Nutritional and metabolic modulation in chronic obstructive pulmonary disease management

PathIntegrate: Multivariate modelling approaches for pathway-based multi-omics data integration

As terabytes of multi-omics data are being generated, there is an ever-increasing need for methods facilitating the integration and interpretation of such data. Current multi-omics integration methods typically output lists, clusters, or subnetworks of molecules related to an outcome. Even with expert domain knowledge, discerning the biological processes involved is a time-consuming activity. Here we propose PathIntegrate, a method for integrating multi-omics datasets based on pathways, designed to exploit knowledge of biological systems and thus provide interpretable models for such studies. PathIntegrate employs single-sample pathway analysis to transform multi-omics datasets from the molecular to the pathway-level, and applies a predictive single-view or multi-view model to integrate the data. Model outputs include multi-omics pathways ranked by their contribution to the outcome prediction, the contribution of each omics layer, and the importance of each molecule in a pathway. Using semi-synthetic data we demonstrate the benefit of grouping molecules into pathways to detect signals in low signal-to-noise scenarios, as well as the ability of PathIntegrate to precisely identify important pathways at low effect sizes. Finally, using COPD and COVID-19 data we showcase how PathIntegrate enables convenient integration and interpretation of complex high-dimensional multi-omics datasets. PathIntegrate is available as an open-source Python package.

PathIntegrate: Multivariate modelling approaches for pathway-based multi-omics data integration

As terabytes of multi-omics data are being generated, there is an ever-increasing need for methods facilitating the integration and interpretation of such data. Current multi-omics integration methods typically output lists, clusters, or subnetworks of molecules related to an outcome. Even with expert domain knowledge, discerning the biological processes involved is a time-consuming activity. Here we propose PathIntegrate, a method for integrating multi-omics datasets based on pathways, designed to exploit knowledge of biological systems and thus provide interpretable models for such studies. PathIntegrate employs single-sample pathway analysis to transform multi-omics datasets from the molecular to the pathway-level, and applies a predictive single-view or multi-view model to integrate the data. Model outputs include multi-omics pathways ranked by their contribution to the outcome prediction, the contribution of each omics layer, and the importance of each molecule in a pathway. Using semi-synthetic data we demonstrate the benefit of grouping molecules into pathways to detect signals in low signal-to-noise scenarios, as well as the ability of PathIntegrate to precisely identify important pathways at low effect sizes. Finally, using COPD and COVID-19 data we showcase how PathIntegrate enables convenient integration and interpretation of complex high-dimensional multi-omics datasets. The PathIntegrate Python package is available at https://github.com/cwieder/PathIntegrate.

The Relationship of Energy Malnutrition, Skeletal Muscle and Physical Functional Performance in Patients with Stable Chronic Obstructive Pulmonary Disease

Weight loss is a factor that affects prognosis in patients with chronic obstructive pulmonary disease (COPD) independent of lung function. One of the major factors for weight loss is energy malnutrition. There have been no reports on the factors related to energy malnutrition in COPD patients. This retrospective observational study aimed to investigate these factors. We included 163 male subjects with COPD. Respiratory quotient (RQ), an index of energy malnutrition, was calculated by expiratory gas analysis using an indirect calorimeter. RQ < 0.85 was defined as the energy-malnutrition group and RQ ≥ 0.85 as the no energy-malnutrition group. Factors related to energy malnutrition were examined by multivariate and decision-tree analysis. We finally analyzed data from 56 selected subjects (median age: 74 years, BMI: 22.5 kg/m2). Energy malnutrition was observed in 43%. The independent factors associated with energy malnutrition were tidal volume (VT) (OR 0.99; 95% CI 0.985−0.998; p = 0.015) and Th12 erector spinae muscle cross-sectional area SMI (Th12ESMSMI) (OR 0.71; 95% CI 0.535−0.946; p = 0.019). In decision-tree profiling of energy malnutrition, VT was extracted as the first distinguishable factor, and Th12ESMSMI as the second. In ROC analysis, VT < 647 mL (AUC, 0.72) or Th12ESMSMI < 10.1 (AUC, 0.70) was the cutoff value for energy malnutrition. Energy malnutrition may be an early warning sign of nutritional disorders.

A systematic review and meta-analysis of homocysteine concentrations in chronic obstructive pulmonary disease

Patients with chronic obstructive pulmonary disease (COPD) often suffer from other conditions, such as cardiovascular disease, that further increase the risk of adverse outcomes in this group. Serum homocysteine concentrations are positively associated with cardiovascular risk and have also been reported to be increased in COPD. This meta-analysis investigated the association between homocysteine concentrations and COPD. A systematic search of publications in the electronic databases PubMed, Web of Science, Scopus, and Google Scholar, from inception to September 2021, was conducted using the following terms: "Homocysteine" or "Hcy" and "Chronic Obstructive Pulmonary Disease" or "COPD". Weighted mean differences (WMDs) were calculated to evaluate differences in homocysteine concentrations between COPD patients and non-COPD subjects. Risk of bias and certainty of evidence were assessed using the Joanna Briggs Institute Critical Appraisal Checklist and GRADE, respectively. Nine studies in 432 COPD patients (mean age 65 years, 65% males) and 311 controls (mean age 65 years, 56% males) were identified. Pooled results showed that serum homocysteine concentrations were significantly higher in patients with COPD (WMD = 2.91 µmol/L, 95% CI 2.00-3.82 µmol/L; p < 0.001; high certainty of evidence). No publication bias was observed. Our results support the hypothesis that increased homocysteine concentrations are significantly associated with COPD and may account, at least in part, for the increased cardiovascular risk in these patients.

Body composition parameters and functional status test in predicting future acute exacerbation risk among hospitalized patients with chronic obstructive pulmonary disease

BACKGROUND & AIMS

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. Nutritional and functional status derangement is a commonly seen in COPD patients, and this is associated with a higher disease severity and mortality. To assess body composition analysis - measured by segmental multi-frequency bioelectrical impedance analysis (BIA)- and functional status and investigate their relationship with the COPD acute exacerbation risk.

METHODS

Eighty COPD patients admitted to hospital for COPD acute exacerbation were prospectively followed-up for one year after discharge, focusing on a new incidence of COPD acute exacerbation. Following discharge, participants' body composition was assessed with the use of segmental multi-frequency BIA, whereas physical function by performing 5-repetitions and 30 s sit-to-stand (STS) tests. Unadjusted and multivariate logistic regression analyses were performed to evaluate the ability of the various measures to predict incidence of future COPD acute exacerbation in one-year period.

RESULTS

Seventy-six out of 80 participants completed the study and were analyzed. Fifty-one [24 male (47.1%)] out of 76 participants (67.1%), mean aged of 69.3 ± 8.9 years, developed at least one new COPD acute exacerbation during the one year follow-up. The probability of COPD acute exacerbation in one year was significantly related to BMI (OR = 0.75, 95% CI; 0.61-0.91, p = 0.004) and Fat Free Mass (OR = 0.88, 95% CI; 0.79-0.97, p = 0.012) after adjustment for sex, age and smoking index (pack × years). Both 5-repetitions and 30 s STS tests had a good predictive ability for the incidence of COPD acute exacerbation in one year (AUC = 0.80, 95% CI; 0.65-0.95, p = 0.009 and AUC = 0.83, 95% CI; 0.70-0.96, p = 0.004, respectively).

CONCLUSION

In an observational study among patients admitted with COPD acute exacerbation, body composition analysis parameters and functional status are related to acute exacerbation risk incidence.

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.

Pulmonary Rehabilitation in the Management of Chronic Obstructive Pulmonary Disease among Asian Indians- Current Status and Moving Forward

Chronic Obstructive Pulmonary Disease (COPD) is a significant public health concern in India with high prevalence and associated disability, morbidity, mortality. The progression of COPD is not confined to the lungs but includes extrapulmonary involvement that reduces the functional capacity and quality of life. Pulmonary Rehabilitation (PR) is an evidence-based intervention, targeting multiple domains of pulmonary and extrapulmonary manifestations, and therefore, is recommended as an integral part of COPD management. The practical implementation of PR in India is poor. In this review, we have summarized the latest pieces of evidence in support of PR and highlight the challenges and potential solutions for PR implementation in India.

OLIVe: A Genetically Encoded Fluorescent Biosensor for Quantitative Imaging of Branched-Chain Amino Acid Levels inside Single Living Cells

Branched-chain amino acids (BCAAs) are essential amino acids, controlling cellular metabolic processes as signaling molecules; therefore, utilization of intracellular BCAAs may be regulated by the availability of nutrients in the environment. However, spatial and temporal regulation of intracellular BCAA concentration in response to environmental conditions has been unclear due to the lack of suitable methods for measuring BCAA concentrations inside single living cells. Here, we developed a Förster resonance energy transfer (FRET)-based genetically encoded biosensor for BCAAs, termed optical biosensor for leucine-isoleucine-valine (OLIVe). The biosensor showed approximately 2-fold changes in FRET values corresponding to BCAA concentrations. Importantly, FRET signals from HeLa cells expressing OLIVe in the cytoplasm and nucleus correlated with bulk intracellular BCAA concentrations determined from populations of cells by a biochemical method, and were decreased by knockdown of L-type amino acid transporter 1 (LAT1), a transporter for BCAAs, indicating that OLIVe can reliably report intracellular BCAA concentrations inside single living cells. We also succeeded in imaging BCAA concentrations in the mitochondria using mitochondria-targeted OLIVe. Using the BCAA imaging technique, we found apparently correlated concentrations between the cytoplasm and the mitochondria. We also found that extracellular non-BCAA amino acids affected intracellular BCAA concentrations. Of these amino acids, extracellular glutamine markedly increased intracellular BCAA concentrations in a LAT1-dependent manner. Unexpectedly, extracellular pyruvate was also found to have significant positive effects on maintaining intracellular BCAA concentrations, suggesting that the cells have pyruvate-dependent systems to import BCAAs and/or to regulate BCAA metabolism.

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.

Prioritizing chronic obstructive pulmonary disease (COPD) candidate genes in COPD-related networks

Chronic obstructive pulmonary disease (COPD) is a multi-factor disease, which could be caused by many factors, including disturbances of metabolism and protein-protein interactions (PPIs). In this paper, a weighted COPD-related metabolic network and a weighted COPD-related PPI network were constructed base on COPD disease genes and functional information. Candidate genes in these weighted COPD-related networks were prioritized by making use of a gene prioritization method, respectively. Literature review and functional enrichment analysis of the top 100 genes in these two networks suggested the correlation of COPD and these genes. The performance of our gene prioritization method was superior to that of ToppGene and ToppNet for genes from the COPD-related metabolic network or the COPD-related PPI network after assessing using leave-one-out cross-validation, literature validation and functional enrichment analysis. The top-ranked genes prioritized from COPD-related metabolic and PPI networks could promote the better understanding about the molecular mechanism of this disease from different perspectives. The top 100 genes in COPD-related metabolic network or COPD-related PPI network might be potential markers for the diagnosis and treatment of COPD.

Chronic obstructive pulmonary disease candidate gene prioritization based on metabolic networks and functional information

Chronic obstructive pulmonary disease (COPD) is a multi-factor disease, in which metabolic disturbances played important roles. In this paper, functional information was integrated into a COPD-related metabolic network to assess similarity between genes. Then a gene prioritization method was applied to the COPD-related metabolic network to prioritize COPD candidate genes. The gene prioritization method was superior to ToppGene and ToppNet in both literature validation and functional enrichment analysis. Top-ranked genes prioritized from the metabolic perspective with functional information could promote the better understanding about the molecular mechanism of this disease. Top 100 genes might be potential markers for diagnostic and effective therapies.

The effects of creatine supplementation on thermoregulation and physical (cognitive) performance: a review and future prospects

Creatine (Cr) is produced endogenously in the liver or obtained exogenously from foods, such as meat and fish. In the human body, 95 % of Cr is located in the cytoplasm of skeletal muscle either in a phosphorylated (PCr) or free form (Cr). PCr is essential for the immediate rephosphorylation of adenosine diphosphate to adenosine triphosphate. PCr is rapidly degraded at the onset of maximal exercise at a rate that results in muscle PCr reservoirs being substantially depleted. A well-established strategy followed to increase muscle total Cr content is to increase exogenous intake by supplementation with chemically pure synthetic Cr. Most Cr supplementation regimens typically follow a well-established loading protocol of 20 g day(-1) of Cr for approximately 5-7 days, followed by a maintenance dose at between 2 and 5 g day(-1) for the duration of interest, although more recent studies tend to utilize a 0.3-g kg(-1) day(-1) supplementation regimen. Some studies have also investigated long-term supplementation of up to 1 year. Uptake of Cr is enhanced when taken together with carbohydrate and protein and/or while undertaking exercise. Cr supplementation has been shown to augment muscle total Cr content and enhance anaerobic performance; however, there is also some evidence of indirect benefits to aerobic endurance exercise through enhanced thermoregulation. While there is an abundance of data supporting the ergogenic effects of Cr supplementation in a variety of different applications, some individuals do not respond, the efficacy of which is dependent on a number of factors, such as dose, age, muscle fiber type, and diet, although further work in this field is warranted. Cr is increasingly being used in the management of some clinical conditions to enhance muscle mass and strength. The application of Cr in studies of health and disease has widened recently with encouraging results in studies involving sleep deprivation and cognitive performance.

Obesity and extent of emphysema depicted at CT

AIM

To investigate the underlying relationship between obesity and the extent of emphysema depicted at CT.

METHODS AND MATERIALS

A dataset of 477 CT examinations was retrospectively collected from a study of chronic obstructive pulmonary disease (COPD). The low attenuation areas (LAAs; ≤950 HU) of the lungs were identified. The extent of emphysema (denoted as %LAA) was defined as the percentage of LAA divided by the lung volume. The association between log-transformed %LAA and body mass index (BMI) adjusted for age, sex, the forced expiratory volume in one second as percent predicted value (FEV1% predicted), and smoking history (pack years) was assessed using multiple linear regression analysis.

RESULTS

After adjusting for age, gender, smoking history, and FEV1% predicted, BMI was negatively associated with severe emphysema in patients with COPD. Specifically, one unit increase in BMI is associated with a 0.93-fold change (95% CI: 0.91-0.96, p<0.001) in %LAA; the estimated %LAA for males was 1.75 (95% CI: 1.36-2.26, p<0.001) times that of females; per 10% increase in FEV1% predicated is associated with a 0.72-fold change (95% CI: 0.69-0.76, p<0.001) in %LAA.

CONCLUSION

Increasing obesity is negatively associated with severity of emphysema independent of gender, age, and smoking history.

Comorbidity Distribution, Clinical Expression and Survival in COPD Patients with Different Body Mass Index

Rationale: Contrary to the general population, in patients with chronic obstructive pulmonary disease (COPD) a low body mass index (BMI) is associated with excess mortality, while obesity appears protective (obesity paradox). We hypothesized that BMI is associated with a distinct number and expression of comorbidities in patients with COPD. The type of comorbidity may relate to mortality variability. Objectives and Methods: We followed 1659 COPD patients for a median of 51 months [IQR 27-77] with detailed comorbidity records and tracking pulmonary function, exercise capacity, dyspnea, health status, and cause of death. The cohort was categorized into the 5 National Heart Lung and Blood Institute (NHLBI) BMI groups with determination made about each group's relationship to specific comorbidities, clinical parameters and risk for death. Results: Whereas osteoporosis, substance abuse, abdominal aortic aneurism and peripheral arterial disease were more prevalent in patients with low BMI, metabolic and cardiac problems were more frequent in those with high BMI. The BMI was inversely related to the ratio of forced expiratory volume in 1 second (FEV₁) to forced vital capacity (FVC)(FEV₁ %), BODE (Body mass index, airway Obstruction, Dyspnea, Exercise capacity) index and hyperinflation, had a "U" shape with dyspnea and the St. George's Respiratory Questionaire (SGRQ) score and an inverse "U" with exercise capacity. The crude mortality rate was 60%, 43%, 37%, 36% and 28% from the lowest to highest BMI groups (p<.0001). More respiratory deaths were observed in the lowest BMI group even though they had a lower number of comorbidities. Conclusions: Different BMI categories are associated with distinct clinical expressions of COPD and comorbidity patterns. The relationship between BMI and mortality in patients with COPD remains an unresolved paradox.

Factors limiting exercise tolerance in chronic lung diseases

The major limitation to exercise performance in patients with chronic lung diseases is an issue of great importance since identifying the factors that prevent these patients from carrying out activities of daily living provides an important perspective for the choice of the appropriate therapeutic strategy. The factors that limit exercise capacity may be different in patients with different disease entities (i.e., chronic obstructive, restrictive or pulmonary vascular lung disease) or disease severity and ultimately depend on the degree of malfunction or miss coordination between the different physiological systems (i.e., respiratory, cardiovascular and peripheral muscles). This review focuses on patients with chronic obstructive pulmonary disease (COPD), interstitial lung disease (ILD) and pulmonary vascular disease (PVD). ILD and PVD are included because there is sufficient experimental evidence for the factors that limit exercise capacity and because these disorders are representative of restrictive and pulmonary vascular disorders, respectively. A great deal of emphasis is given, however, to causes of exercise intolerance in COPD mainly because of the plethora of research findings that have been published in this area and also because exercise intolerance in COPD has been used as a model for understanding the interactions of different pathophysiologic mechanisms in exercise limitation. As exercise intolerance in COPD is recognized as being multifactorial, the impacts of the following factors on patients' exercise capacity are explored from an integrative physiological perspective: (i) imbalance between the ventilatory capacity and requirement; (ii) imbalance between energy demands and supplies to working respiratory and peripheral muscles; and (iii) peripheral muscle intrinsic dysfunction/weakness.

Resting energy expenditure and carbohydrate oxidation are higher in elderly patients with COPD: a case control study

BACKGROUND

Elderly patients with chronic obstructive pulmonary disease (COPD) usually have a compromised nutritional status which is an independent predictor of morbidity and mortality. To know the Resting Energy Expenditure (REE) and the substrate oxidation measurement is essential to prevent these complications. This study aimed to compare the REE, respiratory quotient (RQ) and body composition between patients with and without COPD.

METHODS

This case-control study assessed 20 patients with chronic obstructive pulmonary disease attending a pulmonary rehabilitation program. The group of subjects without COPD (control group) consisted of 20 elderly patients attending a university gym, patients of a private service and a public healthy care. Consumption of oxygen (O₂) and carbon dioxide (CO₂) was determined by indirect calorimetry and used for calculating the resting energy expenditure and respiratory quotient. Body mass index (BMI) and waist circumference (WC) were also measured. Percentage of body fat (%BF), lean mass (kg) and muscle mass (kg) were determined by bioimpedance. The fat free mass index (FFMI) and muscle mass index (MMI) were then calculated.

RESULTS

The COPD group had lower BMI than control (p = 0.02). However, WC, % BF, FFMI and MM-I did not differ between the groups. The COPD group had greater RQ (p = 0.01), REE (p = 0.009) and carbohydrate oxidation (p = 0.002).

CONCLUSIONS

Elderly patients with COPD had higher REE, RQ and carbohydrate oxidation than controls.

Associations between BODE index and systemic inflammatory biomarkers in COPD

BACKGROUND

COPD is a multicomponent disease and systemic inflammation represents one of the possible mechanisms responsible for its systemic manifestations, including skeletal muscle weakness and cachexia. Fat-free mass index (FFMI) that reflects the skeletal muscle mass, has been shown to be associated with both dyspnoea and exercise capacity. We hypothesized that the multidimensional BODE index, that reflects the multicomponent nature of COPD, might be related to biomarkers of systemic inflammation. We further evaluated associations between FFMI and systemic inflammation.

METHODS

BODE index and FFMI were calculated in 222 stable COPD patients and 132 smokers or ex-smokers with normal lung function. Systemic inflammation was evaluated with the measurement of leptin, adiponectin, CRP, IL-6, and TNF-α in serum samples of COPD patients.

RESULTS

In patients with COPD, both BODE index and FFMI presented significant positive and negative associations respectively with leptin levels (R(2) 0.61 and 0.65, respectively), whereas FFMI presented an additional negative association with the levels of TNF-α (R(2) 0.38). No significant associations were observed in smokers or ex-smokers with normal lung function.

CONCLUSIONS

Both BODE index and FFMI, are related to the circulating levels of leptin in patients with COPD, suggesting a possible role for leptin in the systemic component of COPD. The additional association of FFMI with TNF-α may further support a role of systemic inflammation in muscle wasting in COPD.

The impact of obesity on walking and cycling performance and response to pulmonary rehabilitation in COPD

BACKGROUND

We examined the influence of overweight and obesity on pulmonary function, exercise tolerance, quality of life and response to pulmonary rehabilitation in COPD.

METHODS

261 patients with COPD were divided into three groups: normal body mass index (BMI), overweight and obese. Baseline and post rehabilitation pulmonary function, 6-min walking test (6MWT), endurance time during a constant workrate exercise test (CET) and St. George's Respiratory Questionnaire (SGRQ) scores were compared between all three classes of BMI.

RESULTS

At baseline, obese and overweight patients had less severe airflow obstruction compared to normal BMI patients. There was no baseline difference in CET performance or SGRQ scores across BMI classes and 6MWT was reduced in the presence of obesity (p < 0.01). Compared to baseline, post-rehabilitation 6MWT, CET performance and SGRQ scores improved significantly in each group (p < 0.01), but 6MWT was still significantly lower in the presence of obesity.

CONCLUSIONS

Walking, but not cycling performance was worse in obese patients. This difference was maintained post rehabilitation despite significant improvements. Weight excess may counterbalance the effect of a better preserved respiratory function in the performance of daily activities such as walking. However, obesity and overweight did not influence the magnitude of improvement after pulmonary rehabilitation.

Hyperhomocysteinaemia and poor vitamin B status in chronic obstructive pulmonary disease

BACKGROUND AND AIMS

Patients with chronic obstructive pulmonary disease (COPD) are at increased atherothrombotic risk. Preliminary findings have suggested that COPD patients may have increased plasma total homocysteine (tHcy), a cardiovascular risk factor often caused by a poor B vitamin status, but plasma levels of such vitamins were not measured. The aim of this study was to investigate hyperhomocysteinaemia in COPD and to determine whether it may be secondary to poor plasma concentrations of B vitamins.

METHODS AND RESULTS

We performed a case-control, cross-sectional study of 42 patients with COPD and 29 control subjects. Folate, vitamin B12, vitamin B6, tHcy, renal function, C-reactive protein, blood gases and lipids were measured in patients and controls. COPD patients had higher plasma tHcy (median: 13.9mumol/l, interquantile range [IQR]: 12.1-18.5 versus 11.5, IQR: 10.1-14, p=0.002) and lower circulating folate (median: 2.5ng/ml, IQR: 1.2-3.3 versus 2.8, IQR: 2.1-4 of controls, p=0.03) than controls had. Compared to the control group, COPD was associated with higher tHcy concentrations also after adjusting for smoking, heart failure, renal function and C-reactive protein with logistic regression analysis (OR 1.36, 95% CI 1.06-1.72, p=0.01). In the COPD group, low levels of folate (beta=-0.27, p=0.02) and vitamin B12 (beta=-0.24, p=0.04), and hypertriglyceridaemia (beta=0.580, p<0.0001) were independent predictors of the presence of high tHcy concentrations in a multiple linear regression model (adjusted R(2)=0.522).

CONCLUSION

COPD patients have a poor B vitamin status and, as a consequence, increased tHcy. These abnormalities may contribute to the COPD-related atherothrombotic risk.

Targeted treatment in COPD: a multi-system approach for a multi-system disease

Chronic obstructive pulmonary disease is a varied condition when examined from a number of different perspectives including factors which influence disease development, pathological process and clinical features. There may be a complex interaction between the degree by which each of these processes influences the development of COPD and the subsequent clinical phenotype with which the patient presents. The varied host response and subsequent clinical phenotype has generated much interest in recent years. It is possible that failure of treatment to impact on mortality and reverse the disease process is because of the heterogeneous nature of the condition. Identification and targeted treatment of clinical and pathological phenotypes within the broad spectrum of COPD may therefore improve outcome. This article will review previous work which has attempted to phenotype COPD and identify if specific treatment for these phenotypes has been shown to be of benefit. It will examine the work on pathological processes and clinical manifestations, both pulmonary and systemic, and will focus on pharmacological therapies.

Health, treatment and health care resources consumption profile among Spanish adults with diabetes and chronic obstructive pulmonary disease

AIMS

To describe the health, treatment and health care resources consumption profile among Spanish adults with diabetes and chronic obstructive pulmonary disease (COPD), and compare it with that of non-diabetic COPD patients.

PATIENTS AND METHODS

An observational and descriptive epidemiological study (EPIDEPOC study). The study included patients with stable COPD and aged > or =40 years, evaluated in primary care. Data were collected relating to sociodemographic variables, health profile, quality of life (SF-12), treatment and health care resources consumption. The results corresponding to diabetic and non-diabetic patients were compared.

RESULTS

A total of 10,711 patients (75.6% males) with COPD were evaluated. The prevalence of diabetes was 16.9%. The diabetic patients were significantly older, with a larger percentage of women, and a lesser educational level compared with the non-diabetic patients. In addition, the diabetics were more sedentary, smoked less, and presented a higher percentage of obesity (33.6% versus 19.7%) than the non-diabetic patients. The severity of airways obstruction was greater among the diabetics than in the non-diabetic patients (54.57+/-13.37% versus 57.92+/-13.39%, respectively, p<0.05). As to co-morbidity, the diabetics showed a greater frequency of arterial hypertension, hypercholesterolemia, heart disease, depression and anxiety. Both the physical and the mental component as measured by the SF-12 yielded significantly poorer results among the diabetics. On the other hand, the diabetic subjects showed a higher consumption of drugs for COPD. In addition, they consumed significantly more health care (and thus economical) resources than the non-diabetic patients. The results of the multivariate logistic regression analysis showed that the variables that were independently associated to COPD among diabetic patients were: higher age, higher BMI, concomitant chronic heart disease, use of inhaled corticoids, SF-12 mental component, SF-12 physical component and total cost of COPD.

CONCLUSIONS

The presence of diabetes in patients with COPD shows in the bivariate analysis a more severe lung disease, greater co-morbidity, poorer quality of life, and a greater consumption of resources, as well as a less favorable course in the previous year. However, the multivariate logistic regression shows that the variables that are independently associated to COPD among diabetic patients are higher age, higher BMI, concomitant chronic heart disease, use of inhaled corticoids, physical and mental component of quality of life questionnaire and total cost of COPD.

Multidisciplinary care of the patient with chronic obstructive pulmonary disease

The National Emphysema Treatment Trial used a multidisciplinary team approach to implement the maximum medical care protocol, including adjustment of medications and outpatient pulmonary rehabilitation for all patients and nutritional and psychological counseling as needed. This article discusses the benefits of such an approach in the care of the patient with chronic obstructive pulmonary disease. Team member roles complement each other and contribute to the goal of providing the highest-quality medical care. The primary focus of the team is to reinforce the medical plan and to provide patient education and support. This article reviews the elements of the initial patient assessment and the functional and nutritional assessment. Patient education focuses on medication use, recognition and management of chronic obstructive pulmonary disease exacerbation symptoms, smoking cessation, advance directives, and travel.

Effects of lung volume reduction surgery for emphysema on glycolipidic hormones

BACKGROUND

Pulmonary emphysema is associated with cachexia and disregulation of the hormones regulating the glycolipid metabolism, insulin resistance, and altered substrate utilization. This study aimed at identifying the effects of lung volume reduction surgery (LVRS) on glycolipidic hormones compared to respiratory rehabilitation (RR).

METHODS

Thirty-three patients with moderate-to-severe emphysema who were undergoing video-assisted thoracoscopic LVRS were compared to 31 similar patients who refused the operation and followed a standardized RR program. All patients were evaluated before and 12 months after treatment for respiratory function, body composition, glycolipidic hormones, metabolic parameters, and insulin resistance, which was calculated using the homeostatic model assessment index for insulin resistance (HOMA-IR). These groups were compared to a matched healthy control population.

RESULTS

Only after LVRS significant improvements were obtained in respiratory function (FEV1, +25.2%; p<0.0001; residual volume, -19.5%; p<0.0001), metabolic parameters (total cholesterol, +13.1%; p<0.01; high-density lipoprotein cholesterol, +11.2%; p<0.01; triglycerides, +18.4; p<0.001; nonesterified fatty acid, -19.7%; p<0.001), and body composition (fat-free mass [FFM], +6.5%; p<0.01; fat mass [FM], +11.9%; p<0.01). The leptin/FM ratio (-6.1%; p<0.01) and resistin/FM ratio (-5.6%; p<0.01) decreased, whereas the adiponectin/FM ratio (+6.9%; p<0.01) and ghrelin (+9.2%; p<0.01) increased, together with reductions in glycemia (-8.8%; p<0.01), insulin level (-20.4%; p<0.001), and HOMA-IR (-27.2%; p<0.0001). The decrement in residual volume was correlated with increment of FFM (rho=-0.49; p<0.02), FM (rho=-0.55; p<0.009), and ghrelin (rho=-0.52; p<0.01), and also with decreases in leptin corrected for FM (rho=0.50; p<0.02) and, marginally, HOMA-IR (rho=0.35; p=0.07).

CONCLUSIONS

After LVRS, glycolipidic hormone levels and nutritional status significantly improved, along with insulin resistance reduction and more physiologic utilization of substrates. Correlations between residual volume and body composition as well as glycolipidic hormone levels suggest that postoperative recovery in respiratory dynamics may induce favorable clinical changes when compared to RR.

Therapeutic approaches for muscle wasting disorders

Muscle wasting and weakness are common in many disease states and conditions including aging, cancer cachexia, sepsis, denervation, disuse, inactivity, burns, HIV-acquired immunodeficiency syndrome (AIDS), chronic kidney or heart failure, unloading/microgravity, and muscular dystrophies. Although the maintenance of muscle mass is generally regarded as a simple balance between protein synthesis and protein degradation, these mechanisms are not strictly independent, but in fact they are coordinated by a number of different and sometimes complementary signaling pathways. Clearer details are now emerging about these different molecular pathways and the extent to which these pathways contribute to the etiology of various muscle wasting disorders. Therapeutic strategies for attenuating muscle wasting and improving muscle function vary in efficacy. Exercise and nutritional interventions have merit for slowing the rate of muscle atrophy in some muscle wasting conditions, but in most cases they cannot halt or reverse the wasting process. Hormonal and/or other drug strategies that can target key steps in the molecular pathways that regulate protein synthesis and protein degradation are needed. This review describes the signaling pathways that maintain muscle mass and provides an overview of some of the major conditions where muscle wasting and weakness are indicated. The review provides details on some therapeutic strategies that could potentially attenuate muscle atrophy, promote muscle growth, and ultimately improve muscle function. The emphasis is on therapies that can increase muscle mass and improve functional outcomes that will ultimately lead to improvement in the quality of life for affected patients.

The state of the provision of nutritional care to hospitalized patients--results from The Elan-Cuba Study

Current nutritional care provision to 1905 patients hospitalized in 12 Cuban hospitals is presented in this article, diagnosed after conducting the Hospital Nutrition Survey (HNS), as part of the activities comprising the Cuban Study of Hospital Malnutrition (Elan-Cuba). The obtained HNS results were contrasted with standards regarding the nutritional assessment of hospitalized patient, the diagnosis of nutritional disorders occurring in the patient, and the identification of patients in need of nutritional intervention. The Elan-Cuba Study returned a 41.2% malnutrition rate [Barreto Penié J, Cuban Group for the Study of Hospital Malnutrition. State of malnutrition in Cuban hospitals. Nutrition 2005;21:487-97]. However, malnutrition was recorded as an independent diagnosis in only 0.4% of the surveyed clinical charts. It could not be shown that medical care teams were systematically applying any of the techniques and procedures recommended for the assessment of the nutritional status of hospitalized patients. In the best of the cases, only 40.6% of the surveyed patients had their height and weight recorded in their clinical charts at admission, 9.0% of those with more than 15 days of hospitalization had a prospective value of weight, and less than 20.0% of them had their serum albumin levels and/or their counts of Lymphocytes annotated on their clinical charts. Although 10.9% of the surveyed patients (median of the subcategories values; range: 3.5-41.2%) fulfilled an indication for nutritional intervention, support (enteral and/or parenteral) was only provided to less than 15.0% of them, with the exception made of patients on NPO, of whom 32.3% received either of the two modes of artificial nutrition listed above. It is to be noticed that none of the patients with chronic organic failure were on nutritional support at the time of the survey. The current nutritional care provision to the hospitalized patient might explain the increased rates of hospital malnutrition documented in the Elan-Cuba Study, and should lead to the design and urgent implementation of nutritional and metabolic intervention programs in the surveyed hospitals, given the deleterious effects of nutritional disorders upon the ultimate results of the medical and surgical actions, and the quality and costs of medical care.

Chronic Obstructive Pulmonary Disease, inflammation and co-morbidity--a common inflammatory phenotype?

Chronic Obstructive Pulmonary Disease (COPD) is and will remain a major cause of morbidity and mortality worldwide. The severity of airflow obstruction is known to relate to overall health status and mortality. However, even allowing for common aetiological factors, a link has been identified between COPD and other systemic diseases such as cardiovascular disease, diabetes and osteoporosis.

COPD is known to be an inflammatory condition and neutrophil elastase has long been considered a significant mediator of the disease. Pro-inflammatory cytokines, in particular TNF-α (Tumour Necrosis Factor alpha), may be the driving force behind the disease process. However, the roles of inflammation and these pro-inflammatory cytokines may extend beyond the lungs and play a part in the systemic effects of the disease and associated co-morbidities. This article describes the mechanisms involved and proposes a common inflammatory TNF-α phenotype that may, in part, account for the associations.

Manifestações sistêmicas na doença pulmonar obstrutiva crônica

A doença pulmonar obstrutiva crônica é progressiva e está relacionada a uma resposta inflamatória anormal dos pulmões à inalação de partículas e/ou gases tóxicos, sobretudo a fumaça de cigarro. Embora acometa primariamente os pulmões, diversas manifestações extrapulmonares relacionadas a esta enfermidade têm sido descritas. O aumento do número de células inflamatórias, que resulta em produção anormal de citocinas pró-inflamatórias, e o desequilíbrio entre a formação de radicais livres e a capacidade antioxidante, resultando em sobrecarga oxidativa, provavelmente são mecanismos envolvidos na inflamação local e sistêmica. Além disso, a diminuição do condicionamento físico secundária às limitações ventilatórias pode estar envolvida no desenvolvimento de alterações musculares. A doença pulmonar obstrutiva crônica apresenta diversas manifestações sistêmicas que incluem a depleção nutricional, a disfunção dos músculos esqueléticos, que contribui para a intolerância ao exercício, e as manifestações relacionadas a co-morbidades comumente observadas nestes pacientes. Essas manifestações têm sido relacionadas à sobrevida e ao estado geral de saúde dos pacientes. Nesse sentido, esta revisão tem como objetivo discutir os achados da literatura relacionados às manifestações sistêmicas da doença pulmonar obstrutiva crônica, ressaltando o papel da inflação sistêmica, e algumas perspectivas de tratamento.

Novas terapias ergogênicas no tratamento da doença pulmonar obstrutiva crônica

A doença pulmonar obstrutiva crônica é considerada, atualmente, uma doença sistêmica, cujas alterações estruturais e metabólicas podem levar à disfunção muscular esquelética. Esta afeta negativamente o desempenho muscular respiratório e periférico, a capacidade funcional, a qualidade de vida relacionada à saúde e mesmo a sobrevida. A indicação de suplementação de substâncias ergogênicas para pacientes com doença pulmonar obstrutiva crônica baseia-se no fato de que estas drogas podem evitar, ou minimizar, o catabolismo e/ou estimular a síntese protéica, diminuindo a depleção de massa muscular e aumentando a capacidade de exercício. A presente revisão sumariza o conhecimento disponível acerca da utilização de esteróides anabolizantes, creatina, L-carnitina, aminoácidos de cadeia ramificada e hormônio de crescimento em pacientes com doença pulmonar obstrutiva crônica. A vantagem do uso dessas substâncias ergogênicas parece residir no aumento da massa magra e/ou na indução de modificações bioenergéticas. Nesse contexto, a maior experiência acumulada é com os esteróides anabolizantes. Entretanto, os benefícios clínicos em relação à melhora da capacidade de exercício e força muscular, bem como os efeitos na morbimortalidade, não foram, até a presente data, consistentemente demonstrados. A suplementação ergogênica pode vir a se constituir numa ferramenta adjuvante para o tratamento de pacientes com doença pulmonar obstrutiva crônica avançada, especialmente naqueles com depleção muscular e/ou fraqueza periférica.

RETRACTED: Effects of Omega-3 Polyunsaturated Fatty Acids on Inflammatory Markers in COPD

BACKGROUND

COPD, the fifth-leading cause of death worldwide, is characterized by chronic inflammation. However, no available agent can effectively cure this inflammation. A dietary supplement containing omega-3 polyunsaturated fatty acids (PUFAs) has anti-inflammatory effects. In this study, we hypothesized that nutritional support with omega-3 PUFA-rich diets may be useful for treating COPD, and we compared the clinical features and inflammatory mediator levels between the COPD patients who received an omega-3 PUFA-rich supplement and those who received a nonrich supplement.

METHODS

Sixty-four COPD patients received 400 kilocalories per day of an omega-3 PUFA-rich supplement (n-3 group) or an omega-3 PUFA-nonrich supplement (n-6 group) for 2 years. We prospectively investigated the clinical features of these patients and measured the levels of inflammatory mediators.

RESULTS

In 6-min walk testing, the dyspnea Borg scale and decrease of arterial oxygen saturation measured by pulse oximetry significantly improved in the n-3 group. Leukotriene B4 levels in serum and sputum and tumor necrosis factor-alpha and interleukin-8 levels in sputum decreased significantly in the n-3 group, while there was no significant change in the n-6 group. Two patients in the n-3 group and three patients in the n-6 group had mild diarrhea, and three patients in the n-3 group and three patients in the n-6 group had nausea; however, their symptoms were controllable and they improved with treatment. With multiple regression analysis, it was proved that the omega-3 PUFA-rich diet significantly contributed to the change in cytokine levels in this study.

CONCLUSION

We suggest nutritional support with an omega-3 PUFA-rich diet as a safe and practical method for treating COPD.

Modulation of host immunity by HIV may be partly achieved through usurping host autonomic functions

Modulation of host immunity has been observed in human immunodeficiency virus (HIV) infections. HIV is believed to influence host immunity through a variety of mechanisms including direct effects on host T cell survival, indirect effects on cytokine profile through modulation of immune cells, and modulation of endocrine functions that affect immunity such as steroids. We hypothesize that HIV infection may also alter host immunity through modulation of host sympatho-vagal balance. Specifically, we propose that HIV drives autonomic balance towards sympathetic bias, which can contribute to a T helper (Th)2 type immunity. A variety of paraviral syndromes associated with HIV infection such as QT prolongation, cachexia, cardiomyopathy, and lipodystrophy are consistent with evidence of autonomic dysfunction. Immunomodulatory effects of autonomic dysfunction toward Th2 bias are presented. A plausible mechanism by which HIV can influence autonomic balance through hypothalamic manipulation is offered. Shift to Th2 dominance is associated with HIV disease progression and can be viewed as a viral adaptation to promote its own survival. Autonomic remodeling by HIV may exemplify this phenomenon. Our hypothesis has implications for treatment of HIV and its associated syndromes.

Chronic obstructive pulmonary disease, asthma, and risk of type 2 diabetes in women

OBJECTIVE

Inflammation plays a key role in chronic obstructive pulmonary disease (COPD) and asthma. Increasing evidence points toward a role of inflammation in the pathogenesis of type 2 diabetes. We wanted to determine the relation of COPD and asthma with the development of type 2 diabetes.

RESEARCH DESIGN AND METHODS

The Nurses' Health Study is a prospective cohort study. From 1988-1996, 103,614 female nurses were asked biennially about a physician diagnosis of emphysema, chronic bronchitis, asthma, and diabetes.

RESULTS

During 8 years of follow-up, we documented a total of 2,959 new cases of type 2 diabetes. The risk of type 2 diabetes was significantly higher for patients with COPD than those without (multivariate relative risk 1.8, 95% CI 1.1-2.8). By contrast, the risk of type 2 diabetes among asthmatic patients was not increased (1.0, 0.8-1.2). The asthma results remained nonsignificant even when we evaluated diabetes risk by duration of asthma exposure.

CONCLUSIONS

Our findings suggest that COPD may be a risk factor for developing type 2 diabetes. Differences in the inflammation and cytokine profile between COPD and asthma might explain why COPD, but not asthma, is associated with increased risk of type 2 diabetes.