Body mass index and in-hospital mortality in patients with acute exacerbation of idiopathic pulmonary fibrosis

Serum cholesterol levels predict the survival in patients with idiopathic pulmonary fibrosis: A long-term follow up study

BACKGROUND

The relationship between serum lipid with idiopathic pulmonary fibrosis (IPF) required to be explored. We aim to evaluate the association of serum lipid levels with mortality in patients with IPF.

MATERIALS AND METHODS

This retrospective study included IPF patients with more than three years follow-up. We collected baseline demographics information, forced vital capacity (FVC)% predicted, carbon monoxide diffusion capacity (DLCO)% predicted, gender-age-physiology (GAP) index, and serum lipid levels, including triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C). We evaluate the relationship between the serum lipid levels and the disease severity, and the mortality in IPF.

RESULTS

This study enrolled 146 patients, with the three-year survival rate of 71.23 %. The median follow-up time was 46.5 months. There was no significant difference in baseline lipid levels between the survival and non-survival group. TG levels were positively correlated with DLCO% predicted (r = 0.189, p = 0.022) and negatively correlated with GAP index (r = -0.186, p = 0.025). After adjusting for GAP index, smoking history, body mass index and the use of antifibrotic and lipid-lowering drug, lower TC levels (HR: 0.74, 95 % CI: 0.58-0.94, p = 0.013) were identified as an independent risk factor for mortality.

CONCLUSION

This study demonstrated that lower TC levels were associated with increased mortality in IPF. More investigations are required to explore the role of lipid metabolism in the pathogenesis of pulmonary fibrosis.

Body mass index and weight loss as risk factors for poor outcomes in patients with idiopathic pulmonary fibrosis: a systematic review and meta-analysis

OBJECTIVE

The association between nutritional status and prognosis of idiopathic pulmonary fibrosis (IPF) remains unclear. This systematic review and meta-analysis aimed to explore the effect of body mass index (BMI) and weight loss on the prognosis of IPF patients.

METHODS

We accumulated studies on IPF, BMI, and weight loss from databases including PubMed, Embase, Web of science, Scopus, Ovid and Cochrane Library up to 4 August 2023. Using Cox proportional hazard regression model for subgroup analysis, hazard ratio (HR) and 95% confidence intervals (CI) for BMI in relation to mortality, acute exacerbation (AE), and hospitalization in IPF patients were calculated, and HR, odds ratio (OR), and 95% CI for weight loss corresponding to IPF patient mortality were assessed. Sensitivity analysis was peformed by eliminating every study one by one, and publication bias was judged by Egger's test and trim-and-fill method.

RESULTS

A total of 34 eligible studies involving 18,343 IPF patients were included in the meta-analysis. The pooled results by univariate Cox regression analysis showed that baseline BMI was a predictive factor for IPF mortality (HR = 0.93, 95%CI = [0.91, 0.94]). Furthermore, the results by the multivariable regression model indicated that baseline BMI was an independent risk factor for predicting IPF mortality (HR = 0.94, 95%CI = [0.91, 0.98]). Weight loss was identified as a risk factor for IPF mortality (HR = 2.74, 95% CI = [2.12, 3.54]; OR = 4.51, 95% CI = [1.72, 11.82]) and there was no predictive value of BMI for acute exacerbation (HR = 1.00, 95% CI= [0.93, 1.07]) or hospitalization (HR = 0.95, 95% CI = [0.89, 1.02]).

CONCLUSION

Low baseline BMI and weight loss in the course of IPF may indicate a high risk of mortality in patients with IPF, so it is meaningful to monitor and manage the nutritional status of IPF patients, and early intervention should be conducted for low BMI and weight loss.

Percent Predicted vs. Absolute Six-Minute Walk Distance as Predictors of Lung Transplant-Free Survival in Fibrosing Interstitial Lung Diseases

INTRODUCTION

Fibrosing interstitial lung diseases (ILDs) often progress despite treatment and become life-threatening, with lung transplant (LTx) remaining the only curative option. Six-minute walk distance (6MWD) is increasingly recognized as reliable predictor of clinical course, especially when longitudinally considered. The use of reference equations to express 6MWD as percent predicted (6MWD%) has not been previously studied in fibrosing ILDs. We sought to investigate whether the prognostic power of 6MWD% is superior to that of 6MWD expressed in meters (6MWD-m).

METHODS

A retrospective, multicenter cohort analysis was conducted on both idiopathic pulmonary (IPF) and non-IPF fibrosing ILD patients. Patients were divided into a discovery (n = 211) and a validation (n = 260) cohort. Longitudinal changes of 6MWD% and lung function parameters were simultaneously considered. LTx-free survival at 3 years from baseline was the endpoint. Competing risks of death and LTx were considered.

RESULTS

Baseline 6MWD% and its longitudinal changes were significant predictors of LTx-free survival and independent from lung function variables. In both cohorts, on multivariate cox proportional hazard regression analysis, receiver operating characteristics analysis and Kaplan-Meier estimates, 6MWD% was consistently, but only slightly superior to 6MWD-m as a predictor of LTx-free survival.

CONCLUSION

6MWD% has only a slight, yet detectable advantage over 6MWD-m as a predictor of survival in fibrosing ILDs. Utilizing 6MWD% may aid in risk stratification, treatment monitoring, and LTx timing optimization. However, available reference equations do have predicting limitations. Refined predictive equations and standardizing reporting practices are therefore needed to further enhance the clinical utility of 6MWD% in fibrosing ILDs.

Higher body mass index was associated with a lower mortality of idiopathic pulmonary fibrosis: a meta-analysis

PURPOSE

In the past few years, there has been a notable rise in the incidence and prevalence of idiopathic pulmonary fibrosis (IPF) on a global scale. A considerable body of research has highlighted the 'obesity paradox,' suggesting that a higher body mass index (BMI) can confer a protective effect against numerous chronic diseases. However, the relationship between BMI and the risk of mortality in IPF patients remains underexplored in the existing literature. We aim to shed light on this relationship and potentially offer novel insights into prevention strategies for IPF.

METHODS

We conducted a systematic search of the PubMed, Embase, and Web of Science databases to collect all published studies examining the correlation between Body Mass Index (BMI) and the mortality risk in patients with IPF, up until February 14, 2023. For the synthesis of the findings, we employed random-effects models. The statistical significance of the association between BMI and the mortality risk in IPF patients was evaluated using the hazard ratio (HR), with the 95% Confidence Interval (CI) serving as the metric for effect size.

RESULTS

A total of 14 data sets involving 2080 patients with IPF were included in the meta-analysis. The combined results of the random-effects models were suggestive of a significant association between lower BMI and a higher risk of death (HR = 0.94, 95% CI = 0.91-0.97, P < 0.001). For baseline BMI, the risk of death from IPF decreased by 6% for each unit increase. The results of the subgroup analysis suggest that geographic location (Asian subgroup: HR = 0.95, 95%CI = 0.93-0.98, P = 0.001; Western subgroup: HR = 0.91, 95%CI = 0.84-0.98, P = 0.014), study type (RCS subgroup: HR = 0.95, 95%CI = 0.92-0.98, P = 0.004; PCS subgroup: HR = 0.89, 95%CI = 0.84-0.94, P < 0.001), and sample size (< 100 groups: HR = 0.93, 95%CI = 0.87-1.01, P = 0.079; >100 groups: HR = 0.94, 95%CI = 0.91-0.97, P < 0.001 ) were not significant influences on heterogeneity. Of the included literature, those with confounding factors corrected and high NOS scores reduced heterogeneity (HR = 0.93, 95%CI = 0.90-0.96, P < 0.001). Sensitivity analyses showed that the combined results were stable and not significantly altered by individual studies (HR = 0.93 to 0.95, 95% CI = 0.90-0.96 to 0.92-0.98). Egger's test suggested no significant publication bias in the included studies (P = 0.159).

CONCLUSIONS

Higher BMI (BMI ≥ 25 kg/m2) is negatively correlated to some extent with the risk of death in IPF patients, and BMI may become a clinical indicator for determining the prognosis of IPF patients.

Predictive factors of mortality in patients with idiopathic pulmonary fibrosis treated with antifibrotics: a novel prognostic scoring system

BACKGROUND AND AIM

Any test that provides sufficient prognostic information to guide treatment decisions in idiopathic pulmonary fibrosis (IPF) is not available. The aim of our study was to determine the predictive factors of mortality in patients with IPF treated with antifibrotics.

METHODS

Patients with diagnosis of IPF who were treated with antifibrotics between 2016 - 2021 were included in the study. Demographic, clinical and laboratory characteristics of the patients was derived from hospital records retrospectively. Kaplan Meier and multivariate cox regression analysis were achieved for detection of mortality predictors.

RESULTS

Study population was composed of 119 IPF patients with a male predominance of 80.7% (n=96). Mean age of the patients was 67.9 ± 7.07 years. On univariate analysis, sex was not a significant predictor of mortality (HR 1.79; 95% CI: 0.87 - 3.69, p =0.11).  BMI ≤ 26,6 m2/kg, DLCO ≤ 3.11 ml/mmHg/min, age over 62 years, 6DWT ≤ 382 meters, NLR ≤ 2.67 and PDW ≤ 16.7% were found to be significant for predicting mortality. On multivariate cox regression analysis four parameters remained significant for prediction of mortality: RDW > 14%, NLR ≤ 2.67, BMI ≤ 26,6 m2/kg and DLCO ≤ 3.11 ml/mmHg/min (respectively, HR: 2.0. 95% CI: 1.02 - 3.91, p=0.44; HR: 2.68. 95% CI: 1.48 - 4.85, p=0.001, HR: 2.07. 95% CI: 1.14 - 3.76, p=0.02, HR: 3.46. 95% CI: 1.85 - 6.47, p<0.001). A scoring system with these parameters discriminated patients with worse prognosis with a sensitivity of 89.1 % and a specificity of 65.8 % when total point was over 2 (AUC0.83, p<0.001). Conclusions In this study, DLCO, BMI, RDW and NLR levels significantly predicted mortality in IPF patients. Along with GAP index, scoring system with these simple parameters may give information about the prognosis of an IPF patient treated with antifibrotics.

Body mass index is associated with clinical outcomes in idiopathic pulmonary fibrosis

Association between body mass index (BMI) and prognosis in patients with idiopathic pulmonary fibrosis (IPF) remains uncertain. We investigated the association between BMI and clinical outcomes in patients with IPF using national health claims data. The study included 11,826 patients with IPF and rare incurable disease exemption codes (mean age: 68.9 years, male: 73.8%) and available BMI data who visited medical institutions between January 2002 and December 2018. Multivariable Cox proportional hazard models were used to evaluate the association of BMI with all-cause mortality and hospitalization. Based on BMI, 3.1%, 32.8%, 27.8%, and 36.4% were classified as underweight, normal, overweight, and obese, respectively. Multivariable analysis showed independent associations of overweight (hazard ratio [HR] 0.856, 95% confidence interval [CI] 0.801-0.916) and underweight (HR 1.538, 95% CI 1.347-1.757) with mortality in patients with IPF. Similarly, overweight (HR 0.887, 95% CI 0.834-0.943) and underweight (HR 1.265, 95% CI 1.104-1.449) were also associated with hospitalization in patients with IPF in the multivariable analysis. Spline HR curve analysis adjusted for all covariates revealed a non-linear relationship between BMI and mortality in patients with IPF. Our data suggest that BMI is associated with clinical outcomes in patients with IPF.

Usefulness of Combined Measurement of Surfactant Protein D, Thrombin-Antithrombin III Complex, D-Dimer, and Plasmin-α2 Plasmin Inhibitor Complex in Acute Exacerbation of Interstitial Lung Disease: A Retrospective Cohort Study

Background/Objectives: The coagulation cascade due to tissue damage is considered to be one of the causes of poor prognostic outcomes in patients with acute exacerbations of interstitial lung disease (AE-ILD). This study aimed to confirm coagulopathy in AE-ILD by evaluating the differences in the clinical characteristics of coagulation/fibrinolysis markers between stable ILD and AE-ILD. Methods: Overall, 81 patients were enrolled in this retrospective study and categorized into the following two groups: a chronic ILD group comprising 63 outpatients and an acute ILD group comprising 18 inpatients diagnosed with AE-ILD. Serum markers, including thrombin-antithrombin III complex (TAT), D-dimer, plasmin-α2 plasmin inhibitor complex (PIC), and surfactant protein D (SP-D), were compared between the groups. Results: Among the 18 patients with acute ILD, 17 did not meet the International Society of Thrombosis and Hemostasis scoring system for disseminated intravascular coagulation. In acute ILD, the SP-D levels were statistically significantly positively correlated with TAT, D-dimer, and PIC levels, while the Krebs von den Lungen 6 (KL-6) levels showed no correlation with any of these coagulation/fibrinolytic markers. A positive correlation was observed between SP-D levels and TAT, D-dimer, and PIC levels in acute ILD. Serum TAT, D-dimer, and PIC all showed good area under the receiver operating characteristic (ROC) curve (AUC) values in ROC analysis for the diagnosis of acute ILD. Conclusions: In the clinical setting of AE-ILD, it may be important to focus not only on alveolar damage markers such as SP-D but also on coagulation/fibrinolytic markers including TAT, D-dimer, and PIC.

Clinical manifestations and prognostic factors analysis of patients hospitalised with acute exacerbation of idiopathic pulmonary fibrosis and other interstitial lung diseases

BACKGROUND

Acute exacerbation (AE) is a life-threatening condition taking place not only in idiopathic pulmonary fibrosis (IPF) but also in interstitial lung diseases (ILD) other than IPF (non-IPF ILD). This study aims to compare the clinical manifestations between patients hospitalised with AE-IPF and AE-non-IPF ILD, and further analyse the risk factors related to in-hospital mortality.

METHODS

Clinical data of 406 patients hospitalised with AE-IPF (93 cases) and AE-non-IPF ILD (313 cases) were retrospectively collected. Clinical features were compared between the two groups. Risk factors related to in-hospital mortality in patients with overall AE-ILD, AE-IPF and AE-non-IPF ILD were identified by multiple logistic regression analyses, respectively, and assessed by receiver operating characteristic curve.

RESULTS

In addition to having more smokers and males, the AE-IPF group also had more respiratory failure on admission, comorbidities of pulmonary hypertension (PAH) or coronary artery disease/heart failure, a longer history of pre-existing ILD. Comorbidity of coronary heart disease/heart failure, respiratory failure at admission, neutrophil (N)%, serum hydroxybutyrate dehydrogenase (HBDH), lactate dehydrogenase (LDH) and low cholesterol levels were independent risk factors for patients with AE-ILD, while respiratory failure on admission, N%, serum HBDH, urea nitrogen, LDH and low albumin levels were risk factors for the AE-non-IPF ILD group, and fever, N% and PAH were the AE-IPF group's. Among them, HBDH 0.758 (sensitivity 85.5%, specificity 56%, cut-off 237.5 U/L) for patients with AE-ILD; N% 0.838 (sensitivity 62.5%, specificity 91.18%, cut-off 83.55%) for the AE-IPF group and HBDH 0.779 (sensitivity 86.4%, specificity 55.1%, cut-off 243.5 U/L) for the AE-non-IPF ILD group were the risk factors with the highest area under the curve.

CONCLUSIONS

Clinical characteristics differ between patients with AE-IPF and AE-non-IPF ILD. HBDH outperformed LDH in predicting the prognosis for patients with AE-ILD and AE-non-IPF ILD. N% was an independent predictor of death in-hospital in all three groups, especially in the AE-IPF group.

Prognostic factors associated with mortality in acute exacerbations of idiopathic pulmonary fibrosis: A systematic review and meta-analysis

BACKGROUND

Acute exacerbations of idiopathic pulmonary fibrosis (AE-IPF) increases mortality risk, but which factors increase mortality is unknown. We aimed to perform a prognostic review of factors associated with mortality in patients with IPF.

STUDY DESIGN

and methods: We searched MEDLINE, EMBASE, and CINAHL for studies that reported on the association between any prognostic factor and AE-IPF. We assessed risk of bias using the QUIPS tool. We conduced pairwise meta-analyses using REML heterogeneity estimator, and GRADE approach to assess the certainty of the evidence.

RESULTS

We included 35 studies in our analysis. We found that long-term supplemental oxygen at baseline (aHR 2.52 [95 % CI 1.68 to 3.80]; moderate certainty) and a diagnosis of IPF compared to non-IPF ILD (aHR 2.19 [95 % CI 1.22 to 3.92]; moderate certainty) is associated with a higher risk of death in patients with AE-IPF. A diffuse pattern on high resolution computed tomography (HRCT) compared to a non-diffuse pattern (aHR 2.61 [95 % CI 1.32 to 2.90]; moderate certainty) is associated with a higher risk of death in patients with AE-IPF. We found that using corticosteroids prior to hospital admission (aHR 2.19 [95 % CI 1.26 to 3.82]; moderate certainty) and those with increased neutrophils (by % increase) in bronchoalveolar lavage (BAL) during the exacerbation is associated with a higher risk of death (aHR 1.02 [1.01 to 1.04]; moderate certainty).

INTERPRETATION

Our results have implications for healthcare providers in making treatment decisions and prognosticating the clinical trajectory of patients, for researchers to design future interventions to improve patient trajectory, and for guideline developers in making decisions about resource allocation.

The Impact of Chronic Comorbidities on Outcomes in Acute Exacerbations of Idiopathic Pulmonary Fibrosis

INTRODUCTION

Idiopathic pulmonary fibrosis is a chronic progressive lung disease of unknown cause with a high associated mortality. We aimed to compare the impact of chronic medical conditions on hospital outcomes of patients with acute exacerbations of idiopathic pulmonary fibrosis (AE-IPF).

METHODS

This was a retrospective cohort study using the NIS database from 2016 to 2018. We included patients aged 60 and older hospitalized in academic medical centers with the diagnoses of IPF and acute respiratory failure. We examined factors associated with hospital mortality and length of stay (LOS) using survey-weighted multivariate logistic and negative binomial regression.

RESULTS

Out of 4975 patients with AE-IPF, 665 (13.4%) did not survive hospitalization. There was no difference in the mean age between survivors and non-survivors. Patients were more likely to be male, predominantly white, and have Medicare coverage. Most non-survivors were from households with higher median income. Hospital LOS was longer among non-survivors than survivors (9.4 days vs. 9.8 days; p < 0.001). After multivariate-logistic regression, diabetes was found to be protective (aOR 0.62, 95% CI 0.50-0.77; p < 0.0001) while chronic kidney disease (CKD) conferred a significantly higher risk of death after AE-IPF (aOR 6.85, 95% CI 1.90-24.7; p = 0.00). Our multivariate adjusted negative binomial regression model for LOS identified obesity (IRR 0.85, 95% CI 0.76-0.94; p ≤ 0.00) and hypothyroidism (IRR 0.90, 95% CI 0.83-0.98; p = 0.02) to be associated with shorter hospital LOS.

CONCLUSIONS

Our results suggest that CKD is a significant contributor to hospital mortality in AE-IPF, and diabetes mellitus may be protective. Obesity and hypothyroidism are linked with shorter hospital LOS among patients hospitalized with AE-IPF in US academic medical centers.

Polymyxin B-immobilised fibre column treatment for acute exacerbation of idiopathic pulmonary fibrosis patients with mechanical ventilation: a nationwide observational study

BACKGROUND

The prognosis for acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is poor, and there is no established treatment. Hence, we aimed to investigate the effectiveness of a polymyxin B-immobilised fibre column (PMX) for the treatment of AE-IPF.

METHODS

Data were retrospectively collected from the Japanese Diagnosis Procedure Combination database from 1 July 2010 to 31 March 2018. We identified adult patients with idiopathic pulmonary fibrosis who received high-dose methylprednisolone (mPSL) therapy and mechanical ventilation upon admission. Eligible patients (n = 5616) were divided into those receiving PMX treatment combined with high-dose mPSL (PMX group, n = 199) and high-dose mPSL alone (mPSL alone group, n = 5417). To compare outcomes between the two groups, we applied a stabilised inverse probability of treatment weighting (IPTW) using propensity scores. The primary outcome was in-hospital mortality, and the secondary outcomes were 14- and 28-day mortality and length of hospital stay.

RESULTS

The in-hospital mortality rates of the PMX and mPSL alone groups were 79.9% and 76.4%, respectively. The results did not significantly differ between the two groups after performing a stabilised IPTW. The odds ratio of the PMX group compared with the mPSL alone group was 1.56 (95% confidence interval 0.80-3.06; p = 0.19). The 14- and 28-day mortality and length of hospital stay (secondary outcomes) also did not significantly differ between the two groups.

CONCLUSIONS

In AE-IPF patients using mechanical ventilation, the treatment outcome was not significantly better for PMX combined with high-dose mPSL than for high-dose mPSL alone.

Treatable traits: a comprehensive precision medicine approach in interstitial lung disease

Interstitial lung disease (ILD) is a diverse group of inflammatory and fibrotic lung conditions causing significant morbidity and mortality. A multitude of factors beyond the lungs influence symptoms, health-related quality of life, disease progression and survival in patients with ILD. Despite an increasing emphasis on multidisciplinary management in ILD, the absence of a framework for assessment and delivery of comprehensive patient care poses challenges in clinical practice. The treatable traits approach is a precision medicine care model that operates on the premise of individualised multidimensional assessment for distinct traits that can be targeted by specific interventions. The potential utility of this approach has been described in airway diseases, but has not been adequately considered in ILD. Given the similar disease heterogeneity and complexity between ILD and airway diseases, we explore the concept and potential application of the treatable traits approach in ILD. A framework of aetiological, pulmonary, extrapulmonary and behavioural and lifestyle treatable traits relevant to clinical care and outcomes for patients with ILD is proposed. We further describe key research directions to evaluate the application of the treatable traits approach towards advancing patient care and health outcomes in ILD.

Skeletal muscle atrophy and short-term mortality in patients with acute exacerbation of idiopathic pulmonary fibrosis: an observational cohort study

BACKGROUND

Skeletal muscle atrophy, a common complication of idiopathic pulmonary fibrosis (IPF), and its presence upon diagnosis can indicate a poor prognosis. Patients with IPF frequently experience acute exacerbations (AE), which is associated with a high mortality rate. However, the association between skeletal muscle atrophy and short-term mortality remains unknown.

METHODS

We performed a retrospective, multicenter cohort study of patients admitted for AE-IPF in Japan. The cross-sectional areas of the erector spinae muscle (ESM_CSA) and the pectoralis muscle (PM_CSA) were analyzed via single-slice computed tomography (CT). The primary outcome was 90-day mortality. Survival probability was estimated using the Kaplan-Meier method, and the log-rank test was used between the low and high groups of ESM_CSA and PM_CSA. We used multivariable Cox proportional-hazards models to evaluate the association between ESM_CSA and PM_CSA and prognosis.

RESULTS

Of the 212 patients included, 94 (44%) died during the observation period. The low ESM_CSA group (<25.6 cm²) had a significantly worse prognosis than that of the high ESM_CSA group (≥25.6 cm²) (hazard ratio (HR) [95% confidence interval (CI)]: 1.52 [1.00-2.33], P = 0.049). Multivariable analyses showed that all-cause mortality was associated with low ESM_CSA (model 1, adjusted HR [95% CI]: 1.59 [0.98-2.60]; model 2, 1.55 [0.95-2.56], and model 3, 1.67 [1.00-2.78], respectively). The adjusted HR of low PM_CSA (<20.4 cm²) vs. high PM_CSA (≥20.4 cm²) was 1.39 (95% CI: 0.88-2.20).

CONCLUSIONS

Low ESM_CSA on CT images is associated with a high 90-day mortality rate in patients with AE-IPF.

Weight loss and outcomes in subjects with progressive pulmonary fibrosis: data from the INBUILD trial

BACKGROUND

Lower body mass index (BMI) and weight loss have been associated with worse outcomes in some studies in patients with pulmonary fibrosis. We analyzed outcomes in subgroups by BMI at baseline and associations between weight change and outcomes in subjects with progressive pulmonary fibrosis (PPF) in the INBUILD trial.

METHODS

Subjects with PPF other than idiopathic pulmonary fibrosis were randomized to receive nintedanib or placebo. In subgroups by BMI at baseline (< 25, ≥ 25 to < 30, ≥ 30 kg/m²), we analyzed the rate of decline in FVC (mL/year) over 52 weeks and time-to-event endpoints indicating disease progression over the whole trial. We used a joint modelling approach to assess associations between change in weight and the time-to-event endpoints.

RESULTS

Among 662 subjects, 28.4%, 36.6% and 35.0% had BMI < 25, ≥ 25 to < 30 and ≥ 30 kg/m², respectively. The rate of decline in FVC over 52 weeks was numerically greater in subjects with baseline BMI < 25 than ≥ 25 to < 30 or ≥ 30 kg/m² (nintedanib: - 123.4, - 83.3, - 46.9 mL/year, respectively; placebo: - 229.5; - 176.9; - 171.2 mL/year, respectively). No heterogeneity was detected in the effect of nintedanib on reducing the rate of FVC decline among these subgroups (interaction p = 0.83). In the placebo group, in subjects with baseline BMI < 25, ≥ 25 to < 30 and ≥ 30 kg/m², respectively, 24.5%, 21.4% and 14.0% of subjects had an acute exacerbation or died, and 60.2%, 54.5% and 50.4% of subjects had ILD progression (absolute decline in FVC % predicted ≥ 10%) or died over the whole trial. The proportions of subjects with these events were similar or lower in subjects who received nintedanib versus placebo across the subgroups. Based on a joint modelling approach, over the whole trial, a 4 kg weight decrease corresponded to a 1.38-fold (95% CI 1.13, 1.68) increase in the risk of acute exacerbation or death. No association was detected between weight loss and the risk of ILD progression or the risk of ILD progression or death.

CONCLUSIONS

In patients with PPF, lower BMI at baseline and weight loss may be associated with worse outcomes and measures to prevent weight loss may be required.

TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT02999178 .

Database analysis of hypersensitivity pneumonitis in Japan

BACKGROUND

Three epidemiological small-scale studies on hypersensitivity pneumonitis (HP) have been performed in Japan to date. Herein, we aimed to clarify the clinical characteristics of various types of HP diseases using a large nationwide database in Japan.

METHODS

We used the Japanese Diagnostic Procedure Combination database that includes data from 1,031 participant hospitals. Patients with HP from 2011 to 2017 were identified using International Classification of Diseases 10th Revision codes. We analyzed patient characteristics, the yearly transition of the number of HP cases, rate per one million hospitalizations, geographical distribution, seasonality, and risk factors for in-hospital mortality.

RESULTS

In total, 3,634 patients with HP were identified, including summer-type HP (SHP) (n = 490), bird fancier's lung (BFL) (n = 199), ventilation pneumonitis (n = 106), farmer's lung (n = 48), and unspecified HP (n = 2761). The length of hospital stay was significantly longer in patients with BFL (19 days) than in patients with SHP (15 days). SHP was more prevalent in the southwestern region of Japan, and hospitalization occurred mainly in summer (37.8%) and fall (37.3%). Ventilation pneumonitis was predominant in winter (28.6%) and spring (38.7%). In-hospital mortality was significantly associated with old age (p < 0.001), low body mass index (p = 0.016), severe dyspnea (p < 0.001), and BFL diagnosis on admission (p = 0.031).

CONCLUSIONS

This study revealed the clinical characteristics of SHP and BFL, including the frequency of causative antigens, geographical distribution, seasonality, and risk factors for mortality, which may help in diagnosing HP and identifying causative antigens.

Association between weight loss and mortality in idiopathic pulmonary fibrosis

RATIONALE

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disease that has no cure. Many current research efforts center on diagnostic and therapeutic modalities for IPF while other risk factors affecting disease pathogenesis receive less attention. Emerging data support the clinical importance of weight loss in patients with IPF. However, factors associated with weight loss and the impact of weight loss on mortality remain incompletely explored.

OBJECTIVES

Explore the association between weight loss and transplant-free survival in patients with IPF and identify clinical variables associated with weight loss in this population.

METHODS

Kaplan-Meier and Cox proportional hazard regression analyses were generated and stratified by weight loss or use of antifibrotic medications. Conditional logistic regression was used to evaluate for factors associated with weight loss.

RESULTS

There was a significant increase in mortality in patients who lost ≥ 5% of their body weight loss (HR 2.21, [1.29, 4.43] p = .021). The use of supplemental oxygen (adjusted OR 13.16), and ≥ 200 mL loss of FVC over 1 year (adjusted OR 5.44) were both associated with a ≥ 5% weight loss in the year following a diagnosis of IPF. The use of antifibrotic medication did not significantly change median transplant-free survival in patients who lost more than ≥ 5% of their body mass.

CONCLUSIONS

Weight loss over the first year following a diagnosis of IPF is strongly associated with decreased transplant-free survival. More research is needed to determine the mechanisms surrounding weight loss in patients with IPF.

Nutrition implications of intrinsic restrictive lung disease

Restrictive lung disease is defined as a reduction in lung volume that may be due to intraparenchymal or extraparenchymal causes. Intraparenchymal causes falls under the umbrella term of interstitial lung disease (ILD) and includes idiopathic pulmonary fibrosis. This manuscript provides an overview of ILD and can be beneficial for all clinicians working with patients with ILD. Although not well documented, the prevalence of malnutrition in patients with ILD has been reported to be between ~9% and 55%. Body mass index has been shown to predict survival; but more recently, research has suggested that fat-free mass has a larger influence on survival. There is insufficient evidence to support the use of antioxidant or vitamin supplementation to help diminish the chronic inflammatory process that is seen in this patient population. There are data from studies examining the vitamin D status in this patient population, but research on vitamin D supplementation appears to be lacking. Registered dietitian nutritionists should continue to advocate and play a more prominent role in the nutrition management of patients with ILD as part of standard of care.

Recombinant human soluble thrombomodulin for acute exacerbation of idiopathic pulmonary fibrosis: a nationwide observational study

BACKGROUND

Acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is the leading cause of death among patients with IPF. However, there is no established treatment for this condition. Hence, we aimed to investigate the effectiveness and safety of recombinant human soluble thrombomodulin (rTM) for the treatment of AE-IPF.

METHODS

Data were retrospectively collected from the Japanese Diagnosis Procedure Combination database from 1 January 2014 to 31 March 2018. We identified adult patients with IPF who received high-dose methylprednisolone (mPSL) therapy and mechanical ventilation upon admission. Eligible patients (n = 2814) were divided into those receiving high-dose mPSL alone (mPSL alone group, n = 2602) and rTM combined with high-dose mPSL (rTM group, n = 212). A stabilised inverse probability of treatment weighting (IPTW) using propensity scores was performed to compare outcomes between the two groups. The primary outcome was in-hospital mortality, and the secondary outcomes were 14- and 28-day mortality, bleeding events and length of hospital stay.

RESULTS

The in-hospital mortality rates of the mPSL alone and rTM groups were 75.9% and 76.9%, respectively. The results did not significantly differ between the two groups after performing a stabilised IPTW. The odds ratio of the rTM group compared to the mPSL alone group was 1.15 (95% confidence interval: 0.71-1.84; p = 0.57). Moreover, the secondary outcomes did not differ significantly between the two groups.

CONCLUSIONS

In patients with AE-IPF who developed severe respiratory failure, rTM in addition to high-dose mPSL was not associated with a better outcome.

Obesity and the Development of Lung Fibrosis

Obesity is an epidemic worldwide and the obese people suffer from a range of respiratory complications including fibrotic changes in the lung. The influence of obesity on the lung is multi-factorial, which is related to both mechanical injury and various inflammatory mediators produced by excessive adipose tissues, and infiltrated immune cells. Adiposity causes increased production of inflammatory mediators, for example, cytokines, chemokines, and adipokines, both locally and in the systemic circulation, thereby rendering susceptibility to respiratory diseases, and altered responses. Lung fibrosis is closely related to chronic inflammation in the lung. Current data suggest a link between lung fibrosis and diet-induced obesity, although the mechanism remains incomplete understood. This review summarizes findings on the association of lung fibrosis with obesity, highlights the role of several critical inflammatory mediators (e.g., TNF-α, TGF-β, and MCP-1) in obesity related lung fibrosis and the implication of obesity in the outcomes of idiopathic pulmonary fibrosis patients.