Oxygen desaturation during the 6-min walk test as a risk for osteoporosis in non-cystic fibrosis bronchiectasis

Do Causes Influence Functional Aspects and Quality of Life in Patients with Nonfibrocystic Bronchiectasis?

Background

The denomination of noncystic fibrosis bronchiectasis (NCFB) includes several causes, and differences may be expected between the patient subgroups regarding age, comorbidities, and clinical and functional evolution. This study sought to identify the main causes of NCFB in a cohort of stable adult patients and to investigate whether such conditions would be different in their clinical, functional, and quality of life aspects.

Methods

Between 2017 and 2019, all active patients with NCFB were prospectively evaluated searching for clinical data, past medical history, dyspnea severity grading, quality of life data, microbiological profile, and lung function (spirometry and six-minute walk test).

Results

There was a female predominance; mean age was 54.7 years. Causes were identified in 82% of the patients, the most frequent being postinfections (n = 39), ciliary dyskinesia (CD) (n = 32), and chronic obstructive pulmonary disease (COPD) (n = 29). COPD patients were older, more often smokers (or former smokers) and with more comorbidities; they also had worse lung function (spirometry and oxygenation) and showed worse performance in the six-minute walk test (6MWT) (walked distance and exercise-induced hypoxemia). Considering the degree of dyspnea, in the more symptomatic group, patients had higher scores in the three domains and total score in SGRQ, besides having more exacerbations and more patients in home oxygen therapy.

Conclusions

Causes most identified were postinfections, CD, and COPD. Patients with COPD are older and have worse pulmonary function and more comorbidities. The most symptomatic patients are clinically and functionally more severe, besides having worse quality of life.

Effect of pulmonary function on bone mineral density in the United States: results from the NHANES 2007-2010 study

The relationship between pulmonary function (PF) and bone mineral density (BMD) remains controversial. In the US population, we found a positive association between PF and BMD. Mixed variables such as age, gender, and race may influence this association.

INTRODUCTION

Based on the data from the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2010, this study explored whether there is a correlation between PF (1st second forceful expiratory volume as a percentage of expected value (FEV1(% predicted)), (one-second rate (FEV1/FVC)), and bone mineral density.

METHODS

We evaluated the relationship between PF and BMD in 6327 NHANES subjects (mean age 44.51 ± 15.64 years) from 2007 to 2010. The bone mineral density of the whole femur was measured by dual-energy X-ray absorptiometry (DXA). After adjusting for a wide range of confounders, we examined the relationship between PF and total femur BMD using a multiple linear regression model.

RESULTS

Correction of race, age, alcohol consumption, body mass index (BMI), height, poor income ratio (PIR), total protein, serum calcium, serum uric acid, cholesterol, serum phosphorus, blood urea nitrogen, FEV1(% predicted), and femur BMD were positively correlated (β = 0.032, 95% CI: 0.010-0.054, P = 0.004). FEV1/FVC was positively correlated with spine BMD (β = 0.275 95%CI: 0.102-0.448, P = 0.002).

CONCLUSIONS

Our study shows that PF is positively associated with BMD in the US population. A variety of factors such as race and age influence this relationship. the relationship between PF and BMD needs to be further investigated, including specific regulatory mechanisms and confounding factors.

Risk factors and prognostic value of osteoporosis in hospitalized patients with bronchiectasis

BACKGROUND

The risk factors for osteoporosis and its prognostic value in patients with bronchiectasis is not well characterized. We explored the risk factors for osteoporosis and its prognostic impact in hospitalized non-cystic fibrosis bronchiectasis (NCFB) patients in Southeast China.

METHODS

This observational cohort study consecutively enrolled 179 hospitalized patients with NCFB bronchiectasis between 2017 and 2021. The risk factors and the impact of osteoporosis on all-cause mortality were assessed.

RESULTS

21.2% (38/179) of hospitalized NCFB patients were diagnosed with osteoporosis. Patients with osteoporosis had more severe symptoms (assessed by chronic airway assessment test, CAT, median 22 vs. 17, P = 0.017), poorer quality of life (assessed by St. George Respiratory Questionnaires, SQRC, median 42 vs. 27, P = 0.007), more severe disease stage (assessed by bronchiectasis severity index, BSI, median 14 vs. 11, P = 0.02), more comorbidities (assessed by Bronchiectasis Aetiology Comorbidity Index, BACI, median 5 vs. 4, P = 0.021) than patients without. Age, female sex, anemia, post-infection, and history of regular inhaled corticosteroid treatment were independent risk factors for osteoporosis in those patients. 21 patients (11.7%) died over a median follow-up period of 32 months. The all-cause mortality in NCFB patients with osteoporosis [28.94% (11/38)] was significantly higher than those without osteoporosis [7.09% (10/141)] [hazard ratio (HR) 5.34, 95% confidence interval (CI) 2.26-12.67, P < 0.001]. After adjusting for BSI and other confounding factors, osteoporosis was still independently associated with all-cause mortality in hospitalized NCFB patients (HR 4.29, 95% CI 1.75-10.49, P < 0.001).

CONCLUSIONS

Osteoporosis had an independent effect on all-cause mortality in hospitalized NCFB patients. Management of comorbidities, including bone health, is a critical aspect of treating NCFB patients.

Influence of Comorbidities and Airway Clearance on Mortality and Outcomes of Patients With Severe Bronchiectasis Exacerbations in Taiwan

Bronchiectasis is characterized by systemic inflammation and multiple comorbidities. This study aimed to investigate the clinical outcomes based on the bronchiectasis etiology comorbidity index (BACI) score in patients hospitalized for severe bronchiectasis exacerbations. We included non-cystic fibrosis patients hospitalized for severe bronchiectasis exacerbations between January 2008 and December 2016 from the Chang Gung Research Database (CGRD) cohort. The main outcome was the 1-year mortality rate after severe exacerbations. We used the Cox regression model to assess the risk factors of 1-year mortality. Of 1,235 patients who were hospitalized for severe bronchiectasis exacerbations, 641 were in the BACI < 6 group and 594 in the BACI ≥ 6 group. The BACI ≥ 6 group had more previous exacerbations and a lower FEV₁. Pseudomonas aeruginosa (19.1%) was the most common bacterium, followed by Klebsiella pneumoniae (7.5%). Overall, 11.8% of patients had respiratory failure and the hospital mortality was 3.0%. After discharge, compared to the BACI < 6 group, the BACI ≥ 6 group had a significantly higher cumulative incidence of respiratory failure and mortality in a 1-year follow-up. The risk factors for 1-year mortality in a multivariate analysis include age [hazard ratio (HR) 4.38, p = 0.01], being male (HR 4.38, p = 0.01), and systemic corticosteroid usage (HR 6.35, p = 0.001), while airway clearance therapy (ACT) (HR 0.50, p = 0.010) was associated with a lower mortality risk. An increased risk of respiratory failure and mortality in a 1-year follow-up after severe exacerbations was observed in bronchiectasis patients with multimorbidities, particularly older age patients, male patients, and patients with a history of systemic corticosteroid use. ACT could effectively improve the risk for 1-year mortality.

Predicting mortality in non-cystic fibrosis bronchiectasis patients using distance-saturation product

BACKGROUND

The bronchiectasis severity index (BSI) and FACED score are currently used in predicting outcomes of non-cystic fibrosis bronchiectasis (NCFB). Distance-saturation product (DSP), the product of distance walked, and lowest oxygen saturation during the 6-min walk test showed strong predictive power of mortality in non-CF bronchiectasis patients. This study aimed to compare the efficacy of these scores and DSP in predicting mortality.

METHODS AND PATIENTS

Our retrospective study included NCFB patients from January 2004 to December 2017. We recorded the basic data, pulmonary function, radiologic studies, sputum culture results, acute exacerbations (AE), emergency department (ED) visits, hospitalization, and mortality.

RESULTS

A total 130 NCFB patients were analysed. The mean BSI score, FACED score, and DSP were 8.8 ± 4.9, 3.4 ± 1.7, and 413.1 ± 101.5 m%, respectively. BSI and FACED scores had comparable predictive power for AE (p=.011; p=.010, respectively). The BSI score demonstrated a significant correlation with ED visits (p=.0003). There were 12 deaths. Patients were stratified using a DSP cut-off value of 345 m% according to the best area under receiver operator characteristic curve (AUC) value in mortality. DSP was not correlated with AE and ED visits. BSI, FACED scores, and DSP demonstrated statistically significant correlations with hospitalization (p<.0001; p<.0001; p=.0007, respectively). The AUC for overall mortality was similar for BSI, FACED score, and DSP (0.80 versus 0.85, p=.491; 0.85 versus 0.83, p=.831).

CONCLUSION

DSP had comparable predictive power for mortality as the well-validated BSI and FACED scores and is relatively easy to use in clinical practice.KEY MESSAGEDistance-saturation product (DSP) comprised with the product of distance walked, and lowest oxygen saturation during the 6-min walk test, which is common used in clinical practice.DSP demonstrated strong and comparable predictive power of mortality as the well-validated BSI and FACED scores in non-CF bronchiectasis patients.

Correlation between clinical-functional parameters and number of lobes involved in non-cystic fibrosis bronchiectasis

BACKGROUND

Currently, the prognosis of bronchiectasis is based on different prognostic indicators, like BSI and FACED score, founded on clinical-demographic, functional and radiological criteria. Both scoring systems include the number of lobes involved in bronchiectasis, which represents an adverse prognostic index. Our study aimed to investigate the prognostic role of the clinical-functional parameters and the number of involved lobes ratio in adult bronchiectasis.

METHODS

The study was conducted on 52 patients diagnosed with non-cystic fibrosis bronchiectasis (NCFB) between 2015 and 2017 who attended the Pneumology Unit of Monaldi Hospital in Naples, Italy. Correlations between clinical- functional parameters (BMI, smoking history, number of exacerbations in the previous year, spirometry, DLCO, ABG test, and 6MWT) and number of involved lobes were investigated.

RESULTS

At baseline, the number of exacerbations in the previous year had a statistically significant association with the number of involved lobes. Furthermore, at baseline, the radiological criterion was also negatively associated with some functional parameters (FEV1/FVC ratio e FEF25-75%). Statistical significance was lost during the follow up, demonstrating the effectiveness of the therapy.

CONCLUSIONS

Imaging extension represents a promising biomarker of disease severity as well as a helpful follow up tool for non-Cystic Fibrosis bronchiectasis (NCFB).

Etiology and characteristics of patients with bronchiectasis in Taiwan: a cohort study from 2002 to 2016

Background

Bronchiectasis is a chronic infectious respiratory disease with diverse causes and ethnic or geographic differences. However, few large-scale studies of its etiology have been conducted in Asia. This study aimed to determine the etiology and clinical features of bronchiectasis in Taiwan.

Methods

This longitudinal cohort study investigated the etiology and clinical features of newly diagnosed non-cystic fibrosis bronchiectasis patients from January 2002 to December 2016. The clinical, functional and microbiological data of patients were retrieved from the Chang Gung Research Database, which includes seven medical facilities throughout Taiwan. The index date was the date of the first bronchiectasis diagnosis. Known diseases that were diagnosed before the index date were regarded as etiologies of bronchiectasis.

Results

The cohort comprised 15,729 adult patients with bronchiectasis. Idiopathic (32%) was the most common cause, followed by post-pneumonia (24%). Other causes included post-tuberculosis (12%), chronic obstructive pulmonary disease (14%), asthma (10%), gastroesophageal reflux disease (2%) and rheumatic diseases (2%). At diagnosis, 8487 patients had sputum culture. Pseudomonas aeruginosa (5.3%) was the most common bacteria, followed by non-tuberculosis mycobacteria (3.6%), Haemophilus influenzae (3.4%) and Klebsiella pneumoniae (3.1%), but 6155 (72.1%) had negative sputum cultures. Patients with post-tuberculosis had a higher sputum isolation rate of non-tuberculosis mycobacteria than P. aeruginosa. Patients with post-tuberculosis and post-pneumonia bronchiectasis had a higher frequency of chronic lung infection than other groups (p < 0.05). Clinical characteristics, such as gender, lung function, comorbidities and microbiology, were significantly different between idiopathic and known etiologies.

Conclusions

Idiopathic, post-infection and tuberculosis constitute major bronchiectasis etiologies in Taiwan. Clinical characteristics and sputum microbiology were distinct among separate etiology phenotypes.

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.