Weight loss in chronic obstructive pulmonary disease. Mechanisms and implications

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.

Dexamethasone and losartan combination treatment protected cigarette smoke-induced COPD in rats

Chronic Obstructive Pulmonary Disease (COPD) is a dangerous prevalent smoking-related disease characterized by abnormal inflammation and oxidative stress and expected to be the third cause of death in the world next decade. Corticosteroids have low effects in decreasing numbers of inflammatory mediators specifically in long-term use. Our study designed to investigate the possible protective effects of combined dexamethasone (Dex) (2mg/kg) and losartan (Los) (30mg/kg angiotensin receptor blocker, it possesses antioxidant and anti-inflammatory properties in lung injury in mice) against cigarette -smoke (CS) induced COPD in rats compared with dexamethasone and losartan. Male Sprague Dawley rats (N = 40) divided into five groups (n = 8): control group, CS group, Dex group, Los group, and Dex +Los group. COPD induced in rats by CS exposure twice daily for 10 weeks. After the specified treatment period, bronchoalveolar lavage fluid (BALF) and lung tissue were collected for measurement of SOD, NO, MDA, ICAM-, MMP-9, CRP, NF-κB and histopathology scoring. Our results indicated that Los+Dex significantly prevent CS-induced COPD emphysema, congested alveoli, and elevation of lung injury parameters in BALF. They also showed a significant decrease in MDA, ICAM-1, MMP-9, CRP, and NF-κB and a significant increase in SOD and NO. In conclusion, adding Los to Dex potentiating their activity in inhibition the progression of COPD based on its activity on oxidative stress, inflammation, and NF-κB protein expression.

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.

Anthropometric status of individuals with COPD in the city of São Paulo, Brazil, over time - analysis of a population-based study

OBJECTIVE

To evaluate the anthropometric data obtained for residents of the city of São Paulo, Brazil, in a study of Latin America conducted in two phases (baseline, in 2003, and follow-up, in 2012).

METHODS

This was an analysis of data obtained for São Paulo residents in a two-phase population-based study evaluating the prevalence of COPD and its relationship with certain risk factors among individuals ≥ 40 years of age. The anthropometric data included values for weight, height, body mass index (BMI), and waist circumference. In the follow-up phase of that study, the same variables were evaluated in the same population sample as that of the baseline phase.

RESULTS

Of the 1,000 São Paulo residents enrolled in the baseline phase of that study, 587 participated in the follow-up phase, and 80 (13.6%) of those 587 subjects had COPD. Comparing the baseline and follow-up phases, we found increases in all anthropometric measures in both groups (COPD and non-COPD), although the differences were significant only in the non-COPD group. The subjects with mild COPD showed increases in weight and BMI (Δweight = 1.6 ± 5.7 and ΔBMI = 0.7 ± 2.2), whereas those with moderate or severe COPD showed reductions (Δweight = -1.7 ± 8.1 and ΔBMI = -0.4 ± 3.0), as did those with severe or very severe COPD (Δweight = -0.5 ± 5.4 and ΔBMI = -0.8 ± 3.3).

CONCLUSIONS

Between the two phases of the study, the subjects with mild COPD showed increases in weight and BMI, whereas those with a more severe form of the disease showed reductions.

IgG4-Related Neuromyopathy Associated With Recurrent Pleural Effusion

OBJECTIVE

Immunoglobulin G4-related disease (IgG4-RD) is an increasingly recognized idiopathic systemic disorder associated with elevated serum IgG4 level and tissue infiltration by IgG4-positive plasma cells. Multiple neurological manifestations, including peripheral neuropathy, have been described in IgG4-RD. Our objective is to discuss a case report and review of the literature, which would expand the spectrum of IgG4-RD.

METHODS

We describe the clinical features and biopsy findings in a patient with IgG4-RD who presented with features suggestive of neuromyopathy in the setting of recurrent pleural effusion and weight loss.

RESULTS

Electrodiagnostic findings were suggestive of an irritable myopathy and polyradiculoneuropathy with primary demyelination and secondary axonal degeneration. Pleural biopsy and laboratory studies confirmed the diagnosis. Improvement was sustained with steroid therapy.

CONCLUSIONS

We describe the first case, to our knowledge, of IgG4-related neuromyopathy associated with recurrent pleural effusion. Our case expands the clinical spectrum of IgG4-RD. Neurologists should be aware of this treatable disorder and in the appropriate clinical context consider it in the differential diagnosis of neuromyopathy.

Why do thin people have elevated all-cause mortality? Evidence on confounding and reverse causality in the association of adiposity and COPD from the British Women's Heart and Health Study

Low adiposity has been linked to elevated mortality from several causes including respiratory disease. However, this could arise from confounding or reverse causality. We explore the association between two measures of adiposity (BMI and WHR) with COPD in the British Women's Heart and Health Study including a detailed assessment of the potential for confounding and reverse causality for each adiposity measure. Low BMI was found to be associated with increased COPD risk while low WHR was not (OR = 2.2; 95% CI 1.3-3.1 versus OR = 1.2; 95% CI 0.7-1.6). Potential confounding variables (e.g. smoking) and markers of ill-health (e.g. unintentional weight loss) were found to be higher in low BMI but not in low WHR. Women with low BMI have a detrimental profile across a broad range of health markers compared to women with low WHR, and women with low WHR do not appear to have an elevated COPD risk, lending support to the hypothesis that WHR is a less confounded measure of adiposity than BMI. Low adiposity does not in itself appear to increase the risk of respiratory disease, and the apparent adverse consequences of low BMI may be due to reverse causation and confounding.

Current and potential roles of ghrelin in clinical practice

Ghrelin is a novel GH-releasing peptide, which has been identified as an endogenous ligand for GH-secretagogue receptor. Ghrelin is mainly secreted by the stomach and plays a critical role in a variety of physiological processes including endocrine, metabolic, cardiovascular, immunological, and other actions. Ghrelin stimulates food intake via hypothalamic neurons and causes a positive energy balance and body weight gain by decreasing fat utilization and promoting adiposity. Given the multiple effects of ghrelin, its potential clinical applications have been evaluated in various conditions. Preliminary trials have shown that it may prove valuable in the management of disease-induced cachexia. Ghrelin may improve the wasting syndrome through GH-dependent or GH-independent effects. Moreover, ghrelin may play a role in the management of disorders of gut motility and obesity. Finally, other potential clinical applications of ghrelin include the treatment of patients with diabetes mellitus, infections, rheumatological diseases or GH deficiency and the diagnosis of this hormonal disorder.

Obesity and respiratory diseases

Obesity is a worldwide epidemic and is known to increase the risk of cardiovascular disease, type 2 diabetes, and certain forms of cancer. In addition, obesity is now recognized as an important risk factor in the development of several respiratory diseases. Of these respiratory diseases, it has already been well established that obesity can lead to obstructive sleep apnea (OSA) and obesity-hypoventilation syndrome (OHS). More recent data suggest that the prevalence of wheezing and bronchial hyper-responsiveness, two symptoms often associated with asthma, are increased in overweight and obese individual. Indeed, epidemiological studies have reported that obesity is a risk factor for the development of asthma. Furthermore, a number of studies indicate that obesity is also associated with a higher risk of developing deep vein thrombi, pulmonary emboli, pulmonary hypertension, and pneumonia. Finally, weight reduction has been shown to be effective in improving the symptoms and severity of several respiratory diseases, including OSA and asthma. Thus, overweight and obese patients should be encouraged to lose weight to reduce their risk of developing respiratory diseases or improve the course of pre-existing conditions.

Anorexia in chronic obstructive pulmonary disease--association to cachexia and hormonal derangement

BACKGROUND

In patients with chronic obstructive pulmonary disease (COPD) weight loss frequently occurs that may ultimately lead to cachexia as a serious co-morbidity, indicating severely impaired functional capacity, health status and increased mortality. Increased energy expenditure due to mechanic and metabolic inefficiency and systemic inflammation are determinants of a hypermetabolic state that is not balanced by dietary intake. Anorexia may importantly contribute to weight loss in COPD, however, the association between immune and hormonal derangement and altered appetite has not been studied in detail.

AIM

The aim of the present study was to investigate whether anorexia in COPD is related to inflammation and hormonal derangement in association to weight loss.

METHODS

We prospectively enrolled 103 consecutive patients with COPD (age 59.8+/-1.3 years, 35% female, mean FEV1 38.3+/-1.7%) in comparison to healthy controls of similar age (n=15).

RESULTS

In 34 patients (33%) cachexia was diagnosed (weight loss >7.5%, BMI < or = 24 kg/m2). Cachectic COPD patients had lower BMI (19.0+/-0.5 vs 25.6+/-0.7 kg/m2) and impaired lung function (FEV1 31+/-2% vs 42+/-2%, FVC 51+/-3 vs 59+/-3%, both p<0.001). Inflammatory immune activation (IL-6 and IL-6/IL-10 ratio) was significantly higher in cachectic COPD patients. Analysis of the extent of anorexia (visual analogue scale) revealed that cachectic COPD patients had significantly decreased subjective desire to eat compared to non-cachectic patients (3.5+/-0.3 vs 6.3+/-0.2, p<0.001). Patients with COPD and cachexia showed evidence of acquired GH resistance (decreased IGF-1/GH ratio) and insulin resistance (HOMA). Anorexia showed a direct correlation with the IGF-1/GH ratio (r=0.34, p<0.05) and was further related to BMI and % weight loss (both p<0.001).

CONCLUSION

In COPD anorexia relates to hormonal derangement and inflammatory immune activation. Anorexia contributes to development of cachexia. The concept of appetite stimulating therapy emerges as a novel therapeutic option in cachectic COPD patients.

Circulating ghrelin in patients with chronic obstructive pulmonary disease

OBJECTIVE

Unexplained weight loss is common in patients with chronic obstructive pulmonary disease (COPD). Because ghrelin plays an important role in energy homeostasis, this study investigated the plasma level of ghrelin in COPD.

METHODS

Plasma ghrelin levels and levels of leptin, tumor necrosis factor-alpha, and C-reactive protein were measured in 29 patients with COPD and 17 healthy controls. Body composition was assessed with bioelectrical impedance analysis.

RESULTS

Body mass index and percentage of body fat were lower in patients who had COPD than in healthy controls. Plasma ghrelin and leptin concentrations were significantly lower in patients who had COPD than in healthy controls (ghrelin: 0.25+/-0.22 ng/mL versus 0.43+/-0.24 ng/mL, P=0.013; leptin: 1.77+/-0.70 ng/mL versus 2.85+/-0.96 ng/mL, P=0.000). In contrast, tumor necrosis factor-alpha and C-reactive protein were significantly higher in those with COPD than in controls. Plasma ghrelin (log transformed) was positively correlated with body mass index and percentage of body fat in patients with COPD but negatively correlated in control subjects. Plasma ghrelin was negatively correlated with tumor necrosis factor-alpha and C-reactive protein in COPD.

CONCLUSION

Plasma ghrelin level was decreased in COPD and this is different from other weight-loss diseases. These data suggest that decreased ghrelin and other factors may contribute to alterations in metabolic status during inflammatory stress in this disease.

Correlações entre os níveis de L-carnitina plasmática, o estado nutricional e a função ventilatória de portadores de doença pulmonar obstrutiva crônica

OBJETIVO: Avaliar os níveis de L-carnitina livre no plasma, o estado nutricional, a função pulmonar e a tolerância ao exercício em pacientes com doença pulmonar obstrutiva crônica e verificar as correlações entre a composição corporal e as frações de L-carnitina no plasma. MÉTODOS: Quarenta pacientes entre 66,2±9 anos, com diagnóstico clínico de doença pulmonar obstrutiva crônica, foram divididos em dois grupos: G1, com índice de massa corporal menor que 20kg/m², e G2, com índice de massa corporal maior que 20kg/m². Foram mensurados os parâmetros espirométricos, a tolerância ao exercício no teste de caminhada, a força muscular respiratória, a composição corporal por meio da impedância bioelétrica e as dosagens da L-carnitina plasmática, através de amostras de sangue. RESULTADOS: Foram observados menores valores das variáveis espirométricas (p<0,01), da força muscular respiratória e dos níveis de L-carnitina nos pacientes do G1; porém, não houve diferença entre os grupos quanto à capacidade de realizar exercício físico dinâmico de baixa intensidade. Correlações significativas entre o percentual de gordura e os níveis de L-carnitina plasmática foram observadas nos pacientes (r=0,53 com p<0,002); sendo que, nos pacientes com índice de massa corporal menor que 18kg/m², essa relação aumentou (r<0,73 com p<0,01). CONCLUSÃO: Na doença pulmonar obstrutiva crônica, a desnutrição está associada tanto aos prejuízos da função pulmonar e da força muscular respiratória, quanto aos baixos níveis de L-Carnitina plasmática.