.7)],with statistically significant differences(p < 0.05).Conclusion:1.The incidence of pulmonary ventilation dysfunction and diffusion dysfunction in patients with CWP was high.2.Age and pneumoconiosis stage are the main risk factors for the decline of lung function.With the increase of age and the stage of pneumoconiosis,the proportion of pulmonary ventilation function and pulmonary diffusion function decline gradually increases and the degree gradually increases.3.Compared with conventional lung dysfunction,the incidence of small airway dysfunction is higher.Part Ⅱ Risk factors for coal workers’ pneumoconiosis combined with chronic obstructive pulmonary disease and its pulmonary function characteristicsObjective:To investigate the risk factors and pulmonary function characteristics of CWP combined with COPD.Methods:A total of 228 CWP patients in stage I and II who attended the First Hospital of Shanxi Medical University from August 2021 to December 2021 were enrolled.We recorded patients’ baseline information and occupational history.Then we examined their lung ventilation function,lung diffusion function,pulse oscillation resistance,and exhaled nitric oxide measurement.Results:1.Among the 228 coal workers with CWP,17 cases(7.5%)had coexisting COPD,including 5 cases(29.4%)in GOLD stage 1,10 cases(58.8%)in GOLD stage 2,and 2cases(11.8%)in GOLD stage 3.Univariate binary logistic regression analysis showed that age ≥ 60 years,stage II pneumoconiosis,rural residence,family history of respiratory system diseases,and history of respiratory tract infections in childhood were risk factors associated with the development of COPD in coal workers with CWP(p <0.05),while other risk factors showed no statistical significance(p > 0.05).2.The multifactorial Cox proportional hazards model showed that age ≥ 60 years,family history of respiratory system diseases,and history of respiratory tract infections in childhood were closely associated with an increased risk of developing COPD in coal workers with CWP,with hazard ratios(HR)of 3.846,4.746,and 7.314,respectively(p <0.05).3.Coal workers with CWP and coexisting COPD had decreased PEF,MMEF%pred,MEF50%pred,MEF25%pred,and DLCO%pred(P < 0.05),and increased Z5,R5,R20,mean R5-R20,and X5(p < 0.05).Conclusion:1.COPD is common in patients with CWP.2.Risk factors such as increasing ages,increasing pneumoconiosis stages,messy living environment,family history of respiratory diseases,and history of respiratory infections in childhood can lead to an increased risk of CWP combined with COPD.3.Compared with patients with simple CWP,the lung function of patients with CWP combined with COPD decreased,and airway resistance increased.