Randomization to Omega-3 Fatty Acid Supplementation and Endothelial Function in COPD: The COD-Fish Randomized Controlled Trial

Comparative Efficacy of Nutritional Supplements in Modulating Lung Function and Exercise Capacity in COPD Patients: A Network Meta-Analysis

Objective

To compare the effects of nutritional supplements on lung function and exercise tolerance in chronic obstructive pulmonary disease (COPD).

Methods

We searched PubMed, Embase, Cochrane Library, and Web of Science for randomized controlled trials (RCTs) on nutritional supplements in COPD patients, with the search ending December 31, 2023. Two authors independently screened studies, extracted data, and assessed quality using the Cochrane risk of bias tool. Data were analyzed using RevMan 5.4 and R 4.2.3.

Results

Forty-eight studies with 2481 COPD patients were included. Network meta-analysis showed six supplements significantly improved the 6-minute walk distance (6MWD) (all p<0.05), with the top three being: Coenzyme Q10+ Creatine [MD=63, 95% CI (36, 90)], L-carnitine [MD=53, 95% CI (24, 82)], and anabolic steroids [MD=44, 95% CI (7.1, 82)]. Four supplements improved FEV1%(all p<0.05): nanocurcumin [MD=13, 95% CI (7.7, 18)], Vitamin D [MD=7.5, 95% CI (5.1, 9.9)], probiotics [MD=7.1, 95% CI (5.2, 9.1)] and BSO [MD=4.9, 95% CI (1.6, 8.3)]. In pairwise comparisons, nanocurcumin outperformed BSO and Probiotics. Nanocurcumin [MD=12, 95% CI (4.6, 19), p<0.05] improved FEV1/FVC, and nitrate [MD=26, 95% CI (9.7, 42), p<0.05] was effective for the Incremental Shuttle Walk Test (ISWT). Traditional Chinese Medicine (TCM) products [MD=-1.3, 95% CI (-1.9, -0.67)], melatonin (MLT) [MD=-0.9, 95% CI (-1.6, -0.21)] and Calcitriol [MD=-0.66, 95% CI (-0.93, -0.39)] improved the modified Medical Research Council(mMRC) dyspnea score (all p<0.05), with comparable efficacy among them.

Conclusion

Nutritional supplements improve lung function and exercise endurance in COPD. Coenzyme Q10+Creatine is most effective for endurance, while Nanocurcumin has the greatest impact on lung function.

Natural Products for the Management of Asthma and COPD

Chronic airway inflammatory diseases like asthma, chronic obstructive pulmonary disease (COPD), and their associated exacerbations cause significant socioeconomic burden. There are still major obstacles to effective therapy for controlling severe asthma and COPD progression. Advances in understanding the pathogenesis of the two diseases at the cellular and molecular levels are essential for the development of novel therapies. In recent years, significant efforts have been made to identify natural products as potential drug leads for treatment of human diseases and to investigate their efficacy, safety, and underlying mechanisms of action. Many major active components from various natural products have been extracted, isolated, and evaluated for their pharmacological efficacy and safety. For the treatment of asthma and COPD, many promising natural products have been discovered and extensively investigated. In this chapter, we will review a range of natural compounds from different chemical classes, including terpenes, polyphenols, alkaloids, fatty acids, polyketides, and vitamin E, that have been demonstrated effective against asthma and/or COPD and their exacerbations in preclinical models and clinical trials. We will also elaborate in detail their underlying mechanisms of action unraveled by these studies and discuss new opportunities and potential challenges for these natural products in managing asthma and COPD.

Effects of Omega-3 Fatty Acids on Flow-mediated Dilatation and Carotid Intima Media Thickness: A Meta-analysis

PURPOSE OF REVIEW

To investigate the effects of omega-3 fatty acids on flow-mediated dilatation (FMD) and carotid intima-media thickness (CIMT) and explore the factors influencing these effects.

RECENT FINDINGS

FMD was significantly higher in the omega-3 fatty acid group compared to the control group (mean difference = 0.90%; p = 0.0003). In particular, the subgroup with CHD (both EPA + DHA < 1 g/day and ≥ 1 g/day) and the subgroup without CHD but with CHD risk factors (only EPA + DHA ≥ 1 g/day) showed significantly increased FMD after supplementation of omega-3 fatty acids. CIMT was not significantly different between the omega-3 fatty acid and control groups (standardized mean difference = -0.08; p = 0.26). Subgroup analysis of CHD patients was not conducted because of the limited number of studies. Intake of omega-3 fatty acids improved FMD in patients with CHD and patients with risk factors for CHD. Further research is needed on the effects of omega-3 fatty acids on CIMT.

Endothelial function in patients with COPD: an updated systematic review of studies using flow-mediated dilatation

INTRODUCTION

Cardiovascular disease is a significant cause of morbidity and mortality in COPD. Endothelial dysfunction is suggested to be involved in cardiovascular disease pathogenesis, and multiple studies report endothelial dysfunction in COPD. This article summarized the current knowledge on endothelial function in COPD patients.

AREAS COVERED

Databases were screened until November 2022 for studies using ultrasound-based flow-mediated dilation in patients with stable COPD. Pooled effect sizes were calculated using random effects model. Meta-regression analyses assessed the effects of demographic and clinical variables.

EXPERT OPINION

34 studies were identified (1365 COPD patients; 617 controls). Pooled analysis demonstrated an impaired endothelial-dependent (-2.33%; 95%CI -3.30/-1.35; p < 0.001) and endothelial-independent dilation (-3.11%; 95%CI -5.14/-1.08; p = 0.003) in COPD patients when compared to non-COPD controls. Meta-regression identified that higher age, worse severity of airflow obstruction, and current smoking were significantly associated with impaired endothelial function. Studies evaluating the effects of pharmacological and non-pharmacological interventions on endothelial function in COPD patients demonstrated conflicting results.

Habitual fish oil supplementation and incident chronic obstructive pulmonary disease: Data from a prospective cohort study

BACKGROUND

Fish oil is one of the most popular supplements in the UK and other developed countries. However, the relationship between fish oil use and chronic obstructive pulmonary disease (COPD) is unclear.

OBJECTIVE

To prospectively examine the association of habitual fish oil supplementation with incident COPD risk and to evaluate potential effect modification by genetic predisposition.

METHODS

This study included 484,414 participants (mean and standard deviation [SD] age: 56.5 [8.1] years) from the UK Biobank who completed a touchscreen questionnaire on habitual fish oil supplement use between 2006 and 2010 and were followed up through 2018. Cox regression models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (95% CIs) with adjustment for sociodemographic and lifestyle behaviours, health conditions, and other potential confounding factors. A weighted genetic risk score (GRS) for COPD was derived from 112 validated single nucleotide polymorphisms.

RESULTS

During a median follow-up of 9.0 years, 8860 incident COPD events were recorded. A total of 31.4% (152,230) of the study participants reported habitual fish oil supplementation at baseline. Habitual fish oil supplementation was significantly associated with a lower risk of incident COPD (adjusted HR: 0.88; 95% CI: 0.84-0.93). The association with COPD did not differ by GRS strata (P for interaction = 0.880). The results from subgroup and sensitivity analyses supported the robustness of our findings.

CONCLUSIONS

Our findings suggest that habitual fish oil supplementation is associated with a lower risk of incident COPD, irrespective of genetic predisposition.

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.

Effect of Omega-3 Fatty Acids on Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

PURPOSE

Omega-3 fatty acid is an emerging hotspot on anti-inflammation and chronic obstructive pulmonary disease (COPD) is known as a chronic inflammatory disease. The effect of Omega-3 fatty acid supplement on patients with COPD remains mixed for insufficient evidence. This systematic review and meta-analysis is based on neat randomized controlled trials trying to give a clearer impression on the effect of Omega-3 on patients with COPD.

METHODS

This systematic review and meta-analysis was conducted following the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) statements. Randomized clinical trials (RCTs) published in electronic databases including Medline, Embase, Cochrane Library, ClinicalTrials.gov and China National Knowledge Infrastructure (CNKI) by May 10, 2021 were searched. Data extracted from 6 predetermined domains (nutritional condition, lipid composition, inflammatory biomarker, lung function, physical endurance and quality of life [QoL]) were reviewed and analyzed.

RESULTS

A total of 8 RCTs evaluating 418 patients (age, mean [SD] = 67.3 [10.2] years) were included. Statistical differences were found in 3 parameters of 3 domains - weight (Wt) (0.25 [95% CI, 0.02 to 0.48], P = 0.03) in nutritional condition, low-density lipoprotein (LDL) (0.70 [95% CI, 0.30 to 1.10], P = 0.00) in lipid composition and interleukin-6 (IL-6) level (-0.32 [95% CI, -0.60 to -0.05], P = 0.02) in inflammatory biomarker - while no significant difference was found in lung function, physical endurance or QoL.

CONCLUSION

Comparing with placebo, Omega-3 intake was associated with more weight-gaining, LDL increase and IL-6 reduction. These results should be interpreted cautiously for the quality and quantity of available evidence are limited.

Vascular endothelial damage in COPD: current functional assessment methods and future perspectives

Introduction: Cardiovascular disease is a major cause of death in chronic obstructive pulmonary disease (COPD), but the relationship between these two entities is not fully understood; smoking, inflammation, arterial stiffness and endothelial dysfunction are significant determinants. Endothelial dysfunction is not only associated with cardiovascular disease, but also with COPD severity.Areas covered: Several functional methods have been developed to evaluate endothelial function in healthy and diseased individuals; from the invasive angiography of epicardial coronary arteries and Venous-Occlusion-Plethysmography, to more modern, noninvasive approaches such as Flow-Mediated-Dilatation, Peripheral-Arterial-Tonometry and Near-Infrared-Spectroscopy, all these methods have boosted clinical research in this field. In this context, this narrative review, which included articles published in PubMed and Scopus up to 25-November-2020, summarizes available functional methods for endothelial damage assessment in COPD and discusses existing evidence on their associations with comorbidities and outcomes in this population.Expert opinion: Accumulated evidence suggests that endothelial dysfunction occurs in early stages of CΟPD and worsens with pulmonary obstruction severity and during acute exacerbations. Novel methods evaluating endothelial function offer a detailed, real-time assessment of different parameters related to vascular function and should be increasingly used to shed more light on the role of endothelial damage on cardiovascular and COPD progression.