Body mass, fat-free body mass, and prognosis in patients with chronic obstructive pulmonary disease from a random population sample: findings from the Copenhagen City Heart Study

The Obesity Paradox in Pulmonary Rehabilitation: Relevance and Implications to Clinical Practice

Pulmonary rehabilitation (PR) increases exercise capacity, reduces dyspnea, and improves quality of life (QoL) in patients with chronic obstructive pulmonary disease (COPD). Patients requiring PR can present with multiple comorbidities. One of the most common comorbidities is obesity. The prevalence of obesity in patients with COPD is increasing at an alarming rate. To date the efficacy of PR to ameliorate obesity in patients with COPD is unclear. Obesity in patients with COPD is associated with increased morbidity and mortality compared to patients without obesity. However, the benefits of obesity paradox in lower mortality rate health-related QoL and health care utilization remain unclear. This review discusses the challenges of prescribing PR to patients with obesity and COPD. In addition, the definition of and the potential challenges and benefits of the obesity paradox in patients with COPD will be discussed. Treatment strategies that include combining PR with lifestyle management, individually tailored nutritional advice, pharmacotherapy, and surgery need to be tested in prospective, randomized controlled trials. The challenges of providing complex care, prioritizing patient needs, and future directions will also be discussed for patients with obesity and COPD.

Vitamin D Status and Longitudinal Changes in Body Composition in Patients with Chronic Obstructive Pulmonary Disease - A Prospective Observational Study

Background

Alterations in body weight and composition are common in patients with chronic obstructive pulmonary disease (COPD) and are independent predictors for morbidity and mortality. Low vitamin D status is also more prevalent in patients with COPD compared to controls and has been related to lower lung function, muscle atrophy and impaired musculoskeletal function. This study aimed to evaluate the association between vitamin D levels and status with body composition (BC), as well as with its changes over time.

Patients and Methods

Patients with COPD and controls without COPD, participating in the Individualized COPD Evaluation in relation to Ageing (ICE-Age) study, a prospective observational study, were included. Plasma 25-hydroxyvitamin D (25(OH)D) was measured at baseline and BC was measured by dual-energy X-ray absorptiometry scan, at baseline and after two years of follow-up. Multiple linear regression analyses were performed to assess the relationships between 25(OH)D (nmol/l) and longitudinal changes in BMI, fat-free mass index (FFMI), fat mas index (FMI) and bone mineral density (BMD).

Results

A total of 192 patients with COPD (57% males, mean ± SD age, 62 ± 7, FEV1, 49 ± 16% predicted) and 199 controls (45% males, mean ± SD age 61 ± 7) were included in this study. Vitamin D levels were significantly lower in patients with COPD (64 ± 26 nmol/L, 95% CI 60-68 nmol/L versus 75 ± 25 nmol/L, 95% CI 72-79 nmol/L) compared to controls. Both patients and controls presented a significant decline in FFMI and T-score hip, but vitamin D level or status did not determine differences in BC or changes in BC over time in either COPD or controls.

Conclusion

Vitamin D status was not associated with BC or longitudinal changes in BC. However, vitamin D insufficiency and low BMD were more prevalent in patients with COPD compared to controls.

Systematic review and meta-analysis of nutrient supplements for treating sarcopenia in people with chronic obstructive pulmonary disease

Individuals with chronic obstructive pulmonary disease (COPD) are prone to malnutrition and sarcopenia as a result of nutritional deficiencies and increased energy metabolism. However, the effects of nutrient supplements (NS) on treating sarcopenia in patients with COPD are not well established from systematic evidence. This meta-analysis examined the effect of NS on sarcopenia in patients with COPD. A systematic search of multiple databases was conducted, and 29 randomized controlled trials involving 1625 participants (age, mean [SD] = 67.9 [7.8] years) were analyzed. NS demonstrated significant improvements in body weight (MD,1.33 kg; 95% CI, 0.60, 2.05 kg; P = 0.0003; I2 = 87%), fat-free mass index (MD, 0.74 kg/m2; 95% CI, 0.21, 1.27 kg/m2; P = 0.007; I2 = 75%), and 6-min walk test (MD, 19.43 m; 95% CI, 4.91, 33.94 m; P = 0.009; I2 = 81%) compared with control. However, NS had nonsignificant effects on handgrip strength (SMD, 0.36; 95% CI, - 0.15, 0.88; P = 0.16; I2 = 87%) and quadriceps muscle strength (SMD, 0.11; 95% CI, -  0.06, 0.27; P = 0.20; I2 = 25%) compared with the control. In conclusion, NS may be an effective treatment for improving body composition and physical performance in COPD. Future studies should explore the effects of intervention durations, specific NS types, or combined training in patients with COPD and sarcopenia.

Adipose Tissue Hypoxia in Obesity: Clinical Reappraisal of Hypoxia Hypothesis

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

The role and mechanism of gut-lung axis mediated bidirectional communication in the occurrence and development of chronic obstructive pulmonary disease

The current studies have shown that the occurrence and development of chronic obstructive pulmonary disease (COPD) are closely related to the changes in gut health and its microenvironment, and even some gut diseases have significant clinical correlation with COPD. The dysbiosis of gut microbiota observed in COPD patients also suggests a potential bidirectional interaction between the gut and lung. Communication between the gut and lung may occur through circulating inflammatory cells, gut microbial metabolites, and circulating inflammatory mediators, but the mechanism of bidirectional communication between the gut and lung in COPD is still under study. Therefore, more research is still needed in this area. In this review, we summarize recent clinical studies and animal models on the role of the gut-lung axis in the occurrence and development of COPD and its mechanisms, so as to provide ideas for further research in this field. In addition, we also summarized the negative effects of COPD medication on gut microbiota and the gut microbiota risk factors for COPD and proposed the potential prevention and treatment strategies.

Loss of body weight and lean mass in long-stay, hospitalized canine patients

A high prevalence of malnutrition occurs in human hospitals and has been associated with detrimental consequences. By comparison, much less is known in hospitalized veterinary patients. The aims of this study were to evaluate the prevalence of malnutrition and body composition changes in long-stay hospitalised patients using an isotopic dilution technique. An additional objective was to compare the changes in composition with commonly used methods measuring body fat and lean mass. The dogs consumed on average 77.5% of their estimated resting energy requirements during their stay. The majority (78.3%) of dogs lost body weight, of which a greater proportion was lean mass (61.8%) than fat mass (FM) (38.2%). There was a moderate correlation between body condition score and percentage FM measured at admission (Kendall's τ = 0.51; p = 0.002), and at discharge (Kendall's τ = 0.55; p = 0.001). However, there was no correlation between muscle condition score and fat-free mass at either admission or discharge (p > 0.1). Duration of stay was positively associated with loss of body weight (p < 0.001), but was not associated with changes in either lean or FM expressed as a percentage of body weight or in absolute terms (p > 0.1), which was presumed to be explained by small sample size and variation. Food intake was not found to a significant factor for lean or FM loss (p > 0.1). These findings indicate that weight loss is common in hospitalized canine patients, which is not explained by simple under-eating. Other factors such as inflammation and inactivity should be evaluated in future studies to determine their role in influencing muscle and FM changes in hospitalized canine patients.

Incident low muscle mass is associated with greater lung disease and lower circulating leptin in a tobacco-exposed longitudinal cohort

BACKGROUND

Muscle loss is prevalent in chronic obstructive pulmonary disease (COPD). Prior studies evaluating musculoskeletal dysfunction in COPD have focused on individuals with baseline low muscle mass. Currently, there is limited data evaluating clinical characteristics and outcomes associated with progression to incident low muscle mass in a tobacco-exposed cohort of individuals with baseline normal muscle mass.

METHODS

We evaluated 246 participants from a single-center longitudinal tobacco-exposed cohort with serial spirometry, thoracic imaging, dual energy x-ray absorptiometry (DXA) measurements, walk testing, and plasma adipokine measurements. DXA-derived fat free mass index (FFMI) and appendicular skeletal mass index (ASMI) were used as surrogates for muscle mass. Participants with incident low muscle mass (LM) at follow-up were characterized by FFMI < 18.4 kg/m2 in males and < 15.4 kg/m2 in females and/or ASMI < 7.25 kg/m2 in males and < 5.67 kg/m2 in females.

RESULTS

Twenty-five (10%) participants progressed to incident low muscle mass at follow-up. At baseline, the LM subgroup had greater active smoking prevalence (60% v. 38%, p = 0.04), lower FFMI (17.8 ± 1.7 kg/m2 v. 19.7 ± 2.9 kg/m2, p = 0.002), lower ASMI (7.3 ± 0.9 kg/m2 v. 8.2 ± 1.2 kg/m2, p = 0.0003), and lower plasma leptin (14.9 ± 10.1 ng/mL v. 24.0 ± 20.9 ng/mL, p = 0.04). At follow-up, the LM subgroup had higher COPD prevalence (68% v. 43%, p = 0.02), lower FEV1/FVC (0.63 ± 0.12 v. 0.69 ± 0.12, p = 0.02), lower %DLco (66.5 ± 15.9% v. 73.9 ± 16.8%, p = 0.03), and higher annual rate of FFMI decline (-0.17 kg/m2/year v. -0.04 kg/m2/year, p = 0.006). There were no differences in age, gender distribution, pack years smoking history, or walk distance.

CONCLUSIONS

We identified a subgroup of tobacco-exposed individuals with normal baseline muscle mass who progressed to incident DXA-derived low muscle mass. This subgroup demonstrated synchronous lung disease and persistently low circulating leptin levels. Our study suggests the importance of assessing for muscle loss in conjunction with lung function decline when evaluating individuals with tobacco exposure.

Role of nutrition in patients with coexisting chronic obstructive pulmonary disease and sarcopenia

Chronic obstructive pulmonary disease (COPD) is one of the most common chronic diseases in the elderly population and is characterized by persistent respiratory symptoms and airflow obstruction. During COPD progression, a variety of pulmonary and extrapulmonary complications develop, with sarcopenia being one of the most common extrapulmonary complications. Factors that contribute to the pathogenesis of coexisting COPD and sarcopenia include systemic inflammation, hypoxia, hypercapnia, oxidative stress, protein metabolic imbalance, and myocyte mitochondrial dysfunction. These factors, individually or in concert, affect muscle function, resulting in decreased muscle mass and strength. The occurrence of sarcopenia severely affects the quality of life of patients with COPD, resulting in increased readmission rates, longer hospital admission, and higher mortality. In recent years, studies have found that oral supplementation with protein, micronutrients, fat, or a combination of nutritional supplements can improve the muscle strength and physical performance of these patients; some studies have also elucidated the possible underlying mechanisms. This review aimed to elucidate the role of nutrition among patients with coexisting COPD and sarcopenia.

Impaired Skeletal Muscle in Patients with Stable Chronic Obstructive Pulmonary Disease (COPD) Compared with Non-COPD Patients

Purpose

This study was designed to investigate the differences in skeletal-muscle atrophy between patients with stable chronic obstructive pulmonary disease (COPD) and healthy controls; associated factors were also considered. The study comprised selected residents of communities near the First Affiliated Hospital of Soochow University in Suzhou City, East China.

Patients and Methods

Included in this study were 123 COPD patients and 60 controls. All patients completed spirometry as well as examinations to determine their functional exercise capacity, body composition, and handgrip strength (HGS).

Results

COPD patients had less fat-free mass (FFM), a lower FFM index (FFMI), and a lower 6-min walking distance (6MWD) compared with controls (P = 0.007, P = 0.020, and P < 0.001, respectively) (FFMI: 17.59 ± 1.83 vs 18.34 ± 1.64). The HGS of these patients was also lower compared with that of controls (32.88 ± 7.84 vs 35.48 ± 7.42), and HGS tended toward statistical significance (P = 0.064, respectively). In multivariate analysis, age (β = -0.107, P < 0.001), gender (β = 0.212, P < 0.001), body mass index (BMI) (β = 0.462, P < 0.001), FEV1% (β = 0.108, P = 0.009), and calf circumference (CC) (β = 0.457, P < 0.001) were significantly associated with FFMI.

Conclusion

Impaired skeletal muscle mass was more common in COPD patients than in controls. Multiple regression analysis showed that CC may be used to detect the degree of impairment, particularly by health-care providers working outside of the hospital.

Reference equations for quadriceps strength, endurance and power: a multicentre study

Introduction

The lack of reference values of lower-limb muscle function hinders the clinical recommendations of its measurement in patients with COPD. Therefore, this study aimed to develop reference equations to predict reference values for quadriceps strength, endurance and power and evaluate their construct validity in patients with COPD.

Methods

Quadriceps strength, endurance and power were assessed in 158 healthy individuals and 87 patients with COPD. In addition, patients with COPD performed a 6-min walk test (6MWT) and a 1-min sit-to-stand test (1STS). Multiple linear regressions were performed to develop reference equations. The proportion of patients with COPD with reduced quadriceps function was determined, and correlations between quadriceps strength, endurance and power expressed in percentage of predicted values and 6MWT and 1STS performance were used to document the construct validity of the reference equation.

Results

Except for quadriceps isometric endurance, the proposed reference equations explained 50-70% of the variance of the quadriceps properties in healthy individuals. All quadriceps properties were systematically reduced in a large proportion of patients with COPD compared to healthy individuals. Correlation coefficients between quadriceps properties expressed in percentage of predicted values and 6MWT and 1STS performance ranged between 0.28 and 0.49 (all p<0.05).

Conclusion

In healthy individuals, age, sex, height and body mass index explained 50-70% of the variance of quadriceps strength, endurance and power. When expressed in percentage of predicted values, these quadriceps properties correlated with 6MWT and 1STS performance, suggesting construct validity of the reference values in patients with COPD.

Prevalence and Risk Factors for COPD in an Urbanizing Rural Area in Western China: A Cross-Sectional Study

Purpose

To investigate the prevalence and risk factors for chronic obstructive pulmonary disease (COPD) in a rural area in western China with severe air pollution.

Patients and Methods

10% of local residents aged 40 years and above were included using a convenience sampling method. This was a cross-sectional study. A self-designed questionnaire was used to collect participants' demographic data. The screening program was comprised of two steps: First, a portable electronic spirometer was used for COPD screening. Those participants with FEV1/FVC ratio <0.7 were then referred to a confirmatory pulmonary function (PF) test. COPD was confirmed according to the 2020 Global Initiative for Chronic Obstructive Lung Disease criteria.

Results

A total of 4577 participants aged 40 years old or above were included in the final analysis. Examination with a mobile spirometer identified 1159 individuals for confirmatory testing; after that, of the 1159 individuals, 889 were diagnosed with COPD by the confirmatory PF test. The prevalence of COPD among the target group was 19.4%. Older age, male sex (odds ratio [OR] = 1.537, 95% confidence interval [CI] 1.246-1.894), smoking history (OR = 1.338, 95% CI 1.069-1.675), family history of respiratory disease (OR = 1.625, 95% CI 1.350-1.957), education level (OR = 0.735, 95% CI 0.617-0.876), overweight (OR = 0.614, 95% CI 0.517-0.730) and obesity (OR = 0.572, 95% CI 0.449-0.721) were identified as independent factors associated with COPD. The screening program helped earlier detection of COPD in 719 participants.

Conclusion

COPD was highly prevalent in the rural area studied. Rural residents who were older, current or ever-smokers, male and those who had a lower education level were more vulnerable to developing COPD. The COPD screening program may be helpful for earlier disease detection in rural health-care settings.

Comorbid conditions as predictors of mortality in severe COPD - an eight-year follow-up cohort study

Purpose

Co-morbidities are common in chronic obstructive pulmonary disease (COPD) and are associated with increased morbidity and mortality. The aim of the present study was to explore the prevalence of several comorbid conditions in severe COPD, and to investigate and compare their associations with long-term mortality.

Methods

In May 2011 to March 2012, 241 patients with COPD stage 3 or 4 were included in the study. Information was collected on sex, age, smoking history, weight and height, current pharmacological treatment, number of exacerbations the recent year and comorbid conditions. At December 31st, 2019, mortality data (all-cause and cause specific) were collected from the National Cause of Death Register. Data were analyzed using Cox-regression analysis with gender, age, previously established predictors of mortality and comorbid conditions as independent variables, and all-cause mortality and cardiac and respiratory mortality, respectively, as dependent variables.

Results

Out of 241 patients, 155 (64%) were deceased at the end of the study period; 103 patients (66%) died of respiratory disease and 25 (16%) of cardiovascular disease. Impaired kidney function was the only comorbid condition independently associated with increased all-cause mortality (HR (95% CI) 3.41 (1.47-7.93) p=0.004) and respiratory mortality (HR (95%CI) 4.63 (1.61 to 13.4), p = 0.005). In addition, age ≥70, BMI <22 and lower FEV1 expressed as %predicted were significantly associated with increased all-cause and respiratory mortality.

Conclusion

In addition to the risk factors high age, low BMI and poor lung function; impaired kidney function appears to be an important risk factor for mortality in the long term, which should be taken into account in the medical care of patients with severe COPD.

Reduced Skeletal Muscle Mass Is Associated with an Increased Risk of Asthma Control and Exacerbation

BACKGROUND

Skeletal muscle mass (SMM) has been suggested to be associated with multiple health-related outcomes. However, the potential influence of SMM on asthma has not been largely explored.

OBJECTIVE

To study the association between SMM and clinical features of asthma, including asthma control and exacerbation, and to construct a model based on SMM to predict the risk of asthma exacerbation (AEx).

METHODS

In this prospective cohort study, we consecutively recruited patients with asthma (n = 334), classified as the SMM ^Normal group (n = 223), SMM ^Low group (n = 88), and SMM ^High group (n = 23). We investigated the association between SMM and clinical asthma characteristics and explored the association between SMM and asthma control and AEx within a 12-month follow-up period. Based on SMM, an exacerbation prediction model was developed, and the overall performance was externally validated in an independent cohort (n = 157).

RESULTS

Compared with the SMM ^Normal group, SMM ^Low group exhibited more airway obstruction and worse asthma control, while SMM ^High group had a reduced eosinophil percentage in induced sputum. Furthermore, SMM ^Low group was at a significantly increased risk of moderate-to-severe exacerbation compared with the SMM ^Normal group (relative risk _adjusted 2.02 [95% confidence interval (CI), 1.35-2.68]; p = 0.002). In addition, a model involving SMM was developed which predicted AEx (area under the curve: 0.750, 95% CI: 0.691-0.810).

CONCLUSIONS

Low SMM was an independent risk factor for future AEx. Furthermore, a model involving SMM for predicting the risk of AEx in patients with asthma indicated that assessment of SMM has potential clinical implications for asthma management.

Physical Activity, Exercise Capacity, and Body Composition in U.S. Veterans with Chronic Obstructive Pulmonary Disease

Rationale: Differences in body composition may contribute to variability in exercise capacity (EC) and physical activity (PA) in individuals with chronic obstructive pulmonary disease (COPD). Most studies have used bioimpedance-based surrogates of muscle (lean) mass; relatively few studies have included consideration of fat mass, and limited studies have been performed using dual X-ray absorptiometry (DXA) to assess body composition. Objectives: To determine whether DXA-assessed muscle (lean) and fat mass exhibit differential correlations with EC and PA in subjects with COPD. Methods: U.S. veterans with COPD (defined as forced expiratory volume in 1 second/forced vital capacity < 0.7 or emphysema on clinical chest computed tomography) had DXA-assessed body composition, EC (6-minute-walk distance), objective PA (average daily step counts), and self-reported PA measured at enrollment. Associations among EC, PA, and body composition were examined using Spearman correlations and multivariable models adjusted a priori for age, sex, race, and lung function. Results: Subjects (n = 98) were predominantly White (90%), obese (mean body mass index, 30.2 ± 6.2 kg/m2), and male (96%), with a mean age of 69.8 ± 7.9 years and moderate airflow obstruction (mean forced expiratory volume in 1 second percentage predicted, 68 ± 20%). Modest inverse correlations of EC and PA with fat mass were observed (Spearman's rho range, -0.20 to -0.34), whereas measures of muscle (lean) mass were not significantly associated with EC or PA. The ratio of appendicular skeletal muscle mass (ASM) to weight, which considers both muscle (lean) and fat mass, was consistently associated with EC (8.4 [95% confidence interval, 2.9-13.8] meter increase in 6-minute walk distance per 1% increase in ASM-to-weight ratio), objective PA (194.8 [95% confidence interval, 15.2-374.4] steps per day per 1% increase in ASM-to-weight ratio), and self-reported PA in multivariable-adjusted models. Conclusions: DXA-assessed body composition measures that include consideration of both lean and fat mass are associated with cross-sectional EC and PA in COPD populations. Clinical trial registered with www.clinicaltrials.gov (NCT02099799).

Muscle function and functional performance after pulmonary rehabilitation in patients with chronic obstructive pulmonary disease: a prospective observational study

This study aimed to measure changes in different properties of skeletal muscles and evaluate their contribution and relationship to changes in functional performance after pulmonary rehabilitation (PR) in patients with chronic obstructive pulmonary disease (COPD). COPD outpatients attending 5 weeks of conventional PR were recruited. Functional performance [5-repetitions sit-to-stand (5STS), and 4-m gait speed (4mGS)], and muscle function (maximal isometric strength, power, force control, and relative concentric and eccentric activation during 5STS) were assessed after PR and 3 months of follow-up. Twenty patients (71 years; 52% of predicted FEV₁) completed the study. 4mGS and relative concentric activation during 5STS decreased respectively by 7.7% and 26% between the beginning of PR and follow-up. Quadriceps strength, power, and force control improved by 10.4%, 27.3%, and 15.2%, respectively, from the beginning of PR to follow-up the relative eccentric activation during 5STS explained 31% of the variance in 4mGS changes. In conclusion, functional performance appeared to decline after conventional PR, whereas several properties of skeletal muscles were maintained at follow-up in COPD outpatients. Of note, eccentric contractions might play a role in the improvement of functional performance. Therefore, future studies with interventional design should include eccentric training in PR programs during clinical COPD practice.

Association Between Low Serum Creatinine and Mortality in Patients With Severe Chronic Obstructive Pulmonary Disease

Introduction: Muscle mass may be a better predictor of mortality than BMI in chronic obstructive pulmonary disease (COPD). Serum creatinine depends on muscle mass and renal function; low values may predict higher mortality.

Objective: To determine whether there is an association between low serum creatinine and mortality in severe COPD.

Methods: This is a retrospective study of serum creatinine values at admission and within the last year before admission. Outcomes measured were mortality at 30 days and one year after admission in patients with acute type 2 respiratory failure secondary to COPD, who were admitted over a one-year period to a respiratory ward (N = 130). The statistics were calculated using the chi-squared test.

Results: There appears to be a significant relationship between the one-year pre-admission creatinine values and mortality at one year (p = 0.0003).

Conclusions: The relationship with mortality appears to be stronger with pre-admission creatinine values rather than the admission values and appears to predict the patients at the highest risk of mortality one year after admission.

Anabolic-androgenic steroids for patients with chronic obstructive pulmonary disease: A systematic review and meta-analysis

Background

Testosterone deficiency is common in chronic obstructive pulmonary disease (COPD) patients. There has been a growing interest in the potential use of anabolic-androgenic steroids (AASs) in patients with COPD recently. However, whether AASs could improve their clinical outcomes remains unknown.

Methods

In order to explore the efficacy of AASs in patients with COPD, systematic search of MEDLINE, Embase, the Cochrane Library and ClinicalTrials.gov for randomized controlled trials (RCTs) of AASs for COPD published before March 17, 2022 was performed.

Results

Data were extracted from 8 articles involving 520 participants. The median number of participants per study was 39.5 and the mean follow up was 14.2 weeks. As compared to the control group, AASs therapy could significantly improve body weight (weighted mean difference (WMD), 1.38 kg; 95% CI, 0.79 to 1.97 kg), fat-free mass (WMD, 1.56 kg; 95% CI, 0.94 to 2.18 kg) and peak workload (WMD, 6.89W; 95% CI, 3.97 to 9.81W) of COPD patients, but no improvements in spirometry indicators and six-minute walking distances (WMD, 16.88 m; 95%, −3.27 to 37.04 m). Based on the available research data, it is uncertain whether AASs treatment could improve the quality of life of COPD patients.

Conclusions

Limited published evidence indicates that AASs therapy provides clinical benefits in patients with COPD. However, longer and larger studies are needed to better clarify the efficacy of AASs and draw final conclusions.

Prognostic risk factors for moderate-to-severe exacerbations in patients with chronic obstructive pulmonary disease: a systematic literature review

Background

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. COPD exacerbations are associated with a worsening of lung function, increased disease burden, and mortality, and, therefore, preventing their occurrence is an important goal of COPD management. This review was conducted to identify the evidence base regarding risk factors and predictors of moderate-to-severe exacerbations in patients with COPD.

Methods

A literature review was performed in Embase, MEDLINE, MEDLINE In-Process, and the Cochrane Central Register of Controlled Trials (CENTRAL). Searches were conducted from January 2015 to July 2019. Eligible publications were peer-reviewed journal articles, published in English, that reported risk factors or predictors for the occurrence of moderate-to-severe exacerbations in adults age ≥ 40 years with a diagnosis of COPD.

Results

The literature review identified 5112 references, of which 113 publications (reporting results for 76 studies) met the eligibility criteria and were included in the review. Among the 76 studies included, 61 were observational and 15 were randomized controlled clinical trials. Exacerbation history was the strongest predictor of future exacerbations, with 34 studies reporting a significant association between history of exacerbations and risk of future moderate or severe exacerbations. Other significant risk factors identified in multiple studies included disease severity or bronchodilator reversibility (39 studies), comorbidities (34 studies), higher symptom burden (17 studies), and higher blood eosinophil count (16 studies).

Conclusions

This systematic literature review identified several demographic and clinical characteristics that predict the future risk of COPD exacerbations. Prior exacerbation history was confirmed as the most important predictor of future exacerbations. These prognostic factors may help clinicians identify patients at high risk of exacerbations, which are a major driver of the global burden of COPD, including morbidity and mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02123-5.

Lung Cancer in the Course of COPD-Emerging Problems Today

Tobacco smoking remains the main cause of tobacco-dependent diseases like lung cancer, chronic obstructive pulmonary disease (COPD), in addition to cardiovascular diseases and other cancers. Whilst the majority of smokers will not develop either COPD or lung cancer, they are closely related diseases, occurring as co-morbidities at a higher rate than if they were independently triggered by smoking. A patient with COPD has a four- to six-fold greater risk of developing lung cancer independent of smoking exposure, when compared to matched smokers with normal lung function. The 10 year risk is about 8.8% in the COPD group and only 2% in patients with normal lung function. COPD is not a uniform disorder: there are different phenotypes. One of them is manifested by the prevalence of emphysema and this is complicated by malignant processes most often. Here, we present and discuss the clinical problems of COPD in patients with lung cancer and against lung cancer in the course of COPD. There are common pathological pathways in both diseases. These are inflammation with participation of macrophages and neutrophils and proteases. It is known that anticancer immune regulation is distorted towards immunosuppression, while in COPD the elements of autoimmunity are described. Cytotoxic T cells, lymphocytes B and regulatory T cells with the important role of check point molecules are involved in both processes. A growing number of lung cancer patients are treated with immune check point inhibitors (ICIs), and it was found that COPD patients may have benefits from this treatment. Altogether, the data point to the necessity for deeper analysis and intensive research studies to limit the burden of these serious diseases by prevention and by elaboration of specific therapeutic options.

Long-term outcome of chronic obstructive pulmonary disease: A review

Chronic obstructive pulmonary disease (COPD) is a chronic airway inflammation characterized by fixed airflow limitation and chronic respiratory symptoms, such as cough, sputum, and dyspnea. COPD is a progressive disease characterized by a decline in lung function. During the natural course of the disease, acute deterioration of symptoms leading to hospital visits can occur and influence further disease progression and subsequent exacerbation. Moreover, COPD is not only restricted to pulmonary manifestations but can present with other systemic diseases as comorbidities or systemic manifestations, including lung cancer, cardiovascular disease, pulmonary hypertension, sarcopenia, and metabolic abnormalities. These pulmonary and extrapulmonary conditions lead to the aggravation of dyspnea, physical inactivity, decreased exercise capacity, functional decline, reduced quality of life, and increased mortality. In addition, pneumonia, which is attributed to both COPD itself and an adverse effect of treatment (especially the use of inhaled and/or systemic steroids), can occur and lead to further deterioration in the prognosis of COPD. This review summarizes the long-term outcomes of patients with COPD. In addition, recent studies on the prediction of adverse outcomes are summarized in the last part of the review.

The Obesity Paradox in Chronic Heart Disease and Chronic Obstructive Pulmonary Disease

Obesity in recent years has become an epidemic. A high body mass index (BMI) is one of today's most crucial population health indicators. BMI does not directly quantify body fat but correlates well with easier body fat measurements. Like smoking, obesity impacts multiple organ systems and is a major modifiable risk factor for countless diseases. Despite this, reports have emerged that obesity positively impacts the prognosis of patients with chronic illnesses such as chronic heart failure (CHF) and chronic obstructive pulmonary disease (COPD), a phenomenon known as the Obesity Paradox. This article attempts to explain and summarize this phenomenon.

As it stands, two theories explain this paradox. The muscle mass hypothesis states that obese patients are better adapted to tide through acute exacerbations due to increased reserve because of greater muscle mass. The other theory focuses on brown adipose tissue and its anti-inflammatory effects on the body.

We performed a literature review on research articles published in English from 1983 to the present in the following databases - PubMed, Elsevier, and Google Scholar. The following search strings and Medical Subject Headings (MeSH) terms were used: "Obesity," "Heart Failure," "COPD," and "Cardio-Respiratory Fitness." In this review, we looked at the obesity paradox in Heart Failure and COPD. We summarized the current literature on the Obesity Paradox and reviewed its relationship with Cardio-Respiratory Fitness.

Hand Grip Strength and Likelihood of Moderate-to-Severe Airflow Limitation in the General Population

Background and Objective

Sarcopenia is mainly results from aging; however, it is more prevalent in chronic airway disease such as obstructive pulmonary disease (COPD). Hand grip strength (HGS) can be used as an indicator to evaluate sarcopenia. We aimed to assess the association between HGS and severity of airflow limitation (AFL) in the general population.

Methods

We conducted a cross-sectional study using data from the Korea National Health and Nutrition Examination Survey (KNHANES) from 2014 to 2018. Subjects aged ≥40 years who underwent both spirometry and HGS tests were included. AFL was defined by spirometry revealed forced expiratory volume in 1 second (FEV₁)/forced vital capacity (FVC) <0.70). A propensity score-matched comparison was performed, and the risk for moderate-to-very severe AFL was analyzed using logistic regression analysis.

Results

Among 15,950 subjects, 2277 (14.3%) had AFL with mean FEV₁ was 77.1% of the predicted value. Male was predominant in both individuals without AFL and with AFL (74.2% vs 73.5%, p = 0.613). The HGS was 32.9 ± 9.5 kg and 33.3 ± 9.5 kg in participants without AFL and with AFL (p = 0.109). However, HGS was significantly decreased as AFL getting more severe: 34.0 ± 9.6 kg in mild, 33.0 ± 9.5 kg in moderate, and 30.8 ± 8.5 kg in severe to very severe AFL group (p<0.001). As HGS decreased, adjusted odds for moderate-to-very severe AFL increased compared to those with mild AFL (adjusted odds ratio [aOR], 0.97; 95% confidence interval [CI], 0.951–0.987) and both without AFL and mild AFL group (aOR, 0.98; 95% CI, 0.967–0.995) in age-, sex-, and body mass index (BMI)-matched comparisons.

Conclusion

Lower HGS is significantly associated with moderate-to-very severe AFL in age-, sex-, and BMI-matched comparisons.

Brown adipose tissue activation is not related to hypermetabolism in emphysematous chronic obstructive pulmonary disease patients

BACKGROUND

Brown adipose tissue (BAT) has been primarily researched as a potential target for mitigating obesity. However, the physiological significance of BAT in relation to cachexia remains poorly understood. The objective of this study was to investigate the putative contribution of BAT on different components of energy metabolism in emphysematous chronic obstructive pulmonary disease (COPD) patients.

METHODS

Twenty COPD patients (mean ± SD age 62 ± 6, 50% female, median [range] BMI 22.4 [15.1-32.5] kg/m² and 85% low FFMI) were studied. Basal metabolic rate (BMR) was assessed by ventilated hood, total daily energy expenditure (TDEE) by doubly labelled water and physical activity by triaxial accelerometry. BMR was adjusted for fat-free mass (FFM) as assessed by deuterium dilution. Analysis of BAT and WAT was conducted in a subset of ten patients and six age-matched, gender-matched and BMI-matched healthy controls. BAT glucose uptake was assessed by means of cold-stimulated integrated [18F]FDG positron-emission tomography and magnetic resonance imaging. WAT was collected from subcutaneous abdominal biopsies to analyse metabolic and inflammatory gene expression levels. Lung function was assessed by spirometry and body plethysmography and systemic inflammation by high sensitivity C-reactive protein.

RESULTS

Mean TDEE was 2209 ± 394 kcal/day, and mean BMR was 1449 ± 214 kcal/day corresponding to 120% of predicted. FFM-adjusted BMR did not correlate with lung function or C-reactive protein. Upon cooling, energy expenditure increased, resulting in a non-shivering thermogenesis of (median [range]) 20.1% [3.3-41.3] in patients and controls. Mean BAT glucose uptake was comparable between COPD and controls (1.5 [0.1-6.2] vs. 1.1 [0.7-3.9]). In addition, no correlation was found between BMR adjusted for FFM and BAT activity or between cold-induced non-shivering energy expenditure and BAT activity. Gene expression levels of the brown adipocyte or beige markers were also comparable between the groups. No (serious) adverse events were reported.

CONCLUSIONS

Although COPD patients were hypermetabolic at rest, no correlation was found between BMR or TDEE and BAT activity. Furthermore, both BAT activity and gene expression levels of the brown adipocyte or beige markers were comparable between COPD patients and controls.

Association between body composition, sarcopenia and pulmonary function in chronic obstructive pulmonary disease

Background

Chronic Obstructive Pulmonary Disease (COPD) is characterized by progressive and irreversible airflow limitation. Different factors that modify pulmonary function include age, sex, muscular strength, and a history of exposure to toxic agents. However, the impact of body composition compartments and sarcopenia on pulmonary function is not well-established. This study aimed to evaluate how body composition compartments and sarcopenia affect pulmonary function in COPD patients.

Methods

In a cross-sectional study, patients with a confirmed diagnosis of COPD, > 40 years old, and forced expiratory volume in the first second /forced vital capacity ratio (FEV₁/FVC) < 0.70 post-bronchodilator were included. Patients with cancer, HIV, and asthma were excluded. Body composition was measured with bioelectrical impedance. Sarcopenia was defined according to EWGSOP2, and pulmonary function was assessed by spirometry.

Results

185 patients were studied. The mean age was 72.20 ± 8.39 years; 55.14% were men. A linear regression adjusted model showed associations between body mass index, fat-free mass, skeletal muscle mass index, appendicular skeletal muscle mass index, and phase angle (PhA), and sarcopenia with FEV₁ (%). As regards FVC (%), PhA and exercise tolerance had positive associations.

Conclusion

Body composition, especially PhA, SMMI, ASMMI, and sarcopenia, has a significant impact on pulmonary function. Early detection of disturbances of these indexes enables the early application of such therapeutic strategies in COPD patients.

Androgen Deficiency In Men With Chronic Obstructive Pulmonary Disease

Hypogonadism is a clinical condition comprising symptoms and laboratory evidence of testosterone deficiency and low androgen receptor sensitivity. The importance of hypogonadism in clinical practice is often underestimated. Androgen deficiency habitually occurs in various conditions causing abnormal functioning of many organs and systems, as well as impairing the quality of life in patients. Androgen deficiency often occurs with various somatic diseases. Chronic obstructive pulmonary disease (COPD) is one of the most important medical and social problems of modern medicine, in which severe systemic (including hormonal) disorders occur. This review presents data on androgen deficiency in men with COPD and its potential impact on the patients. We have analyzed literary sources in the eLIBRARY and PubMed databases.

Survival Analysis of COPD Patients in a 13-Year Nationwide Cohort Study of the Brazilian National Health System

BACKGROUND

Chronic obstructive pulmonary disease (COPD) has an appreciable socioeconomical impact in low- and middle-income countries, but most epidemiological data originate from high-income countries. For this reason, it is especially important to understand survival and factors associated with survival in COPD patients in these countries.

OBJECTIVE

To assess survival of COPD patients in Brazil, to identify risk factors associated with overall survival, including treatment options funded by the Brazilian National Health System (SUS).

METHODOLOGY

We built a retrospective cohort study of patients dispensed COPD treatment in SUS, from 2003 to 2015 using a National Database created from the record linkage of administrative databases. We further matched patients 1:1 based on sex, age and year of entry to assess the effect of the medicines on patient survival. We used the Kaplan-Meier method to estimate overall survival of patients, and Cox's model of proportional risks to assess risk factors.

RESULT

Thirty seven thousand and nine hundred and thirty eight patients were included. Patient's survival rates at 1 and 10 years were 97.6% (CI 95% 97.4-97.8) and 83.1% (CI 95% 81.9-84.3), respectively. The multivariate analysis showed that male patients, over 65 years old and underweight had an increased risk of death. Therapeutic regimens containing a bronchodilator in a free dose along with a fixed-dose combination of corticosteroid and bronchodilator seem to be a protective factor when compared to other regimens.

CONCLUSION

Our findings contribute to the knowledge of COPD patients' profile, survival rate and related risk factors, providing new evidence that supports the debate about pharmacological therapy and healthcare of these patients.

Alpha-1 Antitrypsin MZ Heterozygosity Is an Endotype of Chronic Obstructive Pulmonary Disease

Rationale: Multiple studies have demonstrated an increased risk of chronic obstructive pulmonary disease (COPD) in heterozygous carriers of the AAT (alpha-1 antitrypsin) Z allele. However, it is not known if MZ subjects with COPD are phenotypically different from noncarriers (MM genotype) with COPD. Objectives: To assess if MZ subjects with COPD have different clinical features compared with MM subjects with COPD. Methods: Genotypes of SERPINA1 were ascertained by using whole-genome sequencing data in three independent studies. We compared outcomes between MM subjects with COPD and MZ subjects with COPD in each study and combined the results in a meta-analysis. We performed longitudinal and survival analyses to compare outcomes in MM and MZ subjects with COPD over time. Measurements and Main Results: We included 290 MZ subjects with COPD and 6,184 MM subjects with COPD across the three studies. MZ subjects had a lower FEV1% predicted and greater quantitative emphysema on chest computed tomography scans compared with MM subjects. In a meta-analysis, the FEV1 was 3.9% lower (95% confidence interval [CI], -6.55% to -1.26%) and emphysema (the percentage of lung attenuation areas <-950 HU) was 4.14% greater (95% CI, 1.44% to 6.84%) in MZ subjects. We found one gene, PGF (placental growth factor), to be differentially expressed in lung tissue from one study between MZ subjects and MM subjects. Conclusions: Carriers of the AAT Z allele (those who were MZ heterozygous) with COPD had lower lung function and more emphysema than MM subjects with COPD. Taken with the subtle differences in gene expression between the two groups, our findings suggest that MZ subjects represent an endotype of COPD.

The importance of body composition assessment in the rehabilitation process

Introduction. This personal study provides several aspects of the importance of body composition assessment in rehabilitation process in order to manage fat mass (FM), fat-free mas imbalances (FFM), pre-sarcopenia status, sarcopenia and risks association and to improve global functionality. Health outcomes and risk estimations regarding fat mass and skeletal muscle mass (SMM) plays a major role and should be integrated into the rehabilitation process routine in order to avoid functional impairment and physical disability by applying specific kinetic programs. Material and method. A number of 14 subjects classified as outpatients who have received physical therapy at home- kinesiotherapy for post-fracture / dislocation status of the lower limbs in accordance with the medical recommendations and legislation in force. At the end of the rehabilitation phase, the body composition was measured using bio impedance in order to adjust the next step of the active rehabilitation. The measurements were obtained with a completely bioelectrical impedance analyzer (BIA). Single frequency BIA (SF-BIA) was used. For each subject major body compartments determined as FFM (including bone mineral tissue, total body water-TBW and visceral protein), SMM and FM were measured as a tissue-system by means of linear empirical equations stored in the system memory together with personal physical data. IBM SPSS software version 25 was used for statistical analysis. Results and discussions. Four age groups determined as follows: 21.43% for 18-39 years, 50-69 years, >70 years each and 35.71% for 40-49 years, based on the rate of muscle loss, because its integrity is essential for rehabilitation program. From the 14 subjects there are 57.14 % men and 42.86% women, from urban environment 78.57% and rural 21.43%. Mean Age is 48.79 years ± 18.792 Std. Deviation. Fat mass from BIA recorded 21.43% cases low and normal each, and high/very high 57.14% of total cases. Consequently, of BMI (body mass index) association, 57.14% are at normal weight, 35.71% overweight and with obesity and 7.14% underweight. One Sample Chi-Square test applied to BMI Type Associate with FM reveals the statistical significance, < .05(.014). Fat-free mass index (FFMI), fat mass index (FMI), skeletal mass index (SMI) were computed by adjusted with height square. FMI somatotype components results are 64.3% adipose cases, 21.4% intermediate and 14.3% lean. One Sample Chi-Square test applied to FMI Types reveals the statistical significance < .05(.046). Regression equation of standard BMI and FMI with scatter plots for 77.8% of cases was computed in the present study. FFMI somatotype components recorded 57.1% intermediate cases, 21.4% slender and solid each. Regression equation of standard BMI and FFMI with scatter plots for 57.4% of cases was computed. Three patients exceeded 15 seconds at the chair stand test so probable sarcopenia was identified. From BIA were extracted the value for the skeletal mass and SMI was calculated by height adjusted: 13 (92.86%) cases have normal values and one (7.14%) case have optimal value. Regression equation of standard BMI and SMI with scatter plots for 66.4% of cases was computed. Pearson correlation (CI =99%) denotes strong statistical relationship between BMI and FMI (r=0.882), FFMI (r=0.815), Age (r=0.659), Water (r=-0.693). FMI also correlates strongly with Age (r= 0.707), Water (r=-0.925) and Proteins values (r=-0.819). FFMI also correlates strongly with SMI (r=0.984). Water correlates with Protein (r=0.848, CI = 99%). Beta regression analysis strongly correlates SMI prediction with FFMI (ß=0.731), Water (ß=0.138) and Protein (ß=-0.370) for p<0.05. Anova significance of .000 (CI=99%) with applicability of 99.8% of the cases (R2 =0.998) proved that constant predictors: Water (%), FFMI, Proteins (%), FMI, BMI interact to influence SMM variability. 64.25% of subjects recorded an insufficient water level and 71.43% of subjects recorded an insufficient proteins level. Body composition evaluation should be integrated into routine clinical practice for the initial assessment and sequential follow-up and the strongest point of BIA is the possibility to replace invasive laboratory analysis with a quick, noninvasive test that can be carried out in a medical office. Body composition evaluation should be performed at the different stages of the disease, during the course of treatments and the rehabilitation phase. Conclusions. For each patient specific kinetic program will be developed. FMI increase (64.3% adipose cases) denotes the risk of metabolic syndrome and insulin resistance. Consequently, resistive and concentric exercises will be applied. For FFMI loss (57.1% intermediate cases, 21.4% slender) and SMI increasing (92.86% cases have normal values but not optimal ones, 21.43% pre-sarcopenia detected by positive chair test) resistance, eccentric/concentric exercises should be applied. All kinetic programs will be preceded by warm-up and followed by stretching taking into account cardiac reserve for each patient. Maximal/sub-maximal force exercises will be used age-related. Additional water (64.25% of subjects recorded an insufficient water level) and proteins levels (71.43% of subjects recorded an insufficient proteins level) must be balanced by nutritional support in accordance with rehabilitation consult and current physician approval in the interdisciplinary team. BIA may be an important supporting tool for health professionals in order to customize the rehabilitation programs for each patient. Keywords: body composition, rehabilitation, bioelectrical impedance, fat-free mass index, fat mass index, skeletal muscle index,

Annual Body Weight Change and Prognosis in Chronic Obstructive Pulmonary Disease

Purpose

Low body mass index (BMI) has been reported to be associated with poor prognosis in patients with chronic obstructive pulmonary disease (COPD). In contrast, a detailed analysis of the association between body weight change over time and prognosis is not sufficient, particularly in Japanese patients with COPD who have been reported to be much thinner compared to Westerners. This study aimed to investigate the relationship between annual body weight change and long-term prognosis in Japanese patients with COPD in two independent cohorts.

Patients and Methods

We analyzed 279 patients with COPD who participated in the Hokkaido COPD cohort study as a discovery cohort. We divided participants into three groups according to quartiles of annual body weight change calculated by the data from the first 5 years: weight loss group (<-0.17 kg/year), no change group (−0.17 to ≤0.20 kg/year), and weight gain group (>0.20 kg/year). The association between annual body weight change and prognosis was replicated in the Kyoto University cohort (n = 247).

Results

In the Hokkaido COPD cohort study, the weight loss group had significantly worse mortality than the other groups, whereas there was no difference in BMI at baseline. In the multivariate analysis, annual body weight change was an independent risk factor for all-cause mortality, which was confirmed in the Kyoto University cohort.

Conclusion

Annual body weight loss is associated with poor prognosis in Japanese patients with COPD, independent of baseline BMI. Longitudinal assessment of body weight is important for the management of COPD.

Nutritional Status and Body Composition in Patients Suffering From Chronic Respiratory Diseases and Its Correlation With Pulmonary Rehabilitation

As part of an individualized intervention to improve the physical, emotional, and social functioning of patients with chronic respiratory diseases in general and chronic obstructive pulmonary disease in particular, awareness of the presence and consequences of changes in body composition increased enormously during the last decades, and nutritional intervention is considered as an essential component in the comprehensive approach of these patients. This review describes the prevalence and the clinical impact of body composition changes and also provides an update of current intervention strategies. It is argued that body composition, preferentially a three-component evaluation of fat, lean, and bone mass, must become part of a thorough assessment of every patient, admitted for pulmonary rehabilitation.

Skeletal muscle is associated with exercise tolerance evaluated by cardiopulmonary exercise testing in Japanese patients with chronic obstructive pulmonary disease

Decreasing exercise tolerance is one of the key features related to a poor prognosis in patients with chronic obstructive pulmonary disease (COPD). Cardiopulmonary exercise testing (CPET) is useful for evaluating exercise tolerance. The present study was performed to clarify the correlation between exercise tolerance and clinical parameters, focusing especially on the cross-sectional area (CSA) of skeletal muscle. The present study investigated 69 patients with COPD who underwent CPET. The correlations between oxygen uptake (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\dot{\text{V}} \text{O}}}_{2}$$\end{document}V˙O2) at peak exercise and clinical parameters of COPD, including skeletal muscle area measured using single-section axial computed tomography (CT), were evaluated. The COPD assessment test score (ρ = − 0.35, p = 0.02) was weakly correlated with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\dot{\text{V}} \text{O}}}_{2}$$\end{document}V˙O2 at peak exercise. In addition, forced expiratory volume in one second (FEV₁) (ρ = 0.39, p = 0.0009), FEV₁/forced vital capacity (ρ = 0.33, p = 0.006), and the CSA of the pectoralis muscles (PMs) (ρ = 0.36, p = 0.007) and erector spinae muscles (ECMs) (ρ = 0.39, p = 0.003) were correlated with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\dot{\text{V}} \text{O}}}_{2}$$\end{document}V˙O2 at peak exercise. Multivariate analysis adjusted by age and FEV₁ indicated that PM_CSA was weakly correlated after adjustment (β value [95% confidence interval] 0.175 [0.03–0.319], p = 0.02). In addition, ECM_CSA tended to be correlated, but not significantly after adjustment (0.192 [− 0.001–0.385] p = 0.052). The COPD assessment test, FEV₁, FEV₁/FVC, PM_CSA, and ECM_CSA were significantly correlated with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\dot{\text{V}} \text{O}}}_{2}$$\end{document}V˙O2 at peak exercise.

RANKL Mediates Muscle Atrophy and Dysfunction in a Cigarette Smoke-induced Model of Chronic Obstructive Pulmonary Disease

Skeletal muscle dysfunction is one of the important comorbidities of chronic obstructive pulmonary disease (COPD); however, the underlying mechanisms remain largely unknown. RANKL (receptor activator of nuclear factor κB ligand), a key mediator in osteoclast differentiation, was also found to play a role in skeletal muscle pathogenesis. Whether RANKL is involved in COPD-related skeletal muscle dysfunction is as-of-yet unknown. We examined the expression of RANKL/RANK in skeletal muscles from mice exposed to cigarette smoke (CS) for 24 weeks. Grip strength and exercise capacity as well as muscular morphology were evaluated in CS-exposed mice with or without anti-RANKL treatment. The expressions of protein synthesis- or muscle growth-related molecules (IGF-1, myogenin, and myostatin), muscle-specific ubiquitin E3 ligases (MuRF1 and atrogin-1), and the NF-κb inflammatory pathway were also evaluated in skeletal muscles. The effect of CS extract on RANKL/RANK expression and that of exogenous RANKL on the ubiquitin-proteasome pathway in C2C12 myotubes were investigated in vitro. Long-term CS exposure induced skeletal muscle dysfunction and atrophy together with upregulation of RANKL/RANK expression in a well-established mouse model of COPD. RANKL neutralization prevented skeletal muscle dysfunction and atrophy. RANKL inhibition decreased expressions of myostatin and MuRF1/Atrogin1 and suppressed the NF-κb pathway in skeletal muscles from CS-exposed mice. In in vitro experiments with C2C12 myotubes, CS extract induced expression of RANKL/RANK, and exogenous RANKL induced activation of the ubiquitin-proteasome pathway and NF-κb pathway via RANK. Our results revealed an important role of the RANKL/RANK pathway in muscle atrophy induced by CS exposure, suggesting that RANKL may be a potential therapeutic target in COPD-related skeletal muscle dysfunction.

Association between obesity and chronic obstructive pulmonary disease in Moroccan adults: Evidence from the BOLD study

Objective:

The Moroccan cross-sectional study aimed to investigate obesity in association to chronic obstructive pulmonary disease in Fez city.

Methods:

A cross-sectional survey was carried out in Moroccan adults. Anthropometric and spirometry measurements were performed using standardized guidelines.

Results:

Among the 744 participants, 53.9% of were women, with a mean age of 55.27 years (SD = 10.29). Nearly all women declared themselves to be never smokers, while 21% of men were current smokers. Overall, chronic obstructive pulmonary disease prevalence decreased with body mass index (p = 0.01) and waist circumference (p < 0.001). The same trends were also observed in women. The adjusted regression analysis showed a significant independent association between chronic obstructive pulmonary disease and decreasing overweight (OR_a: 0.66; CI_95% (0.40–0.98)), obesity (OR_a: 0.66 CI_95%: (0.36–0.89)), and a decreasing waist circumference-abdominal obesity (OR_a: 0.58 CI_95%: (0.34–0.99)) in the whole population. The same association remains significant in women for overweight (OR_a: 0.18 CI_95%: (0.06–0.54)) and for waist circumference-abdominal obesity (OR_a: 0.40 CI_95%: (0.19–0.85)). All these associations disappeared for men.

Conclusion:

Chronic obstructive pulmonary disease decreases with the increase in body mass index and waist circumference. The effect of waist circumference on the chronic obstructive pulmonary disease was greater among women, regardless of the tobacco factor. A multicenter study would help to confirm the accuracy of these findings in a larger sample of the Moroccan population. Developed lifestyle programs in patients with chronic obstructive pulmonary disease should be considered.

Characteristics of chronic obstructive pulmonary disease patients with robust progression of emphysematous change

Emphysema is a major pathological change in chronic obstructive pulmonary disease (COPD). However, the annual changes in the progression of emphysematous have not been investigated. We aimed to determine possible baseline predicting factors of the change in emphysematous progression in a subgroup of COPD patients who demonstrated rapid progression. In this observational study, we analyzed patients with COPD who were followed up by computed tomography (CT) at least two times over a 3-year period (n = 217). We divided the annual change in the low attenuation area percentage (LAA%) into quartiles and defined a rapid progression group (n = 54) and a non-progression group (n = 163). Predictors of future changes in emphysematous progression differed from predictors of high LAA% at baseline. On multivariate logistic regression analysis, low blood eosinophilic count (odds ratio [OR], 3.22; P = 0.04) and having osteoporosis (OR, 2.13; P = 0.03) were related to rapid changes in emphysematous progression. There was no difference in baseline nutritional parameters, but nutritional parameters deteriorated in parallel with changes in emphysematous progression. Herein, we clarified the predictors of changes in emphysematous progression and concomitant deterioration of nutritional status in COPD patients.

Acute Responses to Oxygen Delivery via High Flow Nasal Cannula in Patients with Severe Chronic Obstructive Pulmonary Disease-HFNC and Severe COPD

Differences in oxygen delivery methods to treat hypoxemia have the potential to worsen CO₂ retention in chronic obstructive lung disease (COPD). Oxygen administration using high flow nasal cannula (HFNC) has multiple physiological benefits in treating respiratory failure including reductions in PaCO₂ in a flow-dependent manner. We hypothesized that patients with COPD would develop worsening hypercapnia if oxygen fraction was increased without increasing flow rate. We evaluated the acute response to HFNC in subjects with severe COPD when flow remained constant and inspired oxygen was increased. In total, 11 subjects with severe COPD (FEV1 < 50%) on supplemental oxygen with baseline normocapnia (PaCO₂ < 45 mm Hg; n = 5) and hypercapnia (PaCO₂ ≥ 45 mm Hg; n = 6) were studied. Arterial blood gas responses were studied at three timepoints: Baseline, HFNC at a flow rate of 30 L/min at resting oxygen supplementation for 1 h, and FiO₂ 30% above baseline with the same flow rate for the next hour. The primary endpoint was the change in PaCO₂ from baseline. No significant changes in PaCO₂ were noted in response to HFNC applied at baseline FiO₂ in the normocapnic and hypercapnic group. At HFNC with FiO₂ 30% above baseline, the normocapnic group did not show a change in PaCO₂ (baseline: 38.9 ± 1.8 mm Hg; HFNC at higher FiO₂: 38.8 ± 3.1 mm Hg; p = 0.93), but the hypercapnic group demonstrated significant increase in PaCO₂ (baseline: 58.2 ± 9.3 mm Hg; HFNC at higher FiO₂: 63.3 ± 10.9 mm Hg; p = 0.025). We observed worsening hypercapnia in severe COPD patients and baseline hypercapnia who received increased oxygen fraction when flow remained constant. These data show the need for careful titration of oxygen therapy in COPD patients, particularly those with baseline hypercapnia when flow rate is unchanged.

Frequency and functional translation of low muscle mass in overweight and obese patients with COPD

BACKGROUND

Cut offs for fat-free mass index (FFMI) and appendicular skeletal muscle mass index (ASMI) are available for diagnosing low muscle mass in patients with COPD. This study aimed to investigate: (1) the frequency of low muscle mass (FFMI and ASMI) applying different cut-offs and (2) the functional translation (clinical impact) of low muscle mass, in patients with COPD stratified into BMI categories.

METHODS

Patients with COPD were assessed regarding body composition, exercise capacity, quadriceps muscle strength, symptoms of anxiety and depression, dyspnea and quality of life upon referral to pulmonary rehabilitation. The proportion of patients with low muscle mass was compared among BMI categories. Clinical outcomes between patients with normal and low muscle mass within each BMI category were compared.

RESULTS

469 patients with COPD were included for analyses. The frequency of patients classified as low FFMI varied significantly according to the choice of cut-off (32 to 54%; P < 0.05), whereas the frequency of patients with low ASMI was 62%. When applying age-gender-BMI-specific cut-offs, 254 patients (54%) were classified as low FFMI. The choice of the cut-off affected the frequency of patients with low muscle mass in all BMI categories. Overweight and obese patients with low muscle mass were more frequently males and presented worse pulmonary function, exercise capacity and muscle strength compared with overweight and obese patients with normal muscle mass.

CONCLUSIONS

Approximately half of the overweight and obese patients with COPD have low muscle mass when applying age-gender-BMI-specific cut-offs. Low muscle mass is associated with worse functional outcomes in overweight and obese COPD patients.

Fat-Free Mass Index Controlled for Age and Sex and Malnutrition Are Predictors of Survival in Interstitial Lung Disease

BACKGROUND

Literature focusing on nutritional variables and survival in interstitial lung disease (ILD) is limited by its focus on weight and BMI and has not considered body composition.

OBJECTIVES

The primary objective of this study was to examine whether body composition measures, specifically fat-free mass index z-score (z-FFMI) and body fat mass index z-score (z-BFMI), were predictors of survival in fibrotic ILD patients. The second objective was to examine if nutrition status was a predictor of survival.

METHOD

Seventy-eight outpatients diagnosed with fibrotic ILD were recruited in this cross-sectional study. Body composition data using dual frequency bioelectrical impedance analysis (BodyStat 1500MD; UK) and nutrition status using the subjective global assessment (SGA) were determined. To control for age and sex, z-FFMI and z-BFMI were calculated using population means. Participant charts were reviewed for diagnosis, age, disease severity, and exercise capacity.

RESULTS

Age (HR 1.08, 95% CI [1.03-1.13], p < 0.01), BMI (HR 0.90, 95% CI [0.84-0.97], p < 0.01]), z-FFMI (HR 0.70, 95% CI [0.56-0.87], p = 0.02), z-BFMI (HR 0.74, 95% CI [0.57-0.96], p < 0.01), 6-min walk distance (6MWD) (HR 0.99, 95% CI [0.99-1.00], p < 0.01), percent predicted diffusing capacity for carbon monoxide (%DLco) (HR 0.93, 95% CI [0.89-0.97], p < 0.01), and severe malnutrition (SGA-C) (HR 6.98, 95% CI [2.00-24.27], p < 0.01) were significant predictors of survival. When controlled for exercise capacity and disease severity, z-FFMI and severe malnutrition were significant predictors of survival independent of %DLco.

CONCLUSION

z-FFMI and severe malnutrition were significant predictors of survival in fibrotic ILD patients independent of disease severity.

Respiratory exacerbations are associated with muscle loss in current and former smokers

OBJECTIVES

Muscle wasting is a recognised extra-pulmonary complication in chronic obstructive pulmonary disease and has been associated with increased risk of death. Acute respiratory exacerbations are associated with reduction of muscle function, but there is a paucity of data on their long-term effect. This study explores the relationship between acute respiratory exacerbations and long-term muscle loss using serial measurements of CT derived pectoralis muscle area (PMA).

DESIGN AND SETTING

Participants were included from two prospective, longitudinal, observational, multicentre cohorts of ever-smokers with at least 10 pack-year history.

PARTICIPANTS

The primary analysis included 1332 (of 2501) participants from Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) and 4384 (of 10 198) participants from Genetic Epidemiology of COPD (COPDGene) who had complete data from their baseline and follow-up visits.

INTERVENTIONS

PMA was measured on chest CT scans at two timepoints. Self-reported exacerbation data were collected from participants in both studies through the use of periodic longitudinal surveys.

MAIN OUTCOME MEASURES

Age-related and excess muscle loss over time.

RESULTS

Age, sex, race and body mass index were associated with baseline PMA. Participants experienced age-related decline at the upper end of reported normal ranges. In ECLIPSE, the exacerbation rate over time was associated with an excess muscle area loss of 1.3% (95% CI 0.6 to 1.9, p<0.001) over 3 years and in COPDGene with an excess muscle area loss of 2.1% (95% CI 1.2 to 2.8, p<0.001) over 5 years. Excess muscle area decline was absent in 273 individuals who participated in pulmonary rehabilitation.

CONCLUSIONS

Exacerbations are associated with accelerated skeletal muscle loss. Each annual exacerbation was associated with the equivalent of 6 months of age-expected decline in muscle mass. Ameliorating exacerbation-associated muscle loss represents an important therapeutic target.

Effect of Bronchoscopic Lung Volume Reduction in Advanced Emphysema on Energy Balance Regulation

BACKGROUND

Hypermetabolism and muscle wasting frequently occur in patients with severe emphysema. Improving respiratory mechanics by bronchoscopic lung volume reduction (BLVR) might contribute to muscle maintenance by decreasing energy requirements and alleviating eating-related dyspnoea.

OBJECTIVE

The goal was to assess the impact of BLVR on energy balance regulation.

DESIGN

Twenty emphysematous subjects participated in a controlled clinical experiment before and 6 months after BLVR. Energy requirements were assessed: basal metabolic rate (BMR) by ventilated hood, total daily energy expenditure (TDEE) by doubly labelled water, whole body fat-free mass (FFM) by deuterium dilution, and physical activity by accelerometry. Oxygen saturation, breathing rate, and heart rate were monitored before, during, and after a standardized meal via pulse oximetry and dyspnoea was rated.

RESULTS

Sixteen patients completed follow-up, and among those, 10 patients exceeded the minimal clinically important difference of residual volume (RV) reduction. RV was reduced with median (range) 1,285 mL (-2,430, -540). Before BLVR, 90% of patients was FFM-depleted despite a normal BMI (24.3 ± 4.3 kg/m2). BMR was elevated by 130%. TDEE/BMR was 1.4 ± 0.2 despite a very low median (range) daily step count of 2,188 (739, 7,110). Following BLVR, the components of energy metabolism did not change significantly after intervention compared to before intervention, but BLVR treatment decreased meal-related dyspnoea (4.1 vs. 1.7, p = 0.019).

CONCLUSIONS

Impaired respiratory mechanics in hyperinflated emphysematous patients did not explain hypermetabolism. Clinical Trial Registry Number: NCT02500004 at www.clinicaltrial.gov.

Towards Personalized Management of Sarcopenia in COPD

The awareness of the presence and consequences of sarcopenia has significantly increased over the past decade. Sarcopenia is defined as gradual loss of muscle mass and strength and ultimately loss of physical performance associated with aging and chronic disease. The prevalence of sarcopenia is higher in chronic obstructive pulmonary disease (COPD) compared to age-matched controls. Current literature suggests that next to physical inactivity, COPD-specific alterations in physiological processes contribute to accelerated development of sarcopenia. Sarcopenia in COPD can be assessed according to current guidelines, but during physical performance testing, ventilatory limitation should be considered. Treatment of muscle impairment can halt or even reverse sarcopenia, despite respiratory impairment. Exercise training and protein supplementation are currently at the basis of sarcopenia treatment. Furthermore, effective current and new interventions targeting the pulmonary system (eg, smoking cessation, bronchodilators and lung volume reduction surgery) may also facilitate muscle maintenance. Better understanding of disease-specific pathophysiological mechanisms involved in the accelerated development of sarcopenia in COPD will provide new leads to refine nutritional, exercise and physical activity interventions and develop pharmacological co-interventions.

Impact of Body Mass Index Change on the Prognosis of Chronic Obstructive Pulmonary Disease

BACKGROUND

Low body mass index (BMI) is an important prognostic factor in chronic obstructive pulmonary disease (COPD). However, the prognostic value of longitudinal BMI change in COPD has not been well studied.

OBJECTIVE

We aimed to evaluate the association between longitudinal change of BMI and prognosis of COPD in Korean COPD cohort.

METHODS

This study was conducted in a prospective Korean Obstructive Lung Disease (KOLD) cohort where COPD patients were recruited on an outpatient basis at 17 hospitals in South Korea. Annual BMI was measured over a period of 3 years or more. All patients were categorized into underweight (UW), normal weight (NW), and overweight (OW) groups by BMI. Clinical characteristics and outcomes including exacerbation and mortality were compared based on initial BMI grade and longitudinal change of BMI.

RESULTS

This analysis included 537 COPD patients (mean age = 67.4 ± 7.9 years, male = 97.0%, mean BMI = 23.0 ± 3.1) of KOLD cohort. The proportions of UW, NW, and OW groups were 6.9% (n = 37), 68.9% (n = 370), and 24.2% (n = 130) respectively. The UW group showed lower forced expiratory volume in 1 s (FEV1) (p < 0.001), shorter 6-minute walk distance (p < 0.001), higher modified Medical Research Council score (p = 0.002), higher St. George Respiratory Questionnaire score (p < 0.001), higher emphysema index (p < 0.001) and air-trapping index (p < 0.001), and more frequent (p < 0.001) and severe exacerbations (p = 0.003). Multivariable analyses demonstrated that decrease of BMI (hazard ratio [HR] = 0.786, p = 0.038) and the descent of BMI group (HR = 3.167, p = 0.016) at 3-year follow-up along with age, initial BMI, post-bronchodilator FEV1, and severe exacerbations were significantly associated with mortality.

CONCLUSIONS

This study demonstrated that BMI decrease during follow-up was independently associated with exacerbation and higher mortality of COPD, suggesting BMI reduction in COPD should be carefully managed.

Effect of Body Mass Index on Lung Function in Chinese Patients with Chronic Obstructive Pulmonary Disease: A Multicenter Cross-Sectional Study

Objective

The aim of this study was to explain “obesity paradox” in chronic obstructive pulmonary disease (COPD) by evaluating the effect of body mass index (BMI) on lung function in Chinese patients with COPD.

Methods

A total of 1644 patients diagnosed with COPD were recruited from four Chinese tertiary hospitals and were divided into four groups including underweight, normal weight, overweight and obese according to BMI classification standard. The medical data of these patients were collected and used for the multiple linear regression analyses.

Results

After adjustment for age, sex, educational level, economic status, smoking status, alcohol consumption, duration of COPD history, events of acute exacerbation in previous year, hypertension, diabetes mellitus, cardiovascular disease, cerebrovascular disease and osteoporosis, BMI had a curvilinear correlation with the forced expiratory volume in the first second (FEV₁) in patients with Global Initiative for Obstructive Lung Disease (GOLD) 1–2 grade (first-order coefficient β, 0.09; 95% CI, 0.03–0.16; second-order coefficient β, −0.002; 95% CI, −0.003–-0.001; P<0.01). However, BMI had a positive correlation with FEV₁ in patients with GOLD 3–4 grade (β, 0.01; 95% CI, 0.008–0.017; P<0.01) when BMI was used as a quantitative variable. When BMI was used as a qualitative variable, only FEV₁ in overweight group with GOLD 1–2 grade was significantly higher than that of normal weight group (P<0.01). Interestingly, both overweight and obese groups had higher FEV₁ in GOLD 3–4 grade compared with normal weight group (β, 0.06; 95% CI, 0.02–0.11; β, 0.11; 95% CI, 0.04–0.18; P<0.01). The effect of BMI on predicted percentage of FEV₁ (FEV₁%) was similar to that of FEV₁ in different GOLD grades.

Conclusion

Obesity only had a protective effect on lung function in COPD patients with GOLD 3–4 grade rather than GOLD 1–2 grade.

Trial Registry

ClinicalTrials.gov, No.: NCT 03182309, URL: www.clinicaltrials.gov.

Nutrition and Markers of Disease Severity in Patients With Bronchiectasis

BACKGROUND

Increasing numbers of patients are being diagnosed with bronchiectasis, yet much remains to be elucidated about this heterogeneous patient population. We sought to determine the relationship between nutrition and health outcomes in non-cystic fibrosis (non-CF) bronchiectasis, using data from the U.S. Bronchiectasis Nontuberculous Mycobacterial Research Registry (U.S. BRR).

METHODS

This was a retrospective, observational, longitudinal study using 5-year follow-up data from the BRR. Bronchiectasis was confirmed on computed tomography (CT). We stratified patients into nutrition categories using body mass index (BMI), and correlated BMI to markers of disease severity.

RESULTS

Overall, n = 496 patients (mean age 64.6- ± 13 years; 83.3% female) were included. At baseline 12.3% (n = 61) were underweight (BMI < 18.5kg/m2), 63.9% (n = 317) had normal weight (BMI ≥ 18.5kg/m2 and <25.0kg/m2), 17.3% (n = 86) were overweight (BMI ≥ 25.0kg/m2 and < 30.0kg/m2), and 6.5% (n= 32) were obese (BMI ≥ 30kg/m2). Men were overrepresented in the overweight and obese groups (25.6% and 43.8% respectively, p < 0.0001). Underweight patients had lower lung function (forced expiratory volume in 1 second [FEV1] % predicted) than the other weight groups (64.5 ± 22, versus 73.5 ± 21, 68.5 ± 20, and 76.5 ± 21 in normal, overweight, and obese groups respectively, p = 0.02). No significant differences were noted between BMI groups for other markers of disease severity at baseline, including exacerbation frequency or hospitalization rates. No significant differences were noted in BMI distribution between patients with and without Pseudomonas, non-tuberculous mycobacteria, or by cause of bronchiectasis. The majority of patients demonstrated stable BMI over 5 years.

CONCLUSIONS

Although underweight patients with bronchiectasis have lower lung function, lower BMI does not appear to relate to other markers of disease severity in this patient population.

Low Muscle Mass Is a Predictor of Malnutrition and Prolonged Hospital Stay in Patients With Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Longitudinal Study

BACKGROUND

Malnutrition in chronic obstructive pulmonary disease (COPD) patients is more prevalent during times of exacerbation. Fat-free mass index (FFMI), calf circumference (CC), and adductor muscle pollicis thickness (AMPT) can be used to identify reduced muscle mass and have been found to be good predictors of clinical outcomes in other conditions, but they have not been investigated in COPD. Therefore, this study evaluated low muscle mass as predictor of malnutrition, prolonged length of stay (LOS), and in-hospital death in COPD patients.

METHODS

This prospective cohort study was carried out in hospitalized patients with COPD exacerbation. Malnutrition diagnosis was performed by Subjective Global Assessment, and muscle mass was assessed by FFMI, calculated using fat-free mass from bioelectrical impedance, CC, and AMPT. Clinical outcomes (LOS and in-hospital death) were collected from records.

RESULTS

One hundred seventy-six patients were included (68.2 ± 10.4 years old, 56.2% women); 74.2% were classified as Global Initiative of Chronic Obstructive Lung Disease 2 or 3 and 58.2% as malnourished. The median LOS was 11 (7-19) days, and the incidence of death was 9.1%. Low FFMI and CC predicted malnutrition (low CC: odds ratio [OR], 4.6; 95% CI, 2.2-9.7 and low FFMI: OR, 8.8; 95% CI, 3.7-20.8) and were associated with prolonged LOS (low CC: OR, 2.3; 95% CI, 1.1-4.6 and low FFMI: OR, 2.5; 95% CI, 1.3-4.8).

CONCLUSION

Simple, inexpensive, and noninvasive parameters of muscle mass-FFMI and CC-are good predictors of malnutrition and prolonged LOS in COPD patients experiencing exacerbation.

Muscle mass assessment in renal disease: the role of imaging techniques

Muscle wasting is a frequent finding in patients with chronic kidney disease (CKD), especially in those with end-stage kidney disease (ESKD) on chronic dialysis. Muscle wasting in CKD is a main feature of malnutrition, and results principally from a vast array of metabolic derangements typical of the syndrome, that converge in determining reduced protein synthesis and accelerated protein catabolism. In this clinical setting, muscle wasting is also frequently associated with disability, frailty, infections, depression, worsened quality of life and increased mortality. On these grounds, the evaluation of nutritional status is crucial for an adequate management of renal patients, and consists of a comprehensive assessment allowing for the identification of malnourished patients and patients at nutritional risk. It is based essentially on the assessment of the extent and trend of body weight loss, as well as of spontaneous dietary intake. Another key component of this evaluation is the determination of body composition, which, depending on the selected method among several ones available, can identify accurately patients with decreased muscle mass. The choice will depend on the availability and ease of application of a specific technique in clinical practice based on local experience, staff resources and good repeatability over time. Surrogate methods, such as anthropometry and bioimpedance analysis (BIA), represent the most readily available techniques. Other methods based on imaging modalities [dual-energy X-ray absorptiometry (DXA), magnetic resonance imaging (MRI), and whole body computed tomography (CT)] are considered to be the "gold standard" reference methods for muscle mass evaluation, but their use is mainly confined to research purposes. New imaging modalities, such as segmental CT scan and muscle ultrasound have been proposed in recent years. Particularly, ultrasound is a promising technique in this field, as it is commonly available for bedside evaluation of renal patients in nephrology wards. However, more data are needed before a routine use of ultrasound for muscle mass evaluation can be recommended in clinical practice.

Physical activity and inactivity among different body composition phenotypes in individuals with moderate to very severe chronic obstructive pulmonary disease

BACKGROUND

The phenotype profiling of individuals with chronic obstructive pulmonary disease (COPD) according to impairments in body composition and level of physical activity in daily life (PADL) needs to be determined.

OBJECTIVE

To verify if individuals with COPD classified as physically active/inactive present different characteristics within different body composition phenotypes.

METHODS

Individuals with COPD were cross-sectionally stratified into four groups according to fat-free and fat mass indexes: Normal Body Composition (NBC), Obese (Ob), Sarcopenic (Sarc), and Sarcopenic/Obese (Sarc/Ob). Additionally, individuals had their PADL level objectively assessed through activity monitoring during two weekdays for at least 10h/day, and then were classified as physically active (Act) or inactive (Inact) according to international recommendations. Lung function (spirometry), exercise capacity (6-minute walking test [6MWT]) and peripheral muscle strength (1-repetition maximum [1RM]) were also assessed.

RESULTS

176 individuals with COPD (mean±standard deviation age: 67±8 years, body mass index 26±6kg/m², FEV1 47±16%predicted) were classified as: NBC+Act (17%), NBC+Inact (22%), Ob+Act (6%), Ob+Inact (10%), Sarc+Act (12%), Sarc+Inact (9%), Sarc/Ob+Act (8%) and Sarc/Ob+Inact (16%). The Sarc/Ob+Inact group presented lower 6MWT and 1RM for knee extension compared to NBC+Act, NBC+Inact, and Ob+Act groups (p<0.05). The Sarc/Ob+Inact group also presented lower FEV1% predicted, 1RM for elbow flexion and elbow extension compared to the NBC+Act and NBC+Inact groups and lower 1RM for elbow extension compared to Ob+Inact group (p<0.05).

CONCLUSION

The combination of sarcopenia, obesity, and physical inactivity was shown to be detrimental in individuals with COPD. Therefore, this profile is a main therapeutic target for improving PADL level and/or body composition.

Cluster analysis identifying patients with COPD at high risk of 2-year all-cause mortality

The objective of the article is to identify clusters of patients with COPD according to factors known to be associated with mortality and to verify whether clusters' assignment is associated with 2-year mortality. Patients ( n = 141) were evaluated by bioelectrical impedance, maximal inspiratory pressure (MIP), one-repetition maximum test of the quadriceps femoris (1RMQF) and BODE index (body mass index; airflow obstruction (spirometry); dyspnea (modified Medical Research Council scale); and exercise capacity (6-minute walk test (6MWT) distance). Vital status was retrospectively checked 2 years after the assessments, and time to death was quantified for those deceased in this period. K-means analysis identified two clusters. Patients in cluster one (CL I, n = 69) presented an impaired clinical status in comparison to cluster two (CL II, n = 72). Receiver operating characteristics curves identified the cutoffs discriminating patients composing CL I: forced expiratory volume in the first second <44%pred; 6MWT <479 m; 1RMQF <19 kg; and maximum inspiratory pressures <73 cmH₂O (area under the curve range 0.750-0.857). During the follow-up, 19 (13%) patients deceased, 15 in CL I (22%) and 4 in CL II (0.06%) ( p = 0.005). CL I was associated with a higher risk of 2-year mortality (hazard ratio (95% confidence interval): 4.3 (1.40-12.9), p = 0.01). A cluster of patients with COPD highly associated with 2-year mortality was statistically identified, and cutoffs to identify these subjects were provided.