Body Composition and COPD: A New Perspective

Nutritional Support of Chronic Obstructive Pulmonary Disease

Background: COPD is a heterogenous disease of the respiratory tract caused by diverse genetic factors along with environmental and lifestyle-related effects such as industrial dust inhalation and, most frequently, cigarette smoking. These factors lead to airflow obstruction and chronic respiratory symptoms. Additionally, the increased risk of infections exacerbates airway inflammation in COPD patients. As a consequence of the complex pathomechanisms and difficulty in treatment, COPD is among the leading causes of mortality both in the western countries and in the developing world. Results: The management of COPD is still a challenge for the clinicians; however, alternative interventions such as smoking cessation and lifestyle changes from a sedentary life to moderate physical activity with special attention to the diet may ameliorate patients' health. Here, we reviewed the effects of different dietary components and supplements on the conditions of COPD. Conclusions: COPD patients are continuously exposed to heavy metals, which are commonly present in cigarette smoke and polluted air. Meanwhile, they often experience significant nutrient deficiencies, which affect the detoxification of these toxic metals. This in turn can further disrupt nutritional balance by interfering with the absorption, metabolism, and utilization of essential micronutrients. Therefore, awareness and deliberate efforts should be made to check levels of micronutrients, with special attention to ensuring adequate levels of antioxidants, vitamin D, vitamin K2, magnesium, and iron, as these may be particularly important in reducing the risk of COPD development and limiting disease severity.

Assessment of the Risk of Severe COPD Exacerbations: Balancing Between Fat and Muscle

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Prediction of survival in acute myeloid leukemia patients by extracellular to intracellular water ratio and sarcopenia: development and validation of a novel nomogram

Acute myeloid leukemia (AML) commonly affects the elderly with a poor prognosis. Body water composition analysis provides a new perspective for biomedical research. This study aims to develop and validate a simple nomogram for predicting overall survival (OS) in AML survivors. A total of 291patients were enrolled and randomly divided into a training cohort and an internal validation cohort. The median duration of follow-up was 32.2 months.The LASSO regression was used to screen predictors of survival in the training cohort, and the multivariate Cox model was used to establish a nomogram. The discrimination and calibration of the nomogram were evaluated using the C-index, area under the time-dependent receiver operating characteristic curve (time-dependent AUC), and calibration plots. The net benefits of the nomogram at different threshold probabilities were quantified. Five predictors of AML survival were identified: Age, Extracellular water/Intracellular water (ECW/ICW) ratio, European Leukemia Net Risk, Sarcopenia, and WBC. The nomogram showed good performance in both the training cohort (C-index 0.755, 95% CI 0.728-0.782) and the internal validation cohort (C-index 0.773, 95% CI 0.729 to 0.817). The AUC values for the training cohort were 0.866, 0.849, 0.818, and 0.779 at 12, 24, 36, and 48 months, respectively; the AUC values for the internal validation cohort were 0.799, 0.779, 0.797, and 0.786 at 12, 24, 36, and 48 months, respectively. The calibration curves of the nomogram showed acceptable consistency, and the decision curve analysis indicated higher net benefit in clinical practice. In this study, we developed and validated an easily applicable model to predict OS in AML patients.

Variation of All-Cause Mortality with Fat-Free Mass Index (FFMI) and Fat Mass Index (FMI) in Individuals with Asthma: Results from the NHANES Database Retrospective Cohort Study

BACKGROUND

The relationship between fat-free mass index (FFMI), fat mass index (FMI), and mortality in patients with asthma remains unknown. This study aimed to examine the associations between FFMI and FMI and all-cause mortality in a cohort of American adults diagnosed with asthma.

METHODS

This study included 15,200 adults from NHANES. To assess mortality, we linked participant records to the National Death Index. FMI and FFMI were measured and evaluated using dual-energy X-ray absorptiometry (DXA). Survival differences across quintiles of FFMI and FMI were explored using Kaplan-Meier plots and log-rank tests, with the proportional hazards assumption assessed using Schoenfeld residuals. Cox proportional hazards regression models were used to estimate the hazard ratios (HRs) for mortality associated with FFMI and FMI, adjusting for potential confounders including age, sex, smoking status, physical activity, and other relevant factors. Additionally, stratified analyses based on theoretical considerations were conducted to identify subgroups of individuals exhibiting an elevated risk of mortality. This study also examined the nonlinear relationships between FFMI, FMI, and mortality using restricted cubic splines (RCS).

RESULTS

After a median follow-up of 184 months, 12.11% of individuals had died. Kaplan-Meier plots revealed significant differences in all-cause mortality among patients with asthma across the FFMI and FMI quintiles. Specifically, individuals in the lowest FFMI quintile (Q1, 10.4-16.0, representing the range of FFMI values) exhibited a significantly increased risk of all-cause mortality (HR: 4.63; 95% CI: 1.59, 13.5; p < 0.01). Similarly, elevated risks of all-cause mortality were observed in the upper three quintiles of FMI, with Q3 (4.8-6.1) having an HR of 2.9 (95% CI: 1.20, 7.00; p < 0.05), Q4 (6.2-8.3) having an HR of 3.37 (95% CI: 1.41, 8.03; p < 0.01), and Q5 (8.4-22.8) having an HR of 4.6 (95% CI: 1.31, 16.2; p < 0.05). Moreover, the risk of all-cause mortality increased with increasing FMI and decreasing FFMI (p for non-linearity < 0.001 in both cases). Subgroup analyses further elucidated these associations across different categories. In examining the association between FMI and all-cause mortality among asthma patients across various subgroups, a heightened mortality risk found among males, individuals with medium education levels, medium income levels, and those who consume alcohol.

CONCLUSIONS

The study shows that both high FMI and low FFMI are associated with increased mortality in patients with asthma. These findings underscore the critical role of FMI and FFMI in the health management of asthma patients. Therefore, it is recommended that clinicians proactively monitor and adjust these indices to improve patient prognosis and enhance health outcomes for individuals with asthma..

Assessment of the Relationship Between Genetic Determinants of Obesity, Unhealthy Eating Habits and Chronic Obstructive Pulmonary Disease: A Mendelian Randomisation Study

Background: Clinical studies have shown that the onset and exacerbation of chronic obstructive pulmonary disease (COPD) are related to obesity and dietary behaviours, but the genetic relationship between them is not clear.Aims: To investigate the relationship between the genetic determinants of obesity, dietary habits (alcohol consumption, intake of sweets, salt intake) and COPD.Methods: Exposure and outcome datasets were obtained from the IEU Open GWAS project. The exposure dataset includes dietary habits (Salt added to food, Sweets intake, Alcohol consumption), obesity level (represented by body mass index (BMI) and body fat percentage (BFP) data sets.). The outcome dataset includes COPD and acute COPD admissions. The collected data were imported into the RStudio software and conducted Mendelian randomisation analysis. Additionally, heterogeneity and horizontal pleiotropy tests were conducted on the data to ensure the veracity of the results.Results: The results showed that BMI was positively correlated with the risk of acute COPD admission (OR = 1.74, 95% CI 1.39-2.18) and COPD (OR = 1.81, 95%CI 1.41-2.33). In addition, BFP was also a risk factor for COPD (OR = 1.98, 95% CI 1.42-2.77) and acute exacerbation of COPD admission (OR = 1.99, 95%CI 1.43-2.77). The increase of salt, sugar and alcohol consumption will not increase the risk of COPD and the risk of hospitalisation due to COPD.Conclusion: Therefore, we should strengthen the guidance of diet and living habits of obese patients. For patients with heavier weight and higher body fat rate, they should be instructed to lose weight and fat to prevent the occurrence of COPD. For obese patients with COPD, more attention should be paid to prevent the occurrence of acute exacerbation of COPD in advance.

Phase angle measured by bioelectrical impedance analysis in patients with chronic obstructive pulmonary disease: Associations with physical inactivity and frailty

BACKGROUND

Factors associated with early-stage frailty (pre-frailty) in patients with chronic obstructive pulmonary disease (COPD) remain unestablished. In addition to skeletal muscle quantity, skeletal muscle dysfunction can be estimated using an angular metric from bioelectrical impedance analyzer (BIA), termed the phase angle, that reflects cell membrane reactance representing the structural stability. This study examined whether the phase angle was more closely associated with pre-frailty compared with skeletal muscle quantity in patients with COPD.

METHODS

This cross-sectional analysis included stable smokers with and without COPD whose frailty status was assessed using the Japanese version of the Cardiovascular Health Study criteria. The phase angle and skeletal muscle index (SMI) were measured using BIA, and physical activity over one week was assessed using triaxial accelerometers.

RESULTS

A total of 159 patients were categorized into robust, pre-frail, and frail groups (n = 38, 92, and 29, respectively). The phase angle was significantly smaller in the pre-frail and frail groups than in the robust group after adjusting for age, sex, height, body mass index, smoking history, and lung function. In contrast, SMI did not differ between the robust and pre-frail groups. When combining the pre-frail and frail groups into a non-robust group, 4.8° was determined as the cutoff phase angle value to identify non-robust status. A phase angle <4.8° was associated with shorter durations of moderate-intensity physical activity but not with light physical activity.

CONCLUSIONS

A smaller phase angle was associated with pre-frailty and impaired moderate-intensity physical activity in smokers with and without COPD.

Body compositions phenotypes of older adults with COPD

Purpose

Changes in nutritional status are important extrapulmonary manifestations of the chronic obstructive pulmonary disease (COPD). The study aimed to assess the prevalence of different body composition phenotypes in older patients with COPD and to investigate the relationship between these phenotypes and the severity of the disease, as well as physical performance of the subjects.

Patients and methods

The study included 124 subjects aged ≥60 with COPD. In all of them body composition analysis and muscle strength measurement were performed. Additionally, data from patients' medical records were analyzed. Study sample was divided into four groups based on the phenotypic body composition: normal phenotype (N), sarcopenia, obesity and sarcopenic obesity (SO).

Results

Incidence of sarcopenia was significantly higher in patients with severe or very severe COPD based on GOLD in comparison with subjects with mild or moderate obstruction (p = 0.043). Participants with sarcopenia, obesity and SO had lower results of the 6-min walk test than subjects with N (225.77 m, 275.33 m, 350.67 m, 403.56 m, respectively). Moreover, sarcopenia and SO had lower results than obesity (p = 0.001, p = 0.041, respectively).

Conclusion

Sarcopenia is common in patients with advanced COPD. Sarcopenia and SO are associated with poorer physical performance. All older people with COPD should routinely have their body composition assessed, instead of simply measuring of body weight or body mass index (BMI).

Sarcopenia is independently associated with poor preoperative physical fitness in patients undergoing colorectal cancer surgery

BACKGROUND

Accurate preoperative risk assessment for major colorectal cancer (CRC) surgery remains challenging. Body composition (BC) and cardiopulmonary exercise testing (CPET) can be used to evaluate risk. The relationship between BC and CPET in patients undergoing curative CRC surgery is unclear.

METHODS

Consecutive patients undergoing CPET prior to CRC surgery between 2010 and 2020 were identified between two different UK hospitals. Body composition phenotypes such as sarcopenia, myosteatosis, and visceral obesity were defined using widely accepted thresholds using preoperative single axial slice CT image at L3 vertebrae. Relationships between clinicopathological, BC, and CPET variables were investigated using linear regression analysis.

RESULTS

Two hundred eighteen patients with stage I-III CRC were included. The prevalence of sarcopenia, myosteatosis, and visceral obesity was 62%, 33%, and 64%, respectively. The median oxygen uptake at anaerobic threshold (VO2 at AT) was 12.2 mL/kg/min (IQR 10.6-14.2), and oxygen uptake at peak exercise (VO2 peak) was 18.8 mL/kg/min (IQR 15.4-23). On univariate linear regression analysis, male sex (P < 0.001) was positively associated with VO2 at AT. While ASA grade (P < 0.001) and BMI (P = 0.007) were negatively associated with VO2 at AT, on multivariate linear regression analysis, these variables remained significant (P < 0.05). On univariate linear regression analysis, male sex (P < 0.001) was positively associated with VO2 peak, whereas age (P < 0.001), ASA grade (P < 0.001), BMI (P = 0.003), sarcopenia (P = 0.015), and myosteatosis (P < 0.001) were negatively associated with VO2 peak. On multivariate linear regression analysis age (P < 0.001), ASA grade (P < 0.001), BMI (P < 0.001), and sarcopenia (P = 0.006) were independently and negatively associated with VO2 peak.

CONCLUSIONS

The novel finding that sarcopenia is independently associated with reduced VO2 peak performance in CPET supports the supposition that reduced muscle mass relates to poor physical function in CRC patients. Further work should be undertaken to assess whether sarcopenia diagnosed on CT can act as suitable surrogate for CPET to further enhance personalized risk stratification.

Impact of Body Mass Index on Risk of Exacerbation in Patients With COPD: A Systematic Review and Meta-Analysis

Objective

The objective of this review is to synthesize current evidence of the association between body mass index (BMI) categories and the risk of exacerbation in patients with chronic obstructive pulmonary disease (COPD).

Methods

A systematic search was conducted across 3 electronic databases: PubMed, Embase, and Scopus. Eligible studies must have reported on the association between BMI (either as continuous or categorical) and risk of COPD exacerbation, as defined according to recognized clinical criteria. Observational studies (cohort, case-control, cross-sectional) were eligible for inclusion. The Newcastle Ottawa Scale (NOS) was used to evaluate the methodological quality. Combined effect sizes were reported as relative risk (RR) and corresponding 95% confidence intervals (CI).

Results

A total of 11 studies were included. Of them, 4 studies were prospective, 4 were retrospective cohorts in design, 2 were cross-sectional studies, and one study was a secondary data analysis from a randomized trial. Compared to patients with a normal BMI, underweight patients had an increased risk of COPD exacerbation (RR 1.90, 95% CI: 1.03, 3.48; N=7, I2=94.2%). Overweight and obese BMI status was associated with a similar risk of exacerbation.

Conclusion

Our findings report that underweight, but not overweight or obese patients, have an increased risk of COPD exacerbation, compared to individuals with a normal BMI. This differential association emphasizes the need for nuanced investigations into the underlying mechanisms of the impact of BMI on the course of COPD. Further research is needed to inform personalized interventions and improve COPD management strategies.

Extracellular Water Ratio and Phase Angle as Predictors of Exacerbation in Chronic Obstructive Pulmonary Disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD), characterized by high-energy metabolism, often leads to malnutrition and is linked to exacerbations. This study investigates the association of malnutrition-related body composition and handgrip strength changes with exacerbation frequencies in COPD patients.

METHODS

We analyzed 77 acute exacerbation COPD (AECOPD) patients and 82 stable COPD patients, categorized as frequent and infrequent exacerbators. Assessments included body composition, handgrip strength, nutritional risk, dyspnea scale, and COPD assessment.

RESULTS

Among AECOPD patients, there were 22 infrequent and 55 frequent exacerbators. Infrequent exacerbators showed better muscle parameters, extracellular water ratio, phase angle, and handgrip strength. Significant differences in intracellular water, total cellular water, protein, and body cell mass were observed between groups. Logistic regression indicated that extracellular water ratio (OR = 1.086) and phase angle (OR = 0.396) were independently associated with exacerbation risk. Thresholds for exacerbation risk were identified as 0.393 for extracellular water ratio and 4.85° for phase angle. In stable COPD, 13 frequent and 69 infrequent exacerbators were compared, showing no significant differences in weight, muscle, and adipose parameters, but significant differences in extracellular water ratio, phase angle, and handgrip strength.

CONCLUSIONS

These findings suggest that increased exacerbations in COPD patients correlate with higher extracellular water ratios and lower phase angles.

Maximum Phonation Times as Biomarkers of Lung Function

PURPOSE

To verify whether measurements of maximal phonation times are biomarkers of forced vital capacity in patients with chronic obstructive pulmonary disease, and to characterize the vocal aspects of these patients, taking into account variables, such as age, body mass index, use of bronchodilators, presence of symptoms, and quality of life related to voice.

METHODS

Complete records of 25 subjects with chronic obstructive pulmonary disease, both sexes, aged 31 to 85 years, evaluated by forced vital capacity, maximum phonation times of /a/, and numerical count and number reached at this count, Vocal Symptom Scale, Voice Quality of Life. Data were presented descriptively and statistically analyzed using Student's t test for independent samples and Mann-Whitney U test. A significance level of 5% was accepted. The receiver operating characteristic curve was plotted and the standardized value of forced vital capacity <80% was considered as an indicator of pulmonary dysfunction.

RESULTS

Patients exhibited reduced maximum phonation times for /a/, numeric counting, and reached digits in counting; discrepancies in Vocal Signs and Symptoms and Voice Quality of Life Scale scores. Numeric counting times of up to 12.5 seconds indicated that forced vital capacity may be impaired.

CONCLUSION

The patients with chronic obstructive pulmonary disease examined in this study exhibited vocal deviations as evidenced by reduced maximum phonation times of /a/, numeric counting, and the digit reached during counting, as well as deviations in vocal self-assessment. Maximum phonation time in numerical counting was considered a biomarker of pulmonary function impairment.

Adipose Tissue Hypoxia in Obesity: Clinical Reappraisal of Hypoxia Hypothesis

Obese subjects exhibit lower adipose tissue oxygen consumption in accordance with the lower adipose tissue blood flow. Thereby, compared to lean subjects, obese individuals have almost half lower capillary density and more than half lower vascular endothelial growth factor (VEGF). The VEGF expression together with hypoxia-inducible transcription factor-1 alpha (HIF-1α) activity also requires phosphatidylinositol 3-kinase (PI3K) and mammalian target of rapamycin (mTOR)-mediated signaling. Especially HIF-1α is an important signaling molecule for hypoxia to induce the inflammatory responses. Hypoxia contributes to several biological functions, such as angiogenesis, cell proliferation, apoptosis, inflammation, and insulin resistance (IR). Pathogenesis of obesity-related comorbidities is attributed to intermittent hypoxia (IH), which is mostly observed in visceral obesity. Proinflammatory phenotype of the adipose tissue is a crucial link between IH and the development of IR. Inhibition of adaptive unfolded protein response (UPR) in hypoxia increases β cell death. Moreover, deletion of HIF-1α worsens β cell function. Oxidative stress, as well as the release of proinflammatory cytokines/adipokines in obesity, is proportional to the severity of IH. Reactive oxygen species (ROS) generation at mitochondria is responsible for propagation of the hypoxic signal; however, mitochondrial ROS production is required for hypoxic HIF-1α protein stabilization. Alterations in oxygen availability of adipose tissue directly affect the macrophage polarization and are responsible for the dysregulated adipocytokines production in obesity. Hypoxia both inhibits adipocyte differentiation from preadipocytes and macrophage migration from the hypoxic adipose tissue. Upon reaching a hypertrophic threshold beyond the adipocyte fat loading capacity, excess extracellular matrix (ECM) components are deposited, causing fibrosis. HIF-1α initiates the whole pathological process of fibrosis and inflammation in the obese adipose tissue. In addition to stressed adipocytes, hypoxia contributes to immune cell migration and activation which further aggravates adipose tissue fibrosis. Therefore, targeting HIF-1α might be an efficient way to suppress hypoxia-induced pathological changes in the ECM. The fibrosis score of adipose tissue correlates negatively with the body mass index and metabolic parameters. Inducers of browning/beiging adipocytes and adipokines, as well as modulations of matrix remodeling enzyme inhibitors, and associated gene regulators, are potential pharmacological targets for treating obesity.

Physical activity among adults with chronic obstructive pulmonary disease in Spain (2014-2020): Temporal trends, sex differences, and associated factors

OBJECTIVES

To evaluate trends in the prevalence of physical activity (PA) from 2014 to 2020; to identify sex differences and sociodemographic and health-related factors associated with PA in individuals with chronic obstructive pulmonary disease (COPD); and to compare PA between individuals with and without COPD.

METHODS

Cross-sectional and case-control study.

SOURCE

European Health Interview Surveys for Spain (EHISS) conducted in 2014 and 2020. We included sociodemographic and health-related covariates. We compared individuals with and without COPD after matching for age and sex.

RESULTS

The number of adults with COPD was 1086 and 910 in EHISS2014 and EHISS2020, respectively. In this population, self-reported "Medium or high frequency of PA" remained stable (42.9% in 2014 and 43.5% in 2020; p = 0.779). However, the percentage who walked on two or more days per week rose significantly over time (63.4%-69.9%; p = 0.004). Men with COPD reported more PA than women with COPD in both surveys. After matching, significantly lower levels of PA were recorded in COPD patients than in adults without COPD. Multivariable logistic regression confirmed this trend in COPD patients and showed that male sex, younger age, higher educational level, very good/good self-perceived health, and absence of comorbidities, obesity, and smoking were associated with more frequent PA.

CONCLUSIONS

The temporal trend in PA among Spanish adults with COPD is favorable, although there is much room for improvement. Insufficient PA is more prevalent in these patients than in the general population. Sex differences were found, with significantly more frequent PA among males with COPD.

Association Between Sarcopenia and Chronic Renal Failure (Overt and Concealed) in Chronic Obstructive Pulmonary Disease (COPD) Patients: A Cross-Sectional Study

Background Sarcopenia, a syndrome characterized by a progressive decline in skeletal muscle mass, strength, and function, is frequently associated with chronic diseases such as chronic obstructive pulmonary disease (COPD). Chronic kidney disease (CKD) is a prevalent condition among patients with sarcopenia. Reports suggest that between 15% and 55% of stable COPD patients have sarcopenia. Therefore, the present study aims to determine the association between sarcopenia and chronic renal failure (overt and concealed) in COPD patients. Methodology This institutional-based cross-sectional study was conducted on patients diagnosed with COPD. Hospitalized adult COPD patients who gave consent were included. Sociodemographic information such as age, gender, residence, and prolonged length of stay in the hospital (categorized by a median of 10 days, considering its data distribution in our sample) was obtained using electronic medical records. Skeletal muscle %, visceral fat %, and body fat % were calculated using a bio-electrical impedance analysis device (Omron Body Composition Monitor, Model HBF-702T). Additionally, the strength of the hand grip was measured using a hand dynamometer. Sarcopenia was assessed following the criteria set by the Asian Working Group on Sarcopenia (AWGS). Chronic renal failure (CRF) was assessed by calculating the glomerular filtration rate (GFR) using the Modification of Diet in Renal Disease (MDRD) Study Group equation. Quantitative data were compared using an independent sample t-test. The association was determined using chi-square and multivariate logistic regression analyses. A p-value of <0.05 was considered significant. Results The study found that the proportion of sarcopenia in COPD patients was 52%, with overt and concealed CRF prevalence rates of 31.5% and 27%, respectively. Sarcopenic individuals had significantly lower FEV1 and FEV1/FVC compared to non-sarcopenic patients. The incidence of sarcopenia significantly increased with rising BODE index (body mass index (BMI, B), airflow obstruction (O) as measured by the post-bronchodilator FEV1 (percentage of predicted value), dyspnea (D) assessed by the modified Medical Research Council (MMRC) score, and exercise tolerance (E) measured by 6-minute walking distance) and mMRC (modified Medical Research Council dyspnea scale) dyspnea scale scores. Both concealed CRF and overt CRF patients had four times higher odds of having sarcopenia (AOR=4). Conclusion The study reveals a high prevalence of sarcopenia and provides evidence for the association between sarcopenia and chronic renal failure in COPD patients. These findings underscore the importance of early detection and management of sarcopenia and CRF in COPD patients to optimize their clinical outcomes.

Pulmonary, inflammatory, and oxidative effects of indoor nitrogen dioxide in patients with COPD

Introduction

Indoor nitrogen dioxide (NO2) sources include gas heating, cooking, and infiltration from outdoors. Associations with pulmonary function, systemic inflammation, and oxidative stress in patients with chronic obstructive pulmonary disease (COPD) are uncertain.

Methods

We recruited 144 COPD patients at the VA Boston Healthcare System between 2012 and 2017. In-home NO2 was measured using an Ogawa passive sampling badge for a week seasonally followed by measuring plasma biomarkers of systemic inflammation (C-reactive protein [CRP] and interleukin-6 [IL-6]), urinary oxidative stress biomarkers (8-hydroxy-2'deoxyguanosine [8-OHdG] and malondialdehyde [MDA]), and pre- and postbronchodilator spirometry. Linear mixed effects regression with a random intercept for each subject was used to assess associations with weekly NO2. Effect modification by COPD severity and by body mass index (BMI) was examined using multiplicative interaction terms and stratum-specific effect estimates.

Results

Median (25%ile, 75%ile) concentration of indoor NO2 was 6.8 (4.4, 11.2) ppb. There were no associations observed between NO2 with CRP, 8-OHdG, or MDA. Although the confidence intervals were wide, there was a reduction in prebronchodilator FEV1 and FVC among participants with more severe COPD (FEV1: -17.36 mL; -58.35, 23.60 and FVC: -28.22 mL; -91.49, 35.07) that was greater than in patients with less severe COPD (FEV1: -1.64 mL; -24.80, 21.57 and FVC: -6.22 mL; -42.16, 29.71). In participants with a BMI <30, there was a reduction in FEV1 and FVC.

Conclusions

Low-level indoor NO2 was not associated with systemic inflammation or oxidative stress. There was a suggestive association with reduced lung function among patients with more severe COPD and among patients with a lower BMI.

The Possible Role of Food and Diet in the Quality of Life in Patients with COPD-A State-of-the-Art Review

Diet has been described as a modifiable risk factor for the development and progression of chronic diseases, and emerging evidence increasingly points to its preventive and therapeutic role in chronic obstructive pulmonary disease (COPD). While the relationship between the underlying disease and diet is natural in conditions such as metabolic disorders, obesity, diabetes, etc., the direct effect is not so evident in chronic obstructive pulmonary disease. Poor diet quality and the development of nutrient deficiencies in respiratory diseases, including COPD, can be associated with disease-specific factors such as the exacerbation of respiratory symptoms. These symptoms can be improved by dietary interventions, leading to positive changes in the pathogenesis of the disease and the quality of life of patients. Therefore, our aim was to review the latest randomized controlled trials (RCTs) of dietary interventions in chronic respiratory patients and describe their effects on respiratory function, physical activity, systemic inflammatory parameters, and quality of life. We conducted a literature search on dietary interventions for COPD patients in the PubMed, ClinicalTrials.gov, and Cochrane Central Register of Controlled Trials (CENTRAL) databases, focusing on publications from 1 July 2018 to 1 July 2023. We used specific keywords and MESH terms, focusing on RCTs. A total of 26 articles and 1811 COPD patients were included in this review. On the basis of our findings, dietary interventions, in particular components of the Mediterranean diet such as protein, omega-3 polyunsaturated fatty acids, and vegetables, appear to have beneficial effects in patients with chronic respiratory diseases, and their application is beneficial. However, long-term follow-up studies are still needed to examine the effects of dietary interventions in this patient population.

Impact of Lung-Related Polygenic Risk Scores on Chronic Obstructive Pulmonary Disease Risk and Their Interaction with w-3 Fatty Acid Intake in Middle-Aged and Elderly Individuals

Chronic obstructive pulmonary disease (COPD) is a complex, progressive respiratory disorder with persistent airflow limitation and tissue destruction. We aimed to explore the genetic impact of COPD and its interaction with nutrient intake in 8840 middle-aged and elderly individuals from the Ansan/Ansung cohorts. Participants were diagnosed with COPD if the ratio of forced expiratory volume in 1 s (FEV1) to forced vital capacity (FVC) was less than 0.7 using spirometry, and if they were previously diagnosed with COPD by a physician. Genome-wide association studies (GWAS) were performed to screen for genetic variants associated with COPD risk. Among them, we selected the genetic variants that exhibited interactions using the generalized multifactor dimensionality reduction (GMDR) method. The polygenic risk score (PRS) was computed by summing the number of risk alleles in the SNP-SNP interaction models that adhered to specific rules. Subsequently, participants were categorized into low-PRS, medium-PRS, and high-PRS groups. The participants with COPD exhibited significantly lower FEV1/FVC ratios (0.64) than those without COPD (0.82). It was positively associated with inflammation markers (serum C-reactive protein and white blood cell levels). A higher proportion of COPD participants were smokers and engaged in regular exercise. The 5-SNP model consisted of FAM13A_rs1585258, CAV1_rs1997571, CPD_rs719601, PEPD_rs10405598, and ITGA1_rs889294, and showed a significant association with COPD risk (p < 0.001). Participants in the high-PRS group of this model had a 2.2-fold higher risk of COPD than those in the low-PRS group after adjusting for covariates. The PRS interacted with w-3 fatty acid intake and exercise, thus influencing the risk of COPD. There was an increase in COPD incidence among individuals with a higher PRS, particularly those with low consumption of w-3 fatty acid and engaged in high levels of exercise. In conclusion, adults with a high-PRS are susceptible to COPD risk, and w-3 fatty acid intake and exercise may impact the risk of developing COPD, potentially applying to formulate precision medicines to prevent COPD.