Airflow limitation, lung volumes and systemic inflammation in a general population

Association of high-sensitivity CRP and FEV1%pred: a study on non-pulmonary disease in a population in Beijing, China

BACKGROUND

No studies have investigated whether high-sensitivity C reactive protein (hsCRP) can be used to predict the forced expiratory volume in 1 s (FEV1)/estimated value of FEV1 (FEV1%pred). This study aimed to assess the association between hsCRP and FEV1%pred in middle-aged and elderly individuals without underlying lung disease.

METHODS

The data for this study were obtained from a prospective cohort study that included 1047 middle-aged and elderly citizens from Beijing aged 40-75 years without any evidence of underlying lung diseases with FEV1 >70% after receiving inhalational bronchodilators. The baseline analysis of the participants was performed from 30 May 2018 to 31 October 2018. Restricted cubic spline regression and multivariate linear regression models were used to assess the non-linear association and linear association between hsCRP and FEV1/FEV in 6 s (FEV6) and FEV1%pred, respectively.

RESULTS

The hsCRP values of 851 participants were recorded; the values were normal in 713 (83.8%) participants. The remaining 196 participants (18.7%) had missing data. A non-linear association was observed between normal hsCRP values and FEV1/FEV6. hsCRP was linearly and negatively correlated with FEV1%pred, and each 1 SD increase in hsCRP was significantly associated with a 2.4% lower in FEV1%pred. Significantly higher FEV1/FEV6 differences were observed in the female subgroup than those in the male subgroup (p=0.011 for interaction).

CONCLUSIONS

hsCRP had a non-linear association with FEV1/FEV6 and a linear negative association with FEV1%pred in individuals with normal hsCRP values. hsCRP can be used to predict FEV1%pred, which can be used to predict the development of chronic obstructive pulmonary disease. hsCRP has a stronger association with lung function in women than that in men.

TRIAL REGISTRATION NUMBER

NCT03532893.

Periodontitis is associated with airflow obstruction in the Malmö Offspring Dental Study

AIM

To investigate the association between periodontitis and lung function in the Malmö Offspring Dental Study.

MATERIALS AND METHODS

In all 1001 individuals (49.9% female, mean age: 44.6) from Malmö Offspring Dental Study were included. Periodontitis was assessed by a full-mouth examination protocol including bleeding on probing and classified according to the American Academy of Periodontology/Center for Disease Control definitions. Forced expiratory volume in 1 s (FEV1 ) and forced vital capacity (FVC) were expressed as absolute values and %predicted according to Global Lung Function Initiative reference values. FEV1 , FVC and FEV1 /FVC were analysed in relation to periodontal status using linear regression.

RESULTS

Severe periodontitis was found in 7% of the population. Adjusted regression models showed significant associations between lung function and severe periodontitis with 2.1 unit lower FEV1 /FVC ratio (95% CI: -3.91, -0.23) and odds ratio (adjusted) of 2.56 (95% CI: 1.40, 4.75, p = .003) for airflow obstruction (FEV1 /FVC less than the lower limit of normal) if having severe periodontitis. Lower values of %predicted FEV1 and %predicted FVC, but not FEV1 /FVC, were found in individuals with >25% bleeding on probing.

CONCLUSIONS

Severe periodontitis was associated with lower FEV1 /FVC ratio and airflow obstruction in the present cohort. More large-scale prospective studies and intervention studies are required for a comprehensive evaluation.

Gestational phthalate exposure and lung function during childhood: A prospective population-based study

The potential effect of gestational exposure to phthalates on the lung function levels during childhood is unclear. Therefore, we examined this association at different ages (from 4 to 11 years) and over the whole childhood. Specifically, we measured 9 phthalate metabolites (MEP, MiBP, MnBP, MCMHP, MBzP, MEHHP, MEOHP, MECPP, MEHP) in the urine of 641 gestating women from the INMA study (Spain) and the forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁) and FEV₁/FVC in their offspring at ages 4, 7, 9 and 11. We used linear regression and mixed linear regression with a random intercept for subject to assess the association between phthalates and lung function at each study visit and for the overall childhood, respectively. We also assessed the phthalate metabolites mixture effect on lung function using a Weighted Quantile Sum (WQS) regression. We observed that the phthalate metabolites gestational levels were consistently associated with lower FVC and FEV₁ at all ages, both when assessed individually and jointly as a mixture, although most associations were not statistically significant. Of note, a 10% increase in MiBP was related to lower FVC (-0.02 (-0.04, 0)) and FEV₁ z-scores (-0.02 (-0.04, -0.01) at age 4. Similar significant reductions in FVC were observed at ages 4 and 7 associated with an increase in MEP and MnBP, respectively, and for FEV₁ at age 4 associated with an increase in MBzP. WQS regression consistently identified MBzP as an important contributor to the phthalate mixture effect. We can conclude that the gestational exposure to phthalates was associated with children's lower FVC and FEV₁, especially in early childhood, and in a statistically significant manner for MEP, MiBP, MBzP and MnBP. Given the ubiquity of phthalate exposure and its established endocrine disrupting effects in children, our findings support current regulations that limit phthalate exposure.

Associations of Pulmonary Function with MRI Brain Volumes: A Coordinated Multi-Study Analysis

BACKGROUND

Previous studies suggest poor pulmonary function is associated with increased burden of cerebral white matter hyperintensities and brain atrophy among elderly individuals, but the results are inconsistent.

OBJECTIVE

To study the cross-sectional associations of pulmonary function with structural brain variables.

METHODS

Data from six large community-based samples (N = 11,091) were analyzed. Spirometric measurements were standardized with respect to age, sex, height, and ethnicity using reference equations of the Global Lung Function Initiative. Associations of forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and their ratio FEV1/FVC with brain volume, gray matter volume, hippocampal volume, and volume of white matter hyperintensities were investigated using multivariable linear regressions for each study separately and then combined using random-effect meta-analyses.

RESULTS

FEV1 and FVC were positively associated with brain volume, gray matter volume, and hippocampal volume, and negatively associated with white matter hyperintensities volume after multiple testing correction, with little heterogeneity present between the studies. For instance, an increase of FVC by one unit was associated with 3.5 ml higher brain volume (95% CI: [2.2, 4.9]). In contrast, results for FEV1/FVC were more heterogeneous across studies, with significant positive associations with brain volume, gray matter volume, and hippocampal volume, but not white matter hyperintensities volume. Associations of brain variables with both FEV1 and FVC were consistently stronger than with FEV1/FVC, specifically with brain volume and white matter hyperintensities volume.

CONCLUSION

In cross-sectional analyses, worse pulmonary function is associated with smaller brain volumes and higher white matter hyperintensities burden.

A clinical trial to evaluate the effect of the Mediterranean diet on smokers lung function

Data on the association between lung function and some dietary patterns have been published. However, it is not yet well known if whether the Mediterranean Diet (MD) pattern can preserve or improve lung function. Our purpose is to evaluate the effect of increased MD adherence on lung function in smokers. A multicenter, parallel, cluster-randomized, controlled clinical trial is proposed. A total of 566 active smokers (>10 packs-year), aged 25–75 years will be included, without previous respiratory disease and who sign an informed consent to participate. Twenty Primary Care Centres in Tarragona (Spain) will be randomly assigned to a control or an intervention group (1:1). All participants will receive advice to quit smoking, and the intervention group, a nutritional intervention (2 years) designed to increase MD adherence by: (1) annual visit to deliver personalized nutritional education, (2) annual telephone contact to reinforce the intervention, and (3) access to an online dietary blog. We will evaluate (annually for 2 years): pulmonary function by forced spirometry and MD adherence by a 14-item questionnaire and medical tests (oxidation, inflammation and consumption biomarkers). In a statistical analysis by intention-to-treat basis, with the individual smoker as unit of analysis, pulmonary function and MD adherence in both groups will be compared; logistic regression models will be applied to analyze their associations. We hope to observe an increased MD adherence that may prevent the deterioration of lung function in smokers without previous respiratory disease. This population may benefit from a dietary intervention, together with the recommendation of smoking cessation.

Non-invasive techniques to assess restrictive lung disease in workers exposed to free crystalline silica

Objectives:

To compare the reliability of spirometry and body plethysmography in detecting restrictive lung disease in clay excavation workers exposed to free crystalline silica (FCS). The exhaled breath condensate (EBC) biomarkers of oxidative stress were also assessed in order to evaluate early lung damage.

Methods:

The study involved 62 workers (58 males and 4 females) at a company that extracts and processes clay.

Results:

Body plethysmography (total lung capacity below the lower normal limit) and spirometry respectively indicated restrictive pattern prevalence rates of 22.6% and 1.6%. EBC 4-hydroxynonenale levels were not sufficiently sensitive to highlight a restrictive deficit, but did distinguish low and high rates of occupational exposure. There was no correlation between plethysmography values and the intensity or duration of exposure.

Conclusions:

Only one out of 14 cases of restrictive deficit diagnosed on the basis of body plethysmography values was also identified by means of spirometry. This finding supports the need to use body plethysmography in the health surveillance of clay workers exposed to FCS.

Prospective study of lung function and abdominal aortic aneurysm risk: The Atherosclerosis Risk in Communities study

BACKGROUND AND AIMS

No prospective study has investigated whether individuals with respiratory impairments, including chronic obstructive pulmonary disease (COPD) and restrictive lung disease (RLD), are at increased risk of abdominal aortic aneurysm (AAA). We aimed to prospectively investigate whether those respiratory impairments are associated with increased AAA risk.

METHODS

In 1987-1989, the Atherosclerosis Risk in Communities (ARIC) study followed 14,269 participants aged 45-64 years, without a history of AAA surgery, through 2011. Participants were classified into four groups, "COPD" [forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC)

RESULTS

During the 284,969 person-years of follow-up, 534 incident AAA events were documented. In an age, sex, and race-adjusted proportional hazards model, individuals with respiratory impairments had a significantly higher risk of AAA than the normal reference group. After adjustment for AAA risk factors, including smoking status and pack-years of smoking, AAA risk was no longer significant in the respiratory symptoms with normal spirometry group [HR (95% CI), 1.25 (0.98-1.60)], but was still increased in the other two groups [RLD: 1.45 (1.04-2.02) and COPD: 1.66 (1.34-2.05)]. Moreover, continuous measures of FEV1/FVC, FEV1 and FVC were associated inversely with risk of AAA.

CONCLUSIONS

In the prospective population-based cohort study, obstructive and restrictive spirometric patterns were associated with increased risk of AAA independent of smoking, suggesting that COPD and RLD may increase the risk of AAA.

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Key Words

• Abdominal aortic aneurysm
• COPD
• Epidemiology
• Lung function

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MESH Headings

• Aortic Aneurysm, Abdominal/diagnostic imaging
• Aortic Aneurysm, Abdominal/epidemiology
• Female
• Forced Expiratory Volume
• Humans
• Incidence
• Lung/physiopathology
• Male
• Middle Aged
• Prognosis
• Prospective Studies
• Pulmonary Disease, Chronic Obstructive/diagnosis
• Pulmonary Disease, Chronic Obstructive/epidemiology
• Pulmonary Disease, Chronic Obstructive/physiopathology
• Risk Assessment
• Risk Factors
• Spirometry
• Time Factors
• United States/epidemiology
• Vital Capacity

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Grants

• HHSN268201100012C NHLBI NIH HHS
• HHSN268201100010C NHLBI NIH HHS
• HHSN268201100008C NHLBI NIH HHS
• HHSN268201100007C NHLBI NIH HHS
• HHSN268201100011I NHLBI NIH HHS
• HHSN268201100011C NHLBI NIH HHS
• HHSN268201000011C NHLBI NIH HHS
• HHSN268201100006C NHLBI NIH HHS
• HHSN268201100005I NHLBI NIH HHS
• R01 HL103695 NHLBI NIH HHS
• HHSN268201100009I NHLBI NIH HHS
• HHSN268201000012C NHLBI NIH HHS
• HHSN268201100005G NHLBI NIH HHS
• HHSN268201100008I NHLBI NIH HHS
• HHSN268201100009C NHLBI NIH HHS
• HHSN268201100005C NHLBI NIH HHS
• HHSN268201100007I NHLBI NIH HHS
• HHSN268201000010C NHLBI NIH HHS

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Affiliation(s)

Yasuhiko Kubota Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, MN, USA.
Aaron R Folsom Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, MN, USA
Kunihiro Matsushita Department of Epidemiology and the Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
David Couper Department of Biostatistics, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, NC, USA
Weihong Tang Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, MN, USA

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FEV1 and FVC and systemic inflammation in a spinal cord injury cohort

Background

Systemic inflammation has been associated with reduced pulmonary function in individuals with and without chronic medical conditions. Individuals with chronic spinal cord injury (SCI) have clinical characteristics that promote systemic inflammation and also have reduced pulmonary function. We sought to assess the associations between biomarkers of systemic inflammation with pulmonary function in a chronic SCI cohort, adjusting for other potential confounding factors.

Methods

Participants (n = 311) provided a blood sample, completed a respiratory health questionnaire, and underwent spirometry. Linear regression methods were used to assess cross-sectional associations between plasma C-reactive protein (CRP) and interleukin-6 (IL-6) with forced expiratory volume in one second (FEV₁), forced vital capacity (FVC), and FEV₁/FVC.

Results

There were statistically significant inverse relationships between plasma CRP and IL-6 assessed in quartiles or continuously with FEV₁ and FVC. In fully adjusted models, each interquartile range (5.91 mg/L) increase in CRP was associated with a significant decrease in FEV₁ (−55.85 ml; 95% CI: -89.21, −22.49) and decrease in FVC (−65.50 ml; 95% CI: -106.61, −24.60). There were similar significant findings for IL-6. There were no statistically significant associations observed with FEV₁/FVC.

Conclusion

Plasma CRP and IL-6 in individuals with chronic SCI are inversely associated with FEV₁ and FVC, independent of SCI level and severity of injury, BMI, and other covariates. This finding suggests that systemic inflammation associated with chronic SCI may contribute to reduced pulmonary function.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-017-0459-6) contains supplementary material, which is available to authorized users.

Analysis of the influence of respiratory disorders observed in preoperative spirometry on the dynamics of early inflammatory response in patients undergoing isolated coronary artery bypass grafting

Background

Preoperative spirometry provides measurable information about the occurrence of respiratory disorders. The aim of this study was to assess the association between preoperative spirometry abnormalities and the intensification of early inflammatory responses in patients following coronary artery bypass graft in extracorporeal circulation.

Material and methods

The study involved 810 patients (625 men and 185 women) aged 65.4±7.9 years who were awaiting isolated coronary artery bypass surgery. On the basis of spirometry performed on the day of admittance to the hospital, the patients were divided into three groups. Patients without respiratory problems constituted 78.8% of the entire group. Restricted breathing was revealed by spirometry in 14.9% and obstructive breathing in 6.3% of patients.

Results

Inter-group analysis showed statistically significant differences in C-reactive protein (CRP) between patients with restrictive spirometry abnormalities and patients without any pulmonary dysfunction. CRP concentrations differed before surgery (P=0.006) and on the second (P<0.001), fourth (P=0.005) and sixth days after surgery (P=0.029). There was a negative correlation between CRP levels and FEV₁.

Conclusion

In our study, the most common pulmonary disorders in the coronary artery bypass graft patients were restrictive. Patients with abnormal spirometry results from restrictive respiratory disorders have an elevated level of generalized inflammatory response both before and after the isolated coronary artery bypass surgery. Therefore, this group of patients should be given special postoperative monitoring and, in particular, intensive respiratory rehabilitation immediately after reconstitution.

The German COPD cohort COSYCONET: Aims, methods and descriptive analysis of the study population at baseline

BACKGROUND

The German COPD cohort study COSYCONET ("COPD and SYstemic consequences-COmorbidities NETwork") investigates the interaction of lung disease, comorbidities and systemic inflammation. Recruitment took place from 2010 to 2013 in 31 study centers. In addition to the baseline visit, follow-up visits are scheduled at 6, 18, 36 and 54 months after baseline. The study also comprises a biobank, image bank, and includes health economic data. Here we describe the study design of COSYCONET and present baseline data of our COPD cohort.

METHODS

Inclusion criteria were broad in order to cover a wide range of patterns of the disease. In each visit, patients undergo a large panel of assessments including e.g. clinical history, spirometry, body plethysmography, diffusing capacity, blood samples, 6-min walk-distance, electrocardiogram and echocardiography. Chest CTs are collected if available and CTs and MRIs are performed in a subcohort. Data are entered into eCRFs and subjected to several stages of quality control.

RESULTS

Overall, 2741 subjects with a clinical diagnosis of COPD were included (59% male; mean age 65 ± 8.6 years (range 40-90)). Of these, 8/35/32/9% presented with GOLD stages I-IV; 16% were uncategorized, including the former GOLD-0 category. 24% were active smokers, 68% ex-smokers and 8% never-smokers. Data completeness was 96% for the baseline items.

CONCLUSION

The German COPD cohort comprises patients with advanced and less advanced COPD. This is particularly useful for studying the time course of COPD in relation to comorbidities. Baseline data indicate that COSYCONET offers the opportunity to investigate our research questions in a large-scale, high-quality dataset.

Systemic inflammation and lung function: A longitudinal analysis

BACKGROUND

Systemic inflammation is associated with impaired lung function in healthy adults as well as in patients with lung disease. The mechanism for this association is unknown and it is unclear if systemic inflammation leads to impaired lung function or if poor lung function leads to inflammation. We explored the temporal associations between blood C-reactive protein (CRP), fibrinogen, and white blood cells, and lung function in young adults.

METHODS

Spirometry, plethysmography, and diffusion capacity were measured in a population-based cohort at ages 32 and 38 years. High-sensitivity CRP, fibrinogen, and white blood cells were measured at the same ages.

RESULTS

Higher levels of CRP and, to a lesser extent, fibrinogen were associated with lower lung volumes in cross-sectional analyses at both ages 32 and 38 years. Higher CRP and fibrinogen at age 32 were associated with higher FEV1 and FEV1/FVC at age 38, but not other measures of lung function. Lower lung volumes (total lung capacity, functional residual capacity, and residual volume) but not airflow obstruction (FEV1/FVC) at age 32 were associated with higher CRP at age 38. Associations between age 32 lung function and fibrinogen at follow-up were weaker, but consistent. There were no longitudinal associations between white blood cells and lung function.

CONCLUSIONS

We found no evidence that systemic inflammation causes a decline in lung function. However, lower lung volumes were associated with higher CRP and fibrinogen at follow-up indicating that pulmonary restriction may be a risk factor for systemic inflammation. The mechanism for this association remains unclear.

Individual differences in cognitive ability at age 20 predict pulmonary function 35 years later

BACKGROUND

Poor pulmonary function is associated with mortality and age-related diseases, and can affect cognitive performance. However, extant longitudinal studies indicate that early cognitive ability also affects later pulmonary function. Despite the multifaceted nature of pulmonary function, most longitudinal studies were limited to a single index of pulmonary function: forced expiratory volume in 1 s (FEV1). In this study, we examined whether early adult cognitive ability predicted five different indices of pulmonary function in mid-life.

METHODS

Mixed modelling tested the association between young adult general cognitive ability (mean age=20), measured by the Armed Forces Qualification Test (AFQT), and mid-life pulmonary function (mean age=55), in 1019 men from the Vietnam Era Twin Study of Aging. Pulmonary function was indexed by per cent predicted values for forced vital capacity (FVC%p), FEV1%p, maximum forced expiratory flow (FEFmax%p), and maximal voluntary ventilation (MVV%p), and by the ratio of FEV1 to FVC (FEV1/FVC), an index of lung obstruction.

RESULTS

After adjusting for smoking, pulmonary disease, occupation, income and education, age 20 AFQT was significantly (p<0.05) associated with mid-life FVC%p (β=0.10), FEV1%p (β=0.13), FEFmax%p (β=0.13), and MVV%p (β=0.13), but was not significantly associated with FEV1/FVC (β=0.03, p=0.34).

CONCLUSIONS

Early adult cognitive ability is a predictor of multiple indices of aging-related pulmonary function 35 years later, including lung volume, airflow and ventilator capacity. Cognitive deficits associated with impaired aging-related lung function may, thus, be partly pre-existing. However, results also highlight that early life risk factors may be differentially related to different metrics of later-life pulmonary health.

Red cell distribution width as an independent predictor of exercise intolerance and ventilatory inefficiency in patients with chronic heart failure

PURPOSE

Peak oxygen uptake (peak VO₂) and ventilatory inefficiency (VE/VCO₂ slope) have proven to be strong prognostic markers in patients with chronic heart failure (CHF). Recently increased red cell distribution width (RDW) has emerged as an additional predictor of poor outcome in CHF. We sought to evaluate the relationship between RDW and cardiopulmonary exercise test (CPET) parameters in CHF patients and healthy controls.

MATERIALS AND METHODS

85 ambulatory CHF patients (68 men, 54±10 years) and 107 healthy controls, who underwent a symptom-limited CPET on a treadmill according to the modified Bruce ramp protocol, were enrolled. CHF patients and healthy controls were divided into RDW tertile groups and laboratory, echocardiographic, and CPET results were analyzed.

RESULTS

For patients with CHF, compared with patients in the lowest RDW tertile, those in the highest tertile had lower peak VO₂ (22 mL/kg/min vs. 28 mL/kg/min, p<0.001) and higher VE/VCO₂ slope (31 vs. 25, p=0.004). Multivariate regression analysis revealed RDW to be an independent predictor for peak VO₂ (β=-0.247, p=0.035) and VE/VCO₂ slope (β=0.366, p=0.004). The optimal cutoff value of RDW for predicting peak VO₂ ≤20 mL/kg/min and VE/VCO₂ slope ≥34 was 13.6% (sensitivity 53%, specificity 89%) and 13.4% (sensitivity 75%, specificity 82%), respectively. In contrast, for healthy controls, RDW was not related to both peak VO₂ and VE/VCO₂ slope.

CONCLUSION

Higher RDW is independently related to peak VO₂ and VE/VCO₂ slope only in patients with CHF. RDW assessment, an inexpensive and simple method, might help predict functional capacity and ventilatory efficiency in these patients.

Restrictive pulmonary deficit is associated with inflammation in sub-optimally controlled obese diabetics

Caribbean data linking inflammation, pulmonary dysfunction and diabetes is unavailable. Spirometry, acanthosis nigricans, hs-CRP were assessed in 109 type 2 diabetics (43% males) mean age=55.6 years, BMI=29.29 kg/m(2), waist circumference=103.86 cm. Residual FEV1/FVC increased with age (P=0.005), BMI (P=0.011) and waist circumference (P=0.003). Residual FVC related inversely to hs-CRP (-0.178), P<0.06) systolic (-0.028, P<0.031), diastolic (-0.247, P<0.010) pressure and weight (-0.25, P<0.009). Residual FEV1 related inversely to diastolic pressure (-0.219, P<0.023), hs-CRP (-0.234, P<0.015), acanthosis nigricans (-0.029, P<0.029). HbA1C and residual FEV1 predict high hs-CRP (P=0.011, P=0.046). Low FVC with inflammation presents in poorly controlled obese diabetics.

Pulmonary hypertension in patients with idiopathic pulmonary fibrosis - the predictive value of exercise capacity and gas exchange efficiency

Exercise capacity and survival of patients with IPF is potentially impaired by pulmonary hypertension. This study aims to investigate diagnostic and prognostic properties of gas exchange during exercise and lung function in IPF patients with or without pulmonary hypertension.

In a multicentre setting, patients with IPF underwent right heart catheterization, cardiopulmonary exercise and lung function testing during their initial evaluation. Mortality follow up was evaluated.

Seventy-three of 135 patients [82 males; median age of 64 (56; 72 years)] with IPF had pulmonary hypertension as assessed by right heart catheterization [median mean pulmonary arterial pressure 34 (27; 43) mmHg]. The presence of pulmonary hypertension was best predicted by gas exchange efficiency for carbon dioxide (cut off ≥152% predicted; area under the curve 0.94) and peak oxygen uptake (≤56% predicted; 0.83), followed by diffusing capacity. Resting lung volumes did not predict pulmonary hypertension. Survival was best predicted by the presence of pulmonary hypertension, followed by peak oxygen uptake [HR 0.96 (0.93; 0.98)].

Pulmonary hypertension in IPF patients is best predicted by gas exchange efficiency during exercise and peak oxygen uptake. In addition to invasively measured pulmonary arterial pressure, oxygen uptake at peak exercise predicts survival in this patient population.

A fast and accurate automatic lung segmentation and volumetry method for MR data used in epidemiological studies

In modern epidemiological population-based studies a huge amount of magnetic resonance imaging (MRI) data is analysed. This requires reliable automatic methods for organ extraction. In the current paper, we propose a fast and accurate automatic method for lung segmentation and volumetry. Our approach follows a "coarse-to-fine" segmentation strategy. First, we extract the lungs and trachea excluding the main pulmonary vessels. This step is executed very fast and allows for measuring the volume of both structures. Thereafter, we start a refinement procedure that consists of three main stages: trachea extraction, lung separation, and filling the cavities on the final lung masks. After the trachea extraction step the volumes of both lungs without the main vessels can be measured. The final segmentation step results in the volumes of the left and right lungs including the vessels. The method has been tested by processing MR datasets from ten healthy participants. We compare our results with manually produced masks and obtain high agreement between the expert reading and our method: the True Positive Volume Fraction is more than 95%. The proposed automatic approach is fast and accurate enough to be applied in clinical routine for processing of thousands of participants.