A comparison of peak cough flow and peak expiratory flow in children with neuromuscular disorders.

Spirometry and peak cough flow testing (PCF) are commonly used in the respiratory assessment of children with a neuromuscular disorder (NMD). Testing uses two different machines, increases laboratory time, costs and resource utilisation. No studies have assessed the correlation between peak expiratory flow (PEF) obtained from spirometry and PCF in children with NMD using one device. An audit of children with a NMD managed at the Children's Hospital at Westmead in 2022-2024 aged < 20 years who performed spirometry and PCF testing on the same device (Vyaire Body BoxTM, Ultrasonic flow meter-based, or Vyaire PneumotachographTM, Pneumotach flow meter-based; Germany) was conducted to assess the correlation between PCF and PEF. Fifty-one sets of testing were identified, and 40 subjects (9F) had reproducible testing and were included. Median (range) age was 14.95 (7.20-19.00) years. Median PEF (L/min) was 4.05 (1.22-10.26) and median PCF (L/min) was 4.29 (1.69-10.82). PEF and PCF had a strong Pearson's correlation coefficient, (R = 0.97, p = 0.03). The coefficient of determination was 0.93. If laboratory resources permit, spirometry should be the test of choice for children with NMD. On average, spirometry required multiple practices to achieve reproducibility to meet ATS/ERS standards. PCF testing can be utilised for children where performing technically acceptable spirometry is not possible.

Peak In- and Expiratory Flow Revisited: Reliability and Reference Values in Adults.

BACKGROUND: While peak in- and expiratory flow rates offer valuable information for diagnosis and monitoring in respiratory disease, these indices are usually considered too variable to be routinely used for quantification in clinical practice. OBJECTIVES: The aim of the study was to obtain reproducible measurements of maximal inspiratory flow rates and to construct reference equations for peak in- and expiratory flows (PIF and PEF). METHOD: With coaching for maximal effort, 187 healthy Caucasian subjects (20-80 years) performed at least 3 combined forced inspiratory and expiratory manoeuvres, until at least 2 peak inspiratory flow measurements were within 10% of each other. The effect on PIF preceded by a slow expiration instead of a forced expiration and PIF repeatability over 3 different days was also investigated in subgroups. Reference values and limits of normal for PIF, mid-inspiratory flow, and PEF were obtained according to the Lambda-Mu-Sigma statistical method. RESULTS: A valid PIF could be obtained within 3.3 ± 0.6(SD) attempts, resulting in an overall within-test PIF variability of 4.6 ± 3.2(SD)%. A slow instead of a forced expiration prior to forced inspiration resulted in a significant (p < 0.001) but small PIF increase (2.5% on average). Intraclass correlation coefficient for between-day PIF was 0.981 (95% CI: 0.960-0.992). Over the entire age range, inter-subject PIF variability was smaller than in previous reports, and PIF could be predicted based on its determinants gender, age, and height (r2 = 0.53). CONCLUSIONS: When adhering to similar criteria for the measurement of effort-dependent portions of inspiratory and expiratory flow-volume curves, performed according to current ATS/ERS standards, it is possible to obtain reproducible PIF and PEF values for use in routine clinical practice.

Quantitative analysis of pulmonary vasculature in systemic sclerosis at spirometry-gated chest CT.

OBJECTIVE: To prospectively investigate whether differences in pulmonary vasculature exist in systemic sclerosis (SSc) and how they are distributed in patients with different pulmonary function. METHODS: Seventy-four patients with SSc undergoing chest CT scan for interstitial lung disease (ILD) screening or follow-up were prospectively enrolled. A thorough clinical, laboratory and functional evaluation was performed the same day. Chest CT was spirometry gated at total lung capacity and images were analysed by two automated software programs to quantify emphysema, ILD patterns (ground-glass, reticular, honeycombing), and pulmonary vascular volume (PVV). Patients were divided in restricted (FVC% <80, DLco%<80), isolated DLco% reduction (iDLco- FVC%≥80, DLco%<80) and normals (FVC%≥80, DLco%≥80). Spearman ρ, Mann-Whitney tests and logistic regressions were used to assess for correlations, differences among groups and relationships between continuous variables. RESULTS: Absolute and lung volume normalised PVV (PVV/LV) correlated inversely with functional parameters and positively with all ILD patterns (ρ=0.75 with ground glass, ρ=0.68 with reticular). PVV/LV was the only predictor of DLco at multivariate analysis (p=0.007). Meanwhile, the reticular pattern prevailed in peripheral regions and lower lung thirds, PVV/LV prevailed in central regions and middle lung thirds. iDLco group had a significantly higher PVV/LV (2.2%) than normal (1.6%), but lower than restricted ones (3.8%). CONCLUSIONS: Chest CT in SSc detects a progressive increase in PVV/LV as DLco decreases. Redistribution of perfusion to less affected lung regions rather than angiogenesis nearby fibrotic lung may explain the results. Further studies to ascertain whether the increase in PVV/LV reflects a real increase in blood volume are needed.

Lung disease in patients with common variable immunodeficiency.

BACKGROUND: Common Variable Immunodeficiency (CVID) is characterized by an impaired antibody production and a higher susceptibility to encapsulated bacterial infections. Lung disease is considered to be the most important cause of morbidity and mortality. METHODS: We analyzed clinical, radiological and functional characteristics in 80 patients with CVID assisted in the Unidad Inmunologia e Histocompatibilidad at Durand Hospital from 1982 to 2018. RESULTS: Of the 80 patients, 55 showed pathologic lung Computed Tomography (CT). Twenty of them (36.4%) showed bronchiectasis; 26 (47.3%) interstitial involvement associated with nodules and adenopathies called GLILD (granulomatous-lymphocytic interstitial lung disease); and nine patients (16.3%) showed other lesions. Nine percent of patients with lung disease showed CT progression; none of them had spirometry worsening. GLILD patients had normal and restrictive patterns in lung function tests, in equal proportions. Two patients - one with GLILD and the other one with bronchiectasis - had an increase in spirometric pattern severity without CT progression. Lung biopsy was performed in 19% of GLILD patients, all of whom had histopathologic diagnosis of Lymphoid Interstitial Pneumonia (LIP). CONCLUSIONS: GLILD is the major cause of lung disease in CVID. Computed tomography is useful for diagnosis but not necessary in follow-up, in which functional tests should have better correlation with clinical evolution, reducing radiation exposure. Biopsy should be indicated when the clinical diagnosis is unclear. Treatment should be considered whenever there is clear evidence of disease progression.

Lung cancer resection and postoperative outcomes in COPD: A single-center experience.

Chronic obstructive pulmonary disease (COPD) increases postoperative morbidity and is associated with diminished long-term survival after lung cancer resection. Whether this is also true for mild-to-moderate COPD is uncertain. We conducted a retrospective analysis of all the patients who underwent lung cancer surgery between 2002 and 2012 in a university-affiliated hospital. The severity of airflow limitation was stratified according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) from stage 1 to 4. Data from 1456 cases of lung cancer surgery were reviewed and 1126 patients were included in the study: 672 (59.7%) patients had COPD (GOLD 1, n = 340; GOLD 2, n = 282; GOLD 3, n = 50) and 454 patients had a normal spirometry (controls). Following lung cancer resection, patients with COPD had a higher rate of postoperative morbidities of any kind (p < 0.0001), in particular, pneumonia (7.0% vs. 3.7%; p = 0.0251) and prolonged air leak (17.0% vs. 8.2%; p < 0.0001) than controls. In-hospital mortality was increased in GOLD 3 COPD but the incidence of other postoperative complications was not influenced by COPD severity. Neither COPD nor its severity influenced long-term survival in this population. To conclude, patients with COPD undergoing lung cancer surgery were at higher risk of postoperative complications than patients with normal respiratory function but the procedure was considered safe. The presence of COPD itself did not influence long-term survival. The results of our study apply mainly to patients with a GOLD 1 and 2 COPD since only a small number of patients with GOLD 3 COPD were involved.

Spirometric abnormalities following treatment for pulmonary tuberculosis in Ilorin, Nigeria.

BACKGROUND: Pulmonary tuberculosis (PTB) contributes significantly to morbidity and mortality worldwide, and despite microbiological cure for the disease, many patients still demonstrate residual respiratory symptoms and spirometric abnormalities. AIM AND OBJECTIVES: The study aimed at identifying the prevalence, pattern and factors associated with spirometric abnormalities in patients successfully treated for PTB in Ilorin, Nigeria. MATERIALS AND METHODS: This was a hospital-based cross-sectional study at the pulmonary outpatient clinics of the University of Ilorin Teaching Hospital and Kwara State Specialist Hospital, Sobi, Ilorin. A total of 308 consenting patients who had been certified microbiologically cured for bacteriologically confirmed PTB in the preceding 3 years had assessment of residual pulmonary symptoms, spirometry and plain chest radiograph. RESULTS: The prevalence of abnormal spirometry following treatment for PTB was 72.1% (confidence interval: 0.6682-0.7695), with restrictive pattern being the predominant abnormality (42.2%). Over half of the patients (56.5%) had at least one residual respiratory symptom. The significant predictors of abnormal spirometry were PTB retreatment (adjusted odds ratio [aOR] = 6.918; P = 0.012), increasing modified Medical Research Council dyspnoea scores (aOR = 7.935; P = 0.008) and increasing radiologic scores (aOR = 4.679; P ≤ 0.001) after treatment. CONCLUSION: There is significant residual lung function impairment in majority of the individuals successfully treated for PTB in Ilorin. This highlights the need for spirometric assessment and follow-up after treatment.

[A study on the end criteria of forced vital capacity curve in adults].

Objective: To explore the end criteria of forced vital capacity(FVC) curve in adults. Methods: A multicenter cross-sectional study was performed in Zhongshan Hospital Affiliated to Fudan University, the First Affiliated Hospital of Fujian Medical University, and the Third Affiliated Hospital of Inner Mongolia Medical University from January 2017 to August 2017. A consecutive sample of subjects who completed the spirometry test and FVC curves met end criteria of no volume change (<0.025 L) for ≥ 1 s were qualified in this study. Subjects were divided into a normal group (n=610), an obstructive group (n=536), and a restrictive group(n=306) according to pulmonary function test results. The FET values in different groups were compared. The side effects in the 3 groups and the diagnostic accuracy, specificity and security of different FET in the obstructive group were assessed. Results: The FET values of the normal group, the obstructive group, and the restricted group were (4.00±1.07) s, (8.08±1.56) s and (2.97±0.76) s respectively, and the 95% CI of FET in the 3 groups were between 3.88-4.12 s, 7.02-10.14 and 2.21- 3.73 s (F=2 263.80, P<0.01). When the exhalation platform was used as the standard of FVC curve, the adverse reaction rate in the normal group and the restricted group were 1.1% and 1.3% respectively, lower than the rate of 17.2% in the obstructive group (χ(2)=92.73, χ(2)=48.49 respectively; all P<0.05). In the obstructive group, 7 s as the ending criterion had similar incidence of adverse reactions to 6 s (χ(2)=0.01, P=0.93). With further extension of expiration time, the incidence of adverse reactions increased significantly. In the obstructive group, the sensitivity of FEV(1)/FEV(7) was 99.25%, higher than that at FEV(1)/FEV(6) (χ(2)=4.06, P=0.04), and the specificity of diagnosis was very similar and 100%. Conclusions: FET was variable in subjects with different lung function status. It is not appropriate to use a fixed FET≥ 6 s as the end criterion of spirometry for adults. For patients with normal lung function or restrictive lung function defect, exhalation platform should be used as the end of exhalation standard. For patients with obstructive lung function defect, an FET of up to 7 s is appropriate.

GOLD assessment of COPD severity in the Clinical Practice Research Datalink (CPRD).

PURPOSE: To evaluate availability of spirometry and symptom data in the Clinical Practice Research Datalink (United Kingdom) to assess COPD severity using the Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2016 definition and comparing it with an algorithm used in other studies. METHODS: This was a descriptive, noninterventional, secondary database cohort study of patients with COPD aged 40 years or older, who initiated treatment with specific COPD medications. Patients were classified according to COPD severity (1) in GOLD 2016 "ABCD" categories based on symptoms (Medical Research Council dyspnea grade, COPD Assessment Test, breathlessness), percent predicted FEV1, and exacerbation history and (2) as mild, moderate, severe, or very severe based on treatment and exacerbation history. RESULTS: The study included 63 900 patients with COPD aged 40 years or older that were new users of 1 or more COPD medication of interest. Percent predicted FEV1 was available for 80.9% of patients; symptoms for 75.6% of patients. Classification into GOLD 2016 ABCD categories was possible for 75.6% of the patients. The GOLD 2016 ABCD definition classified more patients under the high-risk categories (22.1%, A; 18.8%, B; 21.3%, C; 37.9%, D) than did the adapted algorithm (7.9%, mild; 48.6%, moderate; 42.1%, severe; 1.4%, very severe). CONCLUSION: Using our adaptation of the GOLD 2016 COPD severity classification, the information in the Clinical Practice Research Datalink allowed us to ascertain COPD severity in approximately 75% of patients with COPD. Algorithms that include medication use tend to misclassify patients with the extreme COPD severity categories.

Accuracy of electronic health record data for the diagnosis of chronic obstructive pulmonary disease in persons living with HIV and uninfected persons.

PURPOSE: No prior studies have addressed the performance of electronic health record (EHR) data to diagnose chronic obstructive pulmonary disease (COPD) in people living with HIV (PLWH), in whom COPD could be more likely to be underdiagnosed or misdiagnosed, given the higher frequency of respiratory symptoms and smoking compared with HIV-uninfected (uninfected) persons. METHODS: We determined whether EHR data could improve accuracy of ICD-9 codes to define COPD when compared with spirometry in PLWH vs uninfected, and quantified level of discrimination using the area under the receiver-operating curve (AUC). The development cohort consisted of 350 participants who completed research spirometry in the Examinations of HIV Associated Lung Emphysema (EXHALE) study, a pulmonary substudy of the Veterans Aging Cohort Study. Results were externally validated in 294 PLWH who performed spirometry for clinical indications from the University of Washington (UW) site of the Centers for AIDS Research Network of Integrated Clinical Systems cohort. RESULTS: ICD-9 codes performed similarly by HIV status, but alone were poor at discriminating cases from non-cases of COPD when compared with spirometry (AUC 0.633 in EXHALE; 0.651 in the UW cohort). However, algorithms that combined ICD-9 codes with other clinical variables available in the EHR-age, smoking, and COPD inhalers-improved discrimination and performed similarly in EXHALE (AUC 0.771) and UW (AUC 0.734). CONCLUSIONS: These data support that EHR data in combination with ICD-9 codes have moderately good accuracy to identify COPD when spirometry data are not available, and perform similarly in PLWH and uninfected individuals.

Bronchodilator responsiveness as a predictor of success for bronchial thermoplasty.

BACKGROUND AND OBJECTIVE: A characteristic feature of asthma is hypertrophied airway smooth muscle, responsible for bronchoconstriction. This is the target of bronchial thermoplasty (BT). It is known that with increasing time and severity some patients develop remodelled airways with fixed airflow obstruction. The question arises whether these patients will still respond to BT. METHODS: Forty-nine consecutive severe asthmatic patients were prospectively evaluated at baseline and then 6 months after BT. The characteristics recorded included medication usage, exacerbation history, spirometry and the Asthma Control Questionnaire 5-Item Version score (ACQ-5). Seven patients were excluded as they did not demonstrate airflow obstruction at baseline (forced expiratory ratio (forced expiratory volume in 1 s (FEV1 )/forced vital capacity (FVC)) < 70%). The remaining 42 patients were divided into two cohorts based on their response to bronchodilator. Eighteen patients in whom the FEV1 improved by at least 12% and 200 mL following bronchodilator were allocated to Group 1 (reversible). The remaining patients were allocated to Group 2 (fixed). The outcomes following BT in these two groups were then compared. RESULTS: The patient age was 57.2 ± 12.4 years, the ACQ-5 was 3.2 ± 1.0 and the FEV1 56.0 ± 16.4% predicted. At baseline, the patient cohorts were very similar, save for the response to bronchodilator, which was 28.1 ± 12.5% in Group 1 and 4.1 ± 5.3% in Group 2. Both groups responded to BT equally well, with significant improvements in ACQ-5, salbutamol usage, exacerbation frequency and the weaning of oral corticosteroids. CONCLUSION: In patients with severe asthma, the presence or absence of variable airflow obstruction as measured by spirometry does not appear to influence outcomes from BT.

Asthma knowledge, care, and outcome during pregnancy: The QAKCOP study.

Asthma is the most common chronic medical condition affecting pregnancy. Optimizing asthma management in pregnancy is paramount for the well-being of both the mother and the baby. The primary objectives of this study were to assess patient's knowledge about asthma, the level of asthma care, and fetal and maternal outcomes among pregnant asthmatic women in this wealthy country with tremendous improvement in maternal and fetal health care. The secondary objective was to identify barriers to asthma control. This was a cross-sectional, face-to-face, prospective study of 80 pregnant women with physician-diagnosed asthma. About 56% of patients reported worsening of their asthma control during pregnancy, of which 52.3% felt this worsening in the third trimester. About 65% of patients had uncontrolled asthma during their pregnancy, and inhaler technique was incorrect in 64.4%. Only 38% of patients knew the difference between controller and reliever asthma medications, 12.7% of patients had received written asthma action plan, 17% had a spirometry done in the previous 5 years, and 3.8% had peak expiratory flow meter at home. The main reasons for uncontrolled asthma were lack of knowledge about right asthma medications in 30% and fear of side effects of inhaled corticosteroids in 19% of patients. No financial reason was reported. Significant associations between total number of pregnancies, poor perception of asthma medications, asthma exacerbation during delivery and poor asthma control were observed. Preeclampsia and congenital anomalies occurred at higher rates than previously reported among general population in this country. The tremendous improvements in maternal health care and socioeconomic status do not seem to be a barrier to the globally recognized poor asthma care in pregnancy. Important strategies are much needed.

Childhood Lung Function Predicts Adult Chronic Obstructive Pulmonary Disease and Asthma-Chronic Obstructive Pulmonary Disease Overlap Syndrome.

RATIONALE: The burden of chronic obstructive pulmonary disease (COPD) is increasing, yet there are limited data on early life risk factors. OBJECTIVES: To investigate the role of childhood lung function in adult COPD phenotypes. METHODS: Prebronchodilator spirometry was performed for a cohort of 7-year-old Tasmanian children (n = 8,583) in 1968 who were resurveyed at 45 years, and a selected subsample (n = 1,389) underwent prebronchodilator and post-bronchodilator spirometry. For this analysis, COPD was spirometrically defined as a post-bronchodilator FEV1/FVC less than the lower limit of normal. Asthma-COPD overlap syndrome (ACOS) was defined as the coexistence of both COPD and current asthma. Associations between childhood lung function and asthma/COPD/ACOS were examined using multinomial regression. MEASUREMENTS AND MAIN RESULTS: At 45 years, 959 participants had neither current asthma nor COPD (unaffected), 269 had current asthma alone, 59 had COPD alone, and 68 had ACOS. The reweighted prevalence of asthma alone was 13.5%, COPD alone 4.1%, and ACOS 2.9%. The lowest quartile of FEV1 at 7 years was associated with ACOS (odds ratio, 2.93; 95% confidence interval, 1.32-6.52), but not COPD or asthma alone. The lowest quartile of FEV1/FVC ratio at 7 years was associated with ACOS (odds ratio, 16.3; 95% confidence interval, 4.7-55.9) and COPD (odds ratio, 5.76; 95% confidence interval, 1.9-17.4), but not asthma alone. CONCLUSIONS: Being in the lowest quartile for lung function at age 7 may have long-term consequences for the development of COPD and ACOS by middle age. Screening of lung function in school age children may identify a high-risk group that could be targeted for intervention. Further research is needed to understand possible modifiers of these associations and develop interventions for children with impaired lung function.

Evaluation of the Global Lung Initiative 2012 Reference Values for Spirometry in African Children.

RATIONALE: Despite the high burden of respiratory disease, no spirometry reference values for African children are available. OBJECTIVES: Investigate whether the Global Lung Initiative (GLI-2012) reference values for spirometry are appropriate for children in sub-Saharan Africa and assess the impact of malnutrition on lung function. METHODS: Anthropometry and spirometry were obtained in children aged 6 to 12 years from urban and semiurban schools in three African countries. Spirometry z-scores were derived using the GLI-2012 prediction equations for African Americans. Thinness (body mass index z-score < -2) was a surrogate for malnutrition. Spirometry outcomes were compared with those of African American children from the third National Health and Nutrition Survey. MEASUREMENTS AND MAIN RESULTS: Spirometry data were analyzed from 1,082 schoolchildren (51% boys) aged 6.0 to 12.8 years in Angola (n = 306), Democratic Republic of the Congo (n = 377), and Madagascar (n = 399). GLI-2012 provided a good fit with mean (SD) z-scores of -0.11 (0.83) for FEV1, -0.08 (0.86) for FVC, and -0.07 (0.83) for FEV1/FVC. Because of low scatter, the fifth centile corresponded to -1.3 z-scores in boys and -1.5 z-scores in girls. Malnourished African children had a normal FEV1/FVC ratio but significant reductions of ∼0.5 z-scores (∼5%) in FEV1 and FVC compared with African American peers from the third National Health and Nutrition Survey. Children in Angola had the lowest, and those in Madagascar had the highest, zFEV1 and zFVC. CONCLUSIONS: The results of this study support the use of GLI-2012 reference values for schoolchildren in sub-Saharan Africa. Malnutrition affects body growth, leading to a proportionately smaller FEV1 and FVC without respiratory impairment, as shown by the normal FEV1/FVC ratio.

Physical activity and sedentary time are related to clinically relevant health outcomes among adults with obstructive lung disease.

BACKGROUND: The purpose of the current study was to determine the association between sedentary time and physical activity with clinically relevant health outcomes among adults with impaired spirometry and those with or without self-reported obstructive lung disease (asthma or COPD). METHODS: Data from participants of the Canadian Longitudinal Study on Aging were used for analysis (n = 4156). Lung function was assessed using spirometry. Adults were said to have impaired spirometry if their Forced Expiratory Volume in 1 s was <5th percentile lower limit of normal (LLN). A modified version of the Physical Activity Scale for the Elderly was used to assess sitting time and physical activity levels. Healthcare use and quality of life outcomes were assessed using self report. RESULTS: Among those with asthma, participating in strengthening activities was associated with lower odds of reporting poor perceived health (OR = 0.65, CI: 0.53, 0.79), poor perceived mental-health (OR = 0.73, CI: 0.60, 0.88), unhealthy aging (OR = 0.68, CI: 0.56, 0.83), and reporting an emergency department visit in the past 12 months (OR = 0.76, CI: 0.60, 0.95). Among those with COPD, those who reported highest weekly sedentary time had higher odds of reporting poor perceived health (OR = 2.70, CI: 1.72, 4.24), poor perceived mental-health (OR = 1.99, CI: 1.29, 3.06), and unhealthy aging (OR = 3.04, CI: 1.96, 4.72). Among those below the LLN, sitting time (OR = 2.57, CI: 1.40, 4.72) and moderate intensity physical activity (OR = 0.23, CI: 0.09, 0.63) were associated with overnight hospital stays. CONCLUSIONS: Higher physical activity levels and lower sedentary time may be associated with lower healthcare use and better quality of life. This research may have implications related to the use of physical activity for improving health outcomes and quality of life among adults with obstructive lung disease or impaired spirometry.

Ethnic differences in lung functions of children in the Colombo District, Sri Lanka

Background: Reference values of lung functions vary with age, height, ethnicity and sex of the reference population. Global Function Initiative 2012 compared reference equations for Sri Lankan children with those of South Indian and South East Asian equations. Sri Lanka has a multi-ethnic society comprising of Sinhalese, Tamils, Moors and other ethnic minorities. Applicability of existing Sri Lankan equations to children from different ethnic groups in the country has not been adequately verified. Our aim was to investigate the effect of ethnicity on spirometry parameters in school aged children. Methods: We enrolled healthy boys and girls between 9-15 years of age from 6 schools in Colombo District using stratified cluster sampling. A pretested self-administered questionnaire collected details on demography, respiratory health and other chronic illnesses. Anthropometric measurements (standing height and weight) were collected. Spirometry was performed with a flow sensing spirometer that complies with American Thoracic Society/European Respiratory Society (ATS/ERS) standards adopted for children. Highest FVC and FEV1 values were obtained from 2 repeatable tests. Results: Spirograms of 849 students were analysed. Majority (n=496) were Sinhalese. There were 240 Tamils and 113 Moors. Multiple regression found that height, age and sex were significantly associated with lung functions (p<0.05). Ethnicity was not significantly associated with parameters measured in spirometry when the regression was performed controlling for height and age. Conclusions: The same spirometry reference equations could could be used for children of all ethnic groups in Sri Lanka aged 9-15 years.

Chronic Hypoxia Accentuates Dysanaptic Lung Growth.

RATIONALE: Adults born and raised at high altitudes have larger lung volumes and greater pulmonary diffusion capacity compared with adults at low altitude; however, it remains unclear whether the air and tissue volumes have comparable increases and whether there is a difference in airway size. OBJECTIVES: To assess the effect of chronic hypoxia on lung growth using in vivo high-resolution computed tomography measurements. METHODS: Healthy adults born and raised at moderate altitude (2,000 m above sea level; n = 19) and at low altitude (400 m above sea level; n = 23) underwent high-resolution computed tomography. Differences in total lung, air, and tissue volume, mean lung density, as well as airway lumen and wall areas in anatomically matched airways were compared between groups. MEASUREMENTS AND MAIN RESULTS: No significant differences for age, sex, weight, or height were found between the two groups (P > 0.05). In a multivariate regression model, altitude was a significant contributor for total lung volume (P = 0.02), air volume (P = 0.03), and tissue volume (P = 0.03), whereby the volumes were greater for the moderate- versus the low-altitude group. However, altitude was not a significant contributor for mean lung density (P = 0.35) or lumen and wall areas in anatomically matched segmental, subsegmental, and subsubsegmental airways. CONCLUSIONS: Our findings suggest that the adult lung did not increase lung volume later in life by expansion of an existing number of alveoli, but rather from increased alveolarization early in life. In addition, chronic hypoxia accentuates dysanaptic lung growth by increasing the lung parenchyma but not the airways.

Association between high-density lipoprotein cholesterol level and pulmonary function in healthy Korean adolescents: the JS high school study.

BACKGROUND: Accumulating evidence suggests that high-density lipoprotein (HDL) cholesterol is associated with pulmonary function and pulmonary disorders. The aim of this study was to evaluate the association between HDL cholesterol and pulmonary function in healthy adolescents. METHODS: This cross-sectional study was based on data collected for the JS High School study. The analysis included 644 adolescents (318 male and 326 female) aged 15-16 years old and free from asthma or chronic obstructive pulmonary disease. Fasting blood samples were collected for hematologic and biochemical assessment. Forced vital capacity volume (FVC) and forced expiratory volume in the 1 s (FEV1) were measured using dry-rolling-seal spirometry. The associations between HDL cholesterol and pulmonary function were analyzed using multiple linear regression models. RESULTS: Among male adolescents, an increase of 1.0 mg/dL in HDL cholesterol was associated with 10 mL decrease in FVC (p = 0.013) and FEV1 (p = 0.013) after adjusting for age, height, weight, alcohol drinking, smoking, physical activity, systolic blood pressure, total cholesterol, triglyceride, and monthly household income. Percent predicted values of FVC (p = 0.036) and FEV1 (p = 0.017) were also inversely associated with HDL cholesterol. However, among female adolescents, HDL cholesterol level was not significantly associated with absolute or percent predictive value of FVC and FEV1. CONCLUSIONS: Higher HDL cholesterol level may be associated with decreased pulmonary function among healthy male adolescents. The sex differences observed in the association between HDL cholesterol and pulmonary function need further investigation.

Estimating prevalence of chronic obstructive pulmonary disease in the Southern Cone of Latin America: how different spirometric criteria may affect disease burden and health policies.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death worldwide. The study aimed to determine and compare the prevalence of COPD in the general population aged 45-74 years old according to fixed ratio and lower limit of normal (LLN) thresholds in four cities in the Southern Cone of Latin America. METHODS: The Pulmonary Risk in South America (PRISA) study used a 4-stage stratified sampling method to select 5814 participants from 4 cities in the Southern Cone of Latin America (Bariloche and Marcos Paz, Argentina; Temuco, Chile; and Pando-Barros Blancos, Uruguay). Data on demographic information, medical history, risk factors, pre-bronchodilator and post-bronchodilator spirometry were obtained using a standard protocol. According to GOLD, COPD was defined as a post-bronchodilator ratio of forced expiratory volume in one second (FEV1) over forced vital capacity (FVC) less than 70%. The LLN threshold was defined as the lower fifth percentile for predicted FEV1/FVC, and was evaluated as an alternative COPD definition. RESULTS: Overall COPD prevalence was 9.3% (95% CI 8.4, 10.2%), and men had a higher prevalence [11.8% (95% CI 10.3, 13.3%)] than women [7.3% (95% CI 6.2, 8.3%)] with the fixed ratio. Overall COPD prevalence using LLN was 4.7% (95% CI 4.1, 5.3%), higher in men: 5.8% (95% CI 4.7, 6.8%) than women: 3.9% (95% CI 3.1, 4.7%). COPD prevalence was significantly higher among those who were older, had