Ectopic fat accumulation in patients with COPD: an ECLIPSE substudy

Postoperative pulmonary complications in patients with chronic obstructive pulmonary disease undergoing primary laparoscopic bariatric surgery: an MBSAQIP analysis

BACKGROUND

Recent research has shown beneficial effects of bariatric surgery (BaS) on the risk of developing acute exacerbations of chronic obstructive pulmonary disease (COPD). However, this patient population may be at increased risk of complications, especially postoperative pulmonary complications (PPC).

OBJECTIVES

To analyze the incidence of PPC in patients with COPD undergoing BaS.

SETTING

Academic Hospital, United States.

METHODS

We performed a retrospective analysis of the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database for patients aged ≥18 years undergoing laparoscopic sleeve gastrectomy and Roux-en-Y gastric bypass during 2015-2019. The primary outcome of the study was any PPC, defined as a composite variable including postoperative pneumonia, mechanical ventilation >48 hours and unplanned endotracheal intubation. A univariate analysis was performed to compare patients with and without COPD, and a multivariate logistic regression was performed to adjust for confounders. A subgroup analysis was performed to compare endpoints in patients with COPD with or without home oxygen requirements.

RESULTS

A total of 752,722 patients were included in our analysis (laparoscopic sleeve gastrectomy = 73.2%, Roux-en-Y gastric bypass = 26.8%). PPC occurred in 2390 patients, 0.3% without COPD versus 1.3% with COPD (P < .001). Multivariable analysis confirmed that COPD independently increases the risk of PPC (OR = 1.7, CI = 1.4-2.1). Subgroup analysis showed that patients who are oxygen dependent had a much higher risk for PPC (2.4% versus 1.1%, P < .001).

CONCLUSION

PPC are higher among patients with obesity and concomitant COPD. Oxygen dependency confers an even higher complication rate. The risk and benefits of BaS in this population must be carefully addressed.

Chronic hypoxia impairs skeletal muscle repair via HIF-2α stabilization

BACKGROUND

Chronic hypoxia and skeletal muscle atrophy commonly coexist in patients with COPD and CHF, yet the underlying physio-pathological mechanisms remain elusive. Muscle regeneration, driven by muscle stem cells (MuSCs), holds therapeutic potential for mitigating muscle atrophy. This study endeavours to investigate the influence of chronic hypoxia on muscle regeneration, unravel key molecular mechanisms, and explore potential therapeutic interventions.

METHODS

Experimental mice were exposed to prolonged normobaric hypoxic air (15% pO2, 1 atm, 2 weeks) to establish a chronic hypoxia model. The impact of chronic hypoxia on body composition, muscle mass, muscle strength, and the expression levels of hypoxia-inducible factors HIF-1α and HIF-2α in MuSC was examined. The influence of chronic hypoxia on muscle regeneration, MuSC proliferation, and the recovery of muscle mass and strength following cardiotoxin-induced injury were assessed. The muscle regeneration capacities under chronic hypoxia were compared between wildtype mice, MuSC-specific HIF-2α knockout mice, and mice treated with HIF-2α inhibitor PT2385, and angiotensin converting enzyme (ACE) inhibitor lisinopril. Transcriptomic analysis was performed to identify hypoxia- and HIF-2α-dependent molecular mechanisms. Statistical significance was determined using analysis of variance (ANOVA) and Mann-Whitney U tests.

RESULTS

Chronic hypoxia led to limb muscle atrophy (EDL: 17.7%, P < 0.001; Soleus: 11.5% reduction in weight, P < 0.001) and weakness (10.0% reduction in peak-isometric torque, P < 0.001), along with impaired muscle regeneration characterized by diminished myofibre cross-sectional areas, increased fibrosis (P < 0.001), and incomplete strength recovery (92.3% of pre-injury levels, P < 0.05). HIF-2α stabilization in MuSC under chronic hypoxia hindered MuSC proliferation (26.1% reduction of MuSC at 10 dpi, P < 0.01). HIF-2α ablation in MuSC mitigated the adverse effects of chronic hypoxia on muscle regeneration and MuSC proliferation (30.9% increase in MuSC numbers at 10 dpi, P < 0.01), while HIF-1α ablation did not have the same effect. HIF-2α stabilization under chronic hypoxia led to elevated local ACE, a novel direct target of HIF-2α. Notably, pharmacological interventions with PT2385 or lisinopril enhanced muscle regeneration under chronic hypoxia (PT2385: 81.3% increase, P < 0.001; lisinopril: 34.6% increase in MuSC numbers at 10 dpi, P < 0.05), suggesting their therapeutic potential for alleviating chronic hypoxia-associated muscle atrophy.

CONCLUSIONS

Chronic hypoxia detrimentally affects skeletal muscle regeneration by stabilizing HIF-2α in MuSC and thereby diminishing MuSC proliferation. HIF-2α increases local ACE levels in skeletal muscle, contributing to hypoxia-induced regenerative deficits. Administration of HIF-2α or ACE inhibitors may prove beneficial to ameliorate chronic hypoxia-associated muscle atrophy and weakness by improving muscle regeneration under chronic hypoxia.

Association between computed tomography-quantified respiratory muscles and chronic obstructive pulmonary disease: a retrospective study

BACKGROUND

This study examined the association between chest muscles and chronic obstructive pulmonary disease (COPD) and the relationship between chest muscle areas and acute exacerbations of COPD (AECOPD).

METHODS

There were 168 subjects in the non-COPD group and 101 patients in the COPD group. The respiratory and accessory respiratory muscle areas were obtained using 3D Slicer software to analysis the imaging of  computed tomography (CT). Univariate and multivariate Poisson regressions were used to analyze the number of AECOPD cases during the preceding year. The cutoff value was obtained using a receiver operating characteristic (ROC) curve.

RESULTS

We scanned 6342 subjects records, 269 of which were included in this study. We then measured the following muscle areas (non-COPD group vs. COPD group): pectoralis major (19.06 ± 5.36 cm2 vs. 13.25 ± 3.71 cm2, P < 0.001), pectoralis minor (6.81 ± 2.03 cm2 vs. 5.95 ± 1.81 cm2, P = 0.001), diaphragmatic dome (1.39 ± 0.97 cm2 vs. 0.85 ± 0.72 cm2, P = 0.011), musculus serratus anterior (28.03 ± 14.95 cm2 vs.16.76 ± 12.69 cm2, P < 0.001), intercostal muscle (12.36 ± 6.64 cm2 vs. 7.15 ± 5.6 cm2, P < 0.001), pectoralis subcutaneous fat (25.91 ± 13.23 cm2 vs. 18.79 ± 10.81 cm2, P < 0.001), paravertebral muscle (14.8 ± 4.35 cm2 vs. 13.33 ± 4.27 cm2, P = 0.007), and paravertebral subcutaneous fat (12.57 ± 5.09 cm2 vs. 10.14 ± 6.94 cm2, P = 0.001). The areas under the ROC curve for the pectoralis major, intercostal, and the musculus serratus anterior muscle areas were 81.56%, 73.28%, and 71.56%, respectively. Pectoralis major area was negatively associated with the number of AECOPD during the preceding year after adjustment (relative risk, 0.936; 95% confidence interval, 0.879-0.996; P = 0.037).

CONCLUSION

The pectoralis major muscle area was negative associated with COPD. Moreover, there was a negative correlation between the number of AECOPD during the preceding year and the pectoralis major area.

Fat infiltration in skeletal muscle: Influential triggers and regulatory mechanism

Fat infiltration in skeletal muscle (also known as myosteatosis) is now recognized as a distinct disease from sarcopenia and is directly related to declining muscle capacity. Hence, understanding the origins and regulatory mechanisms of fat infiltration is vital for maintaining skeletal muscle development and improving human health. In this article, we summarized the triggering factors such as aging, metabolic diseases and metabolic syndromes, nonmetabolic diseases, and muscle injury that all induce fat infiltration in skeletal muscle. We discussed recent advances on the cellular origins of fat infiltration and found several cell types including myogenic cells and non-myogenic cells that contribute to myosteatosis. Furthermore, we reviewed the molecular regulatory mechanism, detection methods, and intervention strategies of fat infiltration in skeletal muscle. Based on the current findings, our review will provide new insight into regulating function and lipid metabolism of skeletal muscle and treating muscle-related diseases.

Assessment of Behavioral Risk Factors in Chronic Obstructive Airway Diseases of the Lung Associated with Metabolic Syndrome

BACKGROUND

Diet and lifestyle play important roles in preventing and improving chronic diseases, and evaluating behavioral risk factors in these pathologies allows for efficient management.

METHODS

A clinical study by screening biochemical parameters and pulmonary function was carried out to evaluate behavioral risk factors in obstructive pulmonary disease associated with metabolic syndrome.

RESULTS

Of the total of 70 patients included in the clinical study, 46 were men and 24 were women (χ2 = 3.9, p = 0.168). Forty-eight patients presented at least three met risk criteria associated with the metabolic syndrome (19 women and 29 men). Regarding the assessment of lung function, only 7 of the patients presented normal spirometry values (χ2 = 75.28, p < 0.001), and the other 63 patients presented with ventilatory dysfunction; most (over 80%) declared that they were smokers or had smoked in the past (χ2 = 5.185, p = 0.075). In terms of body weight, 45 of the patients are overweight or obese, most of them declaring that they do not consume enough vegetable products, they consume large amounts of foods of animal origin (meat, milk, eggs) but also super processed foods (food products type of junk food), do not hydrate properly, and are predominantly sedentary people (54 of the patients do no physical activity at all; χ2 = 2.12, p = 0.713).

CONCLUSION

From the statistical processing of the data, it is noted that insufficient hydration, low consumption of vegetables, increased consumption of hyper-caloric food products rich in additives, sedentary lifestyle, and smoking are the main disruptive behavioral factors that worsen the health status in lung disease associated with the metabolic syndrome. An important conclusion emerging from the study is that the imbalances that aggravate obstructive lung diseases are generated by unhealthy food and an unbalanced lifestyle.

Relationship between trunk intramuscular adipose tissue content and prevalence of metabolic syndrome in middle-aged Japanese men

OBJECTIVES

The aim of the present study was to examine the dose-response relationship between trunk tissue composition and prevalence of metabolic syndrome (MetS) in middle-aged Japanese men.

METHODS

The 1026 men (between 35 and 59 y of age) who participated in the present study were divided into two groups: those with metabolic syndrome (MetS) and those without (non-MetS). Intramuscular adipose tissue (IntraMAT) content and the cross-sectional areas (CSAs) of visceral adipose tissue and skeletal muscle tissue were calculated using low-dose computed tomography images acquired at the level of the third lumbar vertebra. Height, body mass, body fat, waist circumference, the presence of MetS, and lifestyle habits were also assessed.

RESULTS

IntraMAT content was significantly higher in MetS than in non-MetS men. A 10% increase in IntraMAT content correlated with the prevalence of MetS (odds ratio, 4.197; 95% confidence interval, 3.108-7.088; P < 0.001), even after adjustments for age, height, adjusted skeletal muscle CSA, sleeping time, alcohol consumption, exercise habit, and cigarette smoking. Skeletal muscle CSA did not correlate with the prevalence of MetS after adjustments for IntraMAT content and other cofactors.

CONCLUSIONS

Increase in IntraMAT content, not in skeletal muscle CSA, significantly correlated with the prevalence of MetS. These results suggest that countermeasures against the accumulation of trunk IntraMAT effectively prevent MetS in middle-aged Japanese men.

Predictors of longitudinal changes in body weight, muscle and fat in patients with and ever-smokers at risk of COPD

BACKGROUND AND OBJECTIVE

Weight and muscle loss are predictors of poor outcomes in chronic obstructive pulmonary disease. However, to our knowledge, no study has investigated the predictors of longitudinal weight loss or its composition from functional and morphological perspectives.

METHODS

This longitudinal observational study with a median follow-up period of 5 years (range: 3.0-5.8 years) included patients with COPD and ever-smokers at risk of COPD. Using chest computed tomography (CT) images, airway and emphysematous lesions were assessed as the square root of the wall area of a hypothetical airway with an internal perimeter of 10 mm (√Aaw at Pi10) and the percentage of low attenuation volume (LAV%). Muscle mass was estimated using cross-sectional areas (CSAs) of the pectoralis and erector spinae muscles, and fat mass was estimated using the subcutaneous fat thickness at the level of the 8th rib measured using chest CT images. Statistical analyses were performed using the linear mixed-effects models.

RESULTS

In total, 114 patients were enrolled. Their body mass index remained stable during the study period while body weight and muscle CSA decreased over time and the subcutaneous fat thickness increased. Reduced forced expiratory volume in 1 s and peak expiratory flow (PEF) at baseline predicted the future decline in muscle CSA.

CONCLUSION

Severe airflow limitation predicted future muscle wasting in patients with COPD and ever-smokers at risk of COPD. Airflow limitation with a PEF slightly below 90% of the predicted value may require intervention to prevent future muscle loss.

Obesity Paradox in Lung Diseases: What Explains It?

BACKGROUND

Obesity is a globally increasing health problem that impacts multiple organ systems and a potentially modifiable risk factor for many diseases. Obesity has a significant impact on lung function and is strongly linked to the pathophysiology that contributes to lung diseases. On the other hand, reports have emerged that obesity is associated with a better prognosis than for normal weight individuals in some lung diseases, including pneumonia, acute lung injury/acute respiratory distress syndrome, chronic obstructive pulmonary disease, and lung cancer. The lesser mortality and better prognosis in patients with obesity is known as obesity paradox. While obesity paradox is both recognized and disputed in epidemiological studies, recent research has suggested possible mechanisms.

SUMMARY

In this review, we attempted to explain and summarize these factors and mechanisms, including immune response, pulmonary fibrosis, lung function, microbiota, fat and muscle reserves, which are significantly altered by obesity and may contribute to the obesity paradox in lung diseases. We also discuss contrary literature that attributes the "obesity paradox" to confounding.

KEY MESSAGES

The review will illustrate the possible role of obesity in the prognosis or course of lung diseases, leading to a better understanding of the obesity paradox and provide hints for further basic and clinical research in lung diseases.

Association between abdominal and general obesity and respiratory symptoms, asthma and COPD. Results from the RHINE study

INTRODUCTION

Previous studies on the association between abdominal and general obesity and respiratory disease have provided conflicting results.

AIMS AND OBJECTIVES

We aimed to explore the associations of abdominal obesity with respiratory symptoms, asthma, and chronic obstructive pulmonary disease independently from general obesity in women and men.

METHODS

This cross-sectional study was based on the Respiratory Health in Northern Europe (RHINE) III questionnaire (n = 12 290) conducted in 2010-2012. Abdominal obesity was self-measured waist circumference using a sex-specific standard cut-off point: ≥102 cm in males and ≥88 cm in females. General obesity was defined as self-reported BMI ≥30.0 kg/m².

RESULTS

There were 4261 subjects (63% women) with abdominal obesity and 1837 subjects (50% women) with general obesity. Both abdominal and general obesity was independent of each other and associated with respiratory symptoms (odds ratio (OR) from 1.25 to 2.00)). Asthma was significantly associated with abdominal and general obesity in women, OR (95% CI) 1.56 (1.30-1.87) and 1.95 (1.56-2.43), respectively, but not in men, OR 1.22 (0.97-3.17) and 1.28 (0.97-1.68) respectively. A similar sex difference was found for self-reported chronic obstructive pulmonary disease.

CONCLUSIONS

General and abdominal obesity were independent factors associated with respiratory symptoms in adults. Asthma and chronic obstructive pulmonary disease were independently linked to abdominal and general obesity in women but not men.

Body Composition and COPD: A New Perspective

The proportion of obese or overweight patients in COPD patients is increasing. Although BMI, WC and other easy to measure indicators have been proven to be related to the risk of COPD, they cannot accurately reflect the distribution and changes of body composition, ignoring the body composition (such as fat distribution, muscle content, water content, etc.), the relationship between it and disease risk may be missed. By analyzing the correlation between different body composition indexes and COPD patients, we can provide new research ideas for the prognosis judgment or intervention of COPD disease.

Computed tomography-based body composition measures in COPD and their association with clinical outcomes: A systematic review

Background

Computed tomography (CT) is commonly utilized in chronic obstructive pulmonary disease (COPD) for lung cancer screening and emphysema characterization. Computed tomography-morphometric analysis of body composition (muscle mass and adiposity) has gained increased recognition as a marker of disease severity and prognosis. This systematic review aimed to describe the CT-methodology used to assess body composition and identify the association of body composition measures and disease severity, health-related quality of life (HRQL), cardiometabolic risk factors, respiratory exacerbations, and survival in patients with COPD.

Methods

Six databases were searched (inception-September 2021) for studies evaluating adult COPD patients using thoracic or abdominal CT-muscle or adiposity body composition measures. The systematic review was conducted in accordance with the PRISMA guidelines.

Results

Twenty eight articles were included with 15,431 COPD patients, across all GOLD stages with 77% males, age range (mean/median 59–78 years), and BMI range 19.8–29.3 kg/m². There was heterogeneity in assessment of muscle mass and adiposity using thoracic (n = 22) and abdominal (n = 8) CT-scans, capturing different muscle groups, anatomic locations, and adiposity compartments (visceral, subcutaneous, and epicardial). Low muscle mass and increased adiposity were associated with increased COPD severity measures (lung function, exercise capacity, dyspnea) and lower HRQL, but were not consistent across studies. Increased visceral adiposity (n = 6) was associated with cardiovascular disease or risk factors (hypertension, hyperlipidemia, and diabetes). Low muscle CSA was prognostic of respiratory exacerbations or mortality in three of six studies, whereas the relationship with increased intermuscular adiposity and greater mortality was only observed in one of three studies.

Conclusion

There was significant variability in CT-body composition measures. In several studies, low muscle mass was associated with increased disease severity and lower HRQL, whereas adiposity with cardiovascular disease/risk factors. Given the heterogeneity in body composition measures and clinical outcomes, the prognostic utility of CT-body composition in COPD requires further study.

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).

Skeletal Myosteatosis is Associated with Systemic Inflammation and a Loss of Muscle Bioenergetics in Stable COPD

Background

Common features among patients with more advanced chronic obstructive pulmonary disease (COPD) are systemic inflammation and a loss of both muscle mass and normal muscle composition. In the present study, we investigated COPD subjects to better understand how thigh muscle fat infiltration (MFI) and energy metabolism relate to each other and to clinical features of COPD with emphasis on systemic inflammation.

Methods

Thirty-two Caucasians with stable COPD were investigated using questionnaires, lung function tests, blood analysis and magnetic resonance imaging (MRI) for analysis of body- and thigh muscle composition. Bioenergetics in the resting thigh muscle, expressed as the PCr/Pi ratio, were analysed using ³¹phosphorus magnetic resonance spectroscopy (³¹P-MRS).

Results

Based on the combination of the MFI adjusted for sex (MFI_a) and the thigh fat-tissue free muscle volume, expressed as the deviation from the expected muscle volume of a matched virtual control group (FFMV_vcg), all COPD subjects displayed abnormally composed thigh muscles. Clinical features of increased COPD severity, including a decrease of blood oxygenation (r = −0.44, p < 0.05) and FEV₁/FVC ratio, reflecting airway obstruction (r = −0.53, p < 0.01) and an increase of COPD symptoms (r = 0.37, p < 0.05) and breathing frequency at rest (r = 0.41, p < 0.05), were all associated with a raise of the PCr/Pi ratio in the thigh muscle. Increased MFI_a of the thigh muscle correlated positively with markers of systemic inflammation (white blood cell count, r = 0.41, p < 0.05; fibrinogen, r = 0.44, p < 0.05), and negatively with weekly physical activity (r = −0.40, p < 0.05) and the PCr/Pi ratio in the resting thigh muscle (r = −0.41, p < 0.05).

Conclusion

The present study implies a link between systemic inflammation, excessive MFI and a loss of bioenergetics in subjects with stable COPD.

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.

Mortality and Exacerbation Risk by Body Mass Index in Patients with COPD in TIOSPIR and UPLIFT

Rationale: There is an association between body mass index (BMI) and mortality in chronic obstructive pulmonary disease (COPD), with underweight individuals having higher mortality risk. Mortality and exacerbation risks among individuals with higher BMI are unclear. Objectives: To examine the relationship between BMI and adverse outcomes in COPD. Methods: This post hoc analysis included data from TIOSPIR (Tiotropium Safety and Performance in Respimat) (N = 17,116) and tiotropium-treated patients in UPLIFT (Understanding Potential Long-term Impacts on Function with Tiotropium) (N = 2,986). BMI classes (underweight [BMI < 20 kg/m2], normal weight [BMI 20 to <25 kg/m2], overweight [BMI 25 to <30 kg/m2], obesity class I [BMI 30 to <35 kg/m2], obesity class II [BMI 35 to <40 kg/m2], and obesity class III [BMI ⩾ 40 kg/m2]) were examined for adjusted associations with mortality, exacerbation, and nonfatal cardiovascular event risk using over 50,000 patient-years of cumulative follow-up data. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox regression models. Results: In TIOSPIR, obesity prevalence was 22%, overweight 32%, and underweight 12%. The proportion of females was highest in obesity classes II and III. Overweight and obese participants had better baseline lung function versus other BMI classes; underweight participants were more likely to be current smokers. Underweight participants had a significantly higher risk of death (HR, 1.88; 95% CI, 1.62-2.20; P < 0.0001) and severe exacerbations (HR, 1.31; 95% CI, 1.16-1.47; P < 0.0001) versus normal-weight participants; however, overweight and obese participants were at lower to no additional risk. Results from UPLIFT were similar to TIOSPIR. Conclusions: These results suggest that there is a strong association between body weight, COPD events, and risk of death. A holistic management approach taking into account respiratory and cardiovascular risk factors and nutritional status is needed to improve the general well-being of patients with COPD.

Differences in Abdominal Body Composition According to Glycemic Status: An Inverse Probability Treatment Weighting Analysis

BACKGROUND

Several studies have reported that abdominal fat and muscle changes occur in diabetic patients. However, there are few studies about such changes among prediabetic patients. In this study, we evaluated the differences in abdominal fat and muscles based on abdominopelvic computed tomography in prediabetic and diabetic subjects compared to normal subjects.

METHODS

We performed a cross-sectional study using health examination data from March 2014 to June 2019 at Ulsan University Hospital and classified subjects into normal, prediabetic, and diabetic groups. We analyzed the body mass index corrected area of intra-abdominal components among the three groups using inverse probability treatment weighting (IPTW) analysis.

RESULTS

Overall, 8,030 subjects were enrolled; 5,137 (64.0%), 2,364 (29.4%), and 529 (6.6%) subjects were included in the normal, prediabetic, and diabetic groups, respectively. After IPTW adjustment of baseline characteristics, there were significant differences in log visceral adipose tissue index (VATI; 1.22±0.64 cm2/[kg/m2] vs. 1.30±0.63 cm2/[kg/m2] vs. 1.47±0.64 cm2/[kg/m2], P<0.001) and low-attenuation muscle index (LAMI; 1.02±0.36 cm2/[kg/m2] vs. 1.03±0.36 cm2/[kg/m2] vs. 1.09±0.36 cm2/[kg/m2], P<0.001) among the normal, prediabetic, and diabetic groups. Prediabetic subjects had higher log VATI (estimated coefficient= 0.082, P<0.001), and diabetic subjects had higher log VATI (estimated coefficient=0.248, P<0.001) and LAMI (estimated coefficient=0.078, P<0.001) compared to normal subjects.

CONCLUSION

Considering that VATI and LAMI represented visceral fat and lipid-rich skeletal muscle volumes, respectively, visceral obesity was identified in both prediabetic and diabetic subjects compared to normal subjects in this study. However, intra-muscular fat infiltration was observed in diabetic subjects only.

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.

Intramuscular and Intermuscular Abdominal Fat Infiltration in COPD: A Propensity Score Matched Study

Purpose

Low-attenuation muscle area (LAMA) and normal-attenuation muscle area (NAMA) indicate lipid-rich and lipid-poor skeletal muscle areas, respectively. Additionally, intermuscular adipose tissue (IMAT) indicates localized fat between muscle groups. In this study, we aimed to evaluate the intramuscular and intermuscular fat infiltration in individuals with chronic obstructive pulmonary disease (COPD) by performing quantitative assessment of the LAMA, NAMA, and IMAT observed on abdominopelvic computed tomography (APCT) images.

Patients and Methods

We performed a cross-sectional study using data of subjects who underwent a general health examination with APCT at Ulsan University Hospital between March 2014 and June 2019. We classified the subjects into control and COPD groups based on age, smoking history, and pulmonary function results. We compared the attenuation and body mass index adjusted area of intra-abdominal components between the two groups using propensity score matching. We also evaluated these outcomes in COPD subgroups (mild and moderate stage subjects).

Results

Overall, 6,965 subjects were initially enrolled, and 250 pairs of control and COPD subjects were selected after propensity score matching. The NAMA attenuation (unstandardized β=−1.168, P<0.001) was lower, and the IMAT (unstandardized β=0.042, P=0.006) and LAMA (unstandardized β=0.120, P<0.001) indexes were greater in the COPD group than in the control group. In subgroup analysis, those with mild and moderate COPD also had high IMAT (unstandardized β=0.037, P=0.009 and unstandardized β=0.045, P<0.001) and LAMA (unstandardized β=0.089, P=0.002 and unstandardized β=0.147, P<0.001) indexes compared to the control subjects. However, the NAMA attenuation (unstandardized β=−1.075, P<0.001) and NAMA index (unstandardized β=−0.133, P=0.015) were significantly lower in moderate COPD subjects only.

Conclusion

Our study showed that intramuscular and intermuscular abdominal fat infiltration could be present in subjects with mild COPD, and it might be exacerbated in those with moderate COPD.

CT Imaging and Comorbidities in COPD: Beyond Lung Cancer Screening

Comorbidities significantly contribute to morbidity, mortality, and health-care costs in individuals with COPD. Comorbidity prevalence does not always correlate with lung disease severity, and the elevated risk of certain comorbidities is often independent of shared risk factors such as tobacco burden. Although COPD management guidelines recognize the importance of identifying and treating comorbidities as part of the comprehensive management of COPD patients, little guidance is provided regarding best screening practices. Whereas universal comorbidity screening in COPD patients is likely not cost-effective, targeted early screening and treatment in those at highest risk may have a significant impact on COPD outcomes. Recent studies suggest that certain radiographic features on thoracic imaging may serve as surrogate markers of comorbidity in patients with COPD. This review evaluates these studies in the context of the growing availability of chest CT scans in the lung cancer screening era and discusses how chest CT imaging can be leveraged to identify those COPD patients at highest risk for comorbid disease.

Chest computed tomography is a valid measure of body composition in individuals with advanced lung disease

There is growing interest in evaluating body composition using routine clinical computed tomography (CT) scans; however, the validity of this technique in lung transplant patients has not been described. The study objectives were to determine the reliability of measuring fat compartments from thoracic CT and evaluate the validity of muscle and fat cross-sectional area (CSA) from thoracic CT by comparing to bioelectrical impedance analysis (BIA). Thoracic CT scans from lung transplant assessments were obtained for analysis. Total thoracic muscle CSA, pectoral muscle CSA, subcutaneous adipose tissue (SAT), and mediastinal adipose tissue (MAT) were manually segmented by two independent raters. Reliability was analysed using intra-class correlation coefficient (ICC). Correlations were determined between CT measures with fat-free mass index (FFMI), body fat mass index (BFMI) and per cent body fat (%BF) from BIA; and anthropometrics [body mass index (BMI) and waist circumference (WC)]. High inter- and intra-rater reliability were found for SAT and MAT (ICCs = 0.99). Pectoral and total muscle CSA were correlated with FFMI (r = .41, p = .003 and r = .57, p < .001, respectively). SAT was associated with whole-body fat from BIA and with BMI and WC (r = .61 to .80, p < .001). MAT was associated with BMI (r = .58, p < .001) and WC (r = .61, p < .001). This study supports the reliability and validity of using thoracic CT to measure muscle and fat. Future studies are needed to investigate whether these CT-based measures are predictive of clinical and post-transplant outcomes in advanced lung disease.

Metabolic profiles among COPD and controls in the CanCOLD population-based cohort

A high prevalence of intermediate cardiometabolic risk factors and obesity in chronic obstructive pulmonary disease (COPD) has suggested the existence of pathophysiological links between hypertriglyceridemia, insulin resistance, visceral adiposity, and hypoxia or impaired pulmonary function. However, whether COPD contributes independently to the development of these cardiometabolic risk factors remains unclear. Our objective was to compare ectopic fat and metabolic profiles among representative individuals with COPD and control subjects and to evaluate whether the presence of COPD alters the metabolic risk profile. Study participants were randomly selected from the general population and prospectively classified as non-COPD controls and COPD, according to the Global Initiative for Chronic Obstructive Lung Disease classification. The metabolic phenotype, which consisted of visceral adipose tissue area, metabolic markers including homeostasis model assessment of insulin resistance (HOMA-IR), and blood lipid profile, was obtained in 144 subjects with COPD and 119 non-COPD controls. The metabolic phenotype was similar in COPD and controls. The odds ratios for having pathologic values for HOMA-IR, lipids and visceral adipose tissue area were similar in individuals with COPD and control subjects in multivariate analyses that took into account age, sex, body mass index, tobacco status and current medications. In a population-based cohort, no difference was found in the metabolic phenotype, including visceral adipose tissue accumulation, between COPD and controls. Discrepancies between the present and previous studies as to whether or not COPD is a risk factor for metabolic abnormalities could be related to differences in COPD phenotype or disease severity of the study populations.

Low Liver Density Is Linked to Cardiovascular Comorbidity in COPD: An ECLIPSE Cohort Analysis

Purpose

Fatty liver disease is associated with cardiometabolic disorders and represents a potential key comorbidity in Chronic Obstructive Pulmonary Disease (COPD). Some intermediary mechanisms of fatty liver disease (including its histological component steatosis) include tissue hypoxia, low-grade inflammation and oxidative stress that are key features of COPD. Despite these shared physiological pathways, the effect of COPD on the prevalence of hepatic steatosis, and the association between hepatic steatosis and comorbidities in this population remain unclear. Liver density measured by computed tomography (CT)-scan is a non-invasive surrogate of fat infiltration, with lower liver densities reflecting more fat infiltration and a liver density of 40 Hounsfield Units (HU) corresponding to a severe 30% fat infiltration.

Patients and Methods

We took advantage of the international cohort ECLIPSE in which non-enhanced chest CT-scans were obtained in 1554 patients with COPD and 387 healthy controls to analyse the liver density at T12-L1.

Results

The distribution of liver density was similar and the prevalence of severe steatosis (density<40 HU) was not different (4.7% vs 5.2%, p=0.7) between COPD and controls. In patients with COPD, the lowest liver density quartile was associated, after age and sex adjustment, with coronary artery disease (OR_a=1.59, 95% CI 1.12 to 2.24) and stroke (OR_a=2.20, 95% CI 1.07 to 4.50), in comparison with the highest liver density quartile.

Conclusion

The present data indicate that a low liver density emerged as a predictor of cardiovascular comorbidities in the COPD population. However, the distribution of liver density and the prevalence of severe steatosis were similar in patients with COPD and control subjects.

Visceral adipose tissue is associated with poor diet quality and higher fasting glucose in adults with cystic fibrosis

BACKGROUND

Body fat distribution and diet quality influence clinical outcomes in general populations but are understudied in individuals with cystic fibrosis (CF). The aim of this pilot study was to assess body fat distribution and diet quality in relation to fasting glucose and lung function in adults with CF.

METHODS

Subjects were 24 adults (ages 18-50) with CF and 25 age-matched controls. The Healthy Eating Index 2015 (HEI-2015) was calculated from 3-day food records and data were adjusted per 1000 kcal. Whole and regional body composition, including visceral adipose tissue (VAT), was assessed by dual energy X-ray absorptiometry.

RESULTS

Subjects with CF reported more added sugar intake [26.1 (IQR 18.1) vs. 12.9 (12.5) g/1000 kcal, p < 0.001] and had lower HEI-2015 scores [48.3 (IQR 9.9) vs. 63.9 (27.3), p < 0.001] compared to controls. There were no differences in BMI, total body fat, or lean body mass (LBM) between subjects with CF and controls (p > 0.05 for all), although subjects with CF had higher VAT than control subjects [0.3 (IQR 0.3) vs 0.1 (0.3) kg, p = 0.02]. Among subjects with CF, VAT was positively associated with added sugar intake (p < 0.001) and fasting blood glucose (p = 0.04). Lung function was positively associated with BMI (p = 0.005) and LBM (p = 0.03) but not with adiposity indicators.

CONCLUSIONS

These novel data link body fat distribution with diet quality and fasting glucose levels in adults with CF, whereas LBM was associated with lung function. This study highlights the importance of increasing diet quality and assessing body composition and fat distribution in the CF population.

Ectopic adiposity and cardiometabolic health in COPD

Rationale

Obesity/overweight is the most prevalent body composition abnormality in COPD. However, little is known about the impact of fat distribution on cardiometabolic health in COPD.

Objective

To study the associations between ectopic adiposity, cardiometabolic health, and COPD.

Methods

A total of 263 subjects (166 males; age=65±9 years) were randomly selected from the general population. Subjects were classified as non-COPD controls and COPD, according to the Global initiative for chronic Obstructive Lung Disease (GOLD) classification, and the presence of cardiometabolic comorbidities was recorded. Ectopic fat accumulation was documented from computed tomography measurements of visceral adipose tissue cross-sectional areas and muscle mean attenuation, assessed at L4–L5. Blood glucose, lipid, and adipokine profiles were also evaluated.

Results

After correcting for age, sex, and tobacco exposure, visceral adipose tissue cross-sectional area was higher in GOLD 2+ compared to GOLD 1 individuals. Consistent with this, mean muscle tissue attenuation was lower in GOLD 2+ vs GOLD 1 and non-COPD controls (P<0.001). In multiple regression models, visceral adipose tissue cross-sectional area was strongly associated with hypertension (P<0.001) and diabetes (P<0.001), while muscle attenuation was associated with coronary artery disease (P<0.001). Blood glucose, lipid, and adipokine profiles were similar across groups with the exception of leptin level which was higher in GOLD 2+ subjects compared to GOLD 1 and controls.

Conclusion

GOLD 2+ COPD was associated with ectopic fat accumulation which modulated cardiometabolic health.

Obesity and Metabolic Abnormalities in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) and obesity are major causes of morbidity and mortality worldwide, and a relationship between COPD and obesity is increasingly recognized. The nature and underlying mechanisms of the link between obesity and COPD are still largely unknown. Obesity, and abdominal adiposity in particular, is linked to metabolic syndrome. Hypertension, hyperglycemia, and abdominal adiposity seem to be the most prevalent components of metabolic syndrome in COPD. Adipose tissues function as a source of a variety of signaling molecules in the pathobiology of respiratory diseases. Computed tomography allows measurement of various fat depots and allows better understanding of the impact of abdominal visceral fat in the pathophysiology of COPD. Innovative statistical methodology has identified obesity as a relevant and distinguishing characteristic in patients with COPD. Integrated research combining COPD and its multimorbidity network may unravel underlying endotypes to direct future interventions in this specific COPD cluster.

Neglected areas on thorax computed tomography evaluation in patients with chronic obstructive pulmonary disease: Paravertebral muscles and para-aortic adipose tissue

INTRODUCTION

This study, investigated the para-aortic adipose tissue cross-sectional area, a novel predictor of cardiovascular diseases and degenerative changes in the paravertebral muscles, in patients with chronic obstructive pulmonary disease (COPD).

METHOD

One hundred cases diagnosed as COPD and 50 healthy individuals with similar demographic characteristics were evaluated. Para-aortic adipose tissue cross-sectional area (mm2 ), subcutaneous adipose tissue thickness (mm), paravertebral muscle area (mm2 ) and fat deposition in muscle tissue were assessed radiologically.

RESULTS

Paravertebral muscle mass was lower in the patient group compared to the healthy individuals (471.41 ± 157.71 mm2 and 561.58 + 151.03 mm2 , respectively; P = 0.001). Paravertebral muscle attenuation values were also lower in the patient group, and the grade of deposition increased (P = 0.012 and P = 0.045, respectively). Although subcutaneous adipose tissue thicknesses were similar in the patient and control groups, para-aortic adipose tissue cross-sectional area was higher in the patients with COPD than in the control group (439.34 ± 267.17 mm2 and 333.82 ± 165.23 mm2 , respectively, P = 0.012). The correlation between subcutaneous adipose tissue and para-aortic adipose tissue observed in the healthy group was not present in the subjects with COPD.

CONCLUSION

Chronic obstructive pulmonary disease causes morphological changes in paravertebral muscles and para-aortic adipose tissue. Degenerative changes in the paravertebral muscles occur secondary to systemic inflammation, comorbidity and drugs used in COPD. Factors such as insulin resistance and steroid use result in an increase in para-aortic adipose tissue mass.