BACKGROUND: Despite the increasing popularity and use of Global Lung Function Initiative (GLI) spirometric reference equations, the appropriateness of the race-specific and race-neutral GLI spirometric reference models among the Indian population has not been systematically investigated.
METHODS: In this cross-sectional analysis, we used spirometric measurements of 1123 healthy Indian adults (≥18 years of age). We computed reference values and z-scores for forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and FEV1/FVC from race-specific and race-neutral GLI reference equations as well as from a widely used Indian reference equation. We studied heterogeneity between GLI equations and the Indian equations using Bland-Altman analysis, and the differences between the reference and observed values were compared using the Friedman test.
RESULTS: In Bland-Altman analysis, significant heterogeneity in FVC and FEV1 between race-specific and Indian equations was observed (bias: 10.4 % and 14.1 %, respectively), with less bias for FEV1/FVC (3.76 %). The race-neutral equations showed almost similar bias (9.8 %, 13.8 %, and 3.8 % for FVC, FEV1, and FEV1/FVC, respectively). Median differences in race-specific reference values from observed values for FVC and FEV1 were 0.49L and 0.44L, respectively, decreasing slightly with race-neutral equations (0.46L and 0.43L) whereas Indian models showed minimal differences (FVC: 0.10L, FEV1: 0.05L). Z-scores for FVC and FEV1 were significantly different between race-specific and race-neutral GLI equations, and both differed from Indian equations.
CONCLUSIONS: Both race-specific and race-neutral GLI reference equations are significantly different from the Indian equations, which underscores the importance of determining the suitability of global reference models before being used indiscriminately.

BACKGROUND: While the beneficial effects of physical fitness on general health are well-documented, the specific relationship between different types of physical fitness, particularly cardiorespiratory fitness (CRF) and muscular endurance fitness (MEF), and lung function in physically active young adults remains less explored.
OBJECTIVE: This study investigated the relationship between CRF and MEF, and their correlation with lung function in physically active young adults.
METHODS: This cross-sectional study involved a cohort of 1227 physically active young adults without lung diseases. Lung function was assessed using FEV1, FVC, and FEV1/FVC measurements. The 3000-m run was used to assess CRF, and the 2-min push-up and sit-up tests were used to assess MEF. Multivariable linear regression analysis was used to evaluate the relationships between these fitness measures and lung function, adjusting for potential covariates.
RESULTS: Enhanced CRF was associated with superior FEV1 and FVC after adjusting for covariates (β=-.078, p=.015 for FEV1; β=-.086, p=.009 for FVC). Push-ups were positively associated with FEV1 (β=.102, p=.014), but not with FVC. In contrast, sit-ups showed no significant correlation with lung function in the fully adjusted model.
CONCLUSIONS: The study demonstrated a clear association between improved physical fitness and better lung function in physically active young adults, with various exercises showing distinct associations with lung metrics. Notably, push-ups were particularly associated with higher FEV1. A future prospective study is necessary to determine whether routine exercises, such as push-ups, might lead to greater lung function.

The Taihangshan-Yanshan region (TYR) is an important ecological barrier area for Beijing-Tianjin-Hebei, and the effectiveness of its ecological restoration and protection is of great significance to the ecological security pattern of North China. Based on the FVC data from 2000 to 2021, residual analysis, parametric optimal geodetector technique (OPGD) and multi-scale geographically weighted regression analysis (MGWR) were used to clarify the the multivariate driving mechanism of the evolution of FVC in the TYR. Results show that: (1) FVC changes in the TYR show a slowly fluctuating upward trend, with an average growth rate of 0.02/10a, and a spatial pattern of \"high in the northwest and low in the southeast\"; more than half of the FVC increased during the 22-year period. (2) The results of residual analysis showed that the effects of temperature and precipitation on FVC were very limited, and a considerable proportion (80.80% and 76.78%) of the improved and degraded areas were influenced by other factors. (3) The results of OPGD showed that the main influencing factors of the spatial differentiation of FVC included evapotranspiration, surface temperature, land use type, nighttime light intensity, soil type, and vegetation type (q > 0.2); The explanatory rates of the two-factor interactions were greater than those of the single factor, which showed either nonlinear enhancement or bifactorial enhancement, among which, the interaction of evapotranspiration with mean air and surface temperature has the strongest effect on the spatial and temporal evolution of FVC (q = 0.75). Surface temperature between 4.98 and 10.4 °C, evapotranspiration between 638 and 762 mm/a, and nighttime light between 1.96 and 7.78 lm/m2 favoured an increase in vegetation cover, and vegetation developed on lysimetric soils was more inclined to be of high cover. (4) The correlation between each variable and FVC showed different performance, GDP, elevation, slope and FVC showed significant positive correlation in most regions, while population size, urban population proportion, GDP proportion of primary and secondary industries, and nighttime light intensity all showed negative correlation with FVC to different degrees. The results can provide data for formulating regional environmental protection and restoration policies.

We aimed to determine the prevalence and outcomes for forced vital capacity percent predicted (FVCpp) decline among patients with rheumatoid arthritis-associated interstitial lung disease (RA-ILD). We identified patients with RA-ILD in the Mass General Brigham Healthcare system. RA-ILD diagnosis was determined by review of high-resolution computed tomography (HRCT) imaging by up to three thoracic radiologists. We abstracted FVCpp measurements, covariates, lung transplant, and ILD-related death from the medical record. We employed a relative FVCpp decline cutoff of > 10% within 24 months. We also used a group-based trajectory model to obtain patterns of change from RA-ILD diagnosis. We then assessed for associations of each FVC decline definition with risk of lung transplant or ILD-related death using multivariable logistic regression. We analyzed 172 patients with RA-ILD with a median of 6 FVCpp measurements per patient over 6.5 years of follow-up (mean age 62.2 years, 36% male). There were seven (4%) lung transplants and 44 (26%) ILD-related deaths. Ninety-eight (57%) patients had relative decline of FVCpp by > 10% in 24 months. We identified three trajectory groups of FVCpp change: rapidly declining (n = 24/168 [14%]), slowly declining (n = 90/168 [54%]), and stable/improving (n = 54/168 [32%]). The rapidly declining group and FVCpp > 10% had adjusted odds ratios (aOR) for lung transplant/ILD-related death of 19.2 (95%CI 4.9 to 75.5) and 2.8 (95%CI 1.3 to 6.1) respectively. Over half of patients with RA-ILD had declining FVCpp. The different trajectory patterns demonstrate the importance of FVC monitoring for identifying patients at the highest risk of poor outcomes. Key Points • Over half of patients with RA-ILD had declining FVCpp over a median of 6.5 years of follow-up. • The rapidly declining FVCpp trajectory group had stronger associations with lung transplant and ILD-related death compared to those with FVCpp decline by > 10%. • Clinicians can employ FVC monitoring to proactively treat patients who are at risk of poor outcomes.

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.

UNASSIGNED: Diaphragmatic ultrasound is increasingly used to assess patients with Chronic Obstructive Pulmonary Disease (COPD). The present study aims to investigate diaphragmatic dysfunction in COPD patients through a systematic review and meta-analysis.
UNASSIGNED: In December 2022,The researchers studied four international databases such as Medline/PubMed, ProQuest, ISI/WOS, and Scopus. Joanna Briggs Institute (JBI) checklist was used to review and control the quality of articles.
UNASSIGNED: Finally, 6 articles were included in the analysis. Based on the meta-analysis results, forced expiratory volume (FEV1) was significantly lower in COPD patients compared to the control group (Hedges\'s g= -2.99, 95 % CI -4.78, -1.19; P =0.001). Forced vital capacity (FVC) was significantly lower in COPD patients compared to the control group (Hedges\'s g= -1.12, 95 % CI -1.91, - 0.33; P =0.005). COPD patients had significantly lower FEV1/FVC than the control group (Hedges\'s g= -1.57, 95 % CI -2.33, -0.81; P <0.001).
UNASSIGNED: The present study showed that the diaphragm ultrasound (DUS) method could identify the difference in FEV1, FVC, and FEV1/FVC indices in two groups of COPD patients and healthy people.

UNASSIGNED: This study aims to evaluate the association between socioeconomic conditions and the lung function of children below 18 years old.
UNASSIGNED: Systematic review.
UNASSIGNED: PRISMA guidelines were followed to browse relevant studies from 2013 to 2023. Data from the included studies were extracted after the Newcastle-Ottawa risk of bias tool was applied.
UNASSIGNED: Forced expiratory volume in the first second (FEV1) liters.
UNASSIGNED: 20 papers with 89,619 participants were included. Logistic regression model for FEV1 based on multiple SES indices, suggested a positive association between lower respiratory function and a lower SES, with an interquartile odds ratio (OR) of 1.67 (95% CI 1.03-1.34).
UNASSIGNED: Children from a lower socioeconomic status (SES) do exhibit lower lung function and addressing the causes of this can contribute to developing preventive public health strategies.
UNASSIGNED: Lack of appropriate reference values and varied indicators of socioeconomic status in the studies contributed to significant statistical differences.
UNASSIGNED: CRD 42020197658.

BACKGROUND: 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.
CONCLUSIONS: 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.

The association between newborn DNA methylation (DNAm) and asthma acquisition (AA) during adolescence has been suggested. Lung function (LF) has been shown to be associated with asthma risk and its severity. However, the role of LF in the associations between DNAm and AA is unclear, and it is also unknown whether the association between DNAm and AA is consistent with that between DNAm and LF. We address this question through assessing newborn epigenetic features of preadolescence LF and of AA during adolescence, along with their biological pathways and processes. Our study\'s primary medical significance lies in advancing the understanding of asthma\'s early life origins. By investigating epigenetic markers in newborns and their association with lung function in preadolescence, we aim to uncover potential early biomarkers of asthma risk. This could facilitate earlier detection and intervention strategies. Additionally, exploring biological pathways linking early lung function to later asthma development can offer insights into the disease\'s pathogenesis, potentially leading to novel therapeutic targets.
METHODS: The study was based on the Isle of Wight Birth cohort (IOWBC). Female subjects with DNAm data at birth and with no asthma at age 10 years were included (n = 249). The R package ttScreening was applied to identify CpGs potentially associated with AA from 10 to 18 years and with LF at age 10 (FEV1, FVC, and FEV1/FVC), respectively. Agreement in identified CpGs between AA and LF was examined, along with their biological pathways and processes via the R function gometh. We tested the findings in an independent cohort, the Avon Longitudinal Study of Parents and Children (ALSPAC), to examine overall replicability.
RESULTS: In IOWBC, 292 CpGs were detected with DNAm associated with AA and 1517 unique CpGs for LF (514 for FEV1, 436 for FVC, 408 for FEV1/FVC), with one overlapping CpG, cg23642632 (NCKAP1) between AA and LF. Among the IOWBC-identified CpGs, we further tested in ALSPAC and observed the highest agreement between the two cohorts in FVC with respect to the direction of association and statistical significance. Epigenetic enrichment analyses indicated non-specific connections in the biological pathways and processes between AA and LF.
CONCLUSIONS: The present study suggests that FEV1, FVC, and FEV1/FVC (as objective measures of LF) and AA (incidence of asthma) are likely to have their own specific epigenetic features and biological pathways at birth. More replications are desirable to fully understand the complexity between DNAm, lung function, and asthma acquisition.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder affecting the first and second motor neurons. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) have conventionally served as indicators of respiratory muscle strength. Recently, FEV1Q (FEV1 divided by the sex-specific first percentile values of absolute FEV1 in adults with lung disease) has been suggested as a predictor of mortality. While FVC has been utilized as a prognostic factor, FEV1Q has not yet been examined.
METHODS: This retrospective unicenter study evaluated FEV1Q as a predictor of mortality in ALS patients, comparing its predictive efficacy with other measurements, including FEV1, FVC, sniff nasal inspiratory pressure, and maximal inspiratory pressure. The study utilized univariate analysis for each variable employing the Cox proportional hazards model to determine the statistical significance and predictive power of each measurement.
RESULTS: Forty-five patients were included, female predominant (60%) and an average age at diagnosis of 69.2 ± 11 years. Almost all (95%) met the criteria for non-invasive ventilation (NIV) and initiated (93%) during the study period, a mean of 137 days after diagnosis. The mortality rate observed was 57%, occurring at a median of 398 days post-diagnosis. On average, patients underwent 1.7 pulmonary function tests, revealing a decline in various parameters, including FEV1, FEV1Q, and FVC. However, only FEV1Q was a statistically significant predictor of mortality (p < 0.0083) in a Cox regression analysis. A negative coefficient for FEV1Q indicated that higher values were associated with a reduced mortality risk, with an average FEV1Q of 2.68 observed at the time of death.
CONCLUSIONS: FEV1Q emerged as the only statistically significant predictor of mortality among the evaluated respiratory measurements in ALS patients. This study is the first to focus on applying FEV1Q in the clinical evaluation of ALS, marking an initial step in understanding its potential role in patient follow-up. However, further studies are needed before these findings can be incorporated into clinical practice.