Multi-ethnic reference values for spirometry for the 3-95-yr age range: the global lung function 2012 equations

Spirometric evaluation in juvenile systemic lupus erythematosus

OBJECTIVE

Spirometric evaluation in juvenile systemic lupus erythematosus.

METHODS

Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1/FVC, forced expiratory flow between 25-75% of vital capacity (FEF25-75%) and peak expiratory flow rate (PEFR) of 21 patients with juvenile SLE (jSLE) were compared to controls.

RESULTS

Reduced FVC and FEF25-75% was found in 18 and 9 patients, respectively. All had normal FEV1/FVC. None had respiratory complaint. When compared to controls, patients had significantly reduced FVC [mean (SD):1.97 (0.56) vs 2.35 (0.60), P=0.002] and FEF25-75% [2.19 (0.83) vs 2.63 (0.76), P=0.028] but similar FEV1/FVC [86.87(7.03) vs 86.72 (6.35), P=0.639].

CONCLUSION

jSLE patients had significant restrictive pattern and small airway involvement.

Clinical Decision Support Systems (CDSS) for preventive management of COPD patients

BACKGROUND

The use of information and communication technologies to manage chronic diseases allows the application of integrated care pathways, and the optimization and standardization of care processes. Decision support tools can assist in the adherence to best-practice medicine in critical decision points during the execution of a care pathway.

OBJECTIVES

The objectives are to design, develop, and assess a clinical decision support system (CDSS) offering a suite of services for the early detection and assessment of chronic obstructive pulmonary disease (COPD), which can be easily integrated into a healthcare providers' work-flow.

METHODS

The software architecture model for the CDSS, interoperable clinical-knowledge representation, and inference engine were designed and implemented to form a base CDSS framework. The CDSS functionalities were iteratively developed through requirement-adjustment/development/validation cycles using enterprise-grade software-engineering methodologies and technologies. Within each cycle, clinical-knowledge acquisition was performed by a health-informatics engineer and a clinical-expert team.

RESULTS

A suite of decision-support web services for (i) COPD early detection and diagnosis, (ii) spirometry quality-control support, (iii) patient stratification, was deployed in a secured environment on-line. The CDSS diagnostic performance was assessed using a validation set of 323 cases with 90% specificity, and 96% sensitivity. Web services were integrated in existing health information system platforms.

CONCLUSIONS

Specialized decision support can be offered as a complementary service to existing policies of integrated care for chronic-disease management. The CDSS was able to issue recommendations that have a high degree of accuracy to support COPD case-finding. Integration into healthcare providers' work-flow can be achieved seamlessly through the use of a modular design and service-oriented architecture that connect to existing health information systems.

Chronic Obstructive Pulmonary Disease heterogeneity: challenges for health risk assessment, stratification and management

Background and hypothesis

Heterogeneity in clinical manifestations and disease progression in Chronic Obstructive Pulmonary Disease (COPD) lead to consequences for patient health risk assessment, stratification and management. Implicit with the classical "spill over" hypothesis is that COPD heterogeneity is driven by the pulmonary events of the disease. Alternatively, we hypothesized that COPD heterogeneities result from the interplay of mechanisms governing three conceptually different phenomena: 1) pulmonary disease, 2) systemic effects of COPD and 3) co-morbidity clustering, each of them with their own dynamics.

Objective and method

To explore the potential of a systems analysis of COPD heterogeneity focused on skeletal muscle dysfunction and on co-morbidity clustering aiming at generating predictive modeling with impact on patient management. To this end, strategies combining deterministic modeling and network medicine analyses of the Biobridge dataset were used to investigate the mechanisms of skeletal muscle dysfunction. An independent data driven analysis of co-morbidity clustering examining associated genes and pathways was performed using a large dataset (ICD9-CM data from Medicare, 13 million people). Finally, a targeted network analysis using the outcomes of the two approaches (skeletal muscle dysfunction and co-morbidity clustering) explored shared pathways between these phenomena.

Results

(1) Evidence of abnormal regulation of skeletal muscle bioenergetics and skeletal muscle remodeling showing a significant association with nitroso-redox disequilibrium was observed in COPD; (2) COPD patients presented higher risk for co-morbidity clustering than non-COPD patients increasing with ageing; and, (3) the on-going targeted network analyses suggests shared pathways between skeletal muscle dysfunction and co-morbidity clustering.

Conclusions

The results indicate the high potential of a systems approach to address COPD heterogeneity. Significant knowledge gaps were identified that are relevant to shape strategies aiming at fostering 4P Medicine for patients with COPD.

Spirometric reference values for Malagasy adults aged 18-73 years

The American Thoracic Society (ATS) and European Respiratory Society (ERS) recommend that spirometry prediction equations be derived from samples of similar race/ethnicity. Malagasy prediction equations do not exist. The objectives of this study were to establish prediction equations for healthy Malagasy adults, and then compare Malagasy measurements with published prediction equations. We enrolled 2491 healthy Malagasy subjects aged 18-73 years (1428 males) from June 2006 to April 2008. The subjects attempted to meet the ATS/ERS 2005 guidelines when performing forced expiratory spirograms. We compared Malagasy measurements of forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC with predictions from the European Community for Steel and Coal (ECSC), the third National Health and Nutrition Examination Survey (NHANES III) and the ERS Global Lung Function Initiative (GLI) 2012 study. A linear model for the entire population, using age and height as independent variables, best predicted all spirometry parameters for sea level and highland subjects. FEV1, FVC and FEV1/FVC were most accurately predicted by NHANES III African-American male and female, and by GLI 2012 black male and black and South East Asian female equations. ECSC-predicted FEV1, FVC and FEV1/FVC were poorly matched to Malagasy measurements. We provide the first spirometry reference equations for a healthy adult Malagasy population, and the first comparison of Malagasy population measurements with ECSC, NHANES III and GLI 2012 prediction equations.

Pulmonary function of a paediatric cohort of patients with postinfectious bronchiolitis obliterans. A long term follow-up

BACKGROUND

Postinfectious bronchiolitis obliterans (BO) is a chronic respiratory disease that usually follows a severe adenovirus infection.

OBJECTIVE

To determine the evolution of pulmonary function and clinical outcome of children with postinfectious BO during childhood.

METHODS

The study included patients diagnosed with postinfectious BO in whom at least two spirometries were performed within a minimum interval of 3 months.

RESULTS

46 met the inclusion criteria. The mean (±SD) follow-up period was 12.5 (±3.5) years. 197 spirometries and 41 plethysmographies were performed. Initial (9±3 years old) lung function was as follows (z score, mean±SD): forced vital capacity (FVC) -3.8±1; forced expiratory volume in 1 s (FEV1) -4.4±1; FEV1/FVC -2.2±1; forced expiratory flow (FEF)(25-75) -3.7±1; total lung capacity (TLC) 120±26%; residual volume (RV) 309±108%; and RV/TLC 55±13. During childhood, FVC and FEV1 increased by a mean of 11%/year (95% CI 9.3% to 12.6%; p<0.0001) and 9%/year (95% CI 7.7% to 10.2%; p<0.0001), and the FEV1/FVC ratio decreased by 1.9%/year (95% CI 1% to 2.8; p<0.001). The z score for FVC, FEV1 and FEV1/FVC decreased by 0.07 z score/year (95% CI 0.1 to 0.01; p<0.05), 0.09 z score/year (95% CI 0.1 to 0.05; p<0.01) and 0.04 z score/year (95% CI 0.09 to 0.001; p<0.02), respectively. During the follow-up period, 69% of patients required at least one hospital readmission and five required mechanical ventilation. Nine patients developed a thoracic deformity, and seven whose bronchiectasis did not respond to clinical treatment underwent a lobectomy.

CONCLUSIONS

After a 12 year follow-up period, pulmonary function remained severely impaired, showing an obstructive pattern with air trapping that slowly improved during childhood. An unequal growth of lung parenchyma over the airways suggests dysinaptic growth. Patients required frequent readmission due to recurrent respiratory infections, and hypoxaemia improved slowly over time.

Factors predicting future ACS episodes in children with sickle cell anemia

While a doctor-diagnosis of asthma is associated with an increased risk of pain and acute chest syndrome (ACS) in children with sickle cell anemia (SCA), little is known about the relationship between specific asthma characteristics and clinical factors and future morbidity in children with SCA. We evaluated the relationship between (i) asthma risk factors at the time of a clinical visit (respiratory symptoms, maternal history of asthma, allergy skin tests, spirometry results) and (ii) the known risk factor of ACS early in life, on prospective pain and ACS episodes in a cohort of 159 children with SCA followed from birth to a median of 14.7 years. An ACS episode prior to 4 years of age, (incidence rate ratio [IRR] = 2.84; P < 0.001], female gender (IRR = 1.80; P = 0.009), and wheezing causing shortness of breath (IRR = 1.68; P = 0.042) were associated with future ACS rates. We subsequently added spirometry results (obstruction defined as FEV1 /FVC less than the lower limits of normal; and bronchodilator response, FEV1 ≥ 12%) and prick skin test responses to the model. Only ≥ 2 positive skin tests had a significant effect (IRR 1.87; P = 0.01). Thus, early in life ACS events, wheezing causing shortness of breath, and ≥ 2 positive skin tests predict future ACS events.

TargetCOPD: a pragmatic randomised controlled trial of targeted case finding for COPD versus routine practice in primary care: protocol

BACKGROUND

Many people with clinically significant chronic obstructive pulmonary disease (COPD) remain undiagnosed worldwide. There are a number of small studies which have examined possible methods of case finding through primary care, but no large RCTs that have adequately assessed the most cost-effective approach.

METHODS/DESIGN

In this study, using a cluster randomised controlled trial (RCT) in 56 general practices in the West Midlands, we plan to investigate the effectiveness and cost-effectiveness of a Targeted approach to case finding for COPD compared with routine practice. Using an individual patient RCT nested in the Targeted arm, we plan also to compare the effectiveness and cost-effectiveness of Active case finding using a postal questionnaire (with supplementary opportunistic questionnaires), and Opportunistic-only case finding during routine surgery consultations.All ever-smoking patients aged 40-79 years, without a current diagnosis of COPD and registered with participating practices will be eligible. Patients in the Targeted arm who report positive respiratory symptoms (chronic cough or phlegm, wheeze or dyspnoea) using a brief questionnaire will be invited for further spirometric assessment to ascertain whether they have COPD or not. Post-bronchodilator spirometry will be conducted to ATS standards using an Easy One spirometer by trained research assistants.The primary outcomes will be new cases of COPD and cost per new case identified, comparing targeted case finding with routine care, and two types of targeted case finding (active versus opportunistic). A multilevel logistic regression model will be used to model the probability of detecting a new case of COPD for each treatment arm, with clustering of patients (by practice and household) accounted for using a multi-level structure.A trial-based analysis will be undertaken using costs and outcomes collected during the trial. Secondary outcomes include the feasibility, efficiency, long-term cost-effectiveness, patient and primary care staff views of each approach.

DISCUSSION

This will be the largest RCT of its kind, and should inform how best to identify undiagnosed patients with COPD in the UK and other similar healthcare systems. Sensitivity analyses will help local policy-makers decide which sub-groups of the population to target first.

TRIAL REGISTRATION

Current controlled trials ISRCTN14930255.

Spirometric evaluation in juvenile idiopathic arthritis: data from eastern India

OBJECTIVE

To evaluate lung function in juvenile idiopathic arthritis (JIA) patients.

METHODS

This was a case control study carried out at Institute of Post-Graduate Medical Education & Research, Kolkata, involving JIA patients between 5 and 12 y. They were diagnosed and classified on the basis of International League of Associations for Rheumatology (ILAR) criteria and compared with same number of age, sex, height and weight matched controls. Forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1/FVC ratio, forced expiratory flow between 25 and 75% of vital capacity (FEF25-75%) and peak expiratory flow rate (PEFR) of cases were compared to those of matched controls.

RESULTS

Among 36 JIA patients initially recruited, 9 were excluded. Of the remaining 27 patients, male: female ratio was 17:10. Mean age, height and weight of JIA patients were 9.15 y, 124.67 cm and 23.78 kg respectively. Six patients had oligoarthritis, 3 had rheumatoid factor positive (RF+) polyarthritis, 10 had rheumatoid factor negative (RF-) polyarthritis and 8 had systemic JIA. Eleven patients had active disease and 15 patients required methotrexate. None had respiratory symptoms. Mean duration of the disease was 2.96 y. Mean FVC and FEV1 were significantly less in JIA patients compared to controls (p value=0.0003 and 0.0007, respectively). FEV1/FVC in both the groups was similar (p value=0.96). Mean Z scores for FVC and FEV1 were significantly higher in JIA patients (p value=0.0064 and 0.0030, respectively).

CONCLUSION

Spirometry in JIA patients demonstrated statistically significant restrictive pattern of alteration in pulmonary function.

Six-year follow-up study on the effect of combined anterior and posterior spinal fusion on lung function and quality of life in young people with adolescent idiopathic scoliosis

OBJECTIVES

The effects of spinal surgery on lung function and quality of life (QoL) are important patient outcomes. Long-term follow-up of lung function and QoL in those undergoing combined anterior and posterior spinal fusion (A/PSF) for adolescent idiopathic scoliosis (AIS) is poorly documented with only one study extending beyond 2 years, though available evidence points to a decrement in lung function. Our study evaluated long-term change in lung function and QoL following A/PSF for AIS.

DESIGN

Prospective cohort study.

PATIENTS

Patients with AIS.

SETTING

Tertiary paediatric respiratory centre and national spinal service.

DESIGN

Spirometry was performed along with QoL (Scoliosis Research Society-22 (SRS-22) questionnaire). Paired t test and one-way analysis of variance were used to compare pre-A/PSF and post-A/PSF data.

RESULTS

Data were available for 12 patients (9 female) who underwent A/PSF at mean 13.8 (range 11.8-15) years. Mean follow-up was undertaken 5.8 (range 4.1-6.8) years postoperatively. Height increased from mean (SD) 169 (9) cm preoperatively to 175 (5) cm at follow-up (p<0.01). Scoliosis corrected from 100 (15)° to 29 (11)° (p<0.001). Mean (SD) forced expiratory volume in 1 s was -3.4 (1.4) z scores preoperatively versus -3.3 (1) z scores postoperatively (p=0.85); and forced vital capacity was -3.4 (1.7) ) z scores pre-A/PSF and -3.4 (1.1) z scores post-A/PSF (p=0.83). SRS-22 scores improved mean (SD) of 3.6 (0.3) preoperatively to 4.2 (0.3) at 2 years postoperatively, and 4.4 (0.4) at 6 year follow-up (p<0.001, analysis of variance). High patient satisfaction rates (4.8 (0.3)) were recorded. No correlation was noted between changes in forced expiratory volume in 1 s (r=-0.15, p=0.63) or forced vital capacity (r=-0.12, p=0.71) and change in long-term SRS-22 score.

CONCLUSIONS

Long-term follow-up of patients with AIS suggests no deficit in pulmonary function, while QoL shows incremental improvement and patient satisfaction is high over 6 years after A/PSF.

Putting lung function and physiology into perspective: cystic fibrosis in adults

Adult cystic fibrosis (CF) is notable for the wide heterogeneity in severity of disease expression, both between patients and within the lungs of individuals. Although CF airways disease appears to start in the small airways, in adults there is typically widespread bronchiectasis, increased airway secretions, and extensive obstruction and inflammation of the small airways. The complexity and heterogeneity of airways disease in CF means that although there are many different methods of assessing and describing lung 'function', none of these single-dimensional tests is able to provide a comprehensive assessment of lung physiology across the spectrum seen in adult CF. The most widely described measure, the forced expiratory volume in 1 s, remains a useful and simple clinical tool, but is insensitive to early changes and may be dissociated from other more detailed assessments of disease severity such as computed tomography. In this review, we also discuss the use of more sensitive novel assessments such as multiple breath washout tests and impulse oscillometry, as well as the role of cardiopulmonary exercise testing. In the future, hyperpolarized gas magnetic resonance imaging techniques that combine regional structural and functional information may help us to better understand these measures, their applications and limitations.

Forced expiratory flows' contribution to lung function interpretation in schoolchildren

Forced expiratory flow (FEF) at low lung volumes are supposed to be better at detecting lung-function impairment in asthmatic children than a forced volume. The aim of this study was to examine whether FEF results could modify the interpretation of baseline and post-bronchodilator spirometry in asthmatic schoolchildren in whom forced expiratory volumes are within the normal range. Spirometry, with post-bronchodilator vital capacity within 10% of that of baseline in healthy and asthmatic children, was recorded prospectively. We defined abnormal baseline values expressed as z-scores <-1.645, forced expiratory volume in 1 s (FEV1) reversibility as a baseline increase >12%, FEF reversibility as an increase larger than the 2.5th percentile of post-bronchodilator changes in healthy children. Among 66 healthy and 50 asthmatic schoolchildren, only two (1.7%) children with normal vital capacity and no airways obstruction had abnormal baseline forced expiratory flow at 25-75% of forced vital capacity (FEF25-75%). After bronchodilation, among the 45 asthmatic children without FEV1 reversibility, 5 (11.1%) had an FEF25-75% increase that exceeded the reference interval. Isolated abnormal baseline values or significant post-bronchodilator changes in FEF are rare situations in asthmatic schoolchildren with good spirometry quality.

Combined reduced forced expiratory volume in 1 second (FEV1) and peripheral artery disease in sedentary elders with functional limitations

OBJECTIVES

Because they are potentially modifiable and may coexist, we evaluated the combined occurrence of a reduced forced expiratory volume in 1 second (FEV1) and peripheral artery disease (PAD), including its association with exertional symptoms, physical inactivity, and impaired mobility, in sedentary elders with functional limitations.

DESIGN

Cross sectional.

SETTING

Lifestyle Interventions and Independence in Elder (LIFE) Study.

PARTICIPANTS

A total of 1307 sedentary community-dwelling persons, mean age 78.9, with functional limitations (Short Physical Performance Battery [SPPB] <10).

MEASUREMENTS

A reduced FEV1 was defined by a z-score less than -1.64 (

RESULTS

A combined reduced FEV1 and PAD was established in 6.0% (78/1307) of participants. However, among those who had a reduced FEV1, 34.2% (78/228) also had PAD, whereas 20.8% (78/375) of those who had PAD also had a reduced FEV1. The 2 combined conditions were associated with exertional dyspnea (adjusted odds ratio [adjOR] 2.59 [1.20-5.60]) and slow gait speed (adjOR 3.15 [1.72-5.75]) but not with exertional leg symptoms, high sedentary time, and moderate-to-severe mobility impairment.

CONCLUSIONS

In sedentary community-dwelling elders with functional limitations, a reduced FEV1 and PAD frequently coexisted and, in combination, were strongly associated with exertional dyspnea and slow gait speed (a frailty indicator that increases the risk of deleterious outcomes).

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Key Words

• FEV1
• mobility
• peripheral artery disease
• sedentary

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MESH Headings

• Aged
• Aged, 80 and over
• Cross-Sectional Studies
• Female
• Forced Expiratory Volume
• Gait/physiology
• Geriatric Assessment
• Humans
• Male
• Mobility Limitation
• Peripheral Vascular Diseases/physiopathology
• Sedentary Behavior
• Spirometry

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Grants

• UL1 RR029890 NCRR NIH HHS
• UL1 TR000064 NCATS NIH HHS
• R01 HL121023 NHLBI NIH HHS
• U01 AG22376 NIA NIH HHS
• P30AG21342 NIA NIH HHS
• 3U01AG022376-05A2S NIA NIH HHS
• U01 AG022376 NIA NIH HHS
• K07AG043587 NIA NIH HHS
• K07 AG043587 NIA NIH HHS
• P30 AG028740 NIA NIH HHS
• P30 AG021342 NIA NIH HHS
• UL1 TR000142 NCATS NIH HHS
• I01 CX000927 CSRD VA

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Affiliation(s)

Carlos A Vaz Fragoso Clinical Epidemiology Research Center, VA Connecticut, West Haven, CT; Department of Medicine, Yale School of Medicine, New Haven, CT.
Fang-Chi Hsu Department of Biostatistical Sciences, Wake Forest School of Medicine, Winston-Salem, NC
Tina Brinkley Sticht Center on Aging, Wake Forest School of Medicine, Winston-Salem, NC
Timothy Church Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA; Klein Buendel, Inc., Golden, CO
Christine K Liu Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA; Section of Geriatrics, Department of Medicine, Boston University School of Medicine, Boston, MA
Todd Manini Department of Aging and Geriatric Research, University of Florida, Gainesville, FL
Anne B Newman Department of Epidemiology and Medicine, University of Pittsburgh, Pittsburgh, PA
Randall S Stafford Program on Prevention Outcomes and Practices, Stanford Prevention Research Center, Stanford School of Medicine, Stanford, CA
Mary M McDermott Northwestern University Feinberg School of Medicine, Chicago, IL
Thomas M Gill Department of Medicine, Yale School of Medicine, New Haven, CT

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Increased rate of lung function decline in Australian adolescents with cystic fibrosis

INTRODUCTION

Though baseline lung function as measured by spirometry in children with cystic fibrosis (CF) has improved, the annual rate of decline has not changed significantly during the critical period of adolescence. The aim of this study was to describe factors associated with longitudinal decline in lung function in a contemporary cohort of children with CF.

METHODS

Best annual lung function data from children attending the CF service of the Royal Children's Hospital Melbourne were reviewed to determine rate of decline in FEV(1) up until time of transfer to an adult center. Mixed models were used to determine the influence of age, sex, genotype, newborn screening, respiratory hospitalization, CF related diabetes mellitus (CFRD), pancreatic insufficiency, Pseudomonas aeruginosa (PsA) infection, and body mass index (BMI) on lung function decline.

RESULTS

Longitudinal lung function data (range 5-20 years) were obtained for 98 patients with CF (55 male). Overall, the annual rate of decline in FEV(1) % predicted for the entire cohort was 1.4% per annum though the greatest rate of FEV1 decline was seen during adolescence (2.6%). Increasing age, homozygous ΔF508 genotype, CFRD, mucoid PsA infection, pancreatic insufficiency and respiratory hospitalizations were all significant predictors of FEV1 decline.

CONCLUSION

FEV(1) declines at its sharpest rate during adolescence even in the presence of newborn screening. Genotype, increasing age, CFRD, PsA infection, pancreatic insufficiency and a greater number of respiratory hospitalizations are all associated with an increased rate of lung function decline in Australian children and adolescents with cystic fibrosis.

Childhood obesity and risk of allergy or asthma

The simultaneous increment in the prevalence of obesity and allergic diseases suggests a possible link between them. This review focuses on the consequences of obesity on allergic diseases, especially asthma in children and adolescents, and evaluates the available evidence on the possible mechanisms. Obesity is related more strongly to nonatopic than atopic asthma, suggesting non-eosinophilic inflammation and Th1 polarization. Among other allergic diseases, the association is more consistent with eczema compared to allergic rhinitis/rhinoconjunctivitis. The mechanisms of asthma in obese individuals could involve mechanical effects of obesity on lung function, adipokines-mediated inflammation, shared factors (diet, genetics, sedentary lifestyle) and comorbidities.

Sensitisation to Blattella germanica among adults with asthma in Yaounde, Cameroon: a cross-sectional study

Background

German cockroach or Blattella germanica is commonly found in homes across the inter-tropical region. The contribution of sensitisation to Blattella germanica in people with asthma in sub-Saharan Africa has not received attention. The aim of this study was to assess the prevalence and investigate the predicting factors of sensitisation to Blattella germanica in patients with asthma in Yaounde, Cameroon.

Methods

This was a cross-sectional study conducted between January 2012 and June 2013. All patients (aged 15 years and above) with asthma, receiving care at the Yaounde Jamot Hospital and the CEDIMER medical practice during the study period and who had received a prick skin testing for perennial aeroallergens were included in the study.

Results

The final sample comprised 184 patients including 123 (66.8%) women. The median age (25th-75th percentiles) was 38 (24–54) years. Prick skin test for Blattella germanica was positive in 47 (25.5%) patients. Sensitisation to Blattella germanica was associated with a sensitisation to mite in 41 (87.2%) patients, a sensitisation to Alternaria in 18 (38.3%) patients, and a sensitisation to cat or dog dander in 7 (14.9%) patients. Independent predicting factors of a sensitisation to Blattella germanica were the sensitisation to Blomia tropicalis [adjusted odd ratio (95% confidence interval) 4.10 (1.67-10.04), p = 0.002] and sensitisation to Alternaria [3.67 (1.53-7.46), p = 0.003].

Conclusions

Sensitisation to Blattella germanica is present in about a quarter of adult patients with asthma in Yaounde. Sensitisation to Alternaria and Blomia tropicalis appears to be a powerful predicting factor of sensitisation to Blattella germanica in this setting.

Diagnostic accuracy of pre-bronchodilator FEV1/FEV6 from microspirometry to detect airflow obstruction in primary care: a randomised cross-sectional study

Background:

Forced expiratory volume in 1s/forced expiratory volume in 6 s ( FEV₁/FEV₆) assessment with a microspirometer may be useful in the diagnostic work up of subjects who are suspected of having COPD in primary care.

Aim:

To determine the diagnostic accuracy of a negative pre-bronchodilator (BD) microspirometry test relative to a full diagnostic spirometry test in subjects in whom general practitioners (GPs) suspect airflow obstruction.

Methods:

Cross-sectional study in which the order of microspirometry and diagnostic spirometry tests was randomised. Study subjects were (ex-)smokers aged ⩾50 years referred for diagnostic spirometry to a primary care diagnostic centre by their GPs. A pre-BD FEV₁/FEV₆ value <0.73 as measured with the PiKo-6 microspirometer was compared with a post-BD FEV₁/FVC (forced vital capacity) <0.70 and FEV₁/FVC<lower limit of normal (LLN) from diagnostic spirometry.

Results:

One hundred and four subjects were analysed (59.6% males, 42.3% current smokers). Negative predictive values from microspirometry for airflow obstruction based on the fixed and LLN cut-off points were 94.4% (95% confidence interval (CI), 86.4–98.5) and 96.3% (95% CI, 88.2–99.3), respectively. In all, 18% of positive microspirometry results were not confirmed by a post-BD FEV₁/FVC <0.70 and 44% of tests were false positive compared with the LLN criterion for airflow obstruction.

Conclusions:

Pre-bronchodilator microspirometry seems to be able to reliably preselect patients for further assessment of airflow obstruction by means of regular diagnostic spirometry. However, use of microspirometry alone would result in overestimation of airflow obstruction and should not replace regular spirometry when diagnosing COPD in primary care.

Association between quality of life in parents and components of asthma control in children

OBJECTIVE

Describe the association between parents' quality of life and the two components of asthma control in children: impairment and risk.

METHODS

Cross-sectional study with children between 4 and 14 years of age with active asthma recruited at primary care centers in Spain. Asthma control was assessed according to the Third National Asthma Expert Panel Report, classifying "impairment" in three levels (well-controlled asthma, partially controlled, and poorly controlled), and "risk" as high or low. The parents' quality of life was evaluated using the specific Family Impact of Childhood Bronchial Asthma Questionnaire instrument (IFABI-R). The association between asthma control and the parents' quality of life was analyzed using multivariate regression models adjusted for other social and family variables.

RESULTS

Data from 408 children were analyzed. The parents' quality of life was affected in the partially controlled asthma group when compared with well-controlled asthma, as showed by an increase in IFABI-R scores in all dimensions: functional 17.2% (p < 0.001), emotional 10.4% (p = 0.021), and socio-occupational 6.8% (p = 0.056). The differences were higher in poorly controlled asthma compared with well-controlled asthma: functional 24.3% (p = 0.001), emotional 18.9% (p = 0.008), and socio-occupational 11.5% (p = 0.036). The "risk" component was independently associated with the parents' quality of life. Of all the elements used to assess the control, the only one independently associated with the parents' quality of life was recurrent asthma crisis.

CONCLUSIONS

In asthma control, both "impairment" and "risk" in children are gradually associated with the parents' quality of life. The global assessment of the control surpasses the importance of each individual element used in this assessment.

Health-related quality of life and chronic obstructive pulmonary disease in early stages - longitudinal results from the population-based KORA cohort in a working age population

BACKGROUND

It is widely recognized that health-related quality of life (HRQL) is impaired in patients with Chronic Obstructive Pulmonary Disease (COPD), but there is a lack of research on longitudinal associations of COPD and HRQL. This study examined the effects of COPD in early stages of disease on HRQL over ten years in a working-age general population setting in Southern Germany while considering the influence of common comorbidities.

METHODS

In the population-based KORA F4 study (2006-08) 1,321 participants aged 41-61 years performed spirometry and reported information on HRQL (measured by the generic SF-12) and comorbidities. For the same participants, HRQL information was available seven years before and three years after the lung function test from the previous S4 (1999-2001) and the F4L follow-up study (2010). Using linear mixed models, the physical and mental component summary scores (PCS-12 / MCS-12) of the SF-12 were compared over time between COPD groups.

RESULTS

7.8% of participants were classified as having COPD (according to the LLN definition and the Global Lungs Initiative), 59.4% of them in grade 1. Regression models showed a negative cross-sectional association of COPD grade 2+ with PCS-12 which persisted when comorbidities were considered. Adjusted mean PCS-12 scores for the COPD grade 2+ group were reduced (-3.5 (p=0.008) in F4, -3.3 (p=0.014) in S4 and -4.7 (p=0.003) in F4L) compared to the group without airflow limitation. The size of the COPD effect in grade 2+ was similar to the effect of myocardial infarction and cancer. Over ten years, a small decline in PCS-12 was observed in all groups. This decline was larger in participants with COPD grade 2+, but insignificant. Regarding MCS-12, no significant cross-sectional or longitudinal associations with COPD were found.

CONCLUSION

Despite small HRQL differences between COPD patients in early disease stages and controls and small changes over ten years, our results indicate that it is important to prevent subjects with airflow limitation from progression to higher grades. Awareness of HRQL impairments in early stages is important for offering early interventions in order to maintain high HRQL in COPD patients.

Double tracer gas single-breath washout: reproducibility in healthy subjects and COPD

The applicability and interpretation of inert tracer gas washout tests is hampered by the lack of feasible protocols and reproducibility data. We assessed feasibility, variability and reproducibility of a new easy to perform double tracer gas (DTG) single-breath washout (SBW) test and compared this with conventional nitrogen washouts. In 40 healthy nonsmokers and 20 patients with stable chronic obstructive pulmonary disease (COPD), we performed three N2 vital capacity SBWs, three N2 multiple-breath washouts and three tidal DTG-SBW tests. Follow-up was after 1 week, 1 month and 6 months. Main outcomes were the lung clearance index (LCI) (N2 multiple-breath washout), slope of phase III (dN2) (N2 vital capacity SBW) and slope of phase III (SIIIDTG) (DTG-SBW). In healthy subjects, mean±sd LCI at baseline was 6.94±0.61, dN2 0.99±0.42% N2 per litre and SIIIDTG -0.206±0.108 g·mol(-1)·L(-1). In COPD, LCI and dN2 were significantly higher (LCI 12.23±2.67, dN2 7.43±5.38% N2 per litre; p<0.001) and SIIIDTG significantly steeper (-0.653±0.428 g·mol(-1)·L(-1), p<0.001). Reproducibility was high for main outcome parameters: the intraclass correlation coefficient over 6 months was 0.77 (0.86 in COPD) for LCI, 0.82 (0.89) for dN2 and 0.83 (0.93) for SIIIDTG. The tidal DTG-SBW is a reproducible test in healthy and COPD subjects that seems attractive for use in routine clinical settings.

Associations between muscle strength, spirometric pulmonary function and mobility in healthy older adults

Pathological obstruction in lungs leads to severe decreases in muscle strength and mobility in patients suffering from chronic obstructive pulmonary disease. The purpose of this study was to investigate the interdependency between muscle strength, spirometric pulmonary functions and mobility outcomes in healthy older men and women, where skeletal muscle and pulmonary function decline without interference of overt disease. A total of 135 69- to 81-year-old participants were recruited into the cross-sectional study, which was performed as a part of European study MyoAge. Full, partial and no mediation models were constructed to assess the interdependency between muscle strength (handgrip strength, knee extension torque, lower extremity muscle power), spirometric pulmonary function (FVC, FEV1 and FEF50) and mobility (6-min walk and Timed Up and Go tests). The models were adjusted for age, sex, total fat mass, body height and site of enrolment. Partial mediation models, indicating both direct and pulmonary function mediated associations between muscle strength and mobility, fitted best to the data. Greater handgrip strength was significantly associated with higher FVC, FEV1 and FEF50 (p < 0.05). Greater muscle power was significantly associated with better performance in mobility tests. Results suggest that decline in mobility with aging may be caused by decreases in both muscle strength and power but also mediated through decreases in spirometric pulmonary function. Future longitudinal studies are warranted to better understand how loss of function and mass of the respiratory muscles will affect pulmonary function among older people and how these changes are linked to mobility decline.

All-age relationship between arm span and height in different ethnic groups

The objective of the present study was to establish multiethnic, all-age prediction equations for estimating stature from arm span in males and females. The arm span/height ratio (ASHR) from 13 947 subjects (40.9% females), aged 5-99 years, from nine centres (in China, Europe, Ghana, India and Iran) was used to predict ASHR as a function of age using the lambda, mu and sigma method. Z-scores for forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC in 1503 patients were calculated using measured height and height calculated from arm span and age. ASHR varied nonlinearly with age, was higher in males than in females and differed significantly between the nine sites. The data clustered into four groups: Asia, Europe, Ghana and Iran. Average predicted FEV1, FVC and FEV1/FVC using measured or predicted height did not differ, with standard deviations of 4.6% for FEV1, 5.0% for FVC and 0.3% for FEV1/FVC. The percentages of disparate findings for a low FEV1, FVC and FEV1/FVC in patients, calculated using measured or predicted height, were 4.2%, 3.2% and 0.4%, respectively; for a restrictive pattern, there were 1.0% disparate findings. Group- and sex-specific equations for estimating height from arm span and age to derive predicted values for spirometry are clinically useful.

Clinical application of inert gas Multiple Breath Washout in children and adolescents with asthma

INTRODUCTION

Children with asthma often have normal spirometry despite significant disease. The pathology of the small airways in asthma may be assessed using Multiple Breath Washout (MBW) and calculating the Lung Clearance Index (LCI). There are only few studies using MBW in children with asthma and existing data regarding bronchodilator effect are contradictory. The aim of the present pilot study was to compare LCI in asthma and controls and assess the effect of salbutamol in children with asthma on the LCI.

METHODS

Unselected patients with a diagnosis of asthma visiting the outpatient department of our hospital between 04-2010 and 03-2011 were recruited and compared to a healthy control group. MBW was performed as inert gas MBW using sulfurhexafluorid (SF6) as the tracer gas. Clinical data were documented and spirometry and MBW (EasyOne Pro, MBW module, NDD Switzerland) were performed before and after the use of salbutamol (200-400 μg). Healthy controls performed baseline MBW only.

RESULTS

32 children diagnosed with asthma (4.7-17.4 years) and 42 controls (5.3-20.8) were included in the analysis. LCI differed between patients and controls, with a mean LCI (SD) of 6.48 (0.48) and 6.21 (0.38) (P = 0.008). Use of salbutamol had no significant effect on LCI for the group.

CONCLUSION

These pilot data show that clinically stable asthma patients and controls both have a LCI in the normal range. However, in patients the LCI is significantly higher indicating that MBW may have a role in assessing small airways disease in asthma.

Clinical significance of low forced expiratory flow between 25% and 75% of vital capacity following treated pulmonary tuberculosis: a cross-sectional study

OBJECTIVES

The aim of this study was to assess the prevalence and determinants of post-tuberculosis chronic respiratory signs, as well as the clinical impact of a low forced expiratory flow between 25% and 75% (FEF25-75%) in a group of individuals previously treated successfully for pulmonary tuberculosis.

DESIGN

This was a cross-sectional study involving individuals in their post-tuberculosis treatment period. They all underwent a spirometry following the 2005 criteria of the American Thoracic Society/European Respiratory Society. Distal airflow obstruction (DAO) was defined by an FEF25-75% <65% and a ratio forced expiratory volume during the first second (FEV1)/forced vital capacity (FVC) ≥ 0.70. Logistic regression models were used to investigate the determinants of persisting respiratory symptoms following antituberculous treatment.

SETTING

This study was carried out in the tuberculosis diagnosis and treatment centre at Yaounde Jamot Hospital, which serves as a referral centre for tuberculosis and respiratory diseases for the capital city of Cameroon (Yaounde) and surrounding areas.

PARTICIPANTS

All consecutive patients in their post-tuberculosis treatment period were consecutively enrolled between November 2012 and April 2013.

RESULTS

Of the 177 patients included, 101 (57.1%) were men, whose median age (25th-75th centiles) was 32 (24-45.5) years. At least one chronic respiratory sign was present in 110 (62.1%) participants and DAO was found in 67 (62.9%). Independent determinants of persisting respiratory signs were the duration of symptoms prior to tuberculosis diagnosis higher than 12 weeks (adjusted OR 2.91; 95% CI 1.12 to 7.60, p=0.029) and presence of DAO (2.22; 1.13 to 4.38, p=0.021).

CONCLUSIONS

FEF25-75%<65% is useful for the assessment and diagnosis of post-tuberculous DAO. Mass education targeting early diagnosis of pulmonary tuberculosis can potentially reduce the prevalence of post-tuberculosis respiratory signs and distal airflow obstruction.

Estimating population prevalence of potential airflow obstruction using different spirometric criteria: a pooled cross-sectional analysis of persons aged 40-95 years in England and Wales

OBJECTIVES

Consistent estimation of the burden of chronic obstructive pulmonary disease (COPD) has been hindered by differences in methods, including different spirometric cut-offs for impaired lung function. The impact of different definitions on the prevalence of potential airflow obstruction, and its associations with key risk factors, is evaluated using cross-sectional data from two nationally representative population surveys.

DESIGN

Pooled cross-sectional analysis of Wave 2 of the UK Household Longitudinal Survey and the Health Survey for England 2010, including 7879 participants, aged 40-95 years, who lived in England and Wales, without diagnosed asthma and with good-quality spirometry data. Potential airflow obstruction was defined using self-reported physician-diagnosed COPD; a fixed threshold (FT) forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) ratio <0.7 and an age-specific, sex-specific, height-specific and ethnic-specific lower limit of normal (LLN). Standardised questions elicited self-reported information on demography, smoking history, ethnicity, occupation, respiratory symptoms and cardiovascular disease.

RESULTS

Consistent across definitions, participants classed with obstructed airflow were more likely to be older, currently smoke, have higher pack-years of smoking and be engaged in routine occupations. The prevalence of airflow obstruction was 2.8% (95% CI 2.3% to 3.2%), 22.2% (21.2% to 23.2%) and 13.1% (12.2% to 13.9%) according to diagnosed COPD, FT and LLN, respectively. The gap in prevalence between FT and LLN increased in older age groups. Sex differences in the risk of obstruction, after adjustment for key risk factors, was sensitive to the choice of spirometric cut-off, being significantly higher in men when using FT, compared with no significant difference using LLN.

CONCLUSIONS

Applying FT or LLN spirometric cut-offs gives a different picture of the size and distribution of the disease burden. Longitudinal studies examining differences in unscheduled hospital admissions and risk of death between FT and LLN may inform the choice as to the best way to include spirometry in assessments of airflow obstruction.

Airways obstruction and pulmonary capillary blood volume in children with sickle cell disease

OBJECTIVES AND WORKING HYPOTHESIS

Airways obstruction occurs in young children with sickle cell disease (SCD). Our aim was to test the hypothesis that increased pulmonary capillary blood volume at least in part explained the increased airways obstruction as this would inform which therapy might be most appropriate to treat the airway obstruction.

STUDY DESIGN

Observational study.

PATIENT-SUBJECT SELECTION

Twenty-five SCD children and 25 ethnic origin matched controls were recruited.

METHODOLOGY

Respiratory system resistance, using impulse oscillometry at 5 Hz (R5 %pred), pulmonary capillary blood volume (Vc), alveolar volume (VA), and spirometry were assessed before and after bronchodilator (ipratropium bromide). Lung volume measurements were also made.

RESULTS

The SCD children compared to the controls had a higher R5 %pred before (median 133 (range 88-181)% vs. 102 (83-184)%, P = 0.0046) and after (105 (79-150)% vs. 91 (64-147)%, P = 0.0489) bronchodilator and their median Vc/VA (ml/L) was higher before (26 (18-38) vs. 18 (14-28) P < 0.0001) and after (26 (19-41) vs. 18 (13-27) P < 0.0001) bronchodilator. There were similar decreases in R5 %pred post-bronchodilator in the two groups, but no significant changes in Vc/VA in either group. Vc/VA correlated significantly with R5 %pred in the SCD children only.

CONCLUSIONS

Increased pulmonary capillary blood volume contributes to the increased airways obstruction in children with SCD, hence, bronchodilators may be of limited benefit in reducing their airways obstruction.

Prevalence and correlates of airflow obstruction in ∼317,000 never-smokers in China

In China, the burden of chronic obstructive disease (COPD) is high in never-smokers but little is known about its causes in this group. We analysed data on 287 000 female and 30 000 male never-smokers aged 30-79 years from 10 regions in China, who participated in the China Kadoorie Biobank baseline survey (2004-2008). Prevalence of airflow obstruction (AFO) (pre-bronchodilator forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) <0.7 and below the lower limit of normal (LLN)) was estimated, by age and region. Cross-sectional associations of AFO (FEV1/FVC <0.7), adjusted for confounding, were examined. AFO prevalence defined as FEV1/FVC <0.7 was 4.0% in females and 5.1% in males (mean ages 51 and 54 years, respectively). AFO prevalence defined as FEV1/FVC Collapse

Key Words Collapse

MESH Headings

• Adult
• Aged
• Air Pollution, Indoor
• Asthma/diagnosis
• Asthma/epidemiology
• Body Mass Index
• China
• Cooking
• Cross-Sectional Studies
• Female
• Forced Expiratory Volume
• Humans
• Male
• Middle Aged
• Odds Ratio
• Prevalence
• Pulmonary Disease, Chronic Obstructive/diagnosis
• Pulmonary Disease, Chronic Obstructive/epidemiology
• Respiration
• Smoking
• Spirometry
• Surveys and Questionnaires
• Vital Capacity

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Grants

• Wellcome Trust
• MC_U137686851 Medical Research Council

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Affiliation(s)

Margaret Smith Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), University of Oxford, Oxford, UK
Liming Li Chinese Academy of Medical Sciences, Beijing School of Public Health, Peking University Health Sciences Center, Beijing
Mareli Augustyn Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), University of Oxford, Oxford, UK
Om Kurmi Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), University of Oxford, Oxford, UK
Junshi Chen China National Center for Food Safety Risk Assessment, Beijing
Rory Collins Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), University of Oxford, Oxford, UK
Yu Guo Chinese Academy of Medical Sciences, Beijing
Yabin Han Tongxiang Center for Disease Control, Tongxiang
Jingxin Qin Liuzhou Center for Disease Control, Liuzhou
Guanqun Xu Suzhou Center for Disease Control, Suzhou
Jian Wang Pengzhou Center for Disease Control, Pengzhou
Zheng Bian Chinese Academy of Medical Sciences, Beijing
Gang Zhou Henan Center for Disease Control, Zhengzhou, China
Richard Peto Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), University of Oxford, Oxford, UK
Zhengming Chen Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), University of Oxford, Oxford, UK

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Impact of ethnicity and extreme prematurity on infant pulmonary function

The impact of birth before 27 completed weeks of gestation on infant pulmonary function (PF) was explored in a multi-ethnic population in comparison to more mature preterm controls (PTC) and healthy fullterm infants. Plethysmographic lung volume (FRCpleth ) and forced expired volume (FEV0.5 ) were obtained at ∼12 months post-term age in 52 extremely preterm (EP) infants (median [range] gestational age [GA]: 26 [23-27] weeks; 40% White mothers; 79% with BPD), 41 PTC (GA:35 [30-36] weeks; 37% White mothers) and 95 fullterm infants (GA:40 [37-42] weeks; 86% White mothers). Using reference equations based on identical equipment and techniques, results were expressed as z-scores to adjust for age, sex and body size. FEV0.5 was significantly lower in EP infants when compared with PTC (mean difference [95% CI]: -1.02[-1.60; -0.44] z-scores, P < 0.001), as was forced vital capacity (FVC) but there were no significant differences in FRCpleth or FEV0.5 /FVC ratio. FEV0.5 , FVC, and FEV0.5 /FVC were significantly lower in both preterm groups when compared with fullterm controls. On multivariable analyses of the combined preterm dataset: FEV0.5 at ∼1 year was 0.11 [0.05; 0.17] z-scores higher/week GA, and 1.28 (0.49; 2.08) z-scores lower in EP infants with prior BPD. Among non-white preterm infants, FEV0.5 was 0.70 (0.17; 1.24) z-scores lower, with similar reductions in FVC, such that there were no ethnic differences in FEV0.5 /FVC. Similar ethnic differences were observed among fullterm infants. These results confirm the negative impact of preterm birth on subsequent lung development, especially following a diagnosis of BPD, and emphasize the importance of taking ethnic background into account when interpreting results during infancy as in older subjects.

Lung function testing in children: importance of race and ethnic-specific reference equations

Marked differences in lung function occur between children of different racial and ethnic backgrounds even when all known confounders including socioeconomic circumstances have been taken into account. Use of ethnic-specific equations, such as those recently published by the Global Lung Function Initiative, help to minimize such differences, thereby improving the accuracy with which lung disease can be identified and treated during childhood, as well as enabling the true impact of adverse environmental or socioeconomic exposures to be assessed, irrespective of ethnic background. In future, incorporation of ancestry and, within emerging nations undergoing secular changes in anthropometry, sitting height, into normative equations may further improve the accuracy of predicting lung function and hence assessment of disease severity within any given individual.

Official American Thoracic Society technical standards: spirometry in the occupational setting

PURPOSE

This document addresses aspects of the performance and interpretation of spirometry that are particularly important in the workplace, where inhalation exposures can affect lung function and cause or exacerbate lung diseases, such as asthma, chronic obstructive pulmonary disease, or fibrosis.

METHODS

Issues that previous American Thoracic Society spirometry statements did not adequately address with respect to the workplace were identified for systematic review. Medline 1950-2012 and Embase 1980-2012 were searched for evidence related to the following: training for spirometry technicians; testing posture; appropriate reference values to use for Asians in North America; and interpretative strategies for analyzing longitudinal change in lung function. The evidence was reviewed and technical recommendations were developed.

RESULTS

Spirometry performed in the work setting should be part of a comprehensive workplace respiratory health program. Effective technician training and feedback can improve the quality of spirometry testing. Posture-related changes in FEV1 and FVC, although small, may impact interpretation, so testing posture should be kept consistent and documented on repeat testing. Until North American Asian-specific equations are developed, applying a correction factor of 0.88 to white reference values is considered reasonable when testing Asian American individuals in North America. Current spirometry should be compared with previous tests. Excessive loss in FEV1 over time should be evaluated using either a percentage decline (15% plus loss expected due to aging) or one of the other approaches discussed, taking into consideration testing variability, worker exposures, symptoms, and other clinical information.

CONCLUSIONS

Important aspects of workplace spirometry are discussed and recommendations are provided for the performance and interpretation of workplace spirometry.

Interpretation of lung function in infants and young children with cystic fibrosis

The last decade has seen a significant advance in understanding about early lung disease in cystic fibrosis (CF). As studies that have measured lung function in preschool years are conducted in association with surveillance of infection, inflammation and early structural changes, and emerging longitudinal data become available, a better insight into the very early onset and nature of such lung disease is emerging. Interventions during the preschool years are increasingly viewed as being crucial to delaying and minimizing disease progression as this is the most important period of postnatal life in terms of lung development and airway remodelling. Lung function measurement in CF is potentially an important assessment tool and is used in routine clinical practice in several centres already. Results of studies from lung function tests that, on the basis of their underpinning physiology, are viewed as being best suited currently for the early detection of lung disease in CF are reviewed.

Systemic exposure to inhaled beclometasone/formoterol DPI is age and body size dependent

AIM

Prescription of inhaled corticosteroids to children with asthma is recommended at half the nominal dose of adults in order to reduce the risk of systemic side effects. However, there is a lack of pharmacokinetic trials supporting such dose reduction regimens. Therefore, we aimed to compare the systemic exposure to the active ingredients of a fixed dose combination of beclometasone-dipropionate (BDP) and formoterol after dry powder inhaler (DPI) administration in children, adolescents and adults.

METHODS

The pharmacokinetic profiles of formoterol and beclometasone-17-monopropionate (B17MP; active metabolite of BDP) were evaluated over 8 h from two independent studies comprising children (6-11yrs, n = 27), adolescents (12-17 yrs, n = 28) and adults (≥18 yrs, n = 30) receiving a single, fixed dose of BDP/formoterol (children: 200 μg/24 μg, adolescents and adults: 400 μg/24 μg) via DPI.

RESULTS

The systemic exposure (AUC) for children versus adults was almost doubled for formoterol and similar for B17MP despite the halved BDP dose administered in children. In adolescents the AUC for formoterol and B17MP were approximately one third higher than in adults for both compounds. Upon normalization for the BDP/formoterol dose in the three populations the AUC and peak concentration (C(max)) correlated inversely with age and body surface area of the patients (r ≤ -0.53; p < 0.0001).

CONCLUSION

The systemic exposure to the active ingredients of BDP/formoterol administered as DPI correlates inversely with age and body size suggesting that dry powder dosage regimens should be adjusted for age and body size to avoid high systemic drug levels in children.

Lung clearance index during hospital admission in school-age children with cystic fibrosis

BACKGROUND

There is currently limited information regarding lung clearance index (LCI) and its response to treatment of pulmonary exacerbations in CF. We aimed to examine the utility of LCI for assessing short term clinical response to IV antibiotic therapy in school-age children with CF.

METHODS

Subjects experiencing exacerbations and hospitalised for IV antibiotics performed both multiple breath nitrogen washout (MBNW) and spirometry on admission to hospital and prior to discharge.

RESULTS

27 patients (aged 6-20 years) had paired data for MBNW and spirometry. Mean LCI reduced from 12.18 to 11.65 (4.4%) by time of discharge and FEV1z-score improved from -3.05 to -2.86 (6.2%). Overall, LCI improved in n=15 (55%) patients compared with n=18 (67%) where FEV1 improved.

CONCLUSIONS

In summary, these findings do not support the use of LCI (or indeed, FEV1) to gauge the short term clinical response to IV antibiotic therapy in school-age children with cystic fibrosis.

How to avoid misinterpreting lung function tests in children: a few practical tips

Assessments of pulmonary function play an integral part in the clinical management of school age children as well as providing objective outcome measures in clinical and epidemiological research studies. Pulmonary function tests (PFTs) can also be undertaken in sleeping infants and in awake young children from 3 years of age. However, the clinical utility of such assessments, which are generally confined to specialist centres, has yet to be established. Whether requesting or undertaking paediatric PFTs, or simply reading about how these tests have been applied in research studies, it is essential to question whether results have been interpreted in a meaningful way. This review summarises some of the issues that need to be considered, including: why the tests are being performed; which tests are most likely to detect the suspected pathophysiology; how often such tests should be repeated; whether results are likely to be reliable (in terms of data quality, repeatability and the availability of suitable reference equations with which to distinguish the effects of disease from those of growth and development), and whether the selected tests are likely to be feasible in the individual child or study group under investigation.

Body mass index and comorbidities in adult severe asthmatics

Both severe asthma and obesity are growing health problems. Severe asthma leads to a poor quality of life. The relationship among BMI, comorbidities, and severe asthma control in adults is still unclear. The aim of the study is to better understand the effect of the comorbidities as atopy, type II diabetes, OSAS, gastroesophageal reflux, hypertension, cardiovascular diseases, osteoporosis, infections, and psychological factors with BMI on asthma control in a cohort of adult severe asthmatics. One hundred and two patients were enrolled in a cross-sectional study assessing asthma control, treatments, pulmonary function, inflammatory markers, and comorbidities. Patients were divided into 3 classes according to BMI: normal weight, overweight, and obese. We found that the optimal state of asthma control is lower. whereas the score of Asthma Control Questionnaire, the number of asthma exacerbations during last year, the oral corticosteroids requirement during the previous year, and the LABA treatments are higher in obese than in overweight and normal weight severe asthmatics. The number of subjects with type II diabetes and OSAS are higher among obese and overweight patients than in normal weight asthmatics. In conclusion, BMI represents per se a factor for the deterioration in disease control in severe asthma.

The independent and combined effects of lifetime smoke exposures and asthma as they relate to COPD

Chronic obstructive pulmonary disease (COPD) is part of a worldwide tobacco-related disease epidemic, and is associated with progressive airflow obstruction and varying degrees of emphysema and/or hyperinflation. Greater focus has been placed recently on the potential for early life factors to influence the development of COPD, based on the premise that delayed lung growth during childhood and adolescence might predispose to lung disease in later life. For most people, the adverse effects on lung function of adult and early childhood factors are additive, which provides no additional incentive for current smokers to quit. However, if there is a (synergistic) interaction between active smoking and asthma, smoking cessation is likely to have a greater lung function benefit for the smoker who is also asthmatic, especially if quitting occurs at an early age. This article critically evaluates the evidence for the independent associations of lifetime asthma, smoking and smoke exposures with airflow obstruction, plus their interaction when multiple factors are present.

Regional variations in the prevalence and misdiagnosis of air flow obstruction in China: baseline results from a prospective cohort of the China Kadoorie Biobank (CKB)

Background

Despite the great burden of chronic respiratory diseases in China, few large multicentre, spirometry-based studies have examined its prevalence, rate of underdiagnosis regionally or the relevance of socioeconomic and lifestyle factors.

Methods

We analysed data from 512 891 adults in the China Kadoorie Biobank, recruited from 10 diverse regions of China during 2004–2008. Air flow obstruction (AFO) was defined by the lower limit of normal criteria based on spirometry-measured lung function. The prevalence of AFO was analysed by region, age, socioeconomic status, body mass index (BMI) and smoking history and compared with the prevalence of self-reported physician-diagnosed chronic bronchitis or emphysema (CB/E) and its symptoms.

Findings

The prevalence of AFO was 7.3% in men (range 2.5–18.2%) and 6.4% in women (1.5–18.5%). Higher prevalence of AFO was associated with older age (p<0.0001), lower income (p<0.0001), poor education (p<0.001), living in rural regions (p<0.001), those who started smoking before the age of 20 years (p<0.001) and low BMI (p<0.001). Compared with self-reported diagnosis of CB/E, 88.8% of AFO was underdiagnosed; underdiagnosis proportion was highest in 30–39-year olds (96.7%) compared with the 70+ age group (81.1%), in women (90.7%), in urban areas (89.4%), in people earning 5K–10 K ¥ monthly (90.3%) and in those with middle or high school education (92.6%).

Interpretation

In China, the burden of AFO based on spirometry was high and significantly greater than that estimated based on self-reported physician-diagnosed CB/E, especially in rural areas, reflecting major issues with diagnosis of AFO that will impact disease treatment and management.

Reference values for spirometry, including vital capacity, in Japanese adults calculated with the LMS method and compared with previous values

BACKGROUND

Reference values for lung function tests should be periodically updated because of birth cohort effects and improved technology. This study updates the spirometric reference values, including vital capacity (VC), for Japanese adults and compares the new reference values with previous Japanese reference values.

METHODS

Spirometric data from healthy non-smokers (20,341 individuals aged 17-95 years, 67% females) were collected from 12 centers across Japan, and reference equations were derived using the LMS method. This method incorporates modeling skewness (lambda: L), mean (mu: M), and coefficient of variation (sigma: S), which are functions of sex, age, and height. In addition, the age-specific lower limits of normal (LLN) were calculated.

RESULTS

Spirometric reference values for the 17-95-year age range and the age-dependent LLN for Japanese adults were derived. The new reference values for FEV(1) in males are smaller, while those for VC and FVC in middle age and elderly males and those for FEV(1), VC, and FVC in females are larger than the previous values. The LLN of the FEV(1)/FVC for females is larger than previous values. The FVC is significantly smaller than the VC in the elderly.

CONCLUSIONS

The new reference values faithfully reflect spirometric indices and provide an age-specific LLN for the 17-95-year age range, enabling improved diagnostic accuracy. Compared with previous prediction equations, they more accurately reflect the transition in pulmonary function during young adulthood. In elderly subjects, the FVC reference values are not interchangeable with the VC values.

Mutations in RSPH1 cause primary ciliary dyskinesia with a unique clinical and ciliary phenotype

RATIONALE

Primary ciliary dyskinesia (PCD) is a genetically heterogeneous recessive disorder of motile cilia, but the genetic cause is not defined for all patients with PCD.

OBJECTIVES

To identify disease-causing mutations in novel genes, we performed exome sequencing, follow-up characterization, mutation scanning, and genotype-phenotype studies in patients with PCD.

METHODS

Whole-exome sequencing was performed using NimbleGen capture and Illumina HiSeq sequencing. Sanger-based sequencing was used for mutation scanning, validation, and segregation analysis.

MEASUREMENTS AND MAIN RESULTS

We performed exome sequencing on an affected sib-pair with normal ultrastructure in more than 85% of cilia. A homozygous splice-site mutation was detected in RSPH1 in both siblings; parents were carriers. Screening RSPH1 in 413 unrelated probands, including 325 with PCD and 88 with idiopathic bronchiectasis, revealed biallelic loss-of-function mutations in nine additional probands. Five affected siblings of probands in RSPH1 families harbored the familial mutations. The 16 individuals with RSPH1 mutations had some features of PCD; however, nasal nitric oxide levels were higher than in patients with PCD with other gene mutations (98.3 vs. 20.7 nl/min; P < 0.0003). Additionally, individuals with RSPH1 mutations had a lower prevalence (8 of 16) of neonatal respiratory distress, and later onset of daily wet cough than typical for PCD, and better lung function (FEV1), compared with 75 age- and sex-matched PCD cases (73.0 vs. 61.8, FEV1 % predicted; P = 0.043). Cilia from individuals with RSPH1 mutations had normal beat frequency (6.1 ± Hz at 25°C), but an abnormal, circular beat pattern.

CONCLUSIONS

The milder clinical disease and higher nasal nitric oxide in individuals with biallelic mutations in RSPH1 provides evidence of a unique genotype-phenotype relationship in PCD, and suggests that mutations in RSPH1 may be associated with residual ciliary function.

Respiratory muscle decline in Duchenne muscular dystrophy

OBJECTIVES

Duchenne muscular dystrophy (DMD) causes progressive respiratory muscle weakness. The aim of the study was to analyze the trend of a large number of respiratory parameters to gain further information on the course of the disease.

STUDY DESIGN

Retrospective study.

SUBJECT SELECTION

48 boys with DMD, age range between 6 and 19 year old, who were followed in our multidisciplinary neuromuscular clinic between 2001 and 2011.

METHODOLOGY

Lung function, blood gases, respiratory mechanics, and muscle strength were measured during routine follow-up over a 10-year period. Only data from patients with at least two measurements were retained.

RESULTS

The data of 28 patients were considered for analysis. Four parameters showed an important decline with age. Gastric pressure during cough (Pgas cough) was below normal in all patients with a mean decline of 5.7 ± 3.8 cmH2 O/year. Sniff nasal inspiratory pressure (SNIP) tended to increase first followed by a rapid decline (mean decrease 4.8 ± 4.9 cmH2 O; 5.2 ± 4.4% predicted/year). Absolute forced vital capacity (FVC) values peaked around the age of 13-14 years and remained mainly over 1 L but predicted values showed a mean 4.1 ± 4.4% decline/year. Diaphragmatic tension-time index (TTdi) increased above normal values after the age of 14 years with a mean increase of 0.04 ± 0.04 point/year.

CONCLUSIONS

This study confirms the previous findings that FVC and SNIP are among the most important parameters to monitor the evolution of DMD. Expiratory muscle strength, assessed by Pgas cough, and the endurance index, TTdi, which are reported for the first time in a large cohort, appeared to be informative too, even though measured through an invasive method.

Effect of exercise test on pulmonary function of obese adolescents

OBJECTIVE

to investigate the pulmonary response to exercise of non-morbidly obese adolescents, considering the gender.

METHODS

a prospective cross-sectional study was conducted with 92 adolescents (47 obese and 45 eutrophic), divided in four groups according to obesity and gender. Anthropometric parameters, pulmonary function (spirometry and oxygen saturation [SatO2]), heart rate (HR), blood pressure (BP), respiratory rate (RR), and respiratory muscle strength were measured. Pulmonary function parameters were measured before, during, and after the exercise test.

RESULTS

BP and HR were higher in obese individuals during the exercise test (p = 0.0001). SatO2 values decreased during exercise in obese adolescents (p = 0.0001). Obese males had higher levels of maximum inspiratory and expiratory pressures (p = 0.0002) when compared to obese and eutrophic females. Obese males showed lower values of maximum voluntary ventilation, forced vital capacity, and forced expiratory volume in the first second when compared to eutrophic males, before and after exercise (p = 0.0005). Obese females had greater inspiratory capacity compared to eutrophic females (p = 0.0001). Expiratory reserve volume was lower in obese subjects when compared to controls (p ≤ 0,05).

CONCLUSION

obese adolescents presented changes in pulmonary function at rest and these changes remained present during exercise. The spirometric and cardiorespiratory values were different in the four study groups. The present data demonstrated that, in spite of differences in lung growth, the model of fat distribution alters pulmonary function differently in obese female and male adolescents.