Effects of obesity on weight-bearing versus weight-supported exercise testing in patients with COPD

Frequency and Functional Consequences of Low Appendicular Lean Mass and Sarcopenic Obesity in Patients with Asthma Referred for Pulmonary Rehabilitation

INTRODUCTION

One of the most prominent extrapulmonary manifestations in patients with chronic respiratory disease is changes in body weight and composition. However, the frequency and functional consequences of low appendicular lean mass (ALM) or sarcopenic obesity (SO) in patients with asthma are largely unknown. Therefore, the aim of the current study was to assess the frequency and functional consequences of low appendicular lean mass index (ALMI) and SO in patients with asthma.

METHODS

A retrospectively analyzed cross-sectional study was conducted in 687 patients with asthma (60% female, 58 ± 13 years, FEV1 76 ± 25% pred) referred for comprehensive pulmonary rehabilitation (PR). Body composition, pulmonary function, exercise capacity, quadriceps muscle function, and quality of life were assessed. Patients were classified as presenting low ALMI according to the 10th percentiles of age-sex-body mass index (BMI)-specific reference values and as having SO according to the diagnostic procedure proposed by the 2022 ESPEN/EASO consensus. In addition, clinical outcomes between patients with normal and low ALMI or with and without SO were compared.

RESULTS

The frequency of patients classified as low ALMI was 19%, whereas 45% of the patients were obese. Among the obese patients, 29% had SO. In patients with normal weight, those with low ALMI were younger and had worse pulmonary function, exercise capacity and quadriceps muscle function than those with normal ALMI (all p < 0.05). Overweight patients with low ALMI presented poorer pulmonary function and quadriceps muscle function (both strength and total work capacity). In obese class I patients, those with low ALMI showed lower quadriceps strength and maximal oxygen uptake acquired during cardiopulmonary exercise testing. Both male and female patients with SO showed lower quadriceps muscle function and reduced maximal exercise capacity compared to non-SO asthma patients.

CONCLUSION

Approximately one in five asthma patients presented low ALM when age-sex-BMI-specific ALMI cutoffs were applied. Obesity is common among patients with asthma referred for PR. Among the obese patients, a significant proportion presented SO. Low ALM and SO were associated with worse functional outcomes.

Abdominal obesity in COPD is associated with specific metabolic and functional phenotypes

BACKGROUND

Abdominal obesity (AO) is linked to reduced health status and mortality. While it is known that AO is prevalent in chronic obstructive pulmonary disease (AO-COPD), the specific metabolic and functional consequences associated with AO-COPD remain understudied.

METHODS

We studied 199 older adults with COPD and 168 control subjects with and without AO and assessed visceral adipose tissue (VAT) by dual-energy X-ray absorptiometry. VAT > 70th percentile of the control group qualified a subject as AO in a sex specific manner. We measured plasma concentrations and whole body production (WBP) rates of multiple amino acids to assess the metabolic profile. We assessed medical history, body composition by Dual-Energy X-ray Absorptiometry, muscle strength, and cognitive function. We performed statistics by analysis of covariance (p) and FDR (q) for multiple comparisons.

RESULTS

AO-COPD subjects had 27% more VAT (q < 0.01) than AO-Control subjects despite correction for BMI. Branched-chain amino acid concentrations and WBP rates were generally elevated in AO-COPD but whole body clearance rate was only elevated in COPD. Metabolic syndrome comorbidities (p < 0.01) and systemic inflammation (P < 0.05) were most prevalent in the AO-COPD group. Muscle strength was reduced in COPD subjects (p < 0.001), but partially preserved when combined with AO. Cognitive dysfunction and mood disturbances were present in COPD subjects (p < 0.001) with worst performers in AO-COPD (q < 0.05).

CONCLUSION

The presence of AO is associated with specific metabolic and functional phenotypes in COPD. Clinical trial registry Trial registration ClinicalTrials.gov. In the present paper, we report an analysis of the baseline measurements of COPD subjects and healthy controls from the study numbers: NCT01787682, NCT01787682, NCT02157844, NCT02082418, NCT02065141, NCT02770092, NCT02908425, NCT03159390, NCT02780219, NCT03327181, NCT03796455, NCT04928872, NCT04461236, NCT01173354, NCT01154400.

The Association between Fat-Free Mass and Exercise Test Outcomes in People with Chronic Obstructive Pulmonary Disease: A Systematic Review

People with chronic obstructive pulmonary disease (COPD) tend to have abnormally low levels of fat-free mass (FFM), which includes skeletal muscle mass as a central component. The purpose of this systematic review was to synthesise available evidence on the association between FFM and exercise test outcomes in COPD. MEDLINE, Cochrane Library, EMBASE, Web of Science, and Scopus were searched. Studies that evaluated exercise-related outcomes in relation to measures of FFM in COPD were included. Eighty-three studies, containing 18,770 (39% female) COPD participants, were included. Considerable heterogeneity was identified in the ways that FFM and exercise test outcomes were assessed; however, higher levels of FFM were generally associated with greater peak exercise capacity. This association was stronger for some exercise test outcomes (e.g. peak rate of oxygen consumption during incremental cycle exercise testing) than others (e.g. six-minute walking distance). This review identified heterogeneity in the methods used for measuring FFM and exercise capacity. There was, in general, a positive association between FFM and exercise capacity in COPD. There was also an identified lack of studies investigating associations between FFM and temporal physiological and perceptual responses to exercise. This review highlights the significance of FFM as a determinant of exercise capacity in COPD.

Adiposity increases weight-bearing exercise-induced dyspnea despite favoring resting lung hyperinflation in COPD

Objectives

Our aim was to study the associations between resting lung hyperinflation, weight-bearing exercise-induced dyspnea and adipose distribution in obese and normal-weight COPD patients.

Methods

We performed a comparison between 80 obese COPD patients (COPDOB) with 80 age- and FEV1 matched normal-weight COPD patients (COPDNW). Dyspnea was assessed by the mMRC scale and the Borg dyspnea score before and after a 6 min walk test. Further characterization included spirometry, body plethysmography and metronome paced tachypnea (MPT) to estimate dynamic hyperinflation. Body composition was assessed with bioelectrical impedance analysis. Associations between dyspnea scores and BMI and body composition groups were studied using logistic regression models.

Results

COPDOB patients had attenuated increases in TLC, FRC and RV compared to COPDNW patients ( p < 0.01). The groups had comparable 6 min walking distance and ΔFRC upon MPT ( p > 0.05). Compared to COPDNW, COPDOB patients reported more often a mMRC ≥ 2 (65 vs 46%; p = 0.02; OR 3.0, 95% CI 1.4–6.2, p < 0.01) and had higher ΔBorg upon 6MWT: 2.0 (SEM 0.20) vs. 1.4 (SEM 0.16), p = 0.01; OR for ΔBorg ≥ 2: 2.4, 95% CI 1.1–5.2, p = 0.03. Additional logistic regression analyses on the associations between body composition and dyspnea indicated that increased body fat percentage, fat mass index and waist-to-hip ratio were associated with higher ORs for mMRC ≥ 2 and ΔBorg upon 6MWT ≥ 2.

Conclusion

Despite its beneficial effect on resting lung hyperinflation, adiposity is associated with increased weight-bearing exercise-induced dyspnea in COPD.

Interval Versus Continuous Aerobic Exercise Training in Overweight and Obese Patients With Chronic Obstructive Pulmonary Disease: A RANDOMIZED CONTROLLED STUDY

PURPOSE

The aim of this study was to compare the efficacy of the supervised pulmonary rehabilitation programs consisting of either an interval or continuous aerobic exercise program, with a home-based exercise program in patients with chronic obstructive pulmonary disease (COPD) who were overweight or obese.

METHODS

In this randomized controlled study, 72 overweight and obese patients diagnosed as having COPD were randomly assigned to 3 groups. Group 1 received an interval-type (IT) aerobic exercise program, group 2 received a continuous-type (CT) aerobic exercise program (both groups performed home exercises as well) and group 3 was only given a home-based exercise (HE) program. For the evaluation of patients, anthropometric measures, cardiopulmonary exercise testing (CPX), 6-min walk test (6MWT), modified-Borg dyspnea and leg fatigue scores, St George's Respiratory Questionnaire, and Hospital Anxiety and Depression Scale were used.

RESULTS

Both IT and CT groups showed significant improvement on CPX parameters, 6MWT distances, mental health, and health-related quality of life (HRQoL) compared with the HE group in overweight and obese patients with COPD (P < .001). Moreover, the IT group demonstrated a significant decrease in the modified-Borg dyspnea and leg fatigue during the CPX compared with both CT and HE groups (P < .001). Furthermore, the Borg dyspnea and leg fatigue during training were lower in the IT group than in the CT group (P < .05).

CONCLUSIONS

An interval or continuous aerobic exercise program added onto a home-based exercise program improved exercise capacity and HRQoL, and reduced anxiety and depression levels in overweight and obese patients with COPD.

Chemerin: A Potential Regulator of Inflammation and Metabolism for Chronic Obstructive Pulmonary Disease and Pulmonary Rehabilitation

Chronic obstructive pulmonary disease (COPD) features chronic inflammatory reactions of both intra- and extrapulmonary nature. Moreover, COPD is associated with abnormal glucose and lipid metabolism in patients, which influences the prognosis and chronicity of this disease. Abnormal glucose and lipid metabolism are also closely related to inflammation processes. Further insights into the interactions of inflammation and glucose and lipid metabolism might therefore inspire novel therapeutic interventions to promote lung rehabilitation. Chemerin, as a recently discovered adipokine, has been shown to play a role in inflammatory response and glucose and lipid metabolism in many diseases (including COPD). Chemerin recruits inflammatory cells to sites of inflammation during the early stages of COPD, leading to endothelial barrier dysfunction, early vascular remodeling, and angiogenesis. Moreover, it supports the recruitment of antigen-presenting cells that guide immune cells as part of the body's inflammatory responses. Chemerin also regulates metabolism via activation of its cognate receptors. Glucose homeostasis is affected via effects on insulin secretion and sensitivity, and lipid metabolism is changed by increased transformation of preadipocytes to mature adipocytes through chemerin-binding receptors. Controlling chemerin signaling may be a promising approach to improve various aspects of COPD-related dysfunction. Importantly, several studies indicate that chemerin expression in vivo is influenced by exercise. Although available evidence is still limited, therapeutic alterations of chemerin activity may be a promising target of therapeutic approaches aimed at the rehabilitation of COPD patients based on exercises. In conclusion, chemerin plays an essential role in COPD, especially in the inflammatory responses and metabolism, and has a potential to become a target for, and a biomarker of, curative mechanisms underlying exercise-mediated lung rehabilitation.

Add-on interventions during pulmonary rehabilitation

Both pulmonary rehabilitation (PR) and chronic obstructive pulmonary disease (COPD) are generic terms and it increasingly becomes clear that rehabilitation programmes need to be tailored to the complexity and circumstances of the individual patient. Indeed, PR is described as a comprehensive, individualized intervention based on thorough assessment of identifiable treatable traits. The current review summarizes ongoing developments regarding additional interventions and tools to facilitate PR and improve outcomes in patients with a chronic respiratory disease.

Pathobiological mechanisms underlying metabolic syndrome (MetS) in chronic obstructive pulmonary disease (COPD): clinical significance and therapeutic strategies

Chronic obstructive pulmonary disease (COPD) is a major incurable global health burden and is currently the 4th largest cause of death in the world. Importantly, much of the disease burden and health care utilisation in COPD is associated with the management of its comorbidities (e.g. skeletal muscle wasting, ischemic heart disease, cognitive dysfunction) and infective viral and bacterial acute exacerbations (AECOPD). Current pharmacological treatments for COPD are relatively ineffective and the development of effective therapies has been severely hampered by the lack of understanding of the mechanisms and mediators underlying COPD. Since comorbidities have a tremendous impact on the prognosis and severity of COPD, the 2015 American Thoracic Society/European Respiratory Society (ATS/ERS) Research Statement on COPD urgently called for studies to elucidate the pathobiological mechanisms linking COPD to its comorbidities. It is now emerging that up to 50% of COPD patients have metabolic syndrome (MetS) as a comorbidity. It is currently not clear whether metabolic syndrome is an independent co-existing condition or a direct consequence of the progressive lung pathology in COPD patients. As MetS has important clinical implications on COPD outcomes, identification of disease mechanisms linking COPD to MetS is the key to effective therapy. In this comprehensive review, we discuss the potential mechanisms linking MetS to COPD and hence plausible therapeutic strategies to treat this debilitating comorbidity of COPD.

Effectiveness of Pulmonary Rehabilitation in Patients With Chronic Obstructive Pulmonary Disease With Different Degrees of Static Lung Hyperinflation

OBJECTIVE

To evaluate the effect of pulmonary rehabilitation (PR) on exercise performance and quality of life in patients with chronic obstructive pulmonary disease (COPD) with different degrees of static lung hyperinflation (LH).

DESIGN

Retrospective cohort study.

SETTING

PR network.

PARTICIPANTS

A cohort of 1981 patients with COPD (55% men; age: 66.8±9.3y; forced expiratory volume in the first second%: 50.7±19.5; residual volume [RV]%: 163.0±49.7).

INTERVENTION

An interdisciplinary PR program for patients with COPD consisting of 40 sessions.

MAIN OUTCOME MEASURES

Participants were stratified into 5 quintiles according to baseline RV and were evaluated on the basis of pre- and post-PR 6-minute walk distance (6MWD), constant work rate test (CWRT), and Saint George's Respiratory Questionnaire (SGRQ), among other clinical parameters.

RESULTS

With increasing RV quintile, patients were younger, more frequently women, had lower forced expiratory volume in the first second%, lower body mass index and fat-free mass index, shorter 6MWD, shorter CWRT, and worse SGRQ scores (P<.01). All RV strata improved after PR in all 3 outcomes (P<.001). Nevertheless, higher, compared to lower RV categories, had lower ΔCWRT (P<.01) but similar Δ6MWD (P=.948) and ΔSGRQ (P=.086) after PR.

CONCLUSIONS

LH in COPD is related to younger age, female sex, lower body weight, worse exercise capacity and health status, but did not prevent patients from benefitting from PR. LH, however, influences walking and cycling response after PR differently.

The burden of obesity in asthma and COPD: Role of adiponectin

The influence of obesity on development, severity and prognosis of both asthma and COPD is attracting growing interest. The impact of obesity on the respiratory system ranges from structural modifications (decline of total lung capacity) to humoral alterations. Adipose tissue strongly contributes to the establishment of an inflammatory state being an important source of adipokines. Amongst adipokines, adiponectin is an important component of organ cross talk with adipose tissue exerting protective effects on a variety of pathophysiological processes. Adiponectin is secreted in serum where it abundantly circulates as complexes of different molecular weight. Adiponectin properties are mediated by specific receptors that are widely expressed with AdipoR1, AdipoR2, and T-cadherin being present on epithelial and endothelial pulmonary cells indicating a functional role on lung physiology. In COPD, mild to moderate obesity has been shown to have protective effects on patient's survival, while a higher mortality rate has been observed in patients with low BMI. A specific cluster of obese patients has been identified; in this group, asthma features are particularly severe and difficult to treat. Better understanding of the molecular mechanisms at the base of cross talk among different tissues and organs will lead to identification of new targets for both diagnosis and treatment of asthma and COPD.

Management of chronic obstructive pulmonary disease beyond the lungs

Chronic obstructive pulmonary disease (COPD) is an umbrella term that covers many clinical subtypes with clearly different pulmonary and extra-pulmonary characteristics, but with persistent airflow limitation in common. This insight has led to the development of a more personalised approach in bronchodilator therapy, prevention of exacerbations, and advanced treatments (such as non-invasive ventilation and lung volume reduction techniques). However, systemic manifestations and comorbidities of COPD also contribute to different clinical phenotypes and warrant an individualised approach as part of integrated disease management. Alterations in bodyweight and composition, from cachexia to obesity, demand specific management. Psychological symptoms are highly prevalent, and thorough diagnosis and treatment are necessary. Moreover, prevention of exacerbations requires interventions beyond the lungs, including treatment of gastro-oesophageal reflux disease, reduction of cardiovascular risks, and management of dyspnoea and anxiety. In this Review, we discuss the management of COPD beyond the respiratory system and propose treatment strategies on the basis of the latest research and best practices.