Diet and vitamin D as risk factors for lung impairment and COPD

The Associations Between Serum Vitamins and Carotenoids with Chronic Obstructive Pulmonary Disease: Results from the NHANES

Purpose

Vitamins and carotenoids are essential in preventing and treating chronic obstructive pulmonary disease (COPD). This study investigated the associations between serum vitamins, carotenoids, and COPD in adults aged ≥ 40 years in the United States.

Methods

We selected 3487 participants aged ≥40 from the NHANES (2017-2018) and used demographic analysis, sensitivity tests, and different weighted multivariate regression models to investigate the relationship between serum vitamins, carotenoids, and COPD.

Results

Subjects in the highest tertile of serum vitamin C, vitamin E (α-tocopherol), α-carotene, trans-β-carotene, and cis-β-carotene had a 50%, 35%, 51%, 54%, and 51% lower risk of COPD than those in the lowest tertile (P for trend: P=0.0005, <0.0001, 0.0054, 0.0066, and 0.0049). Unfortunately, no significant correlation was found for serum vitamin D levels.

Conclusion

Our analysis of nationally representative data from 3487 participants showed that serum levels of vitamin C, vitamin E (α-tocopherol), α-carotene, and β-carotene were negatively associated with the incidence of COPD in adults over 40 years of age in the US The findings highlighted the importance of antioxidant vitamins and carotenoids in respiratory health, while the data showed no significant correlation between vitamin D (25-OHD) and the incidence of COPD.

Association of Dietary intake of vitamin E with chronic obstructive pulmonary disease events in US adults: A cross-sectional study of NHANES 2013-2018

Introduction

Several studies have demonstrated that vitamin E intake is negatively associated with the development of several diseases, but the relationship between vitamin E intake and COPD in different groups of people is not clear. The aim was to investigate the relationship between vitamin E intake and COPD in different groups of people.

Methods

This study used data from NHANES (National Health and Nutrition Examination Survey) from 2013-2018. A final total of 4,706 participants were included, univariate versus multivariate logistic regression and restricted cubic spline models adjusted for confounders were used to explore the relationship between vitamin E intake and COPD, and subgroup analyses were conducted to assess whether there are differences in the relationship between vitamin E intake and COPD in different populations or conditions.

Results

After adjusting for potential confounders, higher vitamin E intake showed a significant negative association with COPD [Model 1(unadjusted covariates, OR = 0.48;95% CI:0.33-0.70; p < 0.001), Model 2(adjusted for age, sex, and race, OR = 0.48;95% CI:0.31-0.73; p < 0.01), and Model 3(adjusted for all covariates, OR = 0.57;95% CI:0.36-0.91; p = 0.02)]. And a restricted cubic spline curve showed a significant negative correlation between vitamin E intake and COPD (p for nonlinear = 0.2036). In the subgroup analysis, we found a negative association between vitamin E intake and COPD in all subgroups as well.

Conclusion

After analyzing data based on the NHANES database from 2013-2018, the results showed that vitamin E intake among U.S. adults was well below the recommended levels and that higher vitamin E intake was negatively associated with COPD incidence.

Perspectives: on Precision Nutrition Research in Heart, Lung, and Blood Diseases and Sleep Disorders

The release of the 2020-2030 Strategic Plan for NIH Nutrition Research (SPNR) and its emphasis on precision nutrition has provided an opportunity to identify future nutrition research that addresses individual variability in response to diet and nutrition across the life span-including those relevant to the Strategic Vision of the National Heart, Lung, and Blood Institute (NHLBI). The SPNR and the NHLBI's Strategic Vision were developed with extensive input from the extramural research community, and both have 4 overarching strategic goals within which are embedded several objectives for research. For the SPNR, these include 1) spur discovery science and normal biological functions (e.g., role of the microbiome in health and disease), 2) population science to understand individual differences (e.g., biomarkers including 'omics that predict disease status), 3) emerging scientific areas of investigation and their application (e.g., data science, artificial intelligence), and 4) cross-cutting themes (e.g., training the scientific workforce and minority health and health disparities). These strategic goals and objectives serve as blueprints for research and training. Nutrition remains important in the prevention and treatment of heart, lung, blood, and sleep (HLBS) disorders and diseases, and the NHLBI has played a pivotal role in supporting nutrition research. In this paper, we report important gaps in the scientific literature related to precision nutrition in HLBS diseases. Research opportunities that could stimulate precision nutrition and their alignment with the SPNR and the NHLBI Strategic Vision Objectives are provided. These opportunities include 1) exploring individual differences in response to varying dietary patterns and nutrients; 2) investigating genetic/epigenetic, biological (e.g., microbiome, biomarkers), social, psychosocial, and environmental underpinnings of individual variability in diet; 3) elucidating the role of circadian rhythm and chrononutrition; and 4) applying implementation science research methods in precision nutrition interventions relevant to HLBS diseases.

Joint Effects of Carbon Black Exposure and Dietary Antioxidant Vitamin Intake on Small Airway Dysfunction

Objectives: Small airway dysfunction is considered as a precursor of chronic obstructive pulmonary disease and asthma. Our aim was to explore the joint effects of carbon black (CB) exposure and antioxidant vitamin intake on small airway dysfunction.

Methods: A total of 70 CB packers (CBPs) and 107 non-CBPs were enrolled from an established cohort of CBP. Carbon content in airway macrophage (CCAM) quantified in induced sputum was used as a bio-effective dosimetry for exposure to CB. Logistic regression models were used to examine the odds ratios (ORs) of CB and dietary intake of antioxidant vitamins on small airway dysfunction, and the dose–response association.

Results: The prevalence of small airway dysfunction was 32.9% (23 of 70) among CBPs, and 19.6% (21 of 107) among non-CBPs. For each 2.72-fold increase in CCAM, the OR of small airway dysfunction was 2.31 (95% CI = 1.20–4.44). For every 10 mg day⁻¹ increase of the vitamin C intake, the risk of small airway dysfunction decreased by 6% (OR = 0.94, 95% CI = 0.88–0.99). Compared to non-CB exposure and higher vitamin C intake, CB exposure and lower vitamin C intake (OR = 7.56, 95% CI = 1.80 to 31.81) were associated with an increased risk of small airway dysfunction.

Conclusions: Chronic exposure to a high level of CB aerosol increased the risk of small airway dysfunction in CB baggers. Dietary intake of vitamin C might be a modifiable factor for preventing small airway dysfunction.

Dietary ω-6 polyunsaturated fatty acid arachidonic acid increases inflammation, but inhibits ECM protein expression in COPD

Background

The obesity paradox in COPD describes protective effects of obesity on lung pathology and inflammation. However, the underlying relationships between obesity, diet and disease outcomes in COPD are not fully understood. In this study we measured the response to dietary fatty acids upon markers of inflammation and remodelling in human lung cells from people with and without COPD.

Methods

Pulmonary fibroblasts were challenged with ω-3 polyunsaturated fatty acids (PUFAs), ω-6 PUFAs, saturated fatty acids (SFAs) or the obesity-associated cytokine TNFα. After 48–72 h release of the pro-inflammatory cytokines interleukin (IL)-6 and CXCL8 was measured using ELISA and mRNA expression and deposition of the extracellular matrix (ECM) proteins fibronectin, type I collagen, tenascin and perlecan were measured using qPCR or ECM ELISA, respectively.

Results

Challenge with the ω-6 PUFA arachidonic acid (AA), but not ω-3 PUFAs or SFAs, resulted in increased IL-6 and CXCL8 release from fibroblasts, however IL-6 and CXCL8 release was reduced in COPD (n = 19) compared to non-COPD (n = 36). AA-induced cytokine release was partially mediated by downstream mediators of cyclooxygenase (COX)-2 in both COPD and non-COPD. In comparison, TNFα-induced IL-6 and CXCL8 release was similar in COPD and non-COPD, indicating a specific interaction of AA in COPD. In patients with or without COPD, regression analysis revealed no relationship between BMI and cytokine release. In addition, AA, but not SFAs or ω-3 PUFAs reduced the basal deposition of fibronectin, type I collagen, tenascin and perlecan into the ECM in COPD fibroblasts. In non-COPD fibroblasts, AA-challenge decreased basal deposition of type I collagen and perlecan, but not fibronectin and tenascin.

Conclusions

This study shows that AA has disease-specific effects on inflammation and ECM protein deposition. The impaired response to AA in COPD might in part explain why obesity appears to have less detrimental effects in COPD, compared to other lung diseases.

Electronic supplementary material

The online version of this article (10.1186/s12931-018-0919-4) contains supplementary material, which is available to authorized users.

Potential Micronutrients and Phytochemicals against the Pathogenesis of Chronic Obstructive Pulmonary Disease and Lung Cancer

Lung cancer and chronic obstructive pulmonary disease have shared etiology, including key etiological changes (e.g., DNA damage and epigenetics change) and lung function impairment. Focusing on those shared targets may help in the prevention of both. Certain micronutrients (vitamins and minerals) and phytochemicals (carotenoids and phenols) have potent antioxidant or methyl-donating properties and thus have received considerable interest. We reviewed recent papers probing into the potential of nutrients with respect to lung function preservation and prevention of lung cancer risk, and suggest several hypothetical intervention patterns. Intakes of vitamins (i.e., A, C, D, E, B₁₂), carotenoids, flavonoids, curcumins, resveratrol, magnesium, and omega-3 fatty acids all show protective effects against lung function loss, some mainly by improving average lung function and others through reducing decline rate. Dietary interventions early in life may help lung function reserve over the lifespan. Protective nutrient interventions among smokers are likely to mitigate the effects of cigarettes on lung health. We also discuss their underlying mechanisms and some possible causes for the inconsistent results in observational studies and supplementation trials. The role of the lung microbiome on lung health and its potential utility in identifying protective nutrients are discussed as well. More prospective cohorts and well-designed clinical trials are needed to promote the transition of individualized nutrient interventions into health policy.

Can muscle protein metabolism be specifically targeted by nutritional support and exercise training in chronic obstructive pulmonary disease?

Chronic obstructive pulmonary disease (COPD) associates with several extra-pulmonary effects. Muscle dysfunction and wasting is one of the most prominent extra-pulmonary effects and contributes to exercise limitation and health related quality of life (HRQoL), morbidity as well as mortality. The loss of muscle mass is characterised by an impaired balance between protein synthesis (anabolism) and protein breakdown (catabolism) which relates to nutritional disturbances, muscle disuse and the presence of a systemic inflammation, among other factors. Current approaches to reverse skeletal muscle dysfunction and wasting attain only modest improvements. The development of new therapeutic strategies aiming at improving skeletal muscle dysfunction and wasting are needed. This requires a better understanding of the underlying molecular pathways responsible for these abnormalities. In this review we update recent research on protein metabolism, nutritional depletion as well as physical (in)activity in relation to muscle wasting and dysfunction in patients with COPD. We also discuss the role of nutritional supplementation and exercise training as strategies to re-establish the disrupted balance of protein metabolism in the muscle of patients with COPD. Future areas of research and clinical practice directions are also addressed.

Dietary antioxidants and 10-year lung function decline in adults from the ECRHS survey

The relationship between lung function decline and dietary antioxidants over 10 years in adults from three European countries was investigated.

In 2002, adults from three participating countries of the European Community Respiratory Health Survey (ECRHS) answered a questionnaire and underwent spirometry (forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC)), which were repeated 10 years later. Dietary intake was estimated at baseline with food frequency questionnaires (FFQ). Associations between annual lung function decline (mL) and diet (tertiles) were examined with multivariable analyses. Simes’ procedure was applied to control for multiple testing.

A total of 680 individuals (baseline mean age 43.8±6.6 years) were included. A per-tertile increase in apple and banana intake was associated with a 3.59 mL·year⁻¹ (95% CI 0.40, 7.68) and 3.69 mL·year⁻¹ (95% CI 0.25, 7.14) slower decline in FEV₁ and FVC, respectively. Tomato intake was also associated with a slower decline in FVC (4.5 mL·year⁻¹; 95% CI 1.28, 8.02). Only the association with tomato intake remained statistically significant after the Simes’ procedure was performed. Subgroup analyses showed that apple, banana and tomato intake were all associated with a slower decline in FVC in ex-smokers.

Intake of fruits and tomatoes might delay lung function decline in adults, particularly in ex-smokers.

A higher intake of fruits and tomato is associated with a slower lung function decline, particularly in ex-smokershttp://ow.ly/5LLv30gK9Bn

The Impact of a Weight Loss Intervention on Diet Quality and Eating Behaviours in People with Obesity and COPD

There is a paucity of evidence to guide clinicians about appropriate management strategies for people with obesity and Chronic Obstructive Pulmonary Disease (COPD). We have recently published results from the first weight loss intervention in adults (>18 years) with obesity (body mass index; BMI ≥ 30 kg/m²) and COPD, using a low-calorie diet coupled with a partial meal replacement plan and resistance exercise training, which resulted in a 6.4% reduction in weight while maintaining skeletal muscle mass and improving health status. This sub-study aims to evaluate the intervention by (a) examining changes in dietary intake and nutritional biomarkers and (b) examining predictors of weight loss. Dietary intake was evaluated using four-day food diaries, and analysis of plasma fatty acids and plasma carotenoids as biomarkers of dietary fat intake and fruit and vegetable intake, respectively. Twenty-eight obese COPD subjects (n = 17 males, n = 11 females) with a mean (standard deviation; SD) age of 67.6 (6.3) years completed the 12-week weight loss intervention. Pre-intervention, mean (SD) BMI was 36.3 (4.6) kg/m². Micronutrient intake improved from pre- to post-intervention, with the percentage of subjects meeting the Nutrient Reference Values increased for all micronutrients. Post-intervention, significant decreases in total (p = 0.009) and saturated fat intake (p = 0.037), and corresponding decreases in total (p = 0.007) and saturated plasma fatty acids (p = 0.003) were observed. There was a trend towards higher total carotenoids post-intervention (p = 0.078). Older age (p = 0.025), higher pre-intervention uncontrolled eating (p < 0.001) and plasma carotenoids (p = 0.009) predicted weight loss. This demonstrates the efficacy of a weight loss intervention in improving diet quality of obese COPD adults.

Circulating 25-hydroxyvitamin D level and prognosis of lung cancer patients: A systematic review and meta-analysis

BACKGROUND

Previous studies suggested a possible influence of circulating 25-hydroxyvitamin D [25(OH)D] level on the prognosis of lung cancer patients, but conflicting findings were reported. A systematic review and meta-analysis was thus conducted to comprehensively assess the influence of circulating 25(OH)D level on the prognosis of lung cancer patients.

METHODS

Prospective or retrospective cohort studies assessing the influence of circulating 25(OH)D level on the prognosis of lung cancer patients were considered eligible. Hazard Ratios (HR) were pooled using meta-analysis.

RESULTS

Eight studies with 2166 lung cancer patients were included. Meta-analysis of unadjusted HRs from four studies showed low circulating 25(OH)D level was significantly correlated with poor overall survival in lung cancer (HR=1.30, 95%CI 1.08-1.55, P=0.004). Meta-analysis of adjusted HRs from eight studies suggested that low circulating 25(OH)D level was not significantly correlated with poor overall survival (HR=1.25; P=0.13). However, sensitivity analysis suggested an obvious change in the pooled HRs when excluding single study by turns. When the study by Liu et al. was omitted, low circulating 25(OH)D level was significantly correlated with poor overall survival (HR=1.34; P=0.04).

CONCLUSION

The present systematic review and meta-analysis suggested a correlation between low circulating 25(OH)D level and poor overall survival in lung cancer. More studies are needed to further validate the finding above.

Vitamin D deficiency: What does it mean for chronic obstructive pulmonary disease (COPD)? a compherensive review for pulmonologists

OBJECTIVES

Vitamin D deficiency and Chronic Obstructive Pulmonary Disease (COPD) are both under-recognized health problems, world-wide. Although Vitamin D has long been known for calcemic effects it also has less known noncalcemic effects. Recent data have shown that Vitamin D deficiency is highly prevalent in patients with COPD and correlates with forced expiratory volume in one second (FEV₁ ) and FEV₁ decline. The objective of this work was to review the current literature on vitamin D deficiency in relation with COPD.

DATA SOURCE

A literature search, using the words "vitamin D" and "COPD", was undertaken in Pubmed database.

RESULTS

The noncalcemic effects of vitamin D relating with COPD may be summarised as increasing antimicrobial peptide production, regulation of inflammatory response and airway remodelling. Vitamin D inhibits the production of several proinflammatory cytokines and leads to suppression Th1 and Th17 responses which may be involved in the pathogenesis of COPD. Vitamin D insufficiency may also contribute to chronic respiratory infections and airway colonization so returning vitamin D concentrations to an optimal range in patients with COPD might reduce bacterial load and concomitant exacerbations.Vitamin D is also important for COPD-related comorbodities such as osteoporosis, muscle weakness and cardiovascular diseases. Data about the effect of Vitamin D supplementation on those comorbidities in relation with COPD are been scarce.

CONCLUSION

Improving the blood level of Vitamin D into the desired range may have a beneficial effect bones and muscles, but more studies are needed to test to test that hypothesis.

Dietary patterns are associated with lung function among Spanish smokers without respiratory disease

Background

Diet can help preserve lung function in smokers, in addition to avoidance of smoking. The study aimed to evaluate associations between dietary patterns and lung function in smokers without respiratory disease.

Methods

This cross-sectional study analysed baseline data from randomised representative smokers without respiratory disease (n = 207, aged 35–70 years), selected from 20 primary health-care centres. Participants completed a validated semi-quantitative food-frequency questionnaire. Dietary patterns were identified by Principal Component Analysis (PCA). Impaired lung function was defined as FVC <80% and/or FEV1 < 80% of predicted value and/or FEV1/FVC <0.7. Associations were determined by logistic regression.

Results

Three major dietary patterns were identified. In multivariate-adjusted model, impaired lung function was associated with the Alcohol-consumption pattern (OR 4.56, 95% CI 1.58–13.18), especially in women (OR 11.47, 95% CI 2.25–58.47), and with the Westernised pattern in women (OR 5.62, 95% CI 1.17–27.02), whereas it not was associated with the Mediterranean-like pattern (OR 0.71, 95% CI 0.28–1.79).

Conclusion

In smokers without respiratory disease, the Alcohol-consumption pattern and the Westernised pattern are associated with impaired lung function, especially in women. The Mediterranean-like pattern appears to be associated with preserved lung function because no statistical association is observed with impaired lung function. In addition to smoking cessation, modifying dietary patterns has possible clinical application to preserve lung function.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0326-x) contains supplementary material, which is available to authorized users.

A systematic review of methods to assess intake of sugar-sweetened beverages among healthy European adults and children: a DEDIPAC (DEterminants of DIet and Physical Activity) study

OBJECTIVE

Research indicates that intake of sugar-sweetened beverages (SSB) may be associated with negative health consequences. However, differences between assessment methods can affect the comparability of intake data across studies. The current review aimed to identify methods used to assess SSB intake among children and adults in pan-European studies and to inform the development of the DEDIPAC (DEterminants of DIet and Physical Activity) toolbox of methods suitable for use in future European studies.

DESIGN

A literature search was conducted using three electronic databases and by hand-searching reference lists. English-language studies of any design which assessed SSB consumption were included in the review.

SETTING

Studies involving two or more European countries were included in the review.

SUBJECTS

Healthy, free-living children and adults.

RESULTS

The review identified twenty-three pan-European studies which assessed intake of SSB. The FFQ was the most commonly used (n 24), followed by the 24 h recall (n 6) and diet records (n 1). There were several differences between the identified FFQ, including the definition of SSB used. In total, seven instruments that were tested for validity were selected as potentially suitable to assess SSB intake among adults (n 1), adolescents (n 3) and children (n 3).

CONCLUSIONS

The current review highlights the need for instruments to use an agreed definition of SSB. Methods that were tested for validity and used in pan-European populations encompassing a range of countries were identified. These methods should be considered for use by future studies focused on evaluating consumption of SSB.

A systematic review of methods to assess intake of fruits and vegetables among healthy European adults and children: a DEDIPAC (DEterminants of DIet and Physical Activity) study

Objective

Evidence suggests that health benefits are associated with consuming recommended amounts of fruits and vegetables (F&V), yet standardised assessment methods to measure F&V intake are lacking. The current review aims to identify methods to assess F&V intake among children and adults in pan-European studies and inform the development of the DEDIPAC (DEterminants of DIet and Physical Activity) toolbox of methods suitable for use in future European studies.

Design

A literature search was conducted using three electronic databases and by hand-searching reference lists. English-language studies of any design which assessed F&V intake were included in the review.

Setting

Studies involving two or more European countries were included in the review.

Subjects

Healthy, free-living children or adults.

Results

The review identified fifty-one pan-European studies which assessed F&V intake. The FFQ was the most commonly used (n42), followed by 24 h recall (n11) and diet records/diet history (n7). Differences existed between the identified methods; for example, the number of F&V items on the FFQ and whether potatoes/legumes were classified as vegetables. In total, eight validated instruments were identified which assessed F&V intake among adults, adolescents or children.

Conclusions

The current review indicates that an agreed classification of F&V is needed in order to standardise intake data more effectively between European countries. Validated methods used in pan-European populations encompassing a range of European regions were identified. These methods should be considered for use by future studies focused on evaluating intake of F&V.

The effect of dietary antioxidant on the COPD risk: the community-based KoGES (Ansan-Anseong) cohort

Background

Dietary antioxidants have been suggested to have protective role against chronic obstructive pulmonary disease (COPD), but few prospective studies examined this relationship. The prospective study was conducted to evaluate the effect of dietary antioxidants on COPD risk and lung function in the Korean population.

Methods

The data were collected from the community-based Korean Genome Epidemiology Study (KoGES) cohort. To diagnose COPD, forced expiratory volume (FEV₁) and forced vital capacity (FVC) were measured by spirometry. The dietary intake of antioxidant vitamins was estimated from validated Food-Frequency Questionnaire. For the analysis, 325 COPD patients and 6,781 at risk subjects were selected from the cohort of 10,038 subjects. Multiple logistic regression models were used to examine the odds ratio (OR) after adjusting for age, sex, marital status, income, history of asthma, history of tuberculosis, and smoking.

Results

The risk of COPD was positively associated with aging, low education, low household income, lower body mass index, and cigarette smoking. The risk of COPD decreased with increase in the dietary vitamin C (OR_{Q1 vs Q5}=0.66, P_trend=0.03) and vitamin E (OR_{Q1 vs Q5}=0.56, P_trend=0.05) intake, predominantly, in men (P_trend=0.01 and 0.05 for vitamins C and E, respectively). In addition, the lung function was significantly improved with increase in vitamins C (FEV₁, P=0.04; FVC, P=0.03) and E (FEV₁, P=0.03; FVC, P=0.04) intake. No statistically significant interactions were observed between smoking and vitamin C or E intake in relation to COPD risk among men.

Conclusion

Our results suggest the independent beneficial effect of antioxidants, particularly vitamins C and E, on COPD risk and lung function in men.

An Official American Thoracic Society/European Respiratory Society Statement: Research questions in chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity, mortality, and resource use worldwide. The goal of this Official American Thoracic Society (ATS)/European Respiratory Society (ERS) Research Statement is to describe evidence related to diagnosis, assessment, and management; identify gaps in knowledge; and make recommendations for future research. It is not intended to provide clinical practice recommendations on COPD diagnosis and management.

METHODS

Clinicians, researchers, and patient advocates with expertise in COPD were invited to participate. A literature search of Medline was performed, and studies deemed relevant were selected. The search was not a systematic review of the evidence. Existing evidence was appraised and summarized, and then salient knowledge gaps were identified.

RESULTS

Recommendations for research that addresses important gaps in the evidence in all areas of COPD were formulated via discussion and consensus.

CONCLUSIONS

Great strides have been made in the diagnosis, assessment, and management of COPD as well as understanding its pathogenesis. Despite this, many important questions remain unanswered. This ATS/ERS Research Statement highlights the types of research that leading clinicians, researchers, and patient advocates believe will have the greatest impact on patient-centered outcomes.

An official American Thoracic Society/European Respiratory Society statement: research questions in COPD

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity, mortality, and resource use worldwide. The goal of this official American Thoracic Society (ATS)/European Respiratory Society (ERS) research statement is to describe evidence related to diagnosis, assessment and management; identify gaps in knowledge; and make recommendations for future research. It is not intended to provide clinical practice recommendations on COPD diagnosis and management.

Clinicians, researchers, and patient advocates with expertise in COPD were invited to participate. A literature search of Medline was performed, and studies deemed relevant were selected. The search was not a systematic review of the evidence. Existing evidence was appraised and summarised, and then salient knowledge gaps were identified.

Recommendations for research that addresses important gaps in the evidence in all areas of COPD were formulatedviadiscussion and consensus.

Great strides have been made in the diagnosis, assessment and management of COPD, as well as understanding its pathogenesis. Despite this, many important questions remain unanswered. This ATS/ERS research statement highlights the types of research that leading clinicians, researchers, and patient advocates believe will have the greatest impact on patient-centred outcomes.

Risk factors for chronic obstructive pulmonary disease among never-smokers in Korea

Background

Chronic obstructive pulmonary disease (COPD) patients include those who have never smoked. However, risk factors other than smoking in never-smokers have not been elucidated sufficiently. This study investigated the risk factors for COPD among never-smokers in Korea using population-based data.

Methods

The data were retrieved from the Korean National Health and Nutrition Survey IV conducted from 2007 to 2009. Among subjects aged 40 years or older who underwent appropriate pulmonary function tests, never-smokers not diagnosed with asthma and not showing a restrictive pattern on pulmonary function tests were enrolled. Risk factors of COPD in never-smokers were analyzed using logistic regression models.

Results

Among 24,871 participants in the representative Korean cohort, 3,473 never-smokers were enrolled. COPD patients accounted for 7.6% of the never-smokers. In the logistic regression analysis, low education status (odds ratio [OR]: 2.0; 95% confidence interval [CI]: 1.2–3.2), occupational exposure (OR: 2.6; 95% CI: 1.3–5.3), a history of tuberculosis (OR: 4.5; 95% CI: 2.3–8.7), bronchiectasis (OR: 6.0; 95% CI: 1.4–25.4), male sex (OR: 4.2; 95% CI: 2.6–6.7), advanced age (60–69 years vs 40–49 years; OR: 3.8; 95% CI: 2.0–7.0), and being underweight (body mass index <18.5 vs 18.0–24.9 kg/m²; OR: 3.1; 95% CI: 1.0–9.4) were associated with the development of COPD.

Conclusion

Low education status, manual labor, a history of tuberculosis and bronchiectasis, as well as male sex, advanced age and being underweight were risk factors for COPD in Korean never-smokers.

Beverage habits and mortality in Chinese adults

BACKGROUND

There is limited research examining beverage habits, one of the most habitual dietary behaviors, with mortality risk.

OBJECTIVE

This study examined the association between coffee, black and green tea, sugar-sweetened beverages (soft drinks and juice), and alcohol and all-cause and cause-specific mortality.

METHODS

A prospective data analysis was conducted with the use of the Singapore Chinese Health Study, including 52,584 Chinese men and women (aged 45-74 y) free of diabetes, cardiovascular disease (CVD), and cancer at baseline (1993-1998) and followed through 2011 with 10,029 deaths. Beverages were examined with all-cause and cause-specific (cancer, CVD, and respiratory disease) mortality risk with the use of Cox proportional hazards regression.

RESULTS

The associations between coffee, black tea, and alcohol intake and all-cause mortality were modified by smoking status. Among never-smokers there was an inverse dose-response association between higher amounts of coffee and black tea intake and all-cause, respiratory-related, and CVD mortality (black tea only). The fully adjusted HRs for all-cause mortality for coffee for <1/d, 1/d, and ≥2/d relative to no coffee intake were 0.89, 0.86, and 0.83, respectively (P-trend = 0.0003). For the same black tea categories the HRs were 0.95, 0.90, and 0.72, respectively (P-trend = 0.0005). Among ever-smokers there was no association between coffee or black tea and the outcomes. Relative to no alcohol, light to moderate intake was inversely associated with all-cause mortality (HR: 0.87; 95% CI: 0.79, 0.96) in never-smokers with a similar magnitude of association in ever-smokers. There was no association between heavy alcohol intake and all-cause mortality in never-smokers and a strong positive association in ever-smokers (HR: 1.56; 95% CI: 1.40, 1.74). Green tea and sugar-sweetened beverages were not associated with all-cause or cause-specific mortality.

CONCLUSIONS

Higher coffee and black tea intake was inversely associated with mortality in never-smokers, light to moderate alcohol intake was inversely associated with mortality regardless of smoking status, heavy alcohol intake was positively associated with mortality in ever-smokers, and there was no association between sugar-sweetened beverages and green tea and mortality.

Association Between Vitamin D Status and Weaning From Prolonged Mechanical Ventilation in Survivors of Critical Illness

BACKGROUND

In this study, we examined the association between 25-hydroxyvitamin D (25(OH)D) concentration and successful weaning from mechanical ventilation in a cohort of ICU survivors requiring prolonged mechanical ventilation.

METHODS

This was a retrospective cohort study of ICU survivors admitted to a long-term acute care hospital. Demographic data were extracted from medical records, including 25(OH)D concentrations drawn on admission. Subjects were divided into 2 groups based on their 25(OH)D concentrations (deficient, < 20 ng/mL; not deficient, ≥ 20 ng/mL), and associations between 25(OH)D concentration and successful weaning were calculated.

RESULTS

A total of 183 subjects were studied. A high prevalence of 25(OH)D deficiency was found (61%, 111/183). No association was found between 25(OH)D concentration and weaning from mechanical ventilation. Increased comorbidity burden (Charlson comorbidity index) was associated with decreased odds of weaning (odds ratio of 0.50, 95% CI 0.25-0.99, P = .05).

CONCLUSIONS

Vitamin D deficiency is common in ICU survivors requiring prolonged mechanical ventilation. Surprisingly, there was no significant relationship between 25(OH)D concentration and successful weaning. This finding may be due to the low 25(OH)D concentrations seen in our subjects. Given what is known about vitamin D and lung function and given the low vitamin D concentrations seen in patients requiring long-term ventilatory support, interventional studies assessing the effects of 25(OH)D supplementation in these patients are needed.

Alternate Healthy Eating Index 2010 and risk of chronic obstructive pulmonary disease among US women and men: prospective study

OBJECTIVE

To investigate the association between the Alternate Healthy Eating Index 2010 (AHEI-2010)--a measure of diet quality--and the risk of chronic obstructive pulmonary disease (COPD).

DESIGN

Prospective cohort study.

SETTING

Participants in the Nurses' Health Study and the Health Professionals Follow-up Study, United States.

PARTICIPANTS

73,228 female nurses from 1984 to 2000 and 47,026 men from 1986 to 1998, who completed biennial questionnaires.

MAIN OUTCOME MEASURES

The primary outcome was the self report of newly diagnosed COPD. Multivariable Cox proportional hazards models were adjusted for age, physical activity, body mass index, total energy intake, smoking, second hand tobacco exposure (only in the Nurses' Health Study), race/ethnicity, physician visits, US region, spouse's highest educational attainment (only in the Nurses' Health Study), and menopausal status (only in the Nurses' Health Study).

RESULTS

Over the study period, 723 cases of newly diagnosed COPD occurred in women and 167 in men. In the pooled analysis, a significant negative association was seen between the risk of newly diagnosed COPD and fifths of the AHEI-2010: hazard ratios were 0.81 (95% confidence interval 0.51 to 1.29) for the second fifth, 0.98 (0.80 to 1.18) for the third fifth, 0.74 (0.59 to 0.92) for the fourth fifth, and 0.67 (0.53 to 0.85) for participants who ate the healthiest diet according to the AHEI-2010 (that is, were in the highest fifth), compared with those who ate the less healthy diet (participants in the lowest fifth). Similar findings were observed among ex-smokers and current smokers.

CONCLUSIONS

A higher AHEI-2010 diet score (reflecting high intakes of whole grains, polyunsaturated fatty acids, nuts, and long chain omega-3 fats and low intakes of red/processed meats, refined grains, and sugar sweetened drinks) was associated with a lower risk of COPD in both women and men. These findings support the importance of a healthy diet in multi-interventional programs to prevent COPD.

Fish intake and risk of chronic obstructive pulmonary disease in 2 large US cohorts

BACKGROUND

Despite mechanistic data that linked fish and omega-3 (n-3) PUFAs with lower risk of chronic obstructive pulmonary disease (COPD), epidemiologic data remain scarce. Fish and n-3 PUFAs are an important component of the prudent dietary pattern that is thought to be protective in the onset of COPD.

OBJECTIVE

We examined the role of fish and PUFA intakes on risk of developing COPD while taking into account the overall dietary pattern.

DESIGN

We investigated the objective in 120,175 women and men from the Nurses' Health Study and Health Professionals Follow-Up Study. Over the study period (1984-2000), there were 889 cases of newly diagnosed COPD. Cumulative average intakes of fish, eicosapentaenoic acid, docosahexaenoic acid, n-3 PUFAs, n-6 PUFAs, and the n-3:n-6 ratio were calculated from repeated food-frequency questionnaires. Because fish is a food group included in the prudent pattern, we derived a new prudent pattern without the contribution from fish, and we termed this pattern the "modified prudent" pattern. We performed multivariable Cox proportional hazards models.

RESULTS

Before the dietary pattern was taken into account, and with 14 factors controlled for, we showed that more-frequent fish intake (≥4 servings/wk) was inversely associated with risk of COPD [adjusted pooled HR for the highest intake compared with the lowest intake (<1 serving/wk): 0.71; 95% CI: 0.54, 0.94]. After additional adjustment for the dietary pattern (modified prudent and Western patterns), the association was NS (0.84; 95% CI: 0.63, 1.13). No significant associations were shown between PUFA intakes and risk of COPD.

CONCLUSION

Although COPD-prevention efforts should continue to focus on smoking cessation, these prospective findings support the importance of promoting a healthy diet in multi-interventional programs to prevent COPD instead of focusing on changes in an isolated food or nutrient.

Dietary patterns and mortality in a Chinese population

BACKGROUND

Limited research has examined the association between dietary patterns and mortality, especially in non-Western populations.

OBJECTIVE

We examined the association of dietary patterns with all-cause mortality and cause-specific mortality in the Singapore Chinese Health Study, which included a unique ethnic population with strong Western and South Asian cultural influences.

DESIGN

We conducted a prospective data analysis of the Singapore Chinese Health Study, which included 52,584 Chinese men and women (aged 45-74 y) who were free of diabetes, cardiovascular disease (CVD), and cancer at baseline (1993-1998) and followed through 2011 with 10,029 deaths. The following 2 major dietary patterns were identified by using a principal components analysis: a vegetable-, fruit-, and soy-rich (VFS) pattern and a dim sum- and meat-rich (DSM) dietary pattern. Pattern scores for each participant were calculated and examined with all-cause and cause-specific mortality risks by using a Cox proportional hazards regression.

RESULTS

The VFS pattern was inversely associated with all-cause mortality and each cause-specific category (CVD, cancer, and respiratory) of mortality during the follow-up period. Compared with the lowest quintile of the VFS pattern, HRs for quintiles 2-5 for all-cause mortality were 0.90, 0.79, 0.80, and 0.75, respectively (P-trend < 0.0001). The DSM pattern was positively associated with CVD mortality in the whole population (HR for fifth quintile compared with first quintile: 1.23; 95% CI: 1.07, 1.40; P-trend = 0.001). Positive associations between the DSM pattern and cancer and all-cause mortality were only present in ever-smokers. In ever-smokers, relative to the first quintile, HRs for quintiles 2-5 of the DSM pattern for all-cause mortality were 1.04, 1.04, 1.13, and 1.24, respectively (P-trend < 0.0001). Similarly, HRs for quintiles 2-5 for cancer mortality were 1.08, 1.03, 1.25, and 1.34, respectively (P-trend < 0.0001). The DSM pattern was not associated with respiratory mortality.

CONCLUSION

Dietary patterns are strongly associated with mortality in Chinese Singaporeans.

Neutrophils and emerging targets for treatment in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterized by a decreased airflow due to airway narrowing that, once it occurs, is not fully reversible. The disease usually is progressive and associated with an enhanced inflammatory response in the lungs after exposure to noxious particles or gases. After removal of the noxious particles, the inflammation can continue in a self-sustaining manner. It has been established that improper activation of neutrophils lies at the core of the pathology. This paper provides an overview of the mechanisms by which neutrophils can induce the pulmonary damage of COPD. As the pathogenesis of COPD is slowly being unraveled, new points of intervention are discovered, some of which with promising results.

The Association Between Dietary Intake and Phenotypical Characteristics of COPD in the ECLIPSE Cohort

Background: Diet is a potentially modifiable risk factor in the development and progression of many diseases, and there is evidence that diet plays a role in COPD. Objective: Evaluate the relationship between dietary intake and clinical characteristics of COPD in a large and well-characterized population of COPD patients and controls who were part of the ECLIPSE study. Methods: Limited diet records were available from 2,167 participants at 8 time points over a 3-year period. Participants reported the amount they had consumed over the last 24 hours for 8 food categories. Intake of each food group was handled as a dichotomous variable (Yes/last 24 hours at any of the 8 follow-up points vs. No at all 8 points). These 2 groups were then compared using clinical outcome measures at the last available follow-up that included lung function, emphysema, 6-minute walk, St. George's Respiratory Questionaire (SGRQ) scores, the change in these scores over a 3-year period, and inflammatory biomarkers. Multivariate models for each food group and each outcome measure were run to adjust for confounding factors of age, sex, body mass index (BMI), and smoking. Results: Participants who demonstrated recent consumption of foods associated with a healthful diet, including fish, fruit, tea, and dairy products, had greater lung function measures and less decline over time, less emphysema and emphysema progression, greater 6-minute walk and SGRQ scores, and lower levels of certain inflammatory markers. Increasing the number of diet record time points that were included in the analysis improved ability to detect significant associations. Conclusion: Diet as a possible modifiable risk factor in COPD continues to warrant investigation.

Cyclic nucleotide-based therapeutics for chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) defines a group of chronic inflammatory disorders of the airways that are characterised by a progressive and largely irreversible decline in expiratory airflow. Drugs used to treat COPD through actions mediated by cyclic AMP (cAMP) are restricted to long-acting and short-acting β2-adrenoceptor agonists and, in a subset of patients with chronic bronchitis, a phosphodiesterase 4 inhibitor, roflumilast. These agents relax airway smooth muscle and suppress inflammation. At the molecular level, these effects in the airways are mediated by two cAMP effectors, cAMP-dependent protein kinase and exchange proteins activated by cAMP. The pharmacology of newer agents, acting through these systems, is discussed here with an emphasis on their potential to interact and increase therapeutic effectiveness.

Healthy Eating Index 2005 and selected macronutrients are correlated with improved lung function in humans

A number of dietary components have been associated with lung function. However, a comprehensive measure of a healthy diet has not been compared with lung function. Herein, we test the hypothesis that a healthy overall diet, as assessed by the Healthy Eating Index 2005 (HEI-2005), will be associated with increased lung function. This is an investigation using the Atherosclerosis Risk in Communities Research Materials obtained from the National Heart Lung Blood Institute. The study surveyed dietary habits of 15 567 American subjects from 4 communities in 1987 to 1990. Spirometric measures of lung function were also taken at entry to the study and a second time 3 years later. Based on food and nutritional data collected by food frequency questionnaire, an HEI-2005 score was calculated for each subject. This total score, together with its 12 components scores and associated macronutrient, was compared with lung function results by linear regression. Models were controlled for smoking behavior, demographics, and other important covariates. The HEI-2005 total scores were positively associated with forced expiratory volume in 1 second per forced vital capacity (FEV(1)/FVC) at visit 1 (β = .101 per increase in 1 quintile of HEI-2005) and visit 2 (β = .140), and FEV(1) as percentage of the predicted FEV(1) at visit 2 (β = .215) (P < .05). In addition, HEI-2005 component scores that represented high intakes of whole grains (β = .127 and .096); saturated fats (β = -.091); and solid fats, alcohol, and added sugar (β = -.109 and -.131) were significantly associated with FEV(1)/FVC at either visit 1 or visit 2. Intakes of total calories (β =-.082 at visit 1) and saturated fatty acids (β = -.085 at visit 2) were negatively associated with FEV(1)/FVC. Dietary polyunsaturated fatty acids (β = .085 and .116) and long-chain omega-3 fatty acids (β = .109 and .103), animal protein (β = .132 and .093), and dietary fiber (β = .129) were positively associated with lung health. An overall healthy diet is associated with higher lung function.

Relationships among smoking habits, airflow limitations, and metabolic abnormalities in school workers

Background

Chronic obstructive pulmonary disease is caused mainly by habitual smoking and is common among elderly individuals. It involves not only airflow limitation but also metabolic disorders, leading to increased cardiovascular morbidity and mortality.

Objective

We evaluated relationships among smoking habits, airflow limitation, and metabolic abnormalities.

Methods

Between 2001 and 2008, 15,324 school workers (9700 males, 5624 females; age: ≥30 years) underwent medical checkups, including blood tests and spirometry. They also responded to a questionnaire on smoking habits and medical history.

Results

Airflow limitation was more prevalent in current smokers than in ex-smokers and never-smokers in men and women. The frequency of hypertriglyceridemia was higher in current smokers in all age groups, and those of low high-density-lipoprotein cholesterolemia and diabetes mellitus were higher in current smokers in age groups ≥ 40 s in men, but not in women. There were significant differences in the frequencies of metabolic abnormalities between subjects with airflow limitations and those without in women, but not in men. Smoking index was an independent factor associated with increased frequencies of hypertriglyceridemia (OR 1.015; 95% CI: 1.012–1.018; p<0.0001) and low high-density-lipoprotein cholesterolemia (1.013; 1.010–1.016; p<0.0001) in men. Length of smoking cessation was an independent factor associated with a decreased frequency of hypertriglyceridemia (0.984; 0.975–0.994; p = 0.007).

Conclusions

Habitual smoking causes high incidences of airflow limitation and metabolic abnormalities. Women, but not men, with airflow limitation had higher frequencies of metabolic abnormalities.