The relationship of dietary patterns with adult lung function and COPD

Relationship between dietary live microbe intake and the prevalence of COPD in adults: a cross-sectional study of NHANES 2013-2018

OBJECTIVE

To explore the potential association between dietary live microbes and the prevalence of Chronic Obstructive Pulmonary Diseases (COPD).

METHODS

In this cross-sectional study, data of 9791 participants aged 20 years or older in this study were collected from the National Health and Nutrition Examination Survey (NHANES) between 2013 and 2018. Participants in this study were classified into three groups according to the Sanders' dietary live microbe classification system: low, medium, and high dietary live microbe groups. COPD was defined by a combination of self-reported physician diagnoses and standardized medical status questionnaires. Logistic regression and subgroup analysis were used to assess whether dietary live microbes were associated with the risk of COPD.

RESULTS

Through full adjustment for confounders, participants in the high dietary live microbe group had a low prevalence of COPD in contrast to those in low dietary live microbe group (OR: 0.614, 95% CI: 0.474-0.795, and p < 0.001), but no significant association with COPD was detected in the medium and the low dietary live microbe groups. This inverse relationship between dietary live microbe intake and COPD prevalence was more inclined to occur in smokers, females, participants aged from 40 to 59 years old and non-obese participants.

CONCLUSION

A high dietary live microbe intake was associated with a low prevalence of COPD, and this negative correlation was detected especially in smokers, females, participants aged from 40 to 59 years old and non-obese participants.

The Role of Nutrition in the Development and Management of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a prevalent lung condition associated with significant morbidity and mortality. The management of COPD classically involves pulmonary rehabilitation, bronchodilators, and corticosteroids. An aspect of COPD management that is currently lacking in the literature is nutritional management, despite the prevalence of inadequate nutritional status in patients with COPD. In addition, certain nutritional imbalances have been reported to increase the risk of COPD development. This review summarizes the current literature on the role diet and nutrients may play in the risk and management of COPD development.

Physical activity and lung function association in a healthy community-dwelling European population

BACKGROUND

The association of physical activity (PA) and lung function (LF) varies from no measurable effect to delayed LF decline. We assessed the association between accelerometery-assessed PA and LF in a sample of apparently healthy, community-dwelling subjects.

METHODS

We included two cross-sectional studies using data from the PneumoLaus study (2014-17 and 2018-21), conducted in Lausanne, Switzerland. PA was assessed by accelerometry and categorised as inactivity, light, moderate or vigorous. Forced expiratory volume in 1 second (FEV1), forced volume capacity (FVC) and maximal mid-expiratory flow (MMEF) were measured by spirometry and expressed in percentage of predicted value (PV).

RESULTS

Overall, 1'910 (54.7% women, 62.0 ± 9.7 years) and 1'174 (53.4% women, 65.8 ± 9.5 years) participants were included in the first and the second surveys, respectively. In both surveys, moderate and vigorous PA showed a weak but significant correlation with FEV1 in percentage (PV) (R = 0.106 and 0.132 for the first and 0.111 and 0.125 for the second surveys, p < 0.001). Similar correlations with FVC (p < 0.001) were found. Associations held irrespective of smoking status and remained after multivariable adjustment. Fewer associations were detected between LF and light PA or between MMEF and PA.

CONCLUSION

Moderate and vigorous intensity PA are associated with increased LF regardless of smoking status in apparently healthy community-dwelling European population. These associations are statistically but not clinically significant due to the small correlation coefficients (R < 0.30), corresponding to a weak association.

The genomic landscape of chronic obstructive pulmonary disease: Insights from nutrigenomics

Chronic obstructivе pulmonary disеasе (COPD), a rеspiratory disеasе, is influenced by a combination of gеnеtic and еnvironmеntal factors. Thе fiеld of nutrigеnomics, which studiеs thе intеrplay bеtwееn diеt and gеnеs, provides valuable insights into thе gеnomic landscapе of COPD and its implications for production and managеmеnt. This rеviеw providеs a comprеhеnsivе ovеrviеw of thе gеnеtic aspеcts of COPD and thе rolе of nutrigеnomics in advancing our undеrstanding of thе undеrlying mеchanisms. Through studies of gеnomе-widе associations, researchers have identified gеnеtic factors that contribute to suscеptibility to COPD. Thеsе gеnеs arе associatеd with oxidativе strеss, inflammation, and antioxidant dеfеnsе mеchanisms. Nutrigеnomics rеsеarch is currеntly invеstigating how diеtary componеnts interact with gеnеtic variations to modulatе thе dеvеlopmеnt of COPD. Antioxidants, omеga-3 fatty acids and vitamin D havе dеmonstratеd potеntial bеnеfits in rеducing inflammation, improving lung function, and minimizing еxacеrbations in patients with COPD. Therefore, there are sеvеral challеngеs that must be added to the nutrigеnomic rеsеarch. The challenges include thе nееd for largеr clinical trials, adding hеtеrogеnеity and validating biomarkеrs. In the tеrms of futurе dirеctions, prеcision nutrition, gеnе-basеd thеrapiеs, biomarkеr dеvеlopmеnt, intеgration of multi-omics data, systеms biology analysis, longitudinal studiеs, and public hеalth implications arе important arеas to еxplorе. Pеrsonalizеd nutritional intеrvеntions based on an individual's gеnеtic profilе hold grеat promisе for optimizing COPD managеmеnt. In conclusion, nutrigеnomics provides valuable insights into the gеnomic landscapе of COPD and its intеraction with the disease. This knowlеdgе can guidе thе dеvеlopmеnt of pеrsonalizеd diеtary stratеgiеs and gеnе-basеd thеrapiеs for thе prеvеntion and managеmеnt of COPD. Howеvеr, morе rеsеarch is nееdеd to validatе thеsе findings, dеvеlop еffеctivе intеrvеntions, and implеmеnt thеm еffеctivеly in clinical practicе to improvе thе quality of lifе for pеoplе with COPD.

Comprehensive evaluation of smoking exposures and their interactions on DNA methylation

BACKGROUND

Smoking impacts DNA methylation, but data are lacking on smoking-related differential methylation by sex or dietary intake, recent smoking cessation (<1 year), persistence of differential methylation from in utero smoking exposure, and effects of environmental tobacco smoke (ETS).

METHODS

We meta-analysed data from up to 15,014 adults across 5 cohorts with DNA methylation measured in blood using Illumina's EPIC array for current smoking (2560 exposed), quit < 1 year (500 exposed), in utero (286 exposed), and ETS exposure (676 exposed). We also evaluated the interaction of current smoking with sex or diet (fibre, folate, and vitamin C).

FINDINGS

Using false discovery rate (FDR < 0.05), 65,857 CpGs were differentially methylated in relation to current smoking, 4025 with recent quitting, 594 with in utero exposure, and 6 with ETS. Most current smoking CpGs attenuated within a year of quitting. CpGs related to in utero exposure in adults were enriched for those previously observed in newborns. Differential methylation by current smoking at 4-71 CpGs may be modified by sex or dietary intake. Nearly half (35-50%) of differentially methylated CpGs on the 450 K array were associated with blood gene expression. Current smoking and in utero smoking CpGs implicated 3049 and 1067 druggable targets, including chemotherapy drugs.

INTERPRETATION

Many smoking-related methylation sites were identified with Illumina's EPIC array. Most signals revert to levels observed in never smokers within a year of cessation. Many in utero smoking CpGs persist into adulthood. Smoking-related druggable targets may provide insights into cancer treatment response and shared mechanisms across smoking-related diseases.

FUNDING

Intramural Research Program of the National Institutes of Health, Norwegian Ministry of Health and Care Services and the Ministry of Education and Research, Chief Scientist Office of the Scottish Government Health Directorates and the Scottish Funding Council, Medical Research Council UK and the Wellcome Trust.

Association Between Instant Coffee Consumption and the Development of Chronic Obstructive Pulmonary Disease: Results From a Community-Based Prospective Cohort

BACKGROUND

A poor diet is a risk factor for chronic obstructive pulmonary disease (COPD). The interaction between dietary factors and cigarette smoking in the development of COPD is unclear. We investigated the interactions between dietary patterns and smoking status on COPD-related outcomes.

METHODS

We used data from the Anseong-Ansan cohort that has been followed for 20 years. A total of 6,221 individuals without COPD in the baseline survey were analyzed. Five dietary patterns were identified using a semi-quantitative food frequency questionnaire. Associations of dietary patterns with COPD and forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) ratio in different strata of smoking status were evaluated using Cox regression and linear mixed models, respectively.

RESULTS

The highest quartile of the "coffee" pattern (high coffee consumption) was associated with COPD (hazard ratio, 1.46; 95% confidence interval [CI], 1.03-2.08) and lower FEV1/FVC ratio (β = -1.2%; 95% CI, -1.9% to -0.6%) using the lowest quartile as a reference for heavy smokers, but not light or never smokers (P value for interaction = 0.035 for COPD). Regarding the associations between various consumption levels of black coffee, combined coffee, and instant coffee and COPD, an association with COPD was only observed for instant coffee in heavy smokers.

CONCLUSION

High instant coffee consumption is associated with COPD development in heavy smokers, but not in light or never smokers. This may be attributed to sugar and cream in instant coffee mixes.

The association between diet quality and chronic obstructive pulmonary disease: a case-control study

BACKGROUND

Previous investigations have primarily examined the relationship between various dietary patterns and the risk of chronic obstructive pulmonary disease (COPD); however, there have been limited studies that have evaluated the association between diet quality presented by Healthy Eating Index 2010 (HEI-2010) and COPD. The aim of this study was to investigate this association in Iranian population.

METHODS

This case-control study recruited 84 cases and 252 healthy controls who were randomly selected. Diet, smoking, and physical activity were assessed using validated questionnaires. The HEI-2010 score ranged from zero to hundred twenty, with zero indicating an unhealthy diet and hundred twenty indicating a healthy diet. Logistic regression models were utilized to analyze the association between HEI-2010 and the odds of COPD.

RESULTS

Results from logistic regression showed that individuals with higher HEI scores had a significantly lower odds of COPD (OR: 0.34; 95% CI: 0.16-0.72). After adjusting for confounders, individuals with the highest HEI score were 82% less likely to have COPD (OR: 0.18; 95% CI: 0.03-0.96). This association remained significant after adjusting for smoking and physical activity (OR: 0.08; 95% CI: 0.01-0.93) and with additional adjustment for BMI (OR: 0.08; 95% CI: 0.01-0.92).

CONCLUSIONS

This study found a significant association between a higher HEI-2010 score and a lower odd of COPD in the Iranian population. These results suggest that a healthy diet may play a crucial role in reducing the odds of COPD and in improving the function of the lungs. However, further prospective studies are warranted to elucidate this relationship.

Prevalence of small airway dysfunction in the Swiss PneumoLaus Cohort

Background

Recent evidence identified exposure to particulate matter of size ≤2.5 µm (PM2.5) as a risk factor for high prevalence of small airway dysfunction (SAD). We assessed the prevalence of SAD in a European region with low air pollution levels.

Methods

SAD was defined as a maximum mid-expiratory flow (MMEF) <65% of predicted value (PV) or MMEF

Results

Among 3351 participants (97.6% Caucasian, 55.7% female sex, mean age 62.7 years), we observed MMEF <65% PV in 425 (12.7%) and MMEF 65 years only. In an area where ambient PM2.5 concentration was <15 µg·m-3 during the observation period (2010 and 2020), ≥72% of participants with SAD were ever-smokers.

Conclusions

The observed low prevalence of SAD of 5.0-12.7% depending on criteria employed may be related to lower PM2.5 exposure. Smoking was the main factor associated with SAD in an area with low PM2.5 exposure. Employing a MMEF threshold <65% PV carries a risk of SAD overdiagnosis in elderly individuals.

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Imbalance of gut microbiota is involved in the development of chronic obstructive pulmonary disease: A review

Chronic obstructive pulmonary disease (COPD) is a common chronic disease characterized by chronic airway inflammation and remodeling, which seriously endangers human health. Recent developments in genomics and metabolomics have revealed the roles of the gut microbiota and its metabolites in COPD. Dysbiosis of the gut microbiota directly increases gut permeability, thereby promoting the translocation of pathological bacteria. The gut microbiota and associated metabolites may influence the development and progression of COPD by modulating immunity and inflammation. Furthermore, the systemic hypoxia and oxidative stress that occur in COPD may also be involved in intestinal dysfunction. The cross-talk between the gut and lungs is known as the gut-lung axis; however, an overview of its mechanism is lacking. This review highlights the critical and complex interplay of gut microbiota and immune responses in the gut-lung axis, further explores possible links between the gut and lungs, and summarizes new interventions through diet, probiotics, vitamins, and fecal microbiota transplantation, which are critical to COPD.

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.

Associations of adherence to the DASH diet and the Mediterranean diet with chronic obstructive pulmonary disease among US adults

Background

The Dietary Approaches to Stop Hypertension (DASH) and the Mediterranean diet are associated with reduced cardiovascular, tumor, and diabetes risk, but the effect on chronic obstructive pulmonary disease (COPD) is uncertain.

Objective

To investigate the association of the DASH diet and the Mediterranean diet with the risk of COPD in American adults.

Methods

This cross-sectional study included 28,605 participants from the National Health and Nutrition Examination Survey (NHANES) 1999-2018 survey cycle who had complete dietary and other questionnaire data. The scores of healthy eating patterns (the DASH diet and the Mediterranean diet) were derived from a 24-h dietary recall interview [individual food and total nutrient data from NHANES and food pattern equivalents data from the United States Department of Agriculture (USDA)]. The primary outcome was the prevalence of COPD. COPD was defined based on participants self-reported whether or not a doctor or health professional had diagnosed chronic bronchitis or emphysema. Secondary outcomes were lung function and respiratory symptoms. All analyses were adjusted for demographics and standard COPD risk factors (primary tobacco exposure, secondhand smoke exposure, and asthma).

Results

This study included 2,488 COPD participants and 25,607 non-COPD participants. We found that a higher DASH diet score was associated with a lower risk of COPD [odds ratio (OR): 0.83; 95% confidence interval (CI): 0.71-0.97; P = 0.021]. This association persisted in several subgroups [men (OR: 0.73; 95% CI: 0.58-0.93; P = 0.010), relatively young (OR: 0.74; 95% CI: 0.55-1.01; P = 0.050), and smoker (OR: 0.82; 95% CI: 0.67-0.99; P = 0.038)]. In contrast, the Mediterranean diet score was not significantly associated with COPD prevalence in this large cross-sectional analysis representative of the US adult population (OR: 1.03; 95% CI: 0.88-1.20; P = 0.697). In addition, we found a correlation between DASH diet adherence and lung function [β: -0.01; 95% CI: -0.01-0.00; P = 0.003 (FEV1: FVC)] or respiratory symptoms [OR: 0.80; 95% CI: 0.73-0.89; P < 0.001 (dyspnea); OR: 0.80; 95% CI: 0.70-0.91; P = 0.002 (cough); OR: 0.86; 95% CI: 0.74-0.99; P = 0.042 (expectoration)], especially in non-COPD populations.

Conclusion

A higher DASH diet score was associated with improved COPD prevalence, lung function and respiratory symptoms. This new finding supports the importance of diet in the pathogenesis of COPD and expands the scope of the association of the DASH diet score with major chronic diseases.

Efficacy of Vitamin C Supplementation on Chronic Obstructive Pulmonary Disease (COPD): A Systematic Review and Meta-Analysis

Background

In recent years, the pleiotropic roles of antioxidants have drawn extensive attention in various diseases. Vitamin C is a well-known antioxidant, and it has been used to treat patients with chronic obstructive pulmonary disease (COPD). This systematic review and meta-analysis aim to demonstrate the impact of vitamin C supplementation in patients with COPD.

Methods

We searched PubMed, Embase, Cochrane Library, Web of Science, Chinese National Knowledge Infrastructure (CNKI), SinoMed, Wanfang, and China Science and Technology Journal Database (cqvip.com) for eligible randomized controlled trials (RCTs) from their respective inception to May 18^th, 2021, by using the searching terms of COPD, vitamin C, and RCTs. A meta-analysis was performed to evaluate the effects of vitamin C on lung function, antioxidant levels, and nutritional conditions in COPD patients by using Review Manager (Version 5.4).

Results

Ten RCTs including 487 participants were eligible for our study. Meta-analysis results showed that vitamin C supplementation (≥400 mg/day) can significantly improve the forced expiratory volume in one second as a percentage (FEV1%) in COPD (SMD:1.08, 95% CI:0.03, 2.12, P=0.04). Moreover, vitamin C supplementation significantly improved the ratio of forced expiratory volume in 1 second and forced vital capacity (FEV1/FVC) (WMD:0.66, 95% CI: 0.26, 1.06, P=0.001), vitamin C level in serum (SMD:0.63, 95% CI: 0.02, 1.24, P=0.04) and glutathione (GSH) level in serum (SMD:2.47, 95% CI: 1.06, 3.89, P=0.0006). While no statistically significant difference was observed in body mass index (BMI), fat-free mass index (FFMI), vitamin E level and superoxide dismutase (SOD) level in serum.

Conclusion

Vitamin C supplementation could increase the levels of antioxidation in serum (vitamin C and GSH) and improve lung function (FEV1% and FEV1/FVC), especially in patients treated with vitamin C supplementation greater than 400 mg/day. However, further prospective studies are needed to explore the role of vitamin C in improving nutritional status.

The Dietary Inflammatory Index and Early COPD: Results from the National Health and Nutrition Examination Survey

We examined 3962 people aged 20 to 49 years who had information on spirometry testing and underwent a 24 h dietary recall interview from the 2007-2012 National Health and Nutrition Examination Survey (NHANES) and used multivariable logistic regression to evaluate associations between Dietary Inflammatory Index (DII, a pro-inflammatory diet) and early COPD and lung function. The overall prevalence of early COPD was 5.05%. Higher DII was associated with increased odds of early COPD (quartile 4 vs. 1, the OR = 1.657, 95% CI = 1.100-2.496, p = 0.0156). In a full-adjusted model, each unit of increase in DII score was associated with a 90.3% increase in the risk of early COPD. Higher DII is significantly associated with lower FEV1 and FVC among individuals with early COPD, each unit increment in the DII was significantly associated with 0.43 L-0.58 L decrements in FEV1 (β = -0.43, 95% CI = -0.74, -0.12) and FVC (β = -0.58, 95% CI = -1.01, -0.16). These findings demonstrate that higher consumption of a pro-inflammatory diet may contribute to an increased risk of early COPD and lower lung function, and further support dietary interventions as part of a healthy lifestyle in order to preserve lung function and prevent or improve COPD.

Role of Short-Chain Fatty Acids Produced by Gut Microbiota in Innate Lung Immunity and Pathogenesis of the Heterogeneous Course of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a widespread socially significant disease. The development of COPD involves the innate immune system. Interestingly, the regulation of the innate lung immune system is related to the gut microbiota. This connection is due to the production by gut microorganisms of short-chain fatty acids (SCFAs) such as acetate, propionate, and butyrate. Nutritional disturbances and changes in the structure of the intestinal microbiota lead to a decrease in SCFAs production and their effect on pulmonary immunity. The presence of a metabolic and immune axis linking the lungs and gut plays an important role in the pathogenesis of COPD. In addition, the nature of nutrition and SCFAs may participate in the development of the clinically heterogeneous course of COPD.

Antimicrobial therapies for prevention of recurrent acute exacerbations of COPD (AECOPD): beyond the guidelines

Background

Unfortunately, many COPD patients continue to exacerbate despite good adherence to GOLD Class D recommended therapy. Acute exacerbations lead to an increase in symptoms, decline in lung function and increased mortality rate. The purpose of this review is to do a literature search for any prophylactic anti-microbial treatment trials in GOLD class D patients who ‘failed’ recommended therapy and discuss the role of COPD phenotypes, lung and gut microbiota and co-morbidities in developing a tailored approach to anti-microbial therapies for high frequency exacerbators.

Main text

There is a paucity of large, well-conducted studies in the published literature to date. Factors such as single-centre, study design, lack of well-defined controls, insufficient patient numbers enrolled and short follow-up periods were significant limiting factors in numerous studies. One placebo-controlled study involving more than 1000 patients, who had 2 or more moderate exacerbations in the previous year, demonstrated a non-significant reduction in exacerbations of 19% with 5 day course of moxifloxacillin repeated at 8 week intervals. In Pseudomonas aeruginosa (Pa) colonised COPD patients, inhaled antimicrobial therapy using tobramycin, colistin and gentamicin resulted in significant reductions in exacerbation frequency. Viruses were found to frequently cause acute exacerbations in COPD (AECOPD), either as the primary infecting agent or as a co-factor. However, other, than the influenza vaccination, there were no trials of anti-viral therapies that resulted in a positive effect on reducing AECOPD. Identifying clinical phenotypes and co-existing conditions that impact on exacerbation frequency and severity is essential to provide individualised treatment with targeted therapies. The role of the lung and gut microbiome is increasingly recognised and identification of pathogenic bacteria will likely play an important role in personalised antimicrobial therapies.

Conclusion

Antimicrobial therapeutic options in patients who continue to exacerbate despite adherence to guidelines-directed therapy are limited. Phenotyping patients, identification of co-existing conditions and assessment of the microbiome is key to individualising antimicrobial therapy. Given the impact of viruses on AECOPD, anti-viral therapeutic agents and targeted anti-viral vaccinations should be the focus of future research studies.

Fatty Acids, Amphiregulin Production, and Lung Function in a Cohort of Midwestern Veterans

Rationale

The relationship between many fatty acids and respiratory outcomes remains unclear, especially with regard to mechanistic actions. Altered regulation of the process of lung repair is a key feature of chronic lung disease and may impact the potential for pulmonary rehabilitation, but underlying mechanisms of lung repair following injury or inflammation are not well-studied. The epidermal growth factor receptor agonist amphiregulin (AREG) has been demonstrated to promote lung repair following occupational dust exposure in animals. Studies suggest the polyunsaturated fatty acid (PUFA) docosahexaenoic acid (DHA) may enhance the production of AREG. The objective of this study was to determine the relationship between fatty acids and lung function in a population of veterans and determine if fatty acid status is associated with concentrations of AREG.

Materials and Methods

Data were collected from a cross-sectional study of veterans within the Nebraska-Western Iowa Health Care System. Whole blood assays were performed to quantify AREG concentrations via a commercially available ELISA kit. Fatty acids from plasma samples from the same patients were measured using gas-liquid chromatography. Intakes of fatty acids were quantified with a validated food frequency questionnaire. Linear regression models were used to determine whether plasma fatty acids or intakes of fatty acids predicted lung function or AREG concentrations. A p < 0.05 was considered statistically significant.

Results

Ninety participants were included in this analysis. In fully adjusted models, plasma fatty acids were associated with AREG production, including the PUFA eicosapentaenoic acid (EPA) (β = 0.33, p = 0.03) and the monounsaturated fatty acid octadecenoic acid: (β = −0.56, p = 0.02). The omega-3 PUFA docosapentaenoic acid (DPA) was positively associated with lung function (β = 0.28, p = 0.01; β = 26.5, p = 0.05 for FEV₁/FVC ratio and FEV₁ % predicted, respectively), as were the omega-6 PUFAs eicosadienoic acid (β = 1.13, p < 0.001; β = 91.2, p = 0.005 for FEV₁/FVC ratio and FEV₁ % predicted, respectively) and docosadienoic acid (β = 0.29, p = 0.01 for FEV₁/FVC ratio). Plasma monounsaturated and saturated fatty acids were inversely associated with lung function.

Conclusion

Opposing anti- and pro-inflammatory properties of different fatty acids may be associated with lung function in this population, in part by regulating AREG induction.

Dietary Patterns and Risk of Chronic Obstructive Pulmonary Disease among Chinese Adults: An 11-Year Prospective Study

The evidence about the association between dietary patterns and the incidence of chronic obstructive pulmonary disease (COPD) among Chinese adults is limited. In the present study, we analyzed the prospective data of 421,426 participants aged 30−79 years from the China Kadoorie Biobank. Factor analysis with a principal component method was employed to identify dietary patterns. Cox proportional hazard regression models were performed to explore the association between dietary patterns and incident COPD. Two dietary patterns were identified: the traditional northern dietary pattern was characterized by a low intake of rice and a high intake of wheat and other staple foods, while the balanced dietary pattern was characterized by a high intake of fresh fruit and protein-rich foods (soybean, meat, poultry, fish, eggs, and dairy products). During a median follow-up of 11.13 years, 5542 men and 5750 women developed COPD. After adjustments for potential confounders, the balanced dietary pattern was associated with a lower risk of COPD (p for trend <0.001), with a hazard ratio (95% confidence interval) of 0.75 (0.67, 0.84) for those in the highest quintile compared with those in the lowest quintile. Such association was modified by sex, smoking status, and adiposity level.

Fast food and sweet intake pattern is directly associated with the prevalence of asthma in a Qatari population

OBJECTIVE

The relationship between dietary patterns and the prevalence of asthma is not well understood. We aimed to investigate the association between dietary patterns and asthma in adults in Qatar.

METHODS

In this study, cross-sectional data from the Qatar Biobank were used (n = 986). Participants were Qatari or long-term Qatar residents aged ≥20 years old. A food frequency questionnaire was used to collect dietary intakes. Three dietary patterns were identified using factor analysis. Multivariable logistic regression was used to assess the association between dietary patterns scores and asthma.

RESULTS

Among 986 eligible participants, 6.6% (n = 65) reported that they were diagnosed with asthma. Three dietary patterns were identified. These were (1) "Traditional" (high intake of rice, chicken/meat/fish, and breads); (2) "Prudent" (high intake of fruits, vegetables, and fish); and (3) "Fast Food/Sweets" (high intake of desserts, fast food, and soft drinks). The fast food/sweet dietary pattern was associated with increased likelihood of having asthma [comparing high vs. low tertile, OR for asthma = 1.25; 95% CI (1.02-1.54); p = 0.035]. Traditional and Prudent dietary patterns were not associated with the prevalence of asthma.

CONCLUSION

The fast food/sweet dietary pattern was directly associated with the prevalence of asthma among adults in Qatar. Reducing the fast foods and sugary-rich foods may be beneficial for respiratory health.

Association of Intestinal Microbial Dysbiosis With Chronic Obstructive Pulmonary Disease

Normal gut flora plays various beneficial roles for the human body, including the protection against inflammatory states and mucosal viral infections. It also influences the immune system of the body. The metabolites produced by the gut bacteria control local and other systemic organs' immune functions like the lungs and brain, playing a role in their response to acute and chronic illnesses. Probiotics have shown beneficial effects on lung health. On the contrary, dysbiosis is associated with several diseases, including asthma, chronic bronchitis, emphysema, allergies, and other acute viral infections. By altering the diet of patients with respiratory diseases like patients with chronic obstructive pulmonary diseases (COPD), we may be able to mitigate their conditions. This literature review aims to discuss the mechanisms altering the gastrointestinal flora, the pathophysiology of gut and lung axis, the role of diet in gut microbe health, and the association of COPD with gut dysbiosis and peptic ulcer disease (PUD). We have extracted the data from PubMed and Google Scholar, consisting of review articles, case-control studies, and animal studies. The studies showed an association between gut microbes and different lung diseases. It is found that gut dysbiosis not only disrupts intestinal immunity but may also facilitate the development of COPD. Present studies also show an increased seroprevalence of Helicobacter pylori in patients with COPD. The strategies that can improve lung functions, especially in COPD patients, include prebiotics and probiotic supplementation to a diet more balanced than the current average American diet.

Nutriepigenomics and chronic obstructive pulmonary disease: potential role of dietary and epigenetics factors in disease development and management

Over recent decades, a number of studies have revealed the possible role of different types of diets, as well as the nutritional elements they are made up of, in the pathogenesis of chronic obstructive pulmonary disease (COPD). To date, dietary factors have been identified to play a role in the prevention of COPD, with evidence from antioxidant nutrients, vitamins, and fiber intake. Additionally, certain dietary patterns such as the Mediterranean diet, together with other Western diets, provide evidence of the influence on COPD development, promoting lung health through nutritional approaches, and giving us an opportunity for intervention. The effect of diet on COPD is conveyed by 3 mechanisms: regulation of inflammation, oxidative stress, and carbon dioxide produced/oxygen intake. Current advances have begun to highlight the possible role of diet in modifying gene expression in certain individuals that predisposes them to COPD through epigenetic modifications. The relation between dietary intake and epigenetic factors has therefore outlined nutriepigenomics as a possible missing link in the relation between environmental exposure to smoke and the appearance of a subsequent chronic bronchial obstruction. This review summarizes the evidence regarding the influence of dietary patterns and nutrients and epigenetic regulatory mechanisms on COPD development and prevention with the aim of encouraging clinical research on the impact of dietary modifications on COPD-related clinical outcomes. This review highlights the importance of proposing and carrying out future studies focused on the modulating effects of certain nutrients on epigenetic changes in patients with specific COPD phenotypes (bronchiectasis, emphysema, asthma/COPD, chronic bronchitis), and their individual responses to cigarette smoking, environmental pollution, or other noxious particles. The objectives of these future studies must be directed to the development of novel therapeutic approaches and personalized management of COPD.

Anti-Inflammatory Function of Fatty Acids and Involvement of Their Metabolites in the Resolution of Inflammation in Chronic Obstructive Pulmonary Disease

Lipid metabolism plays an important role in many lung functions. Disorders of lipid metabolism are part of the pathogenesis of chronic obstructive pulmonary disease (COPD). Lipids are involved in numerous cross-linkages with inflammation. Recent studies strongly support the involvement of fatty acids as participants in inflammation. They are involved in the initiation and resolution of inflammation, including acting as a substrate for the formation of lipid mediators of inflammation resolution. Specialized pro-inflammatory mediators (SPMs) belonging to the classes of lipoxins, resolvins, maresins, and protectins, which are formed enzymatically from unsaturated fatty acids, are now described. Disorders of their production and function are part of the pathogenesis of COPD. SPMs are currently the subject of active research in order to find new drugs. Short-chain fatty acids are another important participant in metabolic and immune processes, and their role in the pathogenesis of COPD is of great clinical interest.

Lung function, COPD and Alternative Healthy Eating Index in US adults

Background

There is a large burden of COPD in the US. The purpose of this study was to investigate the association between diet quality with lung function, spirometric restriction and spirometrically defined COPD in a nationally representative sample of US adults.

Methods

Adults (19–70 years of age) from the National Health and Nutrition Examination Survey 2007–2012 cycles were included (n=10 428). Diet quality was determined using the Alternative Healthy Eating Index (AHEI-2010). Pre-bronchodilator measurements of forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC) and the FEV₁/FVC were described. Calibrated lower limit of normal (LLN) estimates were derived to determine prevalence of spirometric restriction (FVC<LLN) and COPD (FEV₁/FVC ratio<LLN). Population-weighted linear and logistic regression models were used to investigate the association of AHEI-2010 and respiratory outcomes.

Results

The mean±SD AHEI was 45.3±12.2, equivalent to meeting 41% of the daily recommendations for optimal diet quality. Those in the highest quartile of AHEI had better FEV₁ (adjusted (a)β 47.92, 95% CI 2.27–93.57) and FVC (aβ 80.23, 95% CI 34.03–126.42; p-value interaction (*) of AHEI and smoking >0.05) compared to those in quartile 1. Higher AHEI was also associated with lower odds of spirometric restriction (OR 0.23, 95% CI 0.08–0.67; p-value AHEI*ethnicity >0.05).

Conclusions

Diet quality was independently associated with better FEV₁ and FVC and with lower odds of spirometric restriction. These findings highlight the need for research to further elucidate the possible beneficial role of diet in the preservation of lung function.

In this nationally representative population-based study of US adults, diet quality measured by the AHEI-2010 was low. Better diet quality was associated with better lung function, and with lower prevalence of spirometric restriction.https://bit.ly/3you2Tf

Association Between Diet-Related Inflammation and COPD: Findings From NHANES III

Background and Aims: Little is known about diet-related inflammation in chronic obstructive pulmonary disease (COPD). In this study, we aimed to explore the association between COPD and dietary inflammatory index (DII) scores in adults over 40 years old.

Methods: Data were obtained from the 2013 to 2018 National Health and Nutrition Examination Survey (NHANES). In the present study, 9,929 participants were included and analyzed. The DII score was calculated and divided into tertiles. Logistic regression analysis was performed to determine the odds ratios of DII tertiles.

Results: Participants were categorized into COPD (565, 5.69%) and non-COPD groups (9,364, 94.31%) according to interview information. COPD individuals had higher DII scores than non-COPD individuals (0.429 ± 1.809 vs. −0.191 ± 1.791, p < 0.001). The highest DII score tertile included 46.55% of COPD individuals was associated with lower family incomes and education and a higher smoking rate (p < 0.01). The odds ratios (95% CIs) of COPD according to logistic regression were 0.709 (0.512–0.982) for T1 and 0.645 (0.475–0.877) for T2 of the DII score (p = 0.011).

Conclusion: Higher DII scores were positively correlated with COPD in participants over 40 years old. These results further support that diet can be used as an intervention strategy for COPD management.

Fruit, vegetable and dietary antioxidant intake in school age, respiratory health up to young adulthood

BACKGROUND

Dietary antioxidants may protect the lung against oxidative damage and prevent chronic respiratory disease. We aimed to investigate fruit, vegetable and antioxidant intake (measured as total antioxidant capacity, TAC) at age 8 years in relation to asthma and lung function up to 24 years.

METHODS

In this study of 2506 participants from a Swedish birth cohort, diet was assessed using food frequency questionnaires. Information on asthma was collected by questionnaires, and lung function was measured by spirometry at ages 8, 16 and 24 years. Generalized estimating equations and mixed effect models were used to assess overall, age- and sex-specific associations.

RESULTS

After adjustment for confounders, a higher fruit intake at age 8 years was associated with a tendency to reduced odds of prevalent asthma (T3 vs. T1, OR 0.78; 95% CI 0.60-1.01, p-trend .083), with reduced odds of incident asthma and increased odds of remittent asthma (≥median, OR 0.76; 95% CI 0.58-0.99 and OR 1.60; 95% CI 1.05-2.42, respectively) up to 24 years. Comparable, but non-significant, odds ratios were observed in analyses of long-term fruit intake (mean intake at ages 8 and 16 years). In contrast, no association was observed with vegetable intake. A higher dietary TAC (T3 vs. T1) at 8 years was associated with reduced odds of prevalent asthma (OR 0.73; 95% CI 0.58-0.93, p-trend .010) and improved lung function development (FEV₁ -z +0.11; 95% CI 0.01-0.21, p-trend .036 and FVC-z +0.09; 95% CI -0.01-0.20, p-trend .072) up to 24 years. Associations were more pronounced among males, and regarding asthma, participants sensitized to aeroallergens.

CONCLUSIONS

Antioxidant intake in school age may improve asthma and lung function up to young adulthood. Although our results should be interpreted with caution, they emphasize the importance of following current dietary guidelines regarding consumption of antioxidant-rich foods as part of a balanced diet.

Challenges in the Implementation of Chronic Obstructive Pulmonary Disease Guidelines in Low- and Middle-Income Countries: An Official American Thoracic Society Workshop Report

There is a substantial burden of chronic respiratory diseases, including chronic obstructive pulmonary disease (COPD), in low- and middle-income countries (LMICs). LMICs have particular challenges in delivering cost-effective prevention, diagnosis, and management of COPD. Optimal care can be supported by effective implementation of guidelines. This American Thoracic Society workshop considered challenges to implementation of COPD guidelines in LMICs. We make 10 specific recommendations: 1) relevant organizations should provide LMIC-specific COPD management guidance; 2) patient and professional organizations must persuade policy-makers of the importance of lung function testing programs in LMICs; 3) healthcare education and training should emphasize the early-life origins of COPD; 4) urgent action is required by governments to reduce airborne exposures, including exposures to tobacco smoke and indoor and outdoor air pollution; 5) guidance for COPD in LMICs should explicitly link across Essential Medicine Lists and the World Health Organization package of essential noncommunicable disease interventions for primary health care in low-resource settings and should consider availability, affordability, sustainability, and cost-effective use of medicines; 6) the pharmaceutical industry should work to make effective COPD and tobacco-dependence medicines globally accessible and affordable; 7) implementation of locally adapted, cost-effective pulmonary rehabilitation programs should be an international priority; 8) the World Health Organization Global Action Plan for the Prevention and Control of Noncommunicable Diseases should specify how improvements in respiratory health will be achieved; 9) research funders should increase the proportion of funding allocated to COPD in LMICs; and 10) the respiratory community should leverage the skills and enthusiasm of earlier-career clinicians and researchers to improve global respiratory health.

Longitudinal Association of Economic Growth with Lung Function of Chinese Children and Adolescents over 30 Years: Evidence from Seven Successive National Surveys

(1) Background: Recent studies reported that decrease in lung function of Chinese children and adolescents continues to decline, although the change has been insignificant and has reached a plateau. However, studies have not explored the relationship between lung function and economic development in China. This study sought to explore the longitudinal association between socio-economic indicators and lung function; (2) Method: Data were obtained from seven successive national surveys conducted by the Chinese National Survey on Students' Constitution and Health from 1985 to 2014. Lung function of school-age children (7-22 years) was determined using forced vital capacity (FVC). GDP per capita and urbanization ratio were used as economic indicators. A fixed-effects model was employed to examine the longitudinal association after adjusting for height, weight, and time trends; (3) Results: Socio-economic indicators showed a U-curve relationship with lung function of boys and girls from urban and rural areas. Lung function initially decreased with GDP per capita or urbanization ratio and reached a minimum. Lung function then increased with increase in GDP per capita or urbanization ratio. The findings indicate that the relationship between economic growth and lung function is different in different development stages. In less-developed provinces, economic growth was negatively correlated with lung function, whereas, in developed provinces, economic growth was positively correlated with lung function; (4) Conclusion: The findings of the current study show that economic growth has significantly different effects on lung function at different economic levels. Therefore, governments should improve lung health in children and adolescents from low and middle economic regions.

Household Food Insecurity, Lung Function, and COPD in US Adults

Increasing epidemiological evidence suggests that optimal diet quality helps to improve preservation of lung function and to reduce chronic obstructive pulmonary disease (COPD) risk, but no study has investigated the association of food insecurity (FI) and lung health in the general population. Using data from a representative sample of US adults who participated in the National Health and Nutrition Examination Survey (NHANES) 2007–2012 cycles, we investigated the association between FI with lung function and spirometrically defined COPD in 12,469 individuals aged ≥ 18 years of age. FI (high vs. low) was defined using the US Department of Agriculture’s Food Security Scale). Population-weighted adjusted regression models were used to investigate associations between FI, and forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), their ratio, and spirometrically defined restriction (FVC below the lower limit of normal) and airflow obstruction (COPD). The prevalence of household FI was 13.2%. High household FI was associated with lower FVC (adjusted β-coefficient −70.9 mL, 95% CI −116.6, −25.3), and with higher odds (OR) of spirometric restriction (1.02, 95% CI 1.00, 1.03). Stratified analyses showed similar effect sizes within specific ethnic groups. High FI was associated with worse lung health in a nationally representative sample of adults in the US.

Gut Microbiota, in the Halfway between Nutrition and Lung Function

The gut microbiota is often mentioned as a “forgotten organ” or “metabolic organ”, given its profound impact on host physiology, metabolism, immune function and nutrition. A healthy diet is undoubtedly a major contributor for promoting a “good” microbial community that turns out to be crucial for a fine-tuned symbiotic relationship with the host. Both microbial-derived components and produced metabolites elicit the activation of downstream cascades capable to modulate both local and systemic immune responses. A balance between host and gut microbiota is crucial to keep a healthy intestinal barrier and an optimal immune homeostasis, thus contributing to prevent disease occurrence. How dietary habits can impact gut microbiota and, ultimately, host immunity in health and disease has been the subject of intense study, especially with regard to metabolic diseases. Only recently, these links have started to be explored in relation to lung diseases. The objective of this review is to address the current knowledge on how diet affects gut microbiota and how it acts on lung function. As the immune system seems to be the key player in the cross-talk between diet, gut microbiota and the lungs, involved immune interactions are discussed. There are key nutrients that, when present in our diet, help in gut homeostasis and lead to a healthier lifestyle, even ameliorating chronic diseases. Thus, with this review we hope to incite the scientific community interest to use diet as a valuable non-pharmacological addition to lung diseases management. First, we talk about the intestinal microbiota and interactions through the intestinal barrier for a better understanding of the following sections, which are the main focus of this article: the way diet impacts the intestinal microbiota and the immune interactions of the gut–lung axis that can explain the impact of diet, a key modifiable factor influencing the gut microbiota in several lung diseases.

Lycopene and Caffeic Acid Phenethyl Ester Affect Caspase-3 Activity, but Do Not Alter the NO Pathway in Lung Tissue Damage Induced by Cisplatin

INTRODUCTION

Antioxidants such as lycopene (LCP) and caffeic acid phenethyl ester (CAPE) represent ideal molecules for the treatment of different reactive oxygen species (ROS) associated disorders. Cisplatin is a chemotherapeutic agent, causing an increase in ROS and DNA damage, with numerous side effects, which include lung toxicity. In the presents study, we evaluated and mutually compared the potential of LCP and CAPE in preventing cisplatin-induced rat lung damage.

METHODS

The study was done using pathohistological analysis and a panel of biochemical parameters that reflect lung oxidative tissue damage, inflammation, and apoptosis.

RESULTS

The obtained results suggest that cisplatin (10 mg/kg) causes significant disturbances in the lung tissue morphology, followed by an increase in lipid peroxidization and protein modification. Also, a pronounced inflammatory response and cell apoptosis cascade activation was noted. Both LCP and CAPE were able to mitigate the changes, to a different extent, in oxidative damage and apoptosis progression induced by cisplatin. However, they both had limited effect on inflammation since they only prevented an increase in myeloperoxidase activity but had not been able to prevent the NO generation.

CONCLUSION

It is hard to be exact in saying whether LCP or CAPE is better in preventing cis-platin-induced lung damage since they obviously possess different mechanisms of action.

The Impact of Changes in the Intake of Fiber and Antioxidants on the Development of Chronic Obstructive Pulmonary Disease

Diet is a health-related factor that can modify lung function. This study hypothesized that the change in age-related dietary intake affects lung function. The subjects who undertook a dietary assessment and spirometry in 2012 and 2017, were retrospectively collected in a health screening center. Dietary intakes were directly evaluated using food frequency questionnaires (FFQ) administered by trained dietitians and were compared at the baseline (2012) and 5-year follow-up (2017). A forced expiratory volume in one second (FEV₁)/forced vital capacity (FVC) value below 0.70 was defined as airflow limitation. Logistic regression models were used to estimate the odds ratio (ORs) adjusted for potential confounders. A total of 1439 subjects with normal spirometry were enrolled. New airflow limitations were detected in 48 subjects (3.3%) at the 5-year follow-up, including 41 (85.4%) men and 11 (22.9%) current smokers. After adjusting for age, sex, smoking history, and baseline FEV1/FVC, the odd ratios (OR) for new airflow limitation in fiber, vitamin C, and folic acid per 10% decrease in daily recommended requirement were 2.714 (95% confidence interval (CI), 1.538–4.807; p = 0.001), 1.083 (95% CI: 1.020–1.149; p = 0.007), and 1.495 (95% CI: 1.172–1.913; p = 0.001), respectively. A decreased intake of dietary fiber, vitamin C, and folic acid is associated with a newly developed airflow limitation.

The associations between dietary pattern of chronic obstructive pulmonary disease patients and depression: a cross-sectional study

Background

Chronic obstructive pulmonary disease (COPD) is a common lung disease during middle age which one of its complications is depression. Depression is considered one of the major causes of severe disability worldwide. One of the factors that affect the severity and incidence of this disease is a lifestyle, especially dietary pattern. On the other hand, some studies showed the relationship between dietary patterns and depression. The present study aims to investigate the dietary patterns of people with chronic obstructive pulmonary disease and its association with depression.

Methods

The present cross-sectional study was performed on 220 patients (mean ± SD age = 54.58 ± 5.08) with chronic obstructive pulmonary disease (56.6% men, 43.4% women) from Tabriz, Iran. Questionnaires of general information, food frequency, Beck depression and physical activity were completed. The dominant dietary patterns were determined by factor analysis, and their relationship with depression was discussed by regression analysis.

Results

Three dominant dietary patterns were identified as healthy, unhealthy, and mixed dietary patterns. An inverse relationship was found between healthy and mixed dietary patterns with depression. There is no meaningful connection between unhealthy dietary patterns and depression. Depression had a significant inverse relationship with physical activity. There was no relationship between dietary patterns and Forced Expiratory Volume for 1 s (FEV1) and Forced Vital Capacity (FVC) criteria. A positive and significant relationship was observed between mixed dietary patterns with FEV1/FVC.

Conclusion

Inverse relationships exist between healthy dietary patterns and depression in patients with COPD, and improves the function of the lungs. Further studies are needed to show the exact relationship between diet and COPD depression.

The Association of Dietary Macronutrients with Lung Function in Healthy Adults Using the Ansan-Ansung Cohort Study

This study is aimed to examine the association between macronutrient intake and lung function in healthy adults (n = 5880) using the Ansan-Ansung cohort study. To identify the index of lung function, we used the percentage difference of predicted Forced Expiratory Volume (%FEV_{1_diff}) between baseline and follow-up. Based on the median %FEV_{1_diff}, subjects were classified by two groups as “decreased vs. unchanged/improved”. The dietary macronutrients were estimated and validated using the food-frequency questionnaire. Multiple logistic regression models were used to evaluate the association after adjusting for confounders. Advanced analysis examined the association after stratifying by age and obesity. The average of %FEV₁ is 114.1 and 112.5 at baseline and follow-up, respectively. The positive association of protein and fiber intake with lung function was observed in men. Low fat and high carbohydrate intake decreased the lung function in women only. After stratification by age, the association of protein, fat, and carbohydrate intake with lung function was observed in young men and old women only. Otherwise, the association of protein and fiber with lung function was influenced by abdominal obesity. In conclusion, the lung function was positively associated with high protein and fat intake, but was negatively associated with high carbohydrate intake, which could be influenced by age and obesity.

Fecal microbial transplantation and a high fiber diet attenuates emphysema development by suppressing inflammation and apoptosis

Recent work has suggested a microbial dysbiosis association between the lung and gut in respiratory diseases. Here, we demonstrated that gut microbiome modulation attenuated emphysema development. To modulate the gut microbiome, fecal microbiota transplantation (FMT) and diet modification were adopted in mice exposed to smoking and poly I:C for the emphysema model. We analyzed the severity of emphysema by the mean linear intercept (MLI) and apoptosis by the fluorescent TUNEL assay. Microbiome analysis was also performed in feces and fecal extracellular vesicles (EVs). The MLI was significantly increased with smoking exposure. FMT or a high-fiber diet (HFD) attenuated the increase. Weight loss, combined with smoking exposure, was not noted in mice with FMT. HFD significantly decreased macrophages and lymphocytes in bronchoalveolar lavage fluid. Furthermore, IL-6 and IFN-γ were decreased in the bronchoalveolar lavage fluid and serum. The TUNEL score was significantly lower in mice with FMT or HFD, suggesting decreased cell apoptosis. In the microbiome analysis, Bacteroidaceae and Lachnospiraceae, which are alleged to metabolize fiber into short-chain fatty acids (SCFAs), increased at the family level with FMT and HFD. FMT and HFD attenuated emphysema development via local and systemic inhibition of inflammation and changes in gut microbiota composition, which could provide a new paradigm in COPD treatment.

Relationship between dietary patterns and COPD: a systematic review and meta-analysis

Background

Findings from previous studies reporting on the associations between chronic obstructive pulmonary disease (COPD) and various dietary patterns have been inconsistent. This review aims to summarise the evidence on the strength of the association between dietary patterns and the prevalence and incidence of COPD.

Methods

We conducted a comprehensive search of seven databases between 1 January 1980 and 30 November 2019. Two reviewers independently reviewed each manuscript through the screening, selection, data extraction and quality assessment stages. Data from eight observational studies that met the inclusion criteria were extracted and random-effects meta-analysis was subsequently conducted.

Results

Eight observational studies (all eight reporting on healthy dietary patterns and three on unhealthy dietary patterns) met the inclusion criteria and data were extracted to include in the meta-analysis. Consumption of a healthy dietary pattern was associated with a lower risk of COPD (pooled OR 0.88, 95% CI 0.82–0.94). Consumption of unhealthy dietary patterns was associated with a higher risk of COPD (OR 1.22, 95% CI 0.84–1.76); however, the results were not statistically significant and had high heterogeneity (I²=91%).

Conclusion

Our results suggests that healthy dietary patterns are associated with a lower prevalence of COPD, while unhealthy dietary patterns are not. More studies, particularly adequately powered longitudinal studies, are needed to further elucidate the effects of healthy and unhealthy dietary patterns on risk of COPD.

This review suggests that individuals with healthy dietary pattern have lower risk of chronic obstructive pulmonary diseasehttp://bit.ly/331PVJ1

Evaluation of nutritional status in COPD according to the GOLD-2015 staging system: a prospective observational study

OBJECTIVES

This study aimed to assess nutritional statuses of chronic obstructive pulmonary disease (COPD) patients in four categories of the Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2015 classification and to evaluate associations of body mass index (BMI) and fat-free mass index with respiratory and skeletal muscle strengths.

METHODS

This prospective observational study included COPD patients (≥40 years old) who were followed-up for at least 1 year. Medical histories, smoking status, and anthropometric, spirometry, and hand grip strength measurements were recorded.

RESULTS

This study included 463 COPD patients. They were classified as Group A (n = 119), Group B (n = 58), Group C (n = 117), and Group D (n = 169) according to GOLD. Group D was older (p = 0.001) than other groups. No difference was found among the groups regarding sex (p = 0.163). Fat-free body mass was significantly decreased in Group D compared with Group A (p = 0.014) and BMI were lower in Groups C and D than in other groups (p = 0.001). Spirometry and hand grip strength showed a significant decreasing trend toward Group D (p < 0.001 for both).

CONCLUSIONS

Patients with COPD in advanced-stages had decreased BMI, fat-free body mass, hand grip strength, and respiratory and skeletal muscle functions. Nutritional status should be routinely monitored and considered an important indicator in COPD.

Dietary antioxidant intake in school age and lung function development up to adolescence

Dietary antioxidant intake has been hypothesised to influence lung function. The association between total antioxidant capacity (TAC) of the diet at age 8 years and lung function development up to 16 years in 2307 participants from the Swedish population-based birth cohort BAMSE (Children, Allergy, Milieu, Stockholm, Epidemiology) was investigated.

Information on TAC was obtained from a food frequency questionnaire at 8 years. Lung function was measured by spirometry at 8 and 16 years, impulse oscillometry (IOS) and exhaled nitric oxide fraction (F_eNO) at 16 years. Low lung function was defined as forced expiratory volume in 1 s (FEV₁) z-score below the 25th percentile. Longitudinal associations between TAC and lung function were analysed by mixed effect models adjusted for potential confounders. Stratification by asthma at 8 years was performed to examine effect modification.

The median TAC intake was 10 067 μmol Trolox equivalents (TE)·g⁻¹, with males having a lower mean compared to females (9963 versus 10 819 μmol TE·g⁻¹). In analyses of lung function change between 8 and 16 years, there were no statistically significant associations between TAC in tertiles and spirometry results for the total study population. Among children with asthma at 8 years (prevalence 7%), higher TAC was associated with higher mean FEV₁ (0.46 sd, 95% CI 0.11–0.80) and decreased odds of low lung function at 16 years (OR 0.28, 95% CI 0.12–0.65). There were no associations between TAC and forced vital capacity or IOS/F_eNO results.

High dietary antioxidant intake in school age may be associated with improved lung function development from school age to adolescence among children with asthma.

Dietary antioxidant intake at school age may influence lung function development as measured by FEV₁ up to adolescence among children with asthma. In contrast, no association was observed among children without asthma.http://bit.ly/2CzEZ8W

Findings from an exploration of a social network intervention to promote diet quality and health behaviours in older adults with COPD: a feasibility study

Background

Diet quality in older people with chronic obstructive pulmonary disease (COPD) is associated with better health and lung function. Social factors, such as social support, social networks and participation in activities, have been linked with diet quality in older age. A social network tool—GENIE (Generating Engagement in Network Involvement)—was implemented in a COPD community care context. The study aimed to assess the feasibility of the GENIE intervention to promote diet quality and other health behaviours in COPD.

Methods

Twenty-two community-dwelling older adults with COPD were recruited from a local COPD service. Participants were offered usual care or the GENIE intervention. Process evaluation methods were used to assess intervention implementation, context and mechanisms of impact; these included observations of patient interactions with the intervention, documented in observational field notes and in films of a patient group discussion. Diet quality was assessed by food frequency questionnaire; ‘prudent’ diet scores were used to describe diet quality at baseline and at 3-month follow-up. Change in diet quality was expressed per month, from baseline to follow-up.

Results

Feasibility data showed that the GENIE intervention could be implemented in this sample of community-living older people. The intervention was acceptable to clinicians and older people with COPD, especially for those with less severe disease, when facilitated appropriately and considering the levels of literacy of participants. There was no significant change in diet quality in the intervention group over the follow-up period (median change in prudent diet score per month (interquartile range (IQR), 0.03 (− 0.24–0.07)), whereas an overall fall in diet quality was observed in the control group (− 0.15 (− 0.24–0.03)).

Conclusion

The process evaluation findings suggest that this intervention is feasible and acceptable to both patients and clinicians. Although the sample size achieved in this study was small, findings suggest that the intervention may have a protective effect against declines in diet quality, and other health behaviours, in an older COPD population. Findings from this feasibility study indicate that further evaluation of the GENIE intervention is warranted in a larger study, with a longer follow-up.

Trial registration

ClinicalTrials.gov, NCT02935452. NIH U.S. National Library of Medicine. Registered 17 October 2016.

Skipping breakfast and physical fitness among school-aged adolescents

OBJECTIVES

This study explored the relationship between skipping breakfast and physical fitness in a group of school-aged adolescents in China.

METHODS

This cross-sectional study from the Chinese National Surveillance on Students' Constitution and Health (CNSSCH) survey in Ningbo, China, used a standardized questionnaire to assess the frequency of breakfast consumption. Physical fitness was measured through standing long jump, 50-m sprint, 1,000 (or 800)-m run, and vital capacity tests. Multiple linear regression analysis was used to investigate the relationship between the frequency of breakfast consumption and physical fitness.

RESULTS

Our study included a total of 1,849 school-aged adolescents (aged 15.53±1.80 years). Among boys, non-breakfast-skippers had good scores for 50-m sprints, 1,000-m run, and vital capacity tests when compared with breakfast skippers (all p<0.05). Among girls, non-breakfast-skippers had a good scores for the standing long jump test compared with breakfast skippers (p=0.003). The multiple linear regression model showed that not skipping breakfast was positively associated with vital capacity (β=-173.78, p=0.004) and inversely associated with 50-m sprint (β=-0.12, p=0.018) and 1,000-m run times (β=-8.08, p=0.001) in boys.

CONCLUSION

The results of this cross-sectional study revealed that skipping breakfast might be associated with lower physical fitness in Chinese adolescents aged 13-18 years, especially boys. Breakfast consumption should be promoted among Chinese school-aged boys.

A clinical trial to evaluate the effect of the Mediterranean diet on smokers lung function

Data on the association between lung function and some dietary patterns have been published. However, it is not yet well known if whether the Mediterranean Diet (MD) pattern can preserve or improve lung function. Our purpose is to evaluate the effect of increased MD adherence on lung function in smokers. A multicenter, parallel, cluster-randomized, controlled clinical trial is proposed. A total of 566 active smokers (>10 packs-year), aged 25–75 years will be included, without previous respiratory disease and who sign an informed consent to participate. Twenty Primary Care Centres in Tarragona (Spain) will be randomly assigned to a control or an intervention group (1:1). All participants will receive advice to quit smoking, and the intervention group, a nutritional intervention (2 years) designed to increase MD adherence by: (1) annual visit to deliver personalized nutritional education, (2) annual telephone contact to reinforce the intervention, and (3) access to an online dietary blog. We will evaluate (annually for 2 years): pulmonary function by forced spirometry and MD adherence by a 14-item questionnaire and medical tests (oxidation, inflammation and consumption biomarkers). In a statistical analysis by intention-to-treat basis, with the individual smoker as unit of analysis, pulmonary function and MD adherence in both groups will be compared; logistic regression models will be applied to analyze their associations. We hope to observe an increased MD adherence that may prevent the deterioration of lung function in smokers without previous respiratory disease. This population may benefit from a dietary intervention, together with the recommendation of smoking cessation.

COPD and the gut-lung axis: the therapeutic potential of fibre

Current management strategies for chronic obstructive pulmonary disease (COPD) incorporate a step-wise, multidisciplinary approach to effectively manage patient symptoms and prevent disease progression. However, there has been limited advancement in therapies to address the underlying cause of COPD pathogenesis. Recent research has established the link between the lungs and the gut-the gut-lung axis -and the gut microbiome is a major component. The gut microbiome is likely perturbed in COPD, contributing to chronic inflammation. Diet is a readily modifiable factor and the diet of COPD patients is often deficient in nutrients such as fibre. The metabolism of dietary fibre by gut microbiomes produces anti-inflammatory short chain fatty acid (SCFAs), which could protect against inflammation in the lungs. By addressing the 'fibre gap' in the diet of COPD patients, this targeted dietary intervention may reduce inflammation, both systemically and in the airways, and value-add to the paradigm shift in respiratory medicine, from reactive to personalised and participatory medicine.

Role of Diet in Chronic Obstructive Pulmonary Disease Prevention and Treatment

Chronic obstructive pulmonary disease is one of the leading causes of morbidity and mortality worldwide and a growing healthcare problem. Identification of modifiable risk factors for prevention and treatment of COPD is urgent, and the scientific community has begun to pay close attention to diet as an integral part of COPD management, from prevention to treatment. This review summarizes the evidence from observational and clinical studies regarding the impact of nutrients and dietary patterns on lung function and COPD development, progression, and outcomes, with highlights on potential mechanisms of action. Several dietary options can be considered in terms of COPD prevention and/or progression. Although definitive data are lacking, the available scientific evidence indicates that some foods and nutrients, especially those nutraceuticals endowed with antioxidant and anti-inflammatory properties and when consumed in combinations in the form of balanced dietary patterns, are associated with better pulmonary function, less lung function decline, and reduced risk of COPD. Knowledge of dietary influences on COPD may provide health professionals with an evidence-based lifestyle approach to better counsel patients toward improved pulmonary health.

Long-term consumption of fruits and vegetables and risk of chronic obstructive pulmonary disease: a prospective cohort study of women

Background

Fruits and vegetables, due to high antioxidant capacity, may protect the lung from oxidative damage caused by tobacco smoke and potentially prevent chronic obstructive pulmonary disease (COPD). Only one study based on baseline diet has examined fruit and vegetable consumption in relation to risk of COPD, and no previous studies have examined long-term diet.

Methods

We investigated whether long-term fruit and vegetable consumption was associated with COPD incidence among 34 739 women (age 48-83 years) in the population-based prospective Swedish Mammography Cohort. Fruit and vegetable consumption was assessed twice (1987, 1997) with a self-administered questionnaire. Cases of COPD were identified by linkage to the Swedish health register. Cox proportional hazard regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

During follow-up from 2002 to 2014, 1512 women were diagnosed with COPD. Long-term fruit was associated with lower risk of COPD; women in the highest vs lowest quintile of consumption (≥2.5 vs <0.8 servings/day) had a 37% lower risk of COPD (95% CI: 25-48%; P-trend < 0.0001). No association was observed with long-term vegetable intake. Current and ex-smokers with low long-term consumption of fruits (<1 serving/day) in comparison to never smokers with high consumption (≥3 servings/day) had a 38-fold (HR: 38.1; 95% CI: 20.2-71.7) and 13-fold (HR: 12.5, 95% CI: 6.5-24.1) higher risk of COPD, respectively. However, no significant interaction between smoking status and fruit intake in relation to COPD incidence was observed (P-interaction = 0.95).

Conclusions

In this prospective cohort of middle-age and older women, long-term consumption of fruits but not vegetables was inversely associated with COPD incidence.

Omega-3 fatty acid intake and prevalent respiratory symptoms among U.S. adults with COPD

Background

Omega-3 fatty acids, including alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and derivatives, play a key role in the resolution of inflammation. Higher intake has been linked to decreased morbidity in several diseases, though effects on respiratory diseases like COPD are understudied.

Methods

The National Health and Nutrition Examination Survey (NHANES), with a focus on dietary assessment, provides a unique opportunity to explore relationships between omega-3 intake and morbidity in respiratory diseases marked by inflammation in the United States (US) population. We investigated relationships between ALA or EPA + DHA intake and respiratory symptoms among US adults with COPD, as well as variation in relationships based on personal characteristics or exposures.

Results

Of 878 participants, mean age was 60.6 years, 48% were current smokers, and 68% completed high school. Omega-3 intake was, 1.71 ± 0.89 g (ALA), and 0.11 ± 0.21 g (EPA + DHA). Logistic regression models, adjusting for age, gender, race, body mass index, FEV₁, education, smoking status, pack-years, total caloric intake, and omega-6 (linoleic acid, LA) intake demonstrated no primary associations between omega-3 intake and respiratory symptoms. Interaction terms were used to determine potential modification of relationships by personal characteristics (race, gender, education) or exposures (LA intake, smoking status), demonstrating that at lower levels of LA intake, increasing ALA intake was associated with reduced odds of chronic cough (p_int = 0.015) and wheeze (p_int = 0.037). EPA + DHA, but not ALA, was associated with reduced symptoms only among current smokers who did not complete high school.

Conclusions

Individual factors should be taken into consideration when studying the association of fatty acid intake on respiratory diseases, as differential responses may reveal susceptible subgroups.

Electronic supplementary material

The online version of this article (10.1186/s12890-019-0852-4) contains supplementary material, which is available to authorized users.

Association between Soft Drink Consumption and Asthma among Qatari Adults

We aimed to examine the association between soft drink consumption and asthma and lung function among Qatari adults. In the cross-sectional study, we used data from 986 Qatari participants aged 20 years and above attending the Qatar Biobank Study. Usual consumption of soft drink was assessed using a food frequency questionnaire. Lung function was measured by spirometry and asthma was based on self-report. The associations between soft drink consumption and asthma and lung function were assessed using multivariable logistic and linear regression, respectively. In total, 65 participants out of 986 (6.6%) reported having asthma. A clear dose-response relationship between soft drink consumption and asthma was found. High soft drink consumers (≥7 times/week) were 2.60 (95% CI 1.20–5.63) times more likely to have asthma as compared to non-consumers. The association was partly mediated by BMI and inflammation. Diet soft drink consumption was positively associated with asthma (OR 1.12 (95% CI 1.02–1.23)) but not with lung function. Regular soft drink consumption was inversely associated with FEV1, but not with FVC. In conclusion, soft drink consumption is positively associated with asthma in Qatari adults. The association is partly mediated by obesity and inflammation. Limiting soft drink consumption should be taken into consideration for asthma prevention.

Saturated Fat Intake Is Associated with Lung Function in Individuals with Airflow Obstruction: Results from NHANES 2007⁻2012

Nutritional status is a well-recognized prognostic indicator in chronic obstructive pulmonary disease (COPD); however, very little is known about the relationship between lung function and saturated fat intake. We used data from the cross-sectional National Health and Nutrition Examination Surveys (NHANES) to assess the relationship between saturated fatty acid (SFA) intake and lung function in the general US adult population. Adults in NHANES (2007⁻2012) with pre-bronchodilator spirometry measurements and dietary SFA intake were included. Primary outcomes were lung function including forced expiratory volume in one second (FEV₁)_, FEV₁, forced vital capacity (FVC), FEV₁/FVC ratio, percent predicted FEV₁ and percent predicted FVC. Multivariable regression models in the general population as well as those with spirometry-defined airflow obstruction were used to assess the relationship between lung function measurements and dietary SFA intake after adjustment for confounders. 11,180 eligible participants were included in this study. Univariate analysis revealed a statistically significant positive association between total SFA intake and lung function outcomes; however, these relationships were attenuated after adjustment for covariates. A secondary analysis of individuals with spirometry-defined airflow obstruction (FEV₁/FVC < 0.7) revealed that a lower intake of SFA was associated with reduced FEV₁ (β = -126.4, p = 0.04 for quartile 1 vs. quartile 4), FVC (β = -165.8. p = 0.01 for quartile 1 vs. quartile 4), and percent predicted FVC (β = -3.3. p = 0.04 for quartile 1 vs. quartile 4), after adjustment for relevant confounders. No associations were observed for the FEV₁/FVC ratio and percent predicted FEV₁. It is possible that characteristics such as food source and fatty acid chain length may influence associations between saturated fatty acid intake and health outcomes.

Socioeconomic status and pulmonary function, transition from childhood to adulthood: cross-sectional results from the polish part of the HAPIEE study

OBJECTIVE

Previous studies have reported inverse associations between socioeconomic status (SES) and lung function, but less is known about whether pulmonary function is affected by SES changes. We aimed to describe the relationship of changes of SES between childhood and adulthood with pulmonary function.

DESIGN

Cross-sectional study.

PARTICIPANTS

The study sample included 4104 men and women, aged 45-69 years, residents of Krakow, participating in the Polish part of the Health, Alcohol and Psychosocial Factors in Eastern Europe Project.

MAIN OUTCOME

Forced expiratory volume (FEV₁) and forced vital capacity (FVC) were assessed by the standardised spirometry procedure. Participants were classified into three categories of SES (low, moderate or high) based on information on parent's education, housing standard during childhood, own education, employment status, household amenities and financial status.

RESULTS

The adjusted difference in mean FVC between persons with low and high adulthood SES was 100 mL (p=0.005) in men and 100 mL (p<0.001) in women; the differences in mean FEV₁ were 103 mL (p<0.001) and 80 mL (p<0.001), respectively. Upward social mobility and moderate or high SES at both childhood and adulthood were related to significantly higher FEV₁ and FVC compared with low SES at both childhood and adulthood or downward social mobility.

CONCLUSIONS

Low SES over a life course was associated with the lowest lung function. Downward social mobility was associated with a poorer pulmonary function, while upward mobility or life course and moderate or high SES were associated with a better pulmonary function.