Nonlinear relationship between visceral adiposity index and lung function: a population-based study

The negative association between weight-adjusted-waist index and lung functions: NHANES 2007-2012

Obesity is a common public health issue worldwide, and its negative impact on lung function has garnered widespread attention. This study sought to investigate the possible association between a new obesity metric, the weight-adjusted waist index (WWI), and lung functions, providing a basis for the monitoring and protection of lung functions. We conducted a cross-sectional evaluation, analyzing data from adults in the U.S. gathered through the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2012. To explore the correlation between WWIs and lung functions, we utilized a multivariate logistic regression model with appropriate weighting to ensure accuracy. Smooth curve fitting also helped to confirm the linear nature of this relationship. Subgroup analyses were conducted to confirm the uniformity and dependability of the results. Our study included data from 13,805 adults in the United States. Multivariate linear regression analysis revealed that, in the fully adjusted model, higher WWIs were negatively correlated with forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), FEV1/FVC, peak expiratory flow rate (PEF), and forced expiratory flow rate (FEF) 25%-75% (β = -0.63; 95% confidence interval [CI] [-0.71, -0.55]; β = -0.55; 95% CI [-0.62, -0.48]; β = -0.02; 95% CI [-0.03, -0.01]; β = -1.44; 95% CI [-1.65, -1.23]; β = -0.52; 95% CI [-0.65, -0.39], respectively). Additionally, when analyzing the WWI as a categorical variable, a significant downward trend in the FVC, FEV1, PEF, and FEF 25%-75% was observed from Q2 to Q4 as the WWI increased (trend P < 0.05). Subgroup analysis showed stronger associations between WWI and lung functions, particularly among younger, non-Hispanic white, male participants, and current smokers. Our results indicate that elevated WWI is strongly associated with declining lung functions, demonstrating the importance of long-term monitoring and tracking of WWIs.

Body composition impacts outcome of bronchoscopic lung volume reduction in patients with severe emphysema: a fully automated CT-based analysis

Chronic Obstructive Pulmonary Disease (COPD) is characterized by progressive and irreversible airflow limitation, with individual body composition influencing disease severity. Severe emphysema worsens symptoms through hyperinflation, which can be relieved by bronchoscopic lung volume reduction (BLVR). To investigate how body composition, assessed through CT scans, impacts outcomes in emphysema patients undergoing BLVR. Fully automated CT-based body composition analysis (BCA) was performed in patients with end-stage emphysema receiving BLVR with valves. Post-interventional muscle and adipose tissues were quantified, body size-adjusted, and compared to baseline parameters. Between January 2015 and December 2022, 300 patients with severe emphysema underwent endobronchial valve treatment. Significant improvements were seen in outcome parameters, which were defined as changes in pulmonary function, physical performance, and quality of life (QoL) post-treatment. Muscle volume remained stable (1.632 vs. 1.635 for muscle bone adjusted ratio (BAR) at baseline and after 6 months respectively), while bone adjusted adipose tissue volumes, especially total and pericardial adipose tissue, showed significant increase (2.86 vs. 3.00 and 0.16 vs. 0.17, respectively). Moderate to strong correlations between bone adjusted muscle volume and weaker correlations between adipose tissue volumes and outcome parameters (pulmonary function, QoL and physical performance) were observed. Particularly after 6-month, bone adjusted muscle volume changes positively corresponded to improved outcomes (ΔForced expiratory volume in 1 s [FEV1], r = 0.440; ΔInspiratory vital capacity [IVC], r = 0.397; Δ6Minute walking distance [6MWD], r = 0.509 and ΔCOPD assessment test [CAT], r = -0.324; all p < 0.001). Group stratification by bone adjusted muscle volume changes revealed that groups with substantial muscle gain experienced a greater clinical benefit in pulmonary function improvements, QoL and physical performance (ΔFEV1%, 5.5 vs. 39.5; ΔIVC%, 4.3 vs. 28.4; Δ6MWDm, 14 vs. 110; ΔCATpts, -2 vs. -3.5 for groups with ΔMuscle, BAR% < -10 vs. > 10, respectively). BCA results among patients divided by the minimal clinically important difference for forced expiratory volume of the first second (FEV1) showed significant differences in bone-adjusted muscle and intramuscular adipose tissue (IMAT) volumes and their respective changes after 6 months (ΔMuscle, BAR% -5 vs. 3.4 and ΔIMAT, BAR% -0.62 vs. 0.60 for groups with ΔFEV1 ≤ 100 mL vs > 100 mL). Altered body composition, especially increased muscle volume, is associated with functional improvements in BLVR-treated patients.

Identification of Genes Related to Endoplasmic Reticulum Stress (ERS) in Chronic Obstructive Pulmonary Disease (COPD) and Clinical Validation

Objective

Endoplasmic reticulum stress (ERS) is key in chronic obstructive pulmonary disease (COPD) incidence and progression. This study aims to identify potential ERS-related genes in COPD through bioinformatics analysis and clinical experiments.

Methods

We first obtained a COPD-related mRNA expression dataset (GSE38974) from the Gene Expression Omnibus (GEO) database. The R software was then used to identify potential differentially expressed genes (DEGs) of COPD-related ERS (COPDERS). Subsequently, the identified DEGs were subjected to protein-protein interaction (PPI), correlation, Gene Ontology (GO) enrichment, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Following that, qRT-PCR was used to examine the RNA expression of six ERS-related DEGs in blood samples obtained from the COPD and control groups. The genes were also subjected to microRNA analysis. Finally, a correlation analysis was performed between the DEGs and key clinical indicators.

Results

Six ERS-related DEGs (five upregulated and one downregulated) were identified based on samples drawn from 23 COPD patients and nine healthy individuals enrolled in the study. Enrichment analysis revealed multiple ERS-related pathways. The qRT-PCR and mRNA microarray bioinformatics analysis results showed consistent STC2, APAF1, BAX, and PTPN1 expressions in the COPD and control groups. Additionally, hsa-miR-485-5p was identified through microRNA prediction and DEG analysis. A correlation analysis between key genes and clinical indicators in COPD patients demonstrated that STC2 was positively and negatively correlated with eosinophil count (EOS) and lymphocyte count (LYM), respectively. On the other hand, PTPN1 showed a strong correlation with pulmonary function indicators.

Conclusion

Four COPDERS-related key genes (STC2, APAF1, BAX, and PTPN1) were identified through bioinformatics analysis and clinical validation, and the expressions of some genes exhibited a significant correlation with the selected clinical indicators. Furthermore, hsa-miR-485-5p was identified as a potential key target in COPDERS, but its precise mechanism remains unclear.

Association between viral hepatitis and metabolic syndrome in lung function impairment: A Taiwan community-based study

OBJECTIVES

Metabolic syndrome (MetS) and hepatitis C virus (HCV) are associated with a higher risk of impaired pulmonary function (iPF). This study aimed to investigate the relationships among MetS, iPF, and viral hepatitis.

METHODS

This community-based study enrolled participants undergoing annual health check-ups in southern Taiwan between March and December 2019. We performed multivariable logistic regression analyses adjusted for demographics and characteristics to identify the factors associated with iPF.

RESULTS

A total of 2337 participants completed examinations, of whom 928 (39.7%) had iPF. The participants with iPF were elderly (68.8  ±  12.8 years old) and predominately female (63%). MetS increased the risk of iPF (odds ratio (OR) 1.51, 95% confidence interval (CI) 1.27-1.81, p < 0.001). Beyond age (OR 1.03, 95% CI 1.02-1.04) and smoking (OR 1.309, 95% CI 1.004-1.705), female sex (OR 0.74, 95% CI 0.59-0.93) and high education level (OR 0.96, 95% CI 0.94-0.98, p < 0.001) protected against iPF. HCV was not significantly associated with iPF (OR 1.17, 95% CI 0.90-1.52, p  =  0.235) in multivariable analysis. MetS was associated with a higher risk of iPF in the non-HBV/HCV group (OR 1.86, 95% CI 1.54-2.26) and HBV alone group (OR 3.44, 95% CI 1.89-6.28), but not in the HCV alone group (OR 1.02, 95% CI 0.64-1.62).

DISCUSSION

MetS was an independent predictor of iPF, especially the restrictive type, and had different effects in the HBV/non-viral hepatitis and HCV groups. Female sex and education were inversely associated with iPF.

Mediterranean Diet and Lung Function in Adults Current Smokers: A Cross-Sectional Analysis in the MEDISTAR Project

BACKGROUND

Previous studies have shown that adherence to the Mediterranean Diet (MeDi) has a positive impact on lung function in subjects with lung disease. In subjects free of respiratory diseases, but at risk, this association is not yet well established.

METHODS

Based on the reference data from the MEDISTAR clinical trial (Mediterranean Diet and Smoking in Tarragona and Reus; ISRCTN 03.362.372), an observational study was conducted with 403 middle-aged smokers without lung disease, treated at 20 centres of primary care in Tarragona (Catalonia, Spain). The degree of MeDi adherence was evaluated according to a 14-item questionnaire, and adherence was defined in three groups (low, medium, and high). Lung function were assessed by forced spirometry. Logistic regression and linear regression models were used to analyse the association between adherence to the MeDi and the presence of ventilatory defects.

RESULTS

Globally, the pulmonary alteration prevalence (impaired FEV1 and/or FVC) was 28.8%, although it was lower in participants with medium and high adherence to the MeDi, compared to those with a low score (24.2% and 27.4% vs. 38.5%, p = 0.004). Logistic regression models showed a significant and independent association between medium and high adherence to the MeDi and the presence of altered lung patterns (OR 0.467 [95%CI 0.266, 0.820] and 0.552 [95%CI 0.313, 0.973], respectively).

CONCLUSIONS

MeDi adherence is inversely associated with the risk impaired lung function. These results indicate that healthy diet behaviours can be modifiable risk factors to protect lung function and reinforce the possibility of a nutritional intervention to increase adherence to MeDi, in addition to promoting smoking cessation.

Body Composition and COPD: A New Perspective

The proportion of obese or overweight patients in COPD patients is increasing. Although BMI, WC and other easy to measure indicators have been proven to be related to the risk of COPD, they cannot accurately reflect the distribution and changes of body composition, ignoring the body composition (such as fat distribution, muscle content, water content, etc.), the relationship between it and disease risk may be missed. By analyzing the correlation between different body composition indexes and COPD patients, we can provide new research ideas for the prognosis judgment or intervention of COPD disease.

Dose-response relationship between Chinese visceral adiposity index and type 2 diabetes mellitus among middle-aged and elderly Chinese

INTRODUCTION

China has the largest population of diabetic patients (about 116 million) in the world. As a novel model of the fat index for Chinese people, the Chinese visceral adiposity index (CVAI) was considered a reliable indicator to assess the dysfunction of visceral fat. This study aimed to explore the dose-response relationship between CVAI and type 2 diabetes mellitus (T2DM) in the Chinese population, considering CVAI as a continuous/categorical variable.

METHOD

Baseline and follow-up data were collected from waves 2011 and 2015, respectively, of the China Health and Retirement Longitudinal Study (CHARLS). Multivariate logistic regression models were used to explore the relationship between CVAI and T2DM. We built three models to adjust the possible effect of 10 factors (age, gender, education level, location, marital status, smoking status, drinking status, sleep time, systolic blood pressure (SBP), and diastolic blood pressure (DBP)) on the outcome. The restricted cubic splines were used to examine possible non-linear associations and visualize the dose-response relationship between CVAI and T2DM.

RESULTS

A total of 5,014 participants were included, with 602 (12.00%) T2DM patients. The last CVAI quartile group (Q4) presented the highest risk of T2DM (OR, 2.17, 95% CI, 1.67-2.83), after adjusting for all covariates. There was a non-linear (U-shaped) relationship between the CVAI and the risk of T2DM (p for non-linear <0.001) in the restricted cubic spline regression model. CVAI was a risk factor of T2DM when it exceeded 92.49; every interquartile range (IQR) increment in the CVAI was associated with a 57% higher risk of developing T2DM (OR = 1.57, 95% CI = 1.36-1.83) after adjusting for potential confounders. The area under the receiver operating characteristic curve (AUC) (95% confidence interval) for CVAI was 0.623, and the optimal cutoff point was 111.2. There was a significant interaction between CVAI and gender by stratified analysis.

CONCLUSION

CVAI was closely associated with the risk of T2DM and might possibly be a potential marker in predicting T2DM development. The outcome suggested that it might be better to maintain CVAI within an appropriate range.