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1.
BMC Public Health ; 24(1): 1542, 2024 Jun 07.
Article En | MEDLINE | ID: mdl-38849797

BACKGROUND: Pulmonary function is very important for the healthy development of children and adolescents. However, fewer studies have been conducted on pulmonary function trends in children and adolescents in remote areas. The aim of this study was to estimate the forced vital capacity (FVC) trend and its relationship with body mass index (BMI) among young people in Xinjiang during 1985-2014 using data from seven successive national surveys. METHODS: A total of 19,449 Xinjiang children and adolescents aged 7-18 years were extracted from the Chinese National Survey on Students' Constitution and Health. Height, weight, and FVC were measured repeatedly in each survey. FVC comparisons between adjacent surveys by age and sex were conducted by nonparametric Kruskal-Wallis after Kolmogorov-Smirnov of normality. One-way ANOVA and least significant difference(LSD) method was used to compare differences in FVC levels of Xinjiang children and adolescents with different BMI. The relationship between BMI and FVC was investigated using a nonlinear regression model. RESULTS: The FVC levels of Xinjiang children and adolescents peaked in 2000, with overall FVC levels being 8.7% higher in 2000 than in 1985. Since then, a substantial decline occurred, contrasting to 2000, with FVC levels decreasing by 27% in 2014, which was still lower than that in 1985 by 20.73%. The proportion of overnutrition boys increased from 0.2% in 1985 to 22.1% in 2014, and girls from 0.5% in 1985 to 14.5% in 2014. An inverted U-shape association between FVC and BMI values was obtained for Xinjiang children and adolescents. CONCLUSIONS: Targeted measures should be carried out in schools to control BMI levels to ensure good lung function in children and adolescents in Xinjiang. Future studies should pay more attention to other factors affecting FVC, such as dietary behaviour, physical activity, and racial differences among children and adolescents.


Body Mass Index , Humans , Adolescent , Child , Male , China/epidemiology , Female , Vital Capacity/physiology , Health Surveys
2.
Respir Med ; 227: 107656, 2024 Jun.
Article En | MEDLINE | ID: mdl-38697229

RATIONALE: The proportion of patients who develop progressive pulmonary fibrosis (PPF), along with risk factors for progression remain poorly understood. OBJECTIVES: To examine factors associated with an increased risk of developing PPF among patients at a referral center. METHODS: We identified patients with a diagnosis of interstitial lung disease (ILD) seen within the Cleveland Clinic Health System. Utilizing a retrospective observational approach we estimated the risk of developing progression by diagnosis group and identified key clinical predictors using the FVC component of both the original progressive fibrotic interstitial lung disease (PFILD) and the proposed PPF (ATS) criteria. RESULTS: We identified 5934 patients with a diagnosis of ILD. The cumulative incidence of progression over the 24 months was similar when assessed with the PFILD and PPF criteria (33.1 % and 37.9 % respectively). Of those who met the ATS criteria, 9.5 % did not meet the PFILD criteria. Conversely, 4.3 % of patients who met PFILD thresholds did not achieve the 5 % absolute FVC decline criteria. Significant differences in the rate of progression were seen based on underlying diagnosis. Steroid therapy (HR 1.46, CI 1.31-1.62) was associated with an increased risk of progressive fibrosis by both PFILD and PPF criteria. CONCLUSION: Regardless of the definition used, the cumulative incidence of progressive disease is high in patients with ILD in the 24 months following diagnosis. Some differences are seen in the risk of progression when assessed by PFILD and PPF criteria. Further work is needed to identify modifiable risk factors for the development of progressive fibrosis.


Disease Progression , Lung Diseases, Interstitial , Humans , Lung Diseases, Interstitial/physiopathology , Lung Diseases, Interstitial/epidemiology , Lung Diseases, Interstitial/complications , Male , Female , Retrospective Studies , Vital Capacity/physiology , Middle Aged , Aged , Risk Factors , Pulmonary Fibrosis/physiopathology , Pulmonary Fibrosis/complications , Pulmonary Fibrosis/epidemiology , Incidence
3.
Muscle Nerve ; 70(1): 94-100, 2024 Jul.
Article En | MEDLINE | ID: mdl-38695638

INTRODUCTION/AIMS: Patients with amyotrophic lateral sclerosis (ALS) are susceptible to malnutrition, with appropriate management of nutritional interventions an active area of investigation. We sought to determine the impact of gastrostomy tube placement in ALS patients, exploring the correlation between forced vital capacity (FVC), malnutrition, and perioperative complications. METHODS: A retrospective review was performed of clinically diagnosed ALS patients treated at two multidisciplinary clinics (University of Kansas, University of Nebraska) from January 2009 to September 2020 who were referred for gastrostomy. Data collected included demographics, disease characteristics, and key gastrostomy related dates/outcomes. RESULTS: Two hundred thirty-nine patients were included with a median age of 65 years and median of 589 days from symptom onset to gastrostomy (interquartile range, 404-943). The population was predominantly Non-Hispanic White with bulbar-onset ALS. 30-day mortality was 4% and 30-day morbidity was 13%. Weight loss, body mass index, and predicted FVC at placement showed no increased 30-day morbidity or mortality association. Bulbar-onset ALS patients exhibited higher overall mortality postplacement than limb onset (odds ratio: 1.85, 95% confidence interval: 1.03-3.33). There was a 5% incidence of symptoms suggestive of refeeding syndrome. DISCUSSION: Rates of major/minor complications and 30-day mortality related to gastrostomy placement in our population were similar compared with prior studies in ALS. The lack of difference in outcomes based on FVC at procedure may suggest this is not predictive of outcome, or perhaps, high-quality perioperative respiratory management. Alternative reasons may account for the increased morbidity and mortality of gastrostomy placement in the ALS population.


Amyotrophic Lateral Sclerosis , Enteral Nutrition , Gastrostomy , Humans , Amyotrophic Lateral Sclerosis/therapy , Amyotrophic Lateral Sclerosis/complications , Male , Female , Enteral Nutrition/methods , Aged , Retrospective Studies , Middle Aged , Treatment Outcome , Malnutrition/etiology , Malnutrition/therapy , Vital Capacity/physiology
4.
Med J Aust ; 220(10): 523-529, 2024 Jun 03.
Article En | MEDLINE | ID: mdl-38741358

OBJECTIVES: To evaluate the suitability of the Global Lung Function Initiative (GLI)-2012 other/mixed and GLI-2022 global reference equations for evaluating the respiratory capacity of First Nations Australians. DESIGN, SETTING: Cross-sectional study; analysis of spirometry data collected by three prospective studies in Queensland, the Northern Territory, and Western Australia between March 2015 and December 2022. PARTICIPANTS: Opportunistically recruited First Nations participants in the Indigenous Respiratory Reference Values study (Queensland, Northern Territory; age, 3-25 years; 18 March 2015 - 24 November 2017), the Healthy Indigenous Lung Function Testing in Adults study (Queensland, Northern Territory; 18 years or older; 14 August 2019 - 15 December 2022) and the Many Healthy Lungs study (Western Australia; five years or older; 10 October 2018 - 7 November 2021). MAIN OUTCOME MEASURES: Goodness of fit to spirometry data for each GLI reference equation, based on mean Z-score and its standard deviation, and proportions of participants with respiratory parameter values within 1.64 Z-scores of the mean value. RESULTS: Acceptable and repeatable forced expiratory volume in the first second (FEV1) values were available for 2700 First Nations participants in the three trials; 1467 were classified as healthy and included in our analysis (1062 children, 405 adults). Their median age was 12 years (interquartile range, 9-19 years; range, 3-91 years), 768 (52%) were female, and 1013 were tested in rural or remote areas (69%). Acceptable and repeatable forced vital capacity (FVC) values were available for 1294 of the healthy participants (88%). The GLI-2012 other/mixed and GLI-2022 global equations provided good fits to the spirometry data; the race-neutral GLI-2022 global equation better accounted for the influence of ageing on FEV1 and FVC, and of height on FVC. Using the GLI-2012 other/mixed reference equation and after adjusting for age, sex, and height, mean FEV1 (estimated difference, -0.34; 95% confidence interval [CI], -0.46 to -0.22) and FVC Z-scores (estimated difference, -0.45; 95% CI, -0.59 to -0.32) were lower for rural or remote than for urban participants, but their mean FEV1/FVC Z-score was higher (estimated difference, 0.14; 95% CI, 0.03-0.25). CONCLUSION: The normal spirometry values of healthy First Nations Australians may be substantially higher than previously reported. Until more spirometry data are available for people in urban areas, the race-neutral GLI-2022 global or the GLI-2012 other/mixed reference equations can be used when assessing the respiratory function of First Nations Australians.


Spirometry , Adolescent , Adult , Aged , Child , Child, Preschool , Female , Humans , Male , Middle Aged , Young Adult , Australia , Cross-Sectional Studies , Forced Expiratory Volume/physiology , Prospective Studies , Reference Values , Spirometry/standards , Vital Capacity/physiology , Australian Aboriginal and Torres Strait Islander Peoples
5.
Tunis Med ; 102(5): 266-271, 2024 May 05.
Article En | MEDLINE | ID: mdl-38801283

INTRODUCTION: There is no clear consensus as to what constitutes an obstructive ventilatory impairment (OVI) in pediatric populations. AIM: To determine the percentage of children/adolescents having an OVI among those addressed for spirometry after taking into account the definitions advanced by some international scholarly societies [British Columbia (BC), British thoracic-society (BTS), Canadian thoracic society (CTS), European respiratory society and American thoracic society (ERS-ATS), global initiative for asthma (GINA), Irish college of general practitioners (ICGP), national asthma council (NAC), national institute of clinical excellence (NICE), Société de pneumologie de langue française, Société pédiatrique de pneumologie et allergologie (SPLF-SP2A), and South African thoracic society (SATS)]. METHODS: This bi-centric cross-sectional study involves two medical structures in Sousse/Tunisia, and will encompass children/adolescents aged 6-18 years. A medical questionnaire will be administered, clinical and anthropometric data will be collected, and the spirometric data will be measured by two spirometers. The following six definitions of OVI will be applied: i) GINA: Forced expiratory volume in 1 second (FEV1) < 80% and a FEV1/forced vital capacity (FVC) ≤ 0.90; ii) ICGP: FEV1/FVC < 0.70; iii) ERS-ATS or BTS or SATS or SPLF-SP2A or NAC: FEV1/FVC z-score < -1.645; iv) NICE: FEV1/FVC < 0.70 or FEV1/FVC z-score < -1.645; v) CTS: FEV1/FVC < 0.80 or a FEV1/FVC z-score < -1.645; and vi) ERS: "FEV1 z-score or FEV1/FVC z-score" < -1.645 or "FEV1 or FEV1/FVC" < 0.80. EXPECTED RESULTS: The percentage of children/adolescents having an OVI will significantly vary between the six definitions. CONCLUSION: The frequency of OVI in a pediatric population will depend on the definition chosen.


Spirometry , Humans , Child , Adolescent , Spirometry/methods , Cross-Sectional Studies , Female , Male , Forced Expiratory Volume/physiology , Tunisia/epidemiology , Vital Capacity/physiology , Lung Diseases, Obstructive/diagnosis , Lung Diseases, Obstructive/epidemiology , Lung Diseases, Obstructive/physiopathology , Research Design
6.
Muscle Nerve ; 70(1): 140-147, 2024 Jul.
Article En | MEDLINE | ID: mdl-38742544

INTRODUCTION/AIMS: Evaluations of pulmonary, cough, and swallow function are frequently performed to assess disease progression in amyotrophic lateral sclerosis (ALS), yet the relationship between these functions remains unknown. We therefore aimed to determine relationships between these measures in individuals with ALS. METHODS: One hundred individuals with ALS underwent standardized tests: forced vital capacity (FVC), maximum expiratory/inspiratory pressure (MEP, MIP), voluntary cough peak expiratory flow (PEF), and videofluoroscopic swallow evaluation (VF). Duplicate raters completed independent, blinded ratings using the Dynamic Imaging Grade of Swallowing Toxicity (DIGEST) scale. Descriptives, Spearman's Rho correlations, Kruskal-Wallis analyses, and Pearson's chi-squared tests were completed. RESULTS: Mean and standard deviation across pulmonary and cough measures were FVC: 74.2% predicted (± 22.6), MEP: 91.6 cmH2O (± 46.4), MIP cmH2O: 61.1 (± 28.9), voluntary PEF: 352.7 L/min (± 141.6). DIGEST grades included: 0 (normal swallowing): 31%, 1 (mild dysphagia): 48%, 2 (moderate dysphagia): 10%, 3 (severe dysphagia): 10%, and 4 (life-threatening dysphagia): 1%. Positive correlations were observed: MEP-MIP: r = .76, MIP-PEF: r = .68, MEP-PEF: r = .61, MIP-FVC: r = .60, PEF-FVC: r = .49, and MEP-FVC: r = .46, p < .0001. MEP (p = .009) and PEF (p = .04) differed across DIGEST safety grades. Post hoc analyses revealed significant between group differences in MEP and PEF across DIGEST safety grades 0 versus 1 and grades 0 versus 3, (p < .05). DISCUSSION: In this cohort of individuals with ALS, pulmonary function, and voluntary cough were associated. Expiratory metrics (MEP, PEF) were diminished in individuals with unsafe swallowing, increasing their risk for effectively defending the airway.


Amyotrophic Lateral Sclerosis , Cough , Deglutition Disorders , Deglutition , Humans , Amyotrophic Lateral Sclerosis/physiopathology , Amyotrophic Lateral Sclerosis/complications , Male , Cough/physiopathology , Cough/etiology , Female , Middle Aged , Aged , Deglutition/physiology , Deglutition Disorders/physiopathology , Deglutition Disorders/etiology , Vital Capacity/physiology , Adult , Lung/physiopathology , Lung/diagnostic imaging , Fluoroscopy , Respiratory Function Tests
7.
Br J Sports Med ; 58(11): 586-597, 2024 May 28.
Article En | MEDLINE | ID: mdl-38599680

OBJECTIVE: The primary objective of this cross-sectional study was to compare standard laboratory performance metrics of transgender athletes to cisgender athletes. METHODS: 19 cisgender men (CM) (mean±SD, age: 37±9 years), 12 transgender men (TM) (age: 34±7 years), 23 transgender women (TW) (age: 34±10 years) and 21 cisgender women (CW) (age: 30±9 years) underwent a series of standard laboratory performance tests, including body composition, lung function, cardiopulmonary exercise testing, strength and lower body power. Haemoglobin concentration in capillary blood and testosterone and oestradiol in serum were also measured. RESULTS: In this cohort of athletes, TW had similar testosterone concentration (TW 0.7±0.5 nmol/L, CW 0.9±0.4 nmol/), higher oestrogen (TW 742.4±801.9 pmol/L, CW 336.0±266.3 pmol/L, p=0.045), higher absolute handgrip strength (TW 40.7±6.8 kg, CW 34.2±3.7 kg, p=0.01), lower forced expiratory volume in 1 s:forced vital capacity ratio (TW 0.83±0.07, CW 0.88±0.04, p=0.04), lower relative jump height (TW 0.7±0.2 cm/kg; CW 1.0±0.2 cm/kg, p<0.001) and lower relative V̇O2max (TW 45.1±13.3 mL/kg/min/, CW 54.1±6.0 mL/kg/min, p<0.001) compared with CW athletes. TM had similar testosterone concentration (TM 20.5±5.8 nmol/L, CM 24.8±12.3 nmol/L), lower absolute hand grip strength (TM 38.8±7.5 kg, CM 45.7±6.9 kg, p=0.03) and lower absolute V̇O2max (TM 3635±644 mL/min, CM 4467±641 mL/min p=0.002) than CM. CONCLUSION: While longitudinal transitioning studies of transgender athletes are urgently needed, these results should caution against precautionary bans and sport eligibility exclusions that are not based on sport-specific (or sport-relevant) research.


Athletes , Estradiol , Exercise Test , Testosterone , Transgender Persons , Humans , Cross-Sectional Studies , Male , Testosterone/blood , Female , Adult , Estradiol/blood , Hand Strength/physiology , Muscle Strength/physiology , Young Adult , Body Composition/physiology , Vital Capacity/physiology , Middle Aged , Oxygen Consumption/physiology , Forced Expiratory Volume/physiology
8.
Respir Med ; 227: 107633, 2024 Jun.
Article En | MEDLINE | ID: mdl-38631527

BACKGROUND: Anxiety is common in patients with chronic obstructive pulmonary disease (COPD). However, there is little evidence available regarding gender differences, and severity of dyspnea in relation to anxiety in patients with COPD. AIMS: We examined gender differences and the association of dyspnea with anxiety in a cohort of patients with COPD prior to entering a pulmonary rehabilitation (PR) program. METHOD: We analyzed data from a prospective cohort of COPD patients who attended PR from 2013 to 2019 in Lytham, Lancashire, UK. Patients were aged 40 years or older with a post-bronchodilation forced expiratory volume in 1 s (FEV1) less than 80 % of the predicted normal value and FEV1/FVC (forced vital capacity) ratio less than 0.7. We assessed quality of life (QoL) using the Saint George's Respiratory Questionnaire (SGRQ), anxiety using the Anxiety Inventory for Respiratory disease (AIR), dyspnea using the modified Medical Research Council (mMRC) scale, and exercise capacity using the Incremental Shuttle Walk Test (ISWT). RESULTS: Nine hundred ninety-three patients with COPD (mean age = 71 years, FEV1/FVC = 58 % predicted, 51 % male) entered the PR program. Of these, 348 (35 %) had anxiety symptoms (AIR ≥8); of these 165 (47 %) were male and 183 (53 %) female, (χ2 = 3.33, p = 0.06). On logistic multivariate analysis, the following variables were independently associated with elevated anxiety: younger age (p < 0.001), female sex (p = 0.03), higher SGRQ-total score (p < 0.001) and high FEV1/FVC (p < 0.002). Dyspnea was associated with anxiety r = 0.25, p < 0.001. CONCLUSION: Over a third of COPD patients had clinically relevant anxiety symptoms with a higher prevalence in women than men. Anxiety was associated with younger age, female gender, and impaired QoL. Early recognition and treatment of anxiety in patients with COPD is worthy of consideration for those attending PR, especially women.


Anxiety , Dyspnea , Pulmonary Disease, Chronic Obstructive , Quality of Life , Humans , Pulmonary Disease, Chronic Obstructive/rehabilitation , Pulmonary Disease, Chronic Obstructive/psychology , Pulmonary Disease, Chronic Obstructive/physiopathology , Pulmonary Disease, Chronic Obstructive/complications , Male , Female , Aged , Anxiety/psychology , Dyspnea/psychology , Dyspnea/physiopathology , Dyspnea/etiology , Middle Aged , Prospective Studies , Forced Expiratory Volume/physiology , Sex Factors , Exercise Tolerance/physiology , Vital Capacity/physiology , Severity of Illness Index , Surveys and Questionnaires
9.
Respir Med ; 227: 107638, 2024 Jun.
Article En | MEDLINE | ID: mdl-38641121

RATIONALE: Exposure to burn pit smoke, desert and combat dust, and diesel exhaust during military deployment to Southwest Asia and Afghanistan (SWA) can cause deployment-related respiratory diseases (DRRDs) and may confer risk for worsening lung function after return. METHODS: Study subjects were SWA-deployed veterans who underwent occupational lung disease evaluation (n = 219). We assessed differences in lung function by deployment exposures and DRRD diagnoses. We used linear mixed models to assess changes in lung function over time. RESULTS: Most symptomatic veterans reported high intensity deployment exposure to diesel exhaust and burn pit particulates but had normal post-deployment spirometry. The most common DRRDs were deployment-related distal lung disease involving small airways (DDLD, 41%), deployment-related asthma (DRA, 13%), or both DRA/DDLD (24%). Those with both DDLD/DRA had the lowest estimated mean spirometry measurements five years following first deployment. Among those with DDLD alone, spirometry measurements declined annually, adjusting for age, sex, height, weight, family history of lung disease, and smoking. In this group, the forced expiratory volume in the first second/forced vital capacity (FEV1/FVC) ratio declined 0.2% per year. Those with more intense inhalational exposure had more abnormal lung function. We found significantly lower estimated FVC and total lung capacity five years following deployment among active duty participants (n = 173) compared to those in the reserves (n = 26). CONCLUSIONS: More intense inhalational exposures were linked with lower post-deployment lung function. Those with distal lung disease (DDLD) experienced significant longitudinal decline in FEV1/FVC ratio, but other DRRD diagnosis groups did not.


Afghan Campaign 2001- , Spirometry , Veterans , Humans , Male , Female , Adult , Longitudinal Studies , Occupational Exposure/adverse effects , Forced Expiratory Volume/physiology , Vital Capacity/physiology , Middle Aged , Lung Diseases/physiopathology , Lung Diseases/epidemiology , Lung Diseases/etiology , Military Deployment , Occupational Diseases/physiopathology , Occupational Diseases/epidemiology , Occupational Diseases/etiology , Lung/physiopathology , Respiratory Function Tests , Iraq War, 2003-2011 , September 11 Terrorist Attacks , Asthma/physiopathology , Asthma/epidemiology , United States/epidemiology
10.
Respir Med ; 227: 107614, 2024 Jun.
Article En | MEDLINE | ID: mdl-38670319

INTRODUCTION: Data is limited on influence of forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) in a large adult population, including individuals with normal spirometry at baseline. METHODS: Using the UK Biobank cohort, a multivariable Cox regression analysis was conducted on 406,424 individuals to examine the association between FEV1 and FVC, categorized into three groups based on their percentage of predicted values (%pred) (≥80, 60-80 and < 60), and overall mortality, cardiovascular mortality, myocardial infarction, stroke, and heart failure over approximately 12.5 years. Moreover, a subgroup analysis was conducted on 295,459 individuals who had normal spirometry. RESULTS: Reduced FEV1 and FVC %pred values were associated with an elevated risk across all studied outcomes. Individuals with the lowest FEV1 and FVC %pred values (<60 %) exhibited HR of 1.83 (95 % CI 1.74-1.93) and 1.98 (95 % CI 1.76-2.22) for overall mortality, and 1.96 (95 % CI 1.83-2.1) and 2.26 (95 % CI 1.94-2.63) for cardiovascular mortality. Moreover, a graded association was observed between lower FEV1 and FVC %pred, even among never smokers and individuals with normal spirometry at baseline. DISCUSSION: Reduced FEV1 and FVC represent robust risk factors for cardiovascular disease and mortality. The fact that the increased risk was evident also at FEV1 and FVC levels exceeding 80 %pred challenges the contemporary classification of lung function categories and the notion that the entire FEV1- and FVC-range above 80 % of predicted represents a normal lung function.


Cardiovascular Diseases , Spirometry , Humans , Forced Expiratory Volume/physiology , Vital Capacity/physiology , Male , Female , Middle Aged , Spirometry/methods , Cardiovascular Diseases/mortality , Aged , United Kingdom/epidemiology , Adult , Myocardial Infarction/mortality , Myocardial Infarction/physiopathology , Heart Failure/physiopathology , Heart Failure/mortality , Stroke/mortality , Stroke/physiopathology , Risk Factors , Cohort Studies , Proportional Hazards Models
11.
Thorax ; 79(6): 573-580, 2024 May 20.
Article En | MEDLINE | ID: mdl-38514183

BACKGROUND: Airway obstruction is defined by spirometry as a low forced expiratory volume in 1 s (FEV1) to forced vital capacity (FVC) ratio. This impaired ratio may originate from a low FEV1 (classic) or a normal FEV1 in combination with a large FVC (dysanaptic). The clinical implications of dysanaptic obstruction during childhood and adolescence in the general population remain unclear. AIMS: To investigate the association between airway obstruction with a low or normal FEV1 in childhood and adolescence, and asthma, wheezing and bronchial hyperresponsiveness (BHR). METHODS: In the BAMSE (Barn/Child, Allergy, Milieu, Stockholm, Epidemiology; Sweden) and PIAMA (Prevention and Incidence of Asthma and Mite Allergy; the Netherlands) birth cohorts, obstruction (FEV1:FVC ratio less than the lower limit of normal, LLN) at ages 8, 12 (PIAMA only) or 16 years was classified as classic (FEV1

Airway Obstruction , Asthma , Respiratory Sounds , Spirometry , Humans , Child , Forced Expiratory Volume/physiology , Adolescent , Male , Female , Asthma/physiopathology , Asthma/epidemiology , Respiratory Sounds/physiopathology , Airway Obstruction/physiopathology , Vital Capacity/physiology , Sweden/epidemiology , Prevalence , Cross-Sectional Studies , Bronchial Hyperreactivity/physiopathology , Bronchial Hyperreactivity/epidemiology , Netherlands/epidemiology
12.
Respir Physiol Neurobiol ; 324: 104243, 2024 Jun.
Article En | MEDLINE | ID: mdl-38432596

The determination the forced vital capacity (FVC) and the forced expiratory volume in 1 second (FEV1) during spirometry studies, is at the core of the evaluation of the pulmonary function of patients with respiratory diseases. The Global Lung Function Initiative (GLI) offers the most extensive data set of normal lung functions available, which is currently used to determine the average expected/predicted FEV1 and FVC (predV), and their lower limit of normal (LLN, 5th percentile) at any given height and age for women and men. These prediction equations are currently expressed in a rather complex form: predV = exp [p+ (a x Ln (height) + (n x Ln (age)) + spline] and LLN = exp(Ln (predV) + Ln (1 - 1.645 x S x CV)/S); and are currently used to generate interpretations in commercialized spinographic system. However, as shown in this paper, these equations contain physiological and fundamental allometric information on lung volumes that become obvious when rewriting mean predicted values as a "simple" power function of height and LLN as a percentage of the mean predicted values. We therefore propose to present the equations of prediction obtained from the GLI data using simplified expressions in adults (18-95 years old) to reveal some of their physiological and allometric meaning. Indeed, when predicted FEV1 and FVC (predV) were expressed under the form predV= αx heightax b(age), the resulting exponent (a) ranges between 2 and 3, transforming the one dimension of a length (size) into a volume, akin to the third-order power (cubic) function of height historically used to predict lung volumes. Only one function, b (age), is necessary to replace all the factors related to age, including the tables of discrete data of spline functions original equations. Similarly, LLN can be expressed as LLN = c (age) xpredV to become a simple percentage of the predicted values, as a function of age. The equations with their respective new polynomial functions were validated in 52,764 consecutive spirometry tests performed in 2022 in 22,612 men and 30,152 women at the Cleveland Clinic. Using these equations, it become obvious that for both women and men, FEV1/FVC ratio decreases with the size as the exponent of the power function of height is lower for FEV1 than FVC. We conclude that rewriting the GLI predicted equations with simpler formulations restitutes to the GLI data some of their original allometric meaning, without altering the accuracy of their prediction.


Lung , Adult , Male , Humans , Female , Adolescent , Young Adult , Middle Aged , Aged , Aged, 80 and over , Forced Expiratory Volume/physiology , Reference Values , Lung/physiology , Vital Capacity/physiology , Respiratory Function Tests/methods , Spirometry/methods
13.
J Appl Physiol (1985) ; 136(5): 1144-1156, 2024 May 01.
Article En | MEDLINE | ID: mdl-38420676

Smaller mean airway tree caliber is associated with airflow obstruction and chronic obstructive pulmonary disease (COPD). We investigated whether airway tree caliber heterogeneity was associated with airflow obstruction and COPD. Two community-based cohorts (MESA Lung, CanCOLD) and a longitudinal case-control study of COPD (SPIROMICS) performed spirometry and computed tomography measurements of airway lumen diameters at standard anatomical locations (trachea-to-subsegments) and total lung volume. Percent-predicted airway lumen diameters were calculated using sex-specific reference equations accounting for age, height, and lung volume. The association of airway tree caliber heterogeneity, quantified as the standard deviation (SD) of percent-predicted airway lumen diameters, with baseline forced expired volume in 1-second (FEV1), FEV1/forced vital capacity (FEV1/FVC) and COPD, as well as longitudinal spirometry, were assessed using regression models adjusted for age, sex, height, race-ethnicity, and mean airway tree caliber. Among 2,505 MESA Lung participants (means ± SD age: 69 ± 9 yr; 53% female, mean airway tree caliber: 99 ± 10% predicted, airway tree caliber heterogeneity: 14 ± 5%; median follow-up: 6.1 yr), participants in the highest quartile of airway tree caliber heterogeneity exhibited lower FEV1 (adjusted mean difference: -125 mL, 95%CI: -171,-79), lower FEV1/FVC (adjusted mean difference: -0.01, 95%CI: -0.02,-0.01), and higher odds of COPD (adjusted odds ratio: 1.42, 95%CI: 1.01-2.02) when compared with the lowest quartile, whereas longitudinal changes in FEV1 and FEV1/FVC did not differ significantly. Observations in CanCOLD and SPIROMICS were consistent. Among older adults, airway tree caliber heterogeneity was associated with airflow obstruction and COPD at baseline but was not associated with longitudinal changes in spirometry.NEW & NOTEWORTHY In this study, by leveraging two community-based samples and a case-control study of heavy smokers, we show that among older adults, airway tree caliber heterogeneity quantified by CT is associated with airflow obstruction and COPD independent of age, sex, height, race-ethnicity, and dysanapsis. These observations suggest that airway tree caliber heterogeneity is a structural trait associated with low baseline lung function and normal decline trajectory that is relevant to COPD.


Lung , Pulmonary Disease, Chronic Obstructive , Spirometry , Humans , Female , Male , Aged , Pulmonary Disease, Chronic Obstructive/physiopathology , Spirometry/methods , Lung/physiopathology , Lung/diagnostic imaging , Forced Expiratory Volume/physiology , Case-Control Studies , Vital Capacity/physiology , Middle Aged , Longitudinal Studies , Tomography, X-Ray Computed/methods , Airway Obstruction/physiopathology , Aged, 80 and over
14.
Respirology ; 29(6): 471-478, 2024 Jun.
Article En | MEDLINE | ID: mdl-38403987

BACKGROUND AND OBJECTIVE: Prognostic indices have been developed to predict various outcomes, including mortality. These indices and hazard ratios may be difficult for patients to understand. We investigated the association between smoking, respiratory symptoms and lung function with remaining life expectancy (LE) in older adults. METHODS: Data were from the 2004/05 English Longitudinal Study of Ageing (ELSA) (n = 8930), participants aged ≥50-years, with mortality data until 2012. Respiratory symptoms included were chronic phlegm and shortness of breath (SOB). The association between smoking, respiratory symptoms and FEV1/FVC, and remaining LE was estimated using a parametric survival function and adjusted for covariates including age at baseline and sex. RESULTS: The extent to which symptoms and FEV1/FVC predicted differences in remaining LE varied by smoking. Compared to asymptomatic never smokers with normal lung function (the reference group), in never smokers, only those with SOB had a significant reduction in remaining LE. In former and current smokers, those with respiratory symptoms had significantly lower remaining LE compared to the reference group if they had FEV1/FVC <0.70 compared to those with FEV1/FVC ≥0.70. Males aged 50-years, current smokers with SOB and FEV1/FVC <0.70, had a remaining LE of 19.2 (95%CI: 16.5-22.2) years, a decrease of 8.1 (5.3-10.8) years, compared to the reference group. CONCLUSION: Smoking, respiratory symptoms and FEV1/FVC are strongly associated with remaining LE in older people. The use of remaining LE to communicate mortality risk to patients needs further investigation.


Aging , Life Expectancy , Smoking , Humans , Male , Female , Middle Aged , Longitudinal Studies , Smoking/adverse effects , Smoking/epidemiology , Aged , Aging/physiology , Forced Expiratory Volume/physiology , Lung/physiopathology , Dyspnea/physiopathology , Vital Capacity/physiology , Respiratory Function Tests
15.
Rev. int. med. cienc. act. fis. deporte ; 24(94): 107-118, jan. 2024. tab, graf
Article En | IBECS | ID: ibc-230946

Purpose: College students are the future of a nation; education community needs to prioritize students' health issues. Method:This article compares the measurement data of cardiovascular function, bone density, body composition, and physical fitness between female college students in the exercise group and the control group before and after 12 weeks, in order to explore the impact of basketball on human morphology and physiological function. This can provide more methods and scientific basis for students to enhance their physical fitness and promote physical health. Results: The exercise group's lung capacity after the experimentwas 2517ml, and the control group's lung capacity after the experiment was 2357ml.Conclusion: This article has important practical significance in promoting the improvement of college students' physical fitness, and can also provide reference for ordinary higher education institutions to offer various sports courses (AU)


Humans , Young Adult , Basketball , Student Health , Cardiorespiratory Fitness/physiology , Vital Capacity/physiology , Universities
16.
J Infect Dis ; 229(6): 1750-1758, 2024 Jun 14.
Article En | MEDLINE | ID: mdl-38271235

BACKGROUND: The long-term pulmonary sequelae of mild coronavirus disease 2019 (COVID-19) remains unknown. In this study, we aimed to characterize lung function trajectories in individuals with mild COVID-19 from preinfection to 2 years postinfection. METHODS: We reinvited participants 2 years after infection from our matched cohort study of the Copenhagen General Population who had initially been examined 5.4 months after infection. We repeated lung tests and questionnaires. Linear mixed models were used to estimate dynamics in lung volumes in individuals with COVID-19 patients versus uninfected controls over two intervals: from pre-infection to 6 months postinfection and 6 months postinfection to 2 years postinfection. RESULTS: 52 individuals (48.6%) attended the 2-year examination at median 1.9 years (interquartile range, 1.8-2.4) after COVID-19, all with mild infection. Individuals with COVID-19 had an adjusted excess decline in forced expiratory volume in 1 second (FEV1) of 13.0 mL per year (95% confidence interval [CI], -23.5 to -2.5; P = .02) from before infection to 6 months after infection compared to uninfected controls. From 6 to 24 months after infection, they had an excess decline of 7.5 mL per year (95% CI, -25.6-9.6; P = .40). A similar pattern was observed for forced vital capacity (FVC). Participants had a mean increase in diffusing capacity for carbon monoxide (DLco) of 3.33 (SD 7.97) between the 6- and 24-month examination. CONCLUSIONS: Our results indicate that mild COVID-19 infection affects lung function at the time of infection with limited recovery 2 years after infection.


COVID-19 , Lung , Respiratory Function Tests , SARS-CoV-2 , Humans , COVID-19/physiopathology , Male , Female , Middle Aged , Lung/physiopathology , Adult , Follow-Up Studies , Forced Expiratory Volume , Denmark/epidemiology , Aged , Cohort Studies , Vital Capacity/physiology
17.
BMC Pulm Med ; 24(1): 44, 2024 Jan 20.
Article En | MEDLINE | ID: mdl-38245665

BACKGROUND: In tobacco-exposed persons with preserved spirometry (active smoking or secondhand smoke [SHS] exposure), air trapping can identify a subset with worse symptoms and exercise capacity. The physiologic nature of air trapping in the absence of spirometric airflow obstruction remains unclear. The aim of this study was to examine the underlying pathophysiology of air trapping in the context of preserved spirometry and to determine the utility of bronchodilators in SHS tobacco-exposed persons with preserved spirometry and air trapping. METHODS: We performed a double-blinded placebo-controlled crossover randomized clinical trial in nonsmoking individuals at risk for COPD due to exposure to occupational SHS who had preserved spirometry and air trapping defined as either a residual volume-to-total lung capacity ratio (RV/TLC) > 0.35 or presence of expiratory flow limitation (EFL, overlap of tidal breathing on maximum expiratory flow-volume loop) on spirometry at rest or during cardiopulmonary exercise testing (CPET). Those with asthma or obesity were excluded. Participants underwent CPET at baseline and after 4-week trials of twice daily inhalation of 180 mcg of albuterol or placebo separated by a 2-week washout period. The primary outcome was peak oxygen consumption (VO2) on CPET. Data was analyzed by both intention-to-treat and per-protocol based on adherence to treatment prescribed. RESULTS: Overall, 42 participants completed the entire study (66 ± 8 years old, 91% female; forced expiratory volume in 1 s [FEV1] = 103 ± 16% predicted; FEV1 to forced vital capacity [FVC] ratio = 0.75 ± 0.05; RV/TLC = 0.39 ± 0.07; 85.7% with EFL). Adherence was high with 87% and 93% of prescribed doses taken in the treatment and placebo arms of the study, respectively (P = 0.349 for comparison between the two arms). There was no significant improvement in the primary or secondary outcomes by intention-to-treat or per-protocol analysis. In per-protocol subgroup analysis of those with RV/TLC > 0.35 and ≥ 90% adherence (n = 27), albuterol caused an improvement in peak VO2 (parameter estimate [95% confidence interval] = 0.108 [0.014, 0.202]; P = 0.037), tidal volume, minute ventilation, dynamic hyperinflation, and oxygen-pulse (all P < 0.05), but no change in symptoms or physical activity. CONCLUSIONS: Albuterol may improve exercise capacity in the subgroup of SHS tobacco-exposed persons with preserved spirometry and substantial air trapping. These findings suggest that air trapping in pre-COPD may be related to small airway disease that is not considered significant by spirometric indices of airflow obstruction.


Albuterol , Pulmonary Disease, Chronic Obstructive , Aged , Female , Humans , Male , Middle Aged , Albuterol/pharmacology , Exercise , Forced Expiratory Volume , Lung , Pulmonary Disease, Chronic Obstructive/epidemiology , Spirometry/methods , Vital Capacity/physiology
18.
West Afr J Med ; 40(10): 1029-1034, 2023 Oct 31.
Article En | MEDLINE | ID: mdl-37906250

BACKGROUND: Lung function tests (LFTs) are a collection of clinical examinations used to assess lung function and monitor potential declines in the lungs, respiratory muscles, and chest wall's mechanical performance. This cross-sectional study aimed to identify the relation of age and height to lung function. MATERIAL AND METHODS: The study was conducted at AlHussein Medical City, 70 adult male subjects were enrolled in the study. All subjects were screened physically to ensure that they were normal and there were no respiratory disorders that could affect the lung function. Age and height were taken for these subjects, forced vital capacity (FVC), FEV1 (Forced expiratory volume in first second) as well as FEV1 /FVC ratio were measured. RESULTS: The results of the study showed that the average values of FVC and FEV1 were 4.75 and 3.88 respectively. There was a significant negative correlation observed between age and FVC (r=0.48), FEV1 (r= 0.6). Also there was a significant positive correlation noticed between Height and FVC (r = 0.62), FEV1 (r =0.69). There was a very high correlation evidenced between FEV1 and FVC, the relation between FEV1 and FVC is practically height and age-independent. CONCLUSION: Our study highlights a great interest in the study of the relation between age, height, and lung function. The study also creates simple and convenience equations that can be used for reference standards in clinical practice to give reasonable theoretical values for a large sector of the population.


CONTEXTE: Les tests de fonction pulmonaire (TFP) regroupent une série d'examens cliniques utilisés pour évaluer la fonction pulmonaire et surveiller d'éventuelles réductions des performances mécaniques des poumons, des muscles respiratoires et de la paroi thoracique. Cette étude transversale visait à déterminer la relation entre l'âge et la taille et la fonction pulmonaire. MATÉRIEL ET MÉTHODES: L'étude a été menée à la ville médicale Al-Hussein. Soixante-dix sujets masculins adultes ont été inscrits à l'étude. Tous les sujets ont été soumis à un examen physique pour s'assurer qu'ils étaient en bonne santé et ne présentaient pas de troubles respiratoires susceptibles d'affecter la fonction pulmonaire. L'âge et la taille de ces sujets ont été relevés, et la capacité vitale forcée (CVF), le VEMS (volume expiratoire maximal en une seconde) ainsi que le rapport VEMS/CVF ont été mesurés. RÉSULTATS: Les résultats de l'étude ont montré que les valeurs moyennes de la CVF et du VEMS étaient respectivement de 4,75 et 3,88. Une corrélation négative significative a été observée entre l'âge et la CVF (r = 0,48) ainsi qu'entre l'âge et le VEMS (r = 0,6). De plus, une corrélation positive significative a été remarquée entre la taille et la CVF (r = 0,62) ainsi qu'entre la taille et le VEMS (r = 0,69). Une corrélation très élevée a été mise en évidence entre le VEMS et la CVF, la relation entre le VEMS et la CVF est pratiquement indépendante de la taille et de l'âge. CONCLUSION: Notre étude met en évidence un intérêt particulier pour l'étude de la relation entre l'âge, la taille et la fonction pulmonaire. L'étude crée également des équations simples et pratiques qui peuvent être utilisées comme référence dans la pratique clinique pour fournir des valeurs théoriques raisonnables pour une grande partie de la population. Mots-clés: VEMS, CVF, VEMS/CVF, Spirométrie.


Lung , Adult , Humans , Male , Forced Expiratory Volume/physiology , Cross-Sectional Studies , Spirometry/methods , Respiratory Function Tests , Vital Capacity/physiology
19.
Sci Rep ; 13(1): 17247, 2023 10 11.
Article En | MEDLINE | ID: mdl-37821579

Identification of ventilatory constraint is a key objective of clinical exercise testing. Expiratory flow-limitation (EFL) is a well-known type of ventilatory constraint. However, EFL is difficult to measure, and commercial metabolic carts do not readily identify or quantify EFL. Deep machine learning might provide a new approach for identifying EFL. The objective of this study was to determine if a convolutional neural network (CNN) could accurately identify EFL during exercise in adults in whom baseline airway function varied from normal to mildly obstructed. 2931 spontaneous exercise flow-volume loops (eFVL) were placed within the baseline maximal expiratory flow-volume curves (MEFV) from 22 adults (15 M, 7 F; age, 32 yrs) in whom lung function varied from normal to mildly obstructed. Each eFVL was coded as EFL or non-EFL, where EFL was defined by eFVLs with expired airflow meeting or exceeding the MEFV curve. A CNN with seven hidden layers and a 2-neuron softmax output layer was used to analyze the eFVLs. Three separate analyses were conducted: (1) all subjects (n = 2931 eFVLs, [GRALL]), (2) subjects with normal spirometry (n = 1921 eFVLs [GRNORM]), (3) subjects with mild airway obstruction (n = 1010 eFVLs, [GRLOW]). The final output of the CNN was the probability of EFL or non-EFL in each eFVL, which is considered EFL if the probability exceeds 0.5 or 50%. Baseline forced expiratory volume in 1 s/forced vital capacity was 0.77 (94% predicted) in GRALL, 0.83 (100% predicted) in GRNORM, and 0.69 (83% predicted) in GRLOW. CNN model accuracy was 90.6, 90.5, and 88.0% in GRALL, GRNORM and GRLOW, respectively. Negative predictive value (NPV) was higher than positive predictive value (PPV) in GRNORM (93.5 vs. 78.2% for NPV vs. PPV). In GRLOW, PPV was slightly higher than NPV (89.5 vs. 84.5% for PPV vs. NPV). A CNN performed very well at identifying eFVLs with EFL during exercise. These findings suggest that deep machine learning could become a viable tool for identifying ventilatory constraint during clinical exercise testing.


Exhalation , Lung , Humans , Adult , Lung/physiology , Exhalation/physiology , Forced Expiratory Volume/physiology , Exercise/physiology , Vital Capacity/physiology , Pyrin
20.
J Breath Res ; 18(1)2023 Nov 03.
Article En | MEDLINE | ID: mdl-37875103

Pulmonary function is usually assessed by measuring Vital Capacity (VC) using equipment such as a spirometer or ventilometer, but these are not always available to the population, as they are relatively expensive tests, difficult to transport and require trained professionals. However, the single breath counting technique (SBCT) appears as a possible alternative to respiratory function tests, to help in the pathophysiological understanding of lung diseases. The objective is to verify the applicability of the SBCT as a parameter for evaluating VC. This is a systematic review registered in the International Prospective Register of Systematic Reviews (CRD42023383706) and used for PubMed®, Scientific Electronic Library Online, LILACS, EMBASE, and Web of Science databases of articles published until January 2023. Methodological quality regarding the risk of bias was assessed using Quality Assessment of Diagnostic Accuracy Studies-2 and National Institutes of Health tools. Eleven of a total of 574 studies were included, of these, nine showed a correlation between VC and SBCT (weak in healthy, moderate in neuromuscular and strong in hospitalized patients). One study of hospitalized patients accurately identified a count value of 21 for a VC of 20 ml kg-1(Sensitivity = 94% and Specificity = 77%), and another estimated a count lower than 41 for a VC below 80% of predicted in patients with neuromuscular dystrophy (Sensitivity = 89% and Specificity = 62%), and another showed good intra and inter-examiner reproducibility in young, adult, and elderly populations. A meta-analysis of three studies showed a moderate correlation in subjects with neuromuscular diseases (r= 0.62, 95% CI = 0.52-0.71,p< 0.01). A high risk of bias was identified regarding the justification of the sample size and blinding of the evaluators. SBCT has been presented as an alternative to assess VC in the absence of specific equipment. There is a clear relationship between SBCT and VC, especially in neuromuscular and hospitalized individuals. New validation studies conducted with greater control of potential bias risks are necessary.


Breath Tests , Lung , United States , Adult , Humans , Aged , Reproducibility of Results , Vital Capacity/physiology , Spirometry
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