Mortality risk associated with occupational exposures in people with small airways obstruction.

BACKGROUND: Small airways obstruction (SAO) has been associated with occupational exposures. Whether exposure to harmful occupational agents impacts the survival of people with SAO is unknown. Our aim was to estimate the mortality risk associated with occupational exposures among people with SAO. METHODS: We used data from UK Biobank participants with SAO, defined as a ratio of forced expiratory volume in three seconds to forced expiratory volume in six seconds (FEV3/FEV6) below the lower limit of normal. We assigned lifetime occupational exposures to participants with available occupational histories using the ALOHA+ Job Exposure Matrix. Mortality data were provided by the National Death Registries. We used Cox regression to assess the association of all-cause mortality with lifetime occupational exposures (vapours, gases, dusts, fumes-VGDF; solvents; pesticides; metals), adjusting for potential confounders. RESULTS: The 13,942 participants with SAO had a mean age of 56±7 years, 59% were females and 94.2% were of White ancestry. Overall, there were 457 deaths over a median follow-up of 12.8 years. A greater mortality risk was associated with exposure to VGDF, with hazard ratios of 1.32 (95%CI: 1.04-1.78) for low levels and 1.41 (95%CI: 1.11-1.78) for moderate levels of cumulative exposure. There was no evidence of association for the other occupational exposures. CONCLUSION: Lifetime occupational exposure to VGDF in people with SAO may have a detrimental effect on their survival. Future respiratory health surveillance programmes of people exposed to VGDF should consider assessment for SAO and focus on primary prevention through adequate exposure control.

Small Airways Obstruction and Mortality: Findings From the UK Biobank.

BACKGROUND: Small airways obstruction (SAO) is common in general populations. It has been associated with respiratory symptoms, cardiometabolic diseases, and progression to COPD over time. Whether SAO predicts mortality is largely unknown. RESEARCH QUESTION: Is spirometry-defined SAO associated with increased mortality? METHODS: Data were analyzed from 252,877 adult participants, aged 40 to 69 years at baseline, in the UK Biobank who had provided good-quality spirometry measurements. SAO was defined as the ratio of the forced expiratory volume in 3 s to the forced expiratory volume in 6 s less than the lower limit of normal. SAO was considered to be isolated if present when the FEV1/forced expiratory volume in 6 s ratio was normal (ie, greater than the lower limit of normal). A multivariable Cox regression model was used to assess the association of SAO, and isolated SAO, with all-cause and disease-specific mortality. Sex differences were investigated in these associations, and the primary analysis was repeated, excluding those who ever smoked. All models were adjusted for potential confounders such as sex, BMI, smoking status, smoking pack-years, assessment center, Townsend deprivation index, and ethnicity. RESULTS: A total of 59,744 participants with SAO were identified, of whom 24,004 had isolated SAO. A total of 5,009 deaths were reported over a median of 12.8 years of follow-up. Participants with SAO had increased all-cause (hazard ratio [HR], 1.31; 95% CI, 1.26-1.36), cardiovascular (HR, 1.39; 95% CI, 1.29-1.51), respiratory (HR, 2.20; 95% CI, 1.92-2.51), and neoplasm (HR, 1.23; 95% CI, 1.17-1.29) mortality risk. These associations were not modified by sex. However, in those who never smoked, only respiratory and cardiovascular mortality risk was associated with SAO. Isolated SAO was also associated with an increased mortality risk (HR, 1.14; 95% CI, 1.07-1.20). INTERPRETATION: Individuals with SAO have an increased risk of all-cause and disease-specific mortality. Further studies are needed to determine whether SAO causes mortality or is a marker of underlying disease.

Occupational exposures and small airway obstruction in the UK Biobank Cohort.

Background: Small airways obstruction (SAO) is a key feature of both COPD and asthma, which have been associated with workplace exposures. Whether SAO, which may occur early in the development of obstructive lung disease and without symptoms, also associates with occupational exposures is unknown. Methods: Using UK Biobank data, we derived measurements of SAO from the 65 145 participants with high-quality spirometry and lifetime occupational histories. The ALOHA+ Job Exposure Matrix was used to assign lifetime occupational exposures to each participant. The association between SAO and lifetime occupational exposures was evaluated using a logistic regression model adjusted for potential confounders. A second logistic regression model was also run to account for potential co-exposures. Results: SAO was present in varying proportions of the population depending on definition used: 5.6% (forced expiratory flow between 25 and 75% of the forced vital capacity (FEF25-75) < lower limit of normal (LLN)) and 21.4% (forced expiratory volume in 3 s (FEV3)/forced expiratory volume in 6 s (FEV6)

Identification of an increased lifetime risk of major adverse cardiovascular events in UK Biobank participants with scoliosis.

BACKGROUND: Structural changes caused by spinal curvature may impact the organs within the thoracic cage, including the heart. Cardiac abnormalities in patients with idiopathic scoliosis are often studied post-corrective surgery or secondary to diseases. To investigate cardiac structure, function and outcomes in participants with scoliosis, phenotype and imaging data of the UK Biobank (UKB) adult population cohort were analysed. METHODS: Hospital episode statistics of 502 324 adults were analysed to identify participants with scoliosis. Summary 2D cardiac phenotypes from 39 559 cardiac MRI (CMR) scans were analysed alongside a 3D surface-to-surface (S2S) analysis. RESULTS: A total of 4095 (0.8%, 1 in 120) UKB participants were identified to have all-cause scoliosis. These participants had an increased lifetime risk of major adverse cardiovascular events (MACEs) (HR=1.45, p<0.001), driven by heart failure (HR=1.58, p<0.001) and atrial fibrillation (HR=1.54, p<0.001). Increased radial and decreased longitudinal peak diastolic strain rates were identified in participants with scoliosis (+0.29, Padj <0.05; -0.25, Padj <0.05; respectively). Cardiac compression of the top and bottom of the heart and decompression of the sides was observed through S2S analysis. Additionally, associations between scoliosis and older age, female sex, heart failure, valve disease, hypercholesterolemia, hypertension and decreased enrolment for CMR were identified. CONCLUSION: The spinal curvature observed in participants with scoliosis alters the movement of the heart. The association with increased MACE may have clinical implications for whether to undertake surgical correction. This work identifies, in an adult population, evidence for altered cardiac function and an increased lifetime risk of MACE in participants with scoliosis.