Bone mineral density in patients with idiopathic pulmonary fibrosis

CT-derived vertebral bone mineral density is a useful biomarker to predict COVID-19 outcome

The low vertebral bone computed tomography (CT) Hounsfield unit values measured on CT scans reflect low bone mineral density (BMD) and are known as diagnostic indicators for osteoporosis. The potential prognostic significance of low BMD defined by vertebral bone CT values for the coronavirus disease 2019 (COVID-19) remains unclear. This study aimed to assess the impact of BMD on the clinical outcome in Japanese patients with COVID-19 and evaluate the association between BMD and critical outcomes, such as high-flow nasal cannula, non-invasive and invasive positive pressure ventilation, extracorporeal membrane oxygenation, or death. We examined the effects of COVID-19 severity on the change of BMD over time. This multicenter retrospective cohort study enrolled 1132 inpatients with COVID-19 from the Japan COVID-19 Task Force database between February 2020 and September 2022. The bone CT values of the 4th, 7th, and 10th thoracic vertebrae were measured from chest CT images. The average of these values was defined as BMD. Furthermore, a comparative analysis was conducted between the BMD on admission and its value 3 months later. The low BMD group had a higher proportion of critical outcomes than did the high BMD group. In a subanalysis stratifying patients by epidemic wave according to onset time, critical outcomes were higher in the low BMD group in the 1st-4th waves. Multivariable logistic analysis of previously reported factors associated with COVID-19 severity revealed that low BMD, chronic kidney disease, and diabetes were independently associated with critical outcomes. At 3 months post-infection, patients with oxygen demand during hospitalization showed markedly decreased BMD than did those on admission. Low BMD in patients with COVID-19 may help predict severe disease after the disease onset. BMD may decrease over time in patients with severe COVID-19, and the impact on sequelae symptoms should be investigated in the future.

[Bone metabolism in patients evaluated for lung transplantation]

Introduction

Introduction: the prevalence of osteoporosis among candidates for lung transplantation is high and its pathophysiology is multifactorial. Objectives: to evaluate differences in bone mineral density, risk of fractures and bone remodeling markers in patients with terminal lung disease, at the time they are evaluated for lung transplantation, comparing two types of pathologies. Material and methods: fifty-nine subjects, proposed to receive a lung transplant due to advanced lung disease, were included in this study. They were divided into two groups according to their respiratory pathology: chronic obstructive pulmonary disease (COPD) and diffuse interstitial pulmonary disease (ILD). Demographic data were collected and bone densitometry, blood analysis with markers of bone remodeling, spirometry, six-minute walk test (6MWT), echocardiography and cardiac catheterization were performed Results: no differences were found between the groups, regarding their age, sex, BMI or exposure to tobacco. A higher prevalence of osteoporosis and a higher FRAX were observed in the group with COPD. Regarding bone remodeling markers, higher parathyroid hormone (PTH) and higher osteocalcin were found in the COPD group. Vitamin D was lower in COPD patients. Conclusions: two out of three of the patients evaluated for lung transplantation had osteopenia or osteoporosis. The prevalence of osteoporosis and FRAX is higher in COPD patients. Vitamin D supplementation should be considered in certain patients. Differences in bone remodeling markers may be useful for suspected osteoporosis and therapeutic management.

The impact of chronic obstructive pulmonary disease on bone strength

Chronic obstructive pulmonary disease (COPD) is a lifestyle-related disease that develops in middle-aged and older adults, often due to smoking habits, and has been noted to cause bone fragility. COPD is a risk factor for osteoporosis and fragility fracture, and a high prevalence of osteoporosis and incidence of vertebral fractures have been shown in patients with COPD. Findings of lung tissue analysis in patients with COPD are primarily emphysema with a loss of alveolar septal walls, and the severity of pulmonary emphysema is negatively correlated with thoracic spine bone mineral density (BMD). On the other hand, epidemiological studies on COPD and fracture risk have reported a BMD-independent increase in fracture risk; however, verification in animal models and human bone biopsy samples has been slow, and the essential pathogenesis has not been elucidated. The detailed pathological/molecular mechanisms of musculoskeletal complications in patients with COPD are unknown, and basic research is needed to elucidate the mechanisms. This paper discusses the impacts of COPD on bone strength, focusing on findings in animal models in terms of bone microstructure, bone metabolic dynamics, and material properties.

Association of age with computed tomography airway tree morphology in male and female never smokers without lung disease history

BACKGROUND

Sex and aging may affect the airway tree structure in patients with airway diseases and even healthy subjects. Using chest computed tomography (CT), this study sought to determine whether age is associated with airway morphological features differently in healthy males and females.

METHODS

This retrospective cross-sectional study consecutively incorporated lung cancer screening CT data of asymptomatic never smokers (n = 431) without lung disease history. Luminal areas were measured at the trachea, main bronchi, bronchus intermedius, segmental and subsegmental bronchus, and the ratio of their geometric mean to total lung volume (airway-to-lung size ratio, ALR) was determined. Airway fractal dimension (AFD) and total airway count (TAC) were calculated for the segmented airway tree resolved on CT.

RESULTS

The lumen areas of the trachea, main bronchi, segmental and subsegmental airways, AFD and TAC visible on CT were smaller in females (n = 220) than in males (n = 211) after adjusting for age, height, and body mass index, while ALR or count of the 1st to 5th generation airways did not differ. Furthermore, in males but not in females, older age was associated with larger lumen sizes of the main bronchi, segmental and subsegmental airways, and ALR. In contrast, neither male nor female had any associations between age and AFD or TAC on CT.

CONCLUSION

Older age was associated with larger lumen size of the relatively central airways and ALR exclusively in males. Aging may have a more profound effect on airway lumen tree caliber in males than in females.

The relative contribution of co-morbidities to health-related quality of life of people with idiopathic pulmonary fibrosis using the Assessment of Quality of Life-8-Dimension multi-attribute utility instrument

PURPOSE

Little is known about the impact of co-morbidities on health-related quality of life (HRQoL) for people with idiopathic pulmonary fibrosis (IPF). We aimed to investigate the relative contribution of co-morbidities to HRQoL of people with IPF.

METHODS

N = 157 participants were recruited from the Australian IPF Registry (AIPFR). Health state utilities (HSUs), and the super-dimensions of physical and psychosocial scores were measured using the Assessment of Quality of Life-8-Dimensions (AQoL-8D). The impact of co-morbidities on HRQoL was investigated using linear regression and general dominance analyses.

RESULTS

A higher number of co-morbidities was associated with lower HSUs (p trend = 0.002). Co-morbidities explained 9.1% of the variance of HSUs, 16.0% of physical super-dimensional scores, and 4.2% of psychosocial super-dimensional scores. Arthritis was associated with a significant reduction on HSUs (β =  - 0.09, 95% confidence interval [CI] - 0.16 to - 0.02), largely driven by reduced scores on the physical super-dimension (β =  - 0.13, 95% CI - 0.20 to - 0.06). Heart diseases were associated with a significant reduction on HSUs (β =  - 0.09, 95% CI - 0.16 to - 0.02), driven by reduced scores on physical (β =  - 0.09, 95% CI - 0.16 to - 0.02) and psychosocial (β = -0.10, 95% CI - 0.17 to - 0.02) super-dimensions.

CONCLUSIONS

Co-morbidities significantly impact HRQoL of people with IPF, with markedly negative impacts on their HSUs and physical health. A more holistic approach to the care of people with IPF is important as better management of these co-morbidities could lead to improved HRQoL in people with IPF.

Cutaneous T-cell-attracting chemokine as a novel biomarker for predicting prognosis of idiopathic pulmonary fibrosis: a prospective observational study

Background

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive fibrotic lung disease that leads to respiratory failure and death. Although there is a greater understanding of the etiology of this disease, accurately predicting the disease course in individual patients is still not possible. This study aimed to evaluate serum cytokines/chemokines as potential biomarkers that can predict outcomes in IPF patients.

Methods

A multi-institutional prospective two-stage discovery and validation design using two independent cohorts was adopted. For the discovery analysis, serum samples from 100 IPF patients and 32 healthy controls were examined using an unbiased, multiplex immunoassay of 48 cytokines/chemokines. The serum cytokine/chemokine values were compared between IPF patients and controls; the association between multiplex measurements and survival time was evaluated in IPF patients. In the validation analysis, the cytokines/chemokines identified in the discovery analysis were examined in serum samples from another 81 IPF patients to verify the ability of these cytokines/chemokines to predict survival. Immunohistochemical assessment of IPF-derived lung samples was also performed to determine where this novel biomarker is expressed.

Results

In the discovery cohort, 18 cytokines/chemokines were significantly elevated in sera from IPF patients compared with those from controls. Interleukin-1 receptor alpha (IL-1Rα), interleukin-8 (IL-8), macrophage inflammatory protein 1 alpha (MIP-1α), and cutaneous T-cell-attracting chemokine (CTACK) were associated with survival: IL-1Rα, hazard ratio (HR) = 1.04 per 10 units, 95% confidence interval (95% CI) 1.01–1.07; IL-8, HR = 1.04, 95% CI 1.01–1.08; MIP-1α, HR = 1.19, 95% CI 1.00–1.36; and CTACK, HR = 1.12 per 100 units, 95% CI 1.02–1.21. A replication analysis was performed only for CTACK because others were previously reported to be potential biomarkers of interstitial lung diseases. In the validation cohort, CTACK was associated with survival: HR = 1.14 per 100 units, 95% CI 1.01–1.28. Immunohistochemistry revealed the expression of CTACK and CC chemokine receptor 10 (a ligand of CTACK) in airway and type II alveolar epithelial cells of IPF patients but not in those of controls.

Conclusions

CTACK is a novel prognostic biomarker of IPF.

Trial registration None (because of no healthcare intervention)

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01779-9.

The impact of idiopathic pulmonary fibrosis on health state utility values: evidence from Australia

PURPOSE

Idiopathic pulmonary fibrosis (IPF) is a progressive and universally fatal lung disease, characterised by increasing fibrosis of the lung parenchyma. In this study, we aimed to quantify the health state utility values (HSUVs) for Australians with IPF and to identify the factors affecting these HSUVs.

METHODS

Participants of the Australian IPF Registry (AIPFR), with data on EuroQoL five dimension-five level (EQ-5D-5L) profiles were included. Pulmonary function tests (PFTs) were used to assess disease severity using three IPF -based classification systems. Stepwise multivariable linear regression models assessed the relationship between HSUVs and important demographic and clinical parameters.Query RESULTS: A total of 155 participants provided data for the analysis of HSUVs. For our base case, HSUVs ranged from - 0.57 to 1.00. Mean HSUVs for all participants was 0.65 (95% CI 0.61-0.70). In general, HSUVs decreased with increasing disease severity under all disease severity classification systems. Multivariable linear regression demonstrated a negative association between HSUVs, disease severity and having more than 2 comorbidities.

CONCLUSIONS

Our study has shown that EQ-5D-5L has exhibited discriminatory sensitivity for the study population. We have demonstrated that disease severity and having more than two comorbidities was associated with lower HSUVs in Australians with IPF. Our findings support early diagnosis and appropriate evidence-based treatment to slow or prevent IPF progression; and identification and treatment of associated comorbidities to potentially improve health-related quality of life in people with IPF.

Idiopathic pulmonary fibrosis beyond the lung: understanding disease mechanisms to improve diagnosis and management

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive disorder with an estimated median survival time of 3–5 years after diagnosis. This condition occurs primarily in elderly subjects, and epidemiological studies suggest that the main risk factors, ageing and exposure to cigarette smoke, are associated with both pulmonary and extrapulmonary comorbidities (defined as the occurrence of two or more disorders in a single individual). Ageing and senescence, through interactions with environmental factors, may contribute to the pathogenesis of IPF by various mechanisms, causing lung epithelium damage and increasing the resistance of myofibroblasts to apoptosis, eventually resulting in extracellular matrix accumulation and pulmonary fibrosis. As a paradigm, syndromes featuring short telomeres represent archetypal premature ageing syndromes and are often associated with pulmonary fibrosis. The pathophysiological features induced by ageing and senescence in patients with IPF may translate to pulmonary and extrapulmonary features, including emphysema, pulmonary hypertension, lung cancer, coronary artery disease, gastro-oesophageal reflux, diabetes mellitus and many other chronic diseases, which may lead to substantial negative consequences in terms of various outcome parameters in IPF. Therefore, the careful diagnosis and treatment of comorbidities may represent an outstanding chance to improve quality of life and survival, and it is necessary to contemplate all possible management options for IPF, including early identification and treatment of comorbidities.

Chronic obstructive pulmonary disease severity in middle-aged and older men with osteoporosis associates with decreased bone formation

Objectives

Chronic obstructive pulmonary disease (COPD) is a risk factor for osteoporosis. Nevertheless, much remains unclear regarding the bone metabolism dynamics associated with COPD. The present study focuses on the associations between the COPD severity and serum bone metabolism biomarkers.

Methods

We enrolled 40 patients who visited the orthopedics departments at our institutions and underwent dual-energy X-ray absorptiometry between September 2015 and December 2017. Only male osteoporosis patients over 45 years of age were included, and 5 patients were excluded due to disease or use of internal medicines affecting bone metabolism. All subjects underwent lung function testing, spine radiography, and blood tests. We measured percent forced expiratory volume in 1 second (%FEV₁), which reflects COPD severity, and we examined the relationships between %FEV₁ and serum levels of bone metabolism biomarkers.

Results

All subjects were diagnosed with osteoporosis based on T-scores. %FEV₁ correlated with body weight, body mass index (BMI), and Z-score/T-scores. %FEV₁ moderately correlated with serum levels of alkaline phosphatase (ALP), procollagen type 1 N-terminal propeptide (P1NP), and tartrate-resistant acid phosphatase 5b in the partial correlation analysis adjusted for BMI or T-score in the lumbar vertebrae. We performed a hierarchical multiple regression analysis to identify that serum ALP and P1NP were the independent explanatory variables to %FEV₁ independent of other factors.

Conclusions

The data suggest that the COPD severity in middle-aged and older men with osteoporosis associates with decreased bone formation. COPD patients may exhibit bone metabolism dynamics characterized by low bone turnover with osteogenesis dysfunction as COPD becomes severe.

Desaturation during exercise is not a sufficient mechanism for prediction of osteoporosis in non-cystic fibrosis bronchiectasis

Background

Recent research has proposed an association between desaturation during a six minute walking test (6MWT) and osteoporosis in an elderly group of individuals with non-cystic fibrosis bronchiectasis. A causative pathway through activation of hypoxia-inducible factor 1-alpha (HIF-1α) has been proposed.

Commentary

Queries regarding the statistical approaches used are identified and discussed within this correspondence. These predominate around the use of linear regression models to predict osteoporosis in a group that is already osteoporotic, presenting with extreme values for bone mineral density (BMD). Further queries are raised regarding the HIF-1α pathway, and physical activity (PA) is proposed as an upstream mechanism for both reduced exercise tolerance and low BMD.

Conclusions

It is suggested that osteoporosis cannot be predicted in a group that is already osteoporotic, and that PA is likely to be the causative mechanism between desaturation in the 6MWT and low BMD in non-cystic fibrosis bronchiectasis.

Systemic bone loss, impaired osteogenic activity and type I muscle fiber atrophy in mice with elastase-induced pulmonary emphysema: Establishment of a COPD-related osteoporosis mouse model

Although it is suggested that chronic obstructive pulmonary disease (COPD) and bone are related, almost all of the pathological mechanisms of COPD-related osteoporosis remain unknown. There is a mouse model showing a deterioration of bone quality after cigarette smoke exposure; however, in smoking exposure models, various factors exist that affect bone metabolism, such as smoking and body weight loss (muscle and fat mass loss). We considered it appropriate to use an elastase-induced emphysema model to exclude factors influencing bone metabolism and to investigate the influence of pulmonary emphysema on bone metabolism. The purpose of this study was to establish a COPD/emphysema-related osteoporosis mouse model by using the elastase-induced emphysema model. The lumbar vertebrae and femurs/tibiae exhibited trabecular bone loss and impaired osteogenic activity in 24-week-old male elastase-induced emphysema model mice. In addition, the model mice showed atrophy of type I muscle fibers without atrophy of type II muscle fibers. We believe that the mice described in this experimental protocol will be accepted as a COPD/emphysema-related osteoporosis mouse model and contribute to further investigations.

Association between Mycobacterium avium complex lung disease and serum vitamin D status, antimicrobial peptide levels, and bone mineral density

Vitamin D maintains calcium balance and has immunomodulatory effects. Only few studies have revealed the relationship between vitamin D and its associated factors in Mycobacterium avium complex (MAC) infection. This study aimed to investigate the effects of MAC infection on serum vitamin D, human cationic antimicrobial protein 18, its C-terminal 37 amino acid fragment (hCAP18/LL-37) levels, and bone mineral density (BMD).We enrolled 58 patients with MAC lung disease and 15 control participants. Serum 25-hydroxyvitamin D and hCAP18/LL-37 levels were measured via enzyme-linked immunosorbent assay. Lastly, computed tomography scan density readings of the BMD of the thoracic and lumbar vertebral bones (Th4, Th7, Th10, and L1) were assessed.No significant differences in patient characteristics and serum vitamin D levels were observed. Patients with MAC lung disease had significantly low serum hCAP18/LL-37 levels (P = .049). Moreover, low BMD of the mean thoracic and lumbar vertebrae was observed (mean Th, P = .012; L1, P = .48, respectively). A higher prevalence of scoliosis (P = .031) was observed in the participants with low BMD compared with the control participants. Based on a multivariate analysis, patients with MAC lung disease had significantly lower body mass index [odds ratio (OR), 19.1; 95% confidence interval (CI), 2.0-419.0; P < .01] and vertebral BMD (OR, 12.4; 95% CI, 1.7-160.6; P = .012) than control participants.Serum hCAP18/LL-37 level and BMD were significantly decreased in patients with MAC lung disease without relation to serum vitamin D level. The vitamin D-independent pathway might affect the waning of antimicrobial peptides and decrease in BMD.

Effect of Emphysema Extent on Serial Lung Function in Patients with Idiopathic Pulmonary Fibrosis

RATIONALE

Patients with idiopathic pulmonary fibrosis and emphysema may have artificially preserved lung volumes.

OBJECTIVES

In this post hoc analysis, we investigated the relationship between baseline emphysema and fibrosis extents, as well as pulmonary function changes, over 48 weeks.

METHODS

Data were pooled from two phase III, randomized, double-blind, placebo-controlled trials of IFN-γ-1b in idiopathic pulmonary fibrosis (GIPF-001 [NCT00047645] and GIPF-007 [NCT00075998]). Patients with Week 48 data, baseline high-resolution computed tomographic images, and FEV₁/FVC ratios less than 0.8 or greater than 0.9 (<0.7 or >0.9 in GIPF-007), as well as randomly selected patients with ratios of 0.8-0.9 and 0.7-0.8, were included. Changes from baseline in pulmonary function at Week 48 were analyzed by emphysema extent. The relationship between emphysema and fibrosis extents and change in pulmonary function was assessed using multivariate linear regression.

MEASUREMENTS AND MAIN RESULTS

Emphysema was identified in 38% of patients. A negative correlation was observed between fibrosis and emphysema extents (r = -0.232; P < 0.001). In quartile analysis, patients with the greatest emphysema extent (28 to 65%) showed the smallest FVC decline, with a difference of 3.32% at Week 48 versus patients with no emphysema (P = 0.047). In multivariate analyses, emphysema extent greater than or equal to 15% was associated with significantly reduced FVC decline over 48 weeks versus no emphysema or emphysema less than 15%. No such association was observed for diffusing capacity of the lung for carbon monoxide or composite physiologic index.

CONCLUSIONS

FVC measurements may not be appropriate for monitoring disease progression in patients with idiopathic pulmonary fibrosis and emphysema extent greater than or equal to 15%.

Idiopathic pulmonary fibrosis: Clinical behavior and aging associated comorbidities

Idiopathic pulmonary fibrosis (IPF) is a progressive, irreversible and usually lethal lung disease of unknown etiology. Once considered as a relatively homogeneous, slowly progressive disease, is now recognized that the clinical behavior shows substantial heterogeneity, including an accelerated variant, and the presence of acute exacerbations. In addition, since IPF largely affects individuals over 60 years of age, the patients are at increased risk of several comorbidities that in turn have a remarkable clinical impact on the disease and increases mortality rate. Among others, combined pulmonary fibrosis and emphysema, secondary pulmonary arterial hypertension, lung cancer, and cardiovascular diseases are frequently associated with IPF and impact survival. For these reasons clinical phenotypes and comorbidities should be timely identified and managed. The aim of this review is to describe the common pulmonary and extra-pulmonary comorbidities in IPF, as well as the putative mechanisms involved.

The association between health-related quality of life and disease progression in idiopathic pulmonary fibrosis: a prospective cohort study

Background and objective: Generally, a disease-specific health-related quality of life (HRQOL) measurement is more useful than generic measures in assessing perceived physical and mental health characteristic of a particular disease. The idiopathic pulmonary fibrosis (IPF)-specific version of St. George’s Respiratory Questionnaire (SGRQ-I) has been recently developed for patients with IPF. We proposed to evaluate associations between the SGRQ-I and other clinical indices, as well as its prognostic value in patients with IPF. Methods: Fifty-two patients with IPF were recruited in this prospective cohort study. HRQOL was assessed using the SGRQ-I and the Medical Outcomes Study 36-item Short Form, dyspnea using the modified Medical Research Council (mMRC) dyspnea scale, and psychological status using the Hospital Anxiety and Depression Scale (HADS). We then evaluated the relationship between the SGRQ-I and other clinical measures, as well as one-year clinical deterioration defined as a hospital admission due to respiratory exacerbation or all-cause death. Results: Stepwise multiple-regression analyses revealed that the mMRC dyspnea scale, the HADS anxiety or depression, and minimum oxygen saturation during a six-minute walk test significantly contributed to the Total and three components of the SGRQ-I. In multivariate Cox proportional-hazards analyses, the Total score of SGRQ-I predicted clinical deterioration independent of forced vital capacity, the six-minute walk distance, or partial pressure of arterial oxygen on room air. Conclusions: The SGRQ-I is a multidisciplinary instrument representing physical, functional and psychological impairments in patients with IPF. The SGRQ-I is a significant predictor of short-term disease progression independent of physiological measurements. (Sarcoidosis Vasc Diffuse Lung Dis 2017; 34: 226-235)

Idiopathic pulmonary fibrosis a rare disease with severe bone fragility

Idiopathic pulmonary fibrosis (IPF) is a rare form of chronic, progressive fibrosing interstitial pneumonia of unknown cause. The aim of this cross-sectional study was to assess the prevalence of osteoporosis and fragility fracture in a population of adults with IPF and to identify whether any possible clinical and pulmonary function parameters may be associated with increased bone fragility. In 58 IPF patients (mean age 65.1 ± 9.1 years), we measured bone mineral density (BMD) of the lumbar spine, the femoral neck, and the entire hip. Moreover, the presence of vertebral fractures on a lateral chest X-ray study was evaluated, and a vertebral fracture burden was quantified using the spinal deformity index (SDI). As expected, osteoporosis was significantly more frequent in females with respect to males (57.9 vs 20.5 %, respectively), whereas the fractures prevailed in males with respect to females (38.5 vs 26.3 %, respectively). There were positive correlations between BMD at all skeletal sites and respiratory parameters; in particular for FVC % and DLCO % with BMD at femoral sub-regions. Moreover, we compared the average of DLCO (%) measure by values of SDI score that was higher in those patients with lower values of DLCO (%). The study shows a high prevalence of fragility with vertebral fractures in IPF patients, especially in males. Moreover, the vertebral fracture burden is associated with a worsening of FVC (%) and DLCO (%). Therefore, an evaluation of bone status is recommended, especially in those patients who are candidates for lung transplantation.

Smokers with emphysema and small airway disease on computed tomography have lower bone density

Osteoporosis is more common in patients with COPD and in smokers. The aim of this study was to assess whether measures of emphysema and airway disease on computed tomography (CT) were associated with lower bone density or vertebral fractures in smokers with and without COPD. For this purpose, we included participants from the NELSON lung cancer screening trial. Bone density was measured as Hounsfield Units in the first lumbar vertebra, and vertebral fractures were assessed semiquantitatively. The 15th percentile method (Perc15) was used to assess emphysema, and the airway lumen perimeter (Pi10) was used for airway wall thickness. Expiratory/inspiratory-ratio_{mean lung density} (E/I-ratio_MLD) was used as a measure for air trapping and tracheal index to assess tracheal deformity. Linear regression models and logistic regression models were used to assess associations between CT biomarkers, bone density, and presence of fractures. Exactly 1,093 male participants were eligible for analysis. Lower Perc15 and higher E/I-ratio_MLD were significantly associated with lower bone density (b=−1.27, P=0.02 and b=−0.37, P=0.02, respectively). Pi10 and tracheal index were not associated with bone density changes. CT-derived biomarkers were not associated with fracture prevalence. Bone density is lower with increasing extent of emphysema and small airway disease but is not associated with large airway disease and tracheal deformity. This may indicate the necessity to measure bone density early in smokers with emphysema and air trapping to prevent vertebral fractures.