Increased pulmonary artery diameter is associated with reduced FEV₁ in former World Trade Center workers

Abstract

Rationale:Occupational exposures at the WTC site after September 11, 2001 have been associated with several presumably inflammatory lower airway diseases.Pulmonary arterial enlargement, as suggested by an increased ratio of the diameter of the pulmonary artery to the diameter of the aorta (PAAr) has been reported as a computed tomographic (CT) scan marker of adverse respiratory health outcomes, including WTC-related disease. In this study, we sought to utilize a novel quantitative CT (QCT) measurement of PAAr to test the hypothesis that an increased ratio is associated with FEV 1 below each subject's statistically determined lower limit of normal (FEV 1 < LLN). Methods: In a group of 1,180 WTC workers and volunteers, we examined whether FEV 1 < LLN was associated with an increased QCT-measured PAAr, adjusting for previously identified important covariates. Results: Unadjusted analyses showed a statistically significant association of FEV 1 < LLN with PAAr (35.3% vs 24.7%, P = 0.0001), as well as with height, body mass index, early arrival at the WTC disaster site, shorter WTC exposure duration, post-traumatic stress disorder checklist (PCL) score, wall area percent and evidence of bronchodilator response. The multivariate logistic regression model confirmed the association of FEV 1 < LLN with PAAr (OR 1.63, 95% CI 1.21, 2.20, P = 0.0015) and all the unadjusted associations, except for PCL score. Conclusions: In WTC workers, FEV 1 < LLN is associated with elevated PAAr which, although likely multifactorial, may be related to distal vasculopathy, as has been hypothesized for chronic obstructive pulmonary disease.

Cluster Analysis of World Trade Center Related Lower Airway Diseases

“…We also considered 6 bronchodilator response (BDR) at any visit, most often the baseline, defined as an increase in either FEV 1 or FVC of at least 12% and 200 mL in response to inhaled albuterol administration 7,10 ; body mass index (BMI) in kilograms per square meter measured at the baseline visit 8 ; weight gain (as indicated by longitudinal measured BMI trajectory (BMIslope) in kilograms per square meter per year 10 ). Lastly, from the QCT data, 9 total lung volume (TLV CT ), with calculated predicted values 28 and assessed by z scores, 10 lung attenuation volume percent, either high (HAV% from −600 to −250 Hounsfield units [HU], with >10% as cut point) and low (LAV% less than −950 HU, low attenuation volume percent, with >2.5% as cut point), 4,29 indirect distal airway measurements such as 11 end-expiratory air trapping at −856 HU (AT EXP 856), 8,29 and 12 mean expiratory:inspiratory lung density ratio (MLD EI ), 8 and proximal airway metrics such as 13 wall area percent (WAP) directly measured on the third generation of the right upper lobe, 8,10,29 and 14 Pi10, the average wall thickness of a hypothetical airway with a 10-mm luminal perimeter on CT 29,30 …”

“…and A.P.R.). 4,8,[10][11][12] We selected spirometries that met our quality selection requirement, namely, forced exhalatory time >6 seconds and overall spirometry (reproducibility) grades A, B, or (if at least five trials were available) C. 2,8,23 As previously reported, 23 our spirometry program quality assurance included both daily inspiratory and expiratory volume calibration checks and weekly expiratory linearity checks.…”

“…2,27 We also considered 6 bronchodilator response (BDR) at any visit, most often the baseline, defined as an increase in either FEV 1 or FVC of at least 12% and 200 mL in response to inhaled albuterol administration 7,10 ; body mass index (BMI) in kilograms per square meter measured at the baseline visit 8 ; weight gain (as indicated by longitudinal measured BMI trajectory (BMIslope) in kilograms per square meter per year 10 ). Lastly, from the QCT data, 9 total lung volume (TLV CT ), with calculated predicted values 28 and assessed by z scores, 10 lung attenuation volume percent, either high (HAV% from −600 to −250 Hounsfield units [HU], with >10% as cut point) and low (LAV% less than −950 HU, low attenuation volume percent, with >2.5% as cut point), 4,29 indirect distal airway measurements such as 11 end-expiratory air trapping at −856 HU (AT EXP 856), 8,29 and 12 mean expiratory:inspiratory lung density ratio (MLD EI ), 8 and proximal airway metrics such as 13 wall area percent (WAP) directly measured on the third generation of the right upper lobe, 8,10,29 and 14 Pi10, the average wall thickness of a hypothetical airway with a 10-mm luminal perimeter on CT. 29,30 As in previous studies of longitudinal lung function trajectories among participants in the Mount Sinai WTC GRC cohort, 4,10 we conducted a secondary analysis of the FEV 1 trajectories for the resulting clusters. As in previous work, 4 we estimated the longitudinal FEV 1 slopes for each subject with at least 3 good quality (as defined previously) spirometries performed between July 2002 and December 2018, and used them to define the following three trajectories as follows: rapid FEV 1 decline ("rapid decliner") by an FEV 1 slope < −66.5 mL/y (ie, less than the group mean-0.5 SD), FEV 1 gain ("gainer") by an FEV 1 slope > 0 mL/y, and intermediate FEV 1 decline ("intermediate decliner") by an FEV 1 slope between 0 and −66.5 mL/y (ie, between 0 and the group mean-0.5 SD).…”

“…Among workers engaged in rescue and recovery efforts, occupational exposures to dust and fumes at the World Trade Center (WTC) disaster site have been associated with lower respiratory symptoms, 1 worse lung function 2 and accelerated longitudinal lung function decline trajectories, 3,4 asthma 5 and other chronic airway diseases, 6–8 and both qualitative 9 and quantitative 4,8,10–12 abnormalities on computed tomography (CT) of the chest. Common co-existing morbidities, such as obesity, are linked to greater severity of WTC-related respiratory symptoms, airway disorders, and morbidity 13–19 …”