Ellen Haagen. Thesis number: , June Center for Translational Research in Aging & Longevity (CTRAL)

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1 Clinical Implications of Overweight and Obesity in Chronic Obstructive Pulmonary Disease Thesis number: , June 2011 Center for Translational Research in Aging & Longevity (CTRAL) School of Applied Sciences Amsterdam Nutrition and Dietetics

2 Clinical Implications of Overweight and Obesity in Chronic Obstructive Pulmonary Disease Author: E. Haagen Huygensstraat TK Hilversum The Netherlands Thesis number: Sponsor: Supervisor: Mentor: MPKJ Engelen, Ph.D. Department of Geriatrics Center for Translational Research in Aging & Longevity Donald W. Reynolds Institute on Aging. Room # University of Arkansas for Medical Sciences W. Markham St. Slot 807, Little Rock, AR 72205, U.S.A. R Jonker, BSc. Department of Geriatrics Center for Translational Research in Aging & Longevity Donald W. Reynolds Institute on Aging. Room # University of Arkansas for Medical Sciences W. Markham St. Slot 807, Little Rock, AR 72205, U.S.A. MJJ de Bos Kuil, MSc, MD School of Applied Sciences Domain Sports and Nutrition Department of Nutrition and Dietetics Room A3.90 Dr. Meurerlaan 8, 1067 SM Amsterdam. The Netherlands Copyright 2011 E. Haagen No information from this essay may be reproduced or made public, in any form or in any way, may it be electronic, mechanic, by photocopies or in any other way, without prior consent from the author. 6/14/2011 Project #

3 PREFACE This thesis has been written as completion of the bachelor course Nutrition and Dietetics at the School of Applied Sciences in Amsterdam. Acting upon instructions of the Department of Geriatrics at the Center for Translational Research in Aging & Longevity, data collected mainly of body composition in patients with chronic obstructive pulmonary disease (COPD) were analyzed and interpreted with the objective to gather more clarity on the clinical implications of overweight and obesity in COPD. During the process of writing this thesis I learned a lot about the theoretical and practical aspects of the research field and about COPD as a disease. This has been made possible by several people to whom I would like to show my gratitude. First of all I would like to thank my sponsors Mariëlle Engelen and Nicolaas Deutz for the valuable time they have put in this project and for the possibility to work in the organization. I would like to give special gratitude to my supervisor Renate Jonker who taught, coached and guided me trough this period. Furthermore, I would like to thank my mentor Minse de Bos Kuil for his time, feedback and support. Finally, I would like to thank my family, friends, fellow students and colleagues for their help, support and patience. Little Rock, June /14/2011 Project #

4 ABSTRACT Objective: To examine the relationship between overweight-obesity in chronic obstructive pulmonary disease (COPD) and measures of body composition, lung function and dietary intake. Methods: 20 patients with COPD (11males, 9females) and 9 (6males, 3females) healthy subjects were studied. Body composition by Bioelectrical Impedance Analysis (BIA), Dual Energy X-Ray Absorptiometry (DXA) and Bioelectric Impedance Spectroscopy (BIS) was measured in all subjects. Lung function was measured by spirometry, expressed as Forced Expiratory Volume per second (FEV 1 ). Dietary intake was determined using the 24 hour recall method. Body mass index (BMI) classes were defined by under/normal weight (BMI kg/m 2 ) and overweight/obese (BMI >28 kg/m 2 ). Results: Weight, BMI, fat free mass index (FFMI), fat-mass (FM), fat mass index (FMI) and FM/FFM ratio of the whole body were significantly higher in overweight/obese COPD patients compared to under/normal weight COPD patients. Percentage lean body mass was significantly lower in overweight/obese COPD patients compared to under/normal weight COPD patients. Furthermore, abdominal FFMI, FM, FMI and FM/FFM ratio were significantly higher in overweight/obese COPD patients compared to under/normal weight COPD patients. Also, appendicular FM, FMI and FM/FFM ratio were significantly higher in overweight/obese COPD patients compared to under/normal weight COPD patients. Appendicular muscle mass index (ASMI) was higher in overweight/obese patients with severe COPD compared to under/normal weight patients with severe COPD. Abdominal FM/whole body FM ratio was significantly higher in overweight/obese COPD patients than in under/normal weight COPD patients. No difference in FEV 1 was found between under/normal weight and overweight/obese COPD patients. Conclusion: Despite the fact that overweight/obese COPD patients have proportionally more fat mass which can negatively influence their lung function and systemic inflammation, the larger FFMI and ASMI have a positive effect on physical abilities, diffusion capacity and mortality. However, more research with larger populations is necessary to determine the exact clinical implications of overweight-obesity in COPD patients. Keywords: chronic obstructive pulmonary disease; overweight; obesity; body composition. 6/14/2011 Project #

5 CONTENT 1. INTRODUCTION COPD Stages of COPD Metabolic alterations in COPD Overweight/obesity in COPD Consequences of overweight/obesity in COPD The obesity paradox OBJECTIVE AND SPECIFIC AIMS Objective Specific aims Relevance METHODS Study population Data collection Data analysis RESULTS Body composition in under/normal weight and overweight/obese patients Dietary intake in under/normal weight and overweight/obese patients Muscle/lung function in under/normal weight and overweight/obese patients Muscle wasting in under/normal weight and overweight/obese COPD patients Body composition in COPD compared to healthy controls/reference group Muscle wasting in COPD compared to healthy controls/reference group DISCUSSION Body composition in under/normal weight and overweight/obese patients Dietary intake under/normal weight and overweight/obese patients Function under/normal weight and overweight/obese patients Body composition compared to healthy controls/reference Study limitations GENERAL CONCLUSION REFERENCES 28 6/14/2011 Project #

6 1. INTRODUCTION 1.1 COPD Chronic obstructive pulmonary disease (COPD) is a slowly progressive, chronic, irreversible lung disease, characterized by a limited airflow and a chronic inflammatory response in the airways. Roughly COPD can be divided into two categories: 1) chronic bronchitis; 2) emphysema. Patients with chronic bronchitis have inflamed airways that are structurally changed. Main symptoms of chronic bronchitis are: 1) long term cough that worsens when it gets triggered by irritants, such as cigarette smoke, cold weather and humidity; 2) to give up sputum, as a result of excessive mucus production caused by inflammation; 3) shortness of breath (SOB) and wheezing, due to a limited airflow, especially during physical activity. Emphysema patients have enlarged or destroyed alveoli (tiny air sacs within the lungs where the exchange of oxygen and carbon dioxide takes place). Common symptoms of emphysema are: 1) SOB or tachypnea (rapid breathing), either caused by a lack of oxygen in the body or a need to exhale excess carbon dioxide, 2) exercise intolerance, caused by a disturbed gas exchange, weight loss and/or a barrel chest (bulging chest that resembles the shape of a barrel)[1]. Moreover, several studies show that COPD patients in general have a significantly lower daily physical activity level than age matched healthy subjects respectively [2]. Duration, intensity and activity level were 57%, 75% and 56% of the values obtained in healthy subjects [3]. Furthermore, physical activity is already reduced early in the disease progression (as of GOLD-stage II) [4] From a clinical perspective this is very important, as physical inactivity plays a major role in the development of muscle wasting in COPD [5]. According to the World Health Organization (WHO) currently 64 million people are diagnosed with COPD worldwide [6]. In the United States alone, approximately 12.1 million people suffer from COPD [7]. Notably, the number of deaths caused by the consequences of COPD in women has more than doubled from 1980 to 2000 (20.1/ and 56.7/ respectively), however still more men are diagnosed with COPD and are more likely to die from its consequences (73.0/ in 1980 to 82.6/ in 2000). In total, in 2005 almost 3 million people died from the consequences of COPD, of which more than patients were living in the United States [8]. Most patients diagnosed with COPD are or were long-term cigarette smokers [9]. Due to tobacco smoking, air pollution and occupational dusts and chemicals the number of people with COPD will increase by 30% in the coming 10 years if no intervention takes place and the WHO is predicting that COPD will be the third cause of dead in the world by 2030 [10]. Concerning the economical burden, in 2000, COPD was responsible for 8 million physician s office and hospital outpatient visits, 1.5 million emergency department visits and 726,000 hospitalizations [11]. 1.2 Stages of COPD COPD is diagnosed by spirometry. Because COPD progresses slowly it is mostly diagnosed at the age of 40 years or older [6]. A Spirometer measures the airflow in forced expiratory volume per second (FEV 1 ) and Forced Vital Capacity (FVC). FEV 1 is the maximum amount of air someone can exhale in one second and the FVC is the maximum amount of air someone can exhale after a maximum inspiration. To determine the severity of COPD the Global Initiative for Chronic Obstructive Lung Disease (GOLD) has developed a classification with four stages (Table 1) [12] 6/14/2011 Project #

7 Table 1. GOLD stages in COPD Stage Gold stage 1: mild COPD Gold stage 2: moderate COPD Gold stage 3: severe COPD Gold stage 4: very severe COPD Criteria FEV 1 /FVC<70 FEV 1 80% predicted FEV 1 /FVC<70 FEV 1 <80% - 50% predicted FEV 1 /FVC<70 FEV 1 <50% - 30% predicted FEV 1 /FVC<70 FEV 1 <30% predicted or <50% predicted plus chronic respiratory failure 1.3 Metabolic alterations in COPD COPD is no longer considered a disease of the lungs per se, but is associated with severe systemic and metabolic alterations as well [13]. Three important alterations of current focus are: systemic inflammation, increased energy expenditure and an altered protein metabolism. Once triggered by irritants, inflammatory mediators such as c-reactive protein (CRP), cytokines and certain interleukins (IL), are released in the system which causes not only pulmonary inflammation but also systemic inflammation can be developed due to an overflow of these inflammatory mediators [14]. Van Helvoort et al. found that low-grade systemic inflammation in COPD patients was elevated compared to healthy subjects and tended to be even higher in muscle wasted COPD patients [15]. COPD patients are characterized by changes in their energy and protein metabolism. Their resting energy expenditure (REE) is increased, related to the body s increased need of energy needed for breathing [1], use of certain drugs, such as, the bronchodilators (e.g. Salbutamol) [16], and the presence of systemic inflammation [13]. Furthermore, protein turnover (breakdown and synthesis) is enhanced in COPD [17] and consistently lower concentrations of plasma branched chain amino acids (BCAA s) are found compared to healthy controls. Two factors suggested to contribute to the increase in protein turnover are the presence of systemic inflammation and the elevated levels of insulin in COPD [17]. The three above named alterations all contribute to the muscle wasting found in COPD. Creutzberg et al. found that 27% of 389 patients with moderate COPD had muscle wasting [18], Engelen et al. found that the prevalence was much higher (40-50%) in patients with severe COPD (FEV 1 <35%) [19]. In addition, acute respiratory infections (during pulmonary exacerbations) [5], a reduced dietary intake [20] and physical inactivity [2-4], further aggravate the catabolic state of many COPD patients and research shows that the severity of COPD is negatively correlated to the body s amount of fat-free mass (FFM), expressed as fat free mass index (FFMI) [21]. The significant loss of lean mass as part of weight loss is called cachexia and the development of cachexia increases the risk of death in COPD [12, 22]. 6/14/2011 Project #

8 1.4 Overweight/obesity in COPD In the past COPD was often linked to a low BMI [22]. Underweight (BMI 21 kg/m 2 ) was mostly seen in COPD patients with emphysema, while the prevalence of overweight (BMI kg/m 2 ) and obesity (BMI >30 kg/m 2 ) was higher in COPD patients with bronchitis [9, 23, 24]. Nowadays, reports show an increase in overweight and obesity in COPD patients to higher values than found in the general population [24], though this is not due to the greater number of patients with bronchitis as it did not raise over the past decade [25]. The prevalence of obesity in COPD was 18% in the Netherlands (compared to 10%-12% in the general Dutch population) [26] and up to 54% in Northern California (compared to 20-24% in the general US population) [27]. Therefore, despite the presence of cachexia in a substantial group of COPD patients, the focus of current research should perhaps also be on the consequences of overweight and obesity in COPD and the clinical implications for these patients. 1.5 Consequences of overweight/obesity in COPD Multiple studies focused on the consequences of overweight/obesity in COPD. Table 2 shows an overview of the positive and negative effects of obesity compared to under/normal weight in COPD patients. Table 2. Positive and negative effects of obesity on COPD Positive effects Negative effects Obesity and lung function Higher FEV 1 [9] FVC [28] FEV 1 /FVC [26, 29-31] TLC [32, 33] FRC [32] IC [29, 34] Resting lung hyperventilation [35] Dyspnea ratings at standardized ventilation [35] Obesity and body composition Muscle mass/ffmi [34, 36] Abdominal fat [5] BMD [37] Obesity and physical performance Peak VO 2 in L min - [32, 35] 6MWT [9, 30] Upper and lower body muscle strength [38] Functional impairment [9] Fatigue at initial evaluation [9] MRC score [28] Obesity and metabolic Lung hyperinflation [29, 35] Acute phase reactants [5, 31, 39, 40] Insulin resistance [40] Fasting plasma insulin [40] Obesity and morbidity/mortality Risk osteoporosis [37] Mortality respiratory disease and survival rate until class III obesity (BMI >40 kg/m 2 ) [41] IC Inspiratory capacity, the total amount of air that can be drawn into the lungs after normal expiration; FEV 1, Forced expiratory volume in one second, the maximum amount of air someone can exhale in one second; FVC, Forced vital capacity, the maximum amount of air someone can exhale after a maximum inspiration; TLC, Total lung capacity, the maximum volume of air present in the lungs; FRC, Functional residual capacity, the volume of air present in the lungs, at the end of passive expiration; MRC score, Medical research counsel score, a scale used for grading the effect of breathlessness on daily activities and higher scores equals more breathlessness; 6MWT, Six-minute walking test, a clinical exercise test used as detection of exercise induced asthma, a cardiac stress test and a cardiopulmonary test. This test measures endurance. 6/14/2011 Project #

9 1.5.1 Survival A low BMI, especially a lower lean to fat ratio, is linked to poor prognoses in COPD [21, 42, 43]. Although the WHO has determined that a BMI of <18.5 kg/m 2 is referred to as underweight, research has shown that the cut-off point for increased mortality in COPD is at a BMI <21 kg/m 2 [22]. Obesity in COPD on the other hand is associated with a lower mortality and less likelihood of death by respiratory causes [21, 22, 44]. There are strong indications that a greater lean mass and not a greater fat mass in obese COPD patients is a good predictor of mortality [43], further supported by research indicating that obese COPD patients with a low lean mass (defined as sarcopenic obese), have a similar outcome as normal weight COPD patients with a low lean mass [21]. Research also shows that especially patients with severe COPD benefit from a higher BMI due to a higher FFM [45]. Muscle wasting becomes more pronounced in severe COPD which has a great impact on mortality [22]. Among non-copd subjects the number of hospitalizations rises with increasing BMI [46]. However in obese COPD patients, emergency hospital admissions and length of hospital stay were reduced compared to under/normal weight COPD patients. The risk of death after exacerbations is also decreased in obese COPD patients compared to under/normal weight COPD patients but rising with weight loss independent of BMI [47] Inflammation As shown in Figure 1, obesity influences COPD by effecting local blood supply, activity level, lung function and insulin resistance. These factors directly and indirectly promote inflammation (Figure 1) [13, 24]. Figure 1. Proposed mechanistic links between obesity and COPD [13, 24] 6/14/2011 Project #

10 Elevated levels of CRP, as a measure of systemic inflammation, are often presented in COPD negatively influencing outcomes such as functional exercise capacity [48], daily physical activity level [33], health status [48], cardiac injury [14], arterial stiffness [35], risk for hospitalizations [49] and survival. [50] In fact, increased CRP levels have been suggested as one of the diagnostic components of the chronic systemic inflammatory syndrome [51]. Systemic inflammation is possibly responsible for increased insulin resistance in obese COPD patients [40]. However obesity in COPD patients is linked to reduced hyperinflation of the lungs. This result is stronger in more severe COPD patients [29]. Blood supply in obese COPD patients is reduced due to enlarged fat cells. This can cause local adipose tissue hypoxia because oxygen from the blood cannot reach certain body parts properly. Reduced lung function contributes to lower oxygen levels in the bloodstream. This can cause lack of oxygen in the whole body, also known as systemic hypoxia (figure 1) [13] Respiratory function Although obesity in COPD is related to a lower total lung capacity (TLC) and a lower FVC [14, 28, 48] compared to COPD patients who are not obese, studies also suggest that there are also positive effects of obesity in COPD on respiratory function (Table 2) [5, 9, 32, 33, 49-52]. FEV 1 tends to be higher in overweight/obese COPD patients, possibly related to the higher incidence of obesity in the early stages of COPD [9, 26]. Furthermore, Sharma and colleagues showed in a study examining the risk for obstructive sleep apnea (OSA) in patients with obstructive airway disease (diagnosis of COPD or asthma) and healthy people [53] that a low pulmonary function was not an independent risk factor for OSA. Furthermore, the higher prevalence of OSA found in COPD and asthma (55.2 versus 7.5 in healthy controls) appeared to be due to a higher BMI in this group Skeletal muscle function and physical performance Upper and lower body muscle strength, measured by chest and leg press, related positively to BMI, possibly due to a higher amount of muscle [28, 38]. Furthermore COPD patients also appear to have a higher peak VO 2 in L min - [32, 35] In contrast, obese COPD patients have a higher MRC score (Medical Research Counsel Score). The MRC score is a scale used for grading the effect of breathlessness on daily activities and higher scores equals more breathlessness [28, 54]. Obese COPD patients have a worse performance on the six-minute walking test, lower functional status and feel more fatigued as well, which suggests that although they a higher FFM and muscle strength, they are in a worse physical state [9, 33]. It is clear that loss of FFM in COPD results in muscle weakness and higher mortality. Fat mass (FM) does not influence these factors [24]. Research shows that COPD patients have lower FFM then healthy controls [55], but that obese COPD patients seem to have a higher FFM and thus a higher fat-free mass index (FFMI; FFM adjusted for height) then under/normal weight COPD patients [36].FFMI is a common index used to determine loss of muscle mass (sarcopenia) [21, 43]. 6/14/2011 Project #

11 1.5.5 Sarcopenia Sarcopenia literally means loss of flesh. It is a term used to describe the loss of muscle mass and amongst other things occurs with aging [56]. Related to the different methods used to measure muscle mass it is difficult to determine the actual prevalence of sarcopenia. A number of large-scale studies (table 3) estimated a prevalence of 5-13% in healthy elderly age years to 11-50% in healthy elderly age >80 years [56]. Since COPD is predominantly present in elderly people, sarcopenia is expected to be present as well [57].In line, Vermeeren et al. found a 30% prevalence of sarcopenia in COPD patients [58]. Besides using the FFMI, sarcopenia can also be determined on the basis of lean body mass (fat-free mass from which the bone mineral content in excluded). Janssen et al. has described two different ways to determine sarcopenia based on lean body mass (LBM); 1) an index adjusted for weight (%LBM= lean body mass/weight 100) [59] and 2) an index adjusted for height (LBMI= lean body mass/height 2 ) [60]. Baumgartner et al. has described an index for appendicular skeletal muscle index (ASMI, the skeletal muscle mass for both arms and legs) [61], in which the total amount of appendicular muscle mass is adjusted for height (ASMI= appendicular skeletal muscle mass/height 2 ). Especially with the use of the %LBM adjusted for weight a relative loss of muscle mass can appear in obese populations, as an indicator of sarcopenia. Research shows that COPD patients defined as sarcopenic by FFMI had significantly higher mortality rate [21]. Healthy obese subjects defined as sarcopenic by ASMI were more likely to have three or more out of six physical disabilities (walking distances, shopping for groceries, preparing meals, doing housework, making home repairs and doing laundry) than non-sarcopenic subjects, were more insulin resistant and had a higher chance to develop metabolic syndrome than subjects with either obesity or sarcopenia [61]. Subjects with sarcopenia defined by %LBM had greater functional impairment in daily activities, such as, climbing stairs, stooping, crouching or kneeling compared to non-sarcopenic subjects [59]. Furthermore, subjects with a low LBMI were more likely to be in need of help for personal care, like eating and bathing or handling routine needs like every day household chores or shopping than non-sarcopenic subjects [60]. However, these last three methods were only performed in healthy subjects, not in COPD patients. 6/14/2011 Project #

12 Table 3. Large-scale studies on the prevalence of sarcopenia [56] Cohort (country) CHS (USA) EPIDOS (France) In CHIANTI (Italy) NHANES III (USA) NMEHS (USA) n (% ) Age (y) 5036 (56.4%) > (100%) 1030 (54.5) (47.3%) > >18 (30% >60) 73.6 ± 5.8 ; 73.7 ± 6.1 Definition of sarcopenia (assessment method) Cut off points: LBMI of kg/m 2 moderate, 8.51 kg/m 2 severe sarcopenia in men. LBMI of kg/m 2 moderate, 5.76 kg/m 2 severe sarcopenia in women (BIA) Cut off points: ASM >2 SD below the mean of a young female reference group (DXA) Calf muscle cross sectional area cut off points: >2 SD below population mean (CT scan) Cut off points: class I= %LBM 1 2 SD, class II= %LBM >2 SD from the mean of young subjects (BIA) Cut off points: ASM >2 SD below the mean of a young reference population Sarcopenia prevalence Moderate sarcopenia: 70.7%( ), 41.9% ( ); Severe sarcopenia: 17.1% ( ), 10.7% ( ) Reference [62] 9.5% [63] 20% at 65 years, 70% at 85 years ( ); 5% at 65 years, 15% at 85 years ( ) In subjects aged >60 years: sarcopenia class I: 45% ( ), 59%( ); sarcopenia class II: 7% ( ), 10% ( ) <70 years, % ( ), % ( ); years, % ( ), % ( ); years, %, % ( ); >80 years, % ( ), % ( ) [64] [59] [61] Other metabolic effects COPD patients have an increased risk to develop osteoporosis because of smoking, vitamin D deficiency, low body weight and use of corticosteroids [52, 65]. Obesity in COPD patients however, seems to be a protective factor. Although obesity is linked to an increased production of inflammatory cytokines that can possibly impair bone formation, possibly the weight on the bone mass may prevent abnormal loss of bone mineral [37]. COPD patients die more often from cardiovascular diseases then healthy people. Possible cause for this phenomenon is the fact that the metabolic syndrome is more frequently seen in COPD patients. Almost 50% of COPD patients have one or more components of the metabolic syndrome [66]. Coronary artery disease, high blood pressure, left heart failure and tachyarrhythmia are associated with COPD [67]. 1.6 The obesity paradox As shown in table 2 there a several negative effects of obesity in COPD, mainly inflammation and physical dysfunction. Research however shows that mortality in patients with severe to very severe COPD is the lowest in those with a high BMI and greatest in those with a low BMI [22]. Mainly the higher FFMI in overweight/obese COPD patients seem to have a positive effect on mortality [21, 43]. Though in healthy people obesity is related to greater chance of mortality caused by morbidity like cardiovascular diseases, in COPD patients, obesity seems to have a positive effect on mortality [24, 41]. 6/14/2011 Project #

13 2. OBJECTIVE AND SPECIFIC AIMS 2.1 Objective To examine the relationships between weight in COPD and measures of body composition, lung function and dietary intake. 2.2 Specific aims 1. To test the hypothesis that overweight/obese COPD patients (BMI 28 kg/m 2 ) have a higher energy, protein and fat intake compared to under/normal weight COPD patients (BMI kg/m 2 ). 2. To test the hypothesis that overweight/obese COPD patients (BMI 28 kg/m 2 ) a higher predicted FEV 1 compared to under/normal weight COPD patients (BMI kg/m 2 ). 3. To test the hypothesis that overweight/obese COPD patients (BMI 28 kg/m 2 ) have a higher FFMI and ASMI and thereby muscle function and higher BMD compared to under/normal weight (BMI kg/m 2 ) and that this relationship is more pronounced in patients with severe COPD only (FEV 1 <50%). 4. To test the hypothesis that overweight/obese COPD patients (BMI 28 kg/m 2 ) have a higher abdominal FM/whole-body FM ratio than under/normal weight COPD patients (BMI kg/m 2 ). 5. To test the hypothesis that normal/overweight COPD patients (BMI kg/m 2 ) have a lower FFMI, a lower %LBM and higher abdominal FM/FFM ratio than healthy controls (BMI kg/m 2 ). 6. To test the hypothesis that normal/overweight COPD patients (BMI kg/m2) have a lower FFMI and %LBM than a healthy reference population. 2.3 Relevance Nutritional intervention is a crucial in the treatment of (skeletal) muscle loss in patients with COPD and although not directly apparent in overweight/obese COPD patients, these patients might also suffer from (relative) muscle loss (hidden depletion) and therefore qualify for nutritional intervention. In this thesis the presence of (skeletal) muscle loss in a group of COPD patients who are overweight/obese (hidden FFM depletion) is examined and its relationship with pulmonary function and dietary intake. Furthermore, when the amount of body fat-free mass is related to a lesser decline over time in pulmonary function (FEV 1 predicted) recommendations can be made for COPD patients to improve their muscle mass by exercise and diet. 6/14/2011 Project #

14 3. METHODS 3.1 Study population 20 patients with COPD and 9 healthy subjects were recruited at UAMS clinics or by responding to distributed flyers in the community. All study subjects were informed via direct contact with the PI or research staff followed by a telephone contact. Study subject were enrolled (males and females of all races) based on the inclusion/exclusion criteria described below (Table 4 and 5). All subjects were able to walk, sit and stand up on their own. Screening procedures not already performed in the context of their care for COPD were done prior to the study. Table 4. Inclusion/exclusion criteria for COPD patients Inclusion criteria: 1. Diagnosis of chronic airflow limitation, defined as measured forced expiratory volume in one second (FEV 1 ) less than 70% of reference FEV 1 2. Shortness of breath on exertion 3. Age 45 years and older 4. Clinically stable condition. Exclusion criteria: 1. Established diagnosis of malignancy 2. Presence of fever within the last 3 days 3. Established diagnosis of Diabetes Mellitus 4. Untreated metabolic diseases including hepatic or renal disorder 5. Presence of acute illness or metabolically unstable chronic illness 6. Not suffering from respiratory tract infection or exacerbation of their disease (defined as a combination of increased cough, sputum purulence, shortness of breath, systemic symptoms such as fever, and a decrease in FEV 1 > 10% compared with values when clinically stable in the preceding year) at least 4 weeks prior to the study 7. Recent myocardial infarction (less than 1 year) 8. Use of long-term oral corticosteroids or short course of oral corticosteroids in the preceding month before enrollment 9. Any other condition according to the PI or study physicians would interfere with proper conduct of the study / safety of the patient 10. Failure to give informed consent Table 5. Inclusion/exclusion criteria for healthy subjects Inclusion criteria Exclusion criteria 1. Age 40 years and older 1.Established diagnosis of malignancy. 2.Presence of fever within the last 3 days 3.BMI > 40 kg/m 2 4.Untreated metabolic diseases including hepatic or renal disorder 5.Presence of acute illness or metabolically unstable chronic illness 6.Diagnosis of moderate to severe chronic airflow limitation, defined as measured forced expiratory volume in one second (FEV 1 ) 70% of reference FEV 1. 7.Use of supplements enriched with amino acids 8.Any other condition according to the PI or study physicians would interfere with proper conduct of the study / safety of the patient 9.Failure to give informed consent 6/14/2011 Project #

15 3.2 Data collection General data Age, gender and other demographics were collected from the medical file or verified at the screening Dietary intake Macronutrient intake was assessed on two study days using the 24-hour recall method and processed with The Food Processor SQL for Windows Body composition Body height was measured using a stadiometer (Novel Products Inc.) with the subject barefoot and standing, and was determined to the nearest 0.5 cm. Body weight was measured to the nearest 0.1 kg using the Indicator standard (I5S indicator, Ohaus cooperation, Florham Park, NJ, USA). Body composition was determined by Dual Energy X-Ray Absorptiometry (DXA, Hologic QDR 4500W; Bedford, MA). DXA was performed on the screening day or on one of the study days and results were used to determine fat and lean mass in different body compartments (arms, legs and trunk). Subjects were asked to remove all metal objects and to lie on the table pad, where they were positioned in the centre using the centre lines for indication. The whole body, including feet was positioned entirely within the scan limit. Subjects were instructed to look at the ceiling and hold the head in this position. Arms were placed at the patients side with palms down, separated from the thighs. Feet were pointing up and rotated 25 until the toes touch and then held in position with tape. Subjects were instructed to remain still and breathe normally. The six minutes scan was preformed on the whole body. To define separate body parts template lines in the Point Mode were used. To determine whole body fat-free mass, fat mass, %LBM and LBMI Bioelectric Impedance Spectroscopy (BIS; Xitron Hydra 4200; Xitron Technologies, Inc. San Diego, CA) was performed in subjects. The resistance of the body to an electrical current at multiple frequencies was measured. Measurements were done with electrodes placed on hand and foot. The measurement lasted about 1 minute, was validated, non-invasive and without any risks for the patient. BIS was performed on the screening visit and/or on the first test day. For COPD patients fat-free mass was calculated with a COPD and gender adjusted formula of Steiner et al. [68]. The fat-free mass in healthy was calculated with Xitron equations [69]. To determine the %LBM and LBMI for COPD patients as well as healthy subjects, first the amount of skeletal muscle was calculated, using the formula of Janssen et al.[70]. Then by using two other formals of Jansen et al. the %LBM [59]and LBMI [60] could be retrieved BMI classification Underweight in COPD was defined by a BMI <21 kg/m 2 [22]. Normal weight in COPD was defined by a BMI kg/m 2, overweight was defined by a BMI kg/m 2 and obesity was defined by a BMI >30 kg/m 2, according to the WHO BMI classification [10]. 6/14/2011 Project #

16 3.2.5 Sarcopenia Due to the absence of generally accepted guidelines, sarcopenia was defined in several ways: - FFMI <17.1 kg/m 2 in men, <14.6 kg/m 2 in women. Cut-off points defined by Vestbo et al. using the data of the CCHS study subjects with COPD age >20 years were measured by BIA [21]. - FFMI <16 kg/m 2 in men, <15 kg/m 2 in women. Cut-off points defined by Schols et al. 225 stable COPD patients were measured by DXA [43]. - FFMI <25 th percentile, adjusted for age and gender. Cut-off point defined by Schutz et al healthy subjects age all Caucasians were measured by BIA [71]. - FFM <25 th percentile, adjusted for age, race and gender. Cut-off point defined in the NHANES survey subjects were measured by DXA. - FFM <25 th percentile, adjusted for age and gender. Cut-off point defined by Kyle et al healthy subjects age all ambulatory white (West-European) were measured by BIA [72]. - ASM/height 2 <7.26 kg/m 2 in men, <5.45 kg/m 2 in women. Cut-off point defined by Baumgartner et al. 883 elderly Hispanic and non-hispanic white men and women living in New Mexico were measured by DXA to calculate appendicular skeletal muscle mass (ASM) [61]. - %LBM <31% in men, <22% in women. Cut-off points defined by Janssen et al subjects age >60 years were measured by BIA. LBM between 1-2 SD under mean of young adults (age 18-39) for class 1 sarcopenia, >2 SD under mean of young adults (age 18-39) for class 2 sarcopenia [59]. - LBMI kg/m 2 moderate, 8.51 severe sarcopenia in men, kg/m 2 moderate, 5.76 severe sarcopenia in women. Cut-off points defined by Janssen et al non-hispanic white, non-hispanic black and Mexican American subjects age >60 years were measured by BIA [60] Lung function FEV 1 and PEF were measured with a spirometer. A clip was placed on the subjects nose to avoid air to escape. The subject was asked to sit or stand up straight, hold the monitor with both hands on the two rubber areas, take a deep breath, cover the mouthpiece tightly with the lips and blow into the measuring tube as hard and fast as possible. The measurement was performed three times (best effort was used for data analysis). Between measurements there was a one minute break to let the subject recover Healthy reference group The healthy reference group is a cross selection of the general US population as described earlier by Borrud et al. [73]. All subjects were 8 years or older and were eligible to be measured by DXA. The survey was completed in the period Data analysis All analyses were performed with the statistical program Graphpad PRISM (version 5.02 for Windows). Results are expressed as mean ± SD. Linear regression was used to determine correlation between different measurements of body composition, muscle function and lung function. The Mann-Whitney-U test was used to compare the measurements of under/normal weight COPD patients with overweight/obese COPD patients and to compare measurements of normal/overweight COPD patients with healthy subjects. Significance of difference was set at the 0.05 probability level. 6/14/2011 Project #

17 4. RESULTS Eighteen COPD patients met the inclusion criteria for aim 1 to 4. General characteristics of the COPD patients are shown in Table 6. Table 6. General characteristics of the COPD patients Total group Range Under/normal weight COPD BMI <25 kg/m 2 Overweight/obese COPD BMI >28 kg/m 2 n 18 (9M, 9F) 8 (4M, 4F) 10 (5M, 5F) Age (y) 63.7 ± ± ± 9.8 FEV 1 (%) 40.8 ± ± ± 11.3 Height (m) 1.69 ± ± ± 0.08 Weight (kg) 77.4 ± ± ± 4.2 BMI (kg/m 2 ) 27.1 ± ± ± 2.4 %LBM (%)* 31.6 ± ± ± 8.4 LBMI (kg/m 2 )* 8.2 ± ± ± 2.3 ASMI (kg/m 2 ) 6.6 ± ± ± 0.8 Whole body FFM (kg) 49.0 ± ± ± 8.1 FFMI (kg/m 2 ) 17.0 ± ± ± 1.8 FM (kg) 27.1 ± ± ± 4.9 FMI (kg/m 2 ) 9.6 ± ± ± 2.8 FM/FFM ratio 0.6 ± ± ± 0.2 Abdominal FFM (kg) 24.7 ± ± ± 4.4 FFMI (kg/m 2 ) 8.6 ± ± ± 1.0 FM (kg) 14.6 ± ± ± 2.7 FMI (kg/m 2 ) 5.1 ± ± ± 1.1 FM/FFM ratio 0.4 ± ± ± 0.1 Appendicular FFM (kg) 20.1 ± ± ± 3.4 FFMI (kg/m 2 ) 7.0 ± ± ± 0.8 FM (kg) 11.5 ± ± ± 4.3 FMI (kg/m 2 ) 4.1 ± ± ± 2.1 FM/FFM ratio 0.6 ± ± ± 0.2 Appendicular/abdominal ratio FFM 0.8 ± ± ± 0.1 FM 0.8 ± ± ± 0.3 Abdominal/whole body FM 0.5 ± ± ± 0.1 Appendicular/whole body FFM 0.41 ± ± ± 0.02 Bone Mineral Density (g/cm 2 ) 1.1 ± ± ± 0.2 Dietary intake** Energy (kcal) 1838 ± ± ± 489 Protein (g) 68.8 ± ± ± 26.4 Protein (en%) 15.9 ± ± ± 3.1 Fat (g) 71.9 ± ± ± 30.7 Fat (en%) 35.0 ± ± ± 30.7 Results are expressed as mean ± SD. COPD Chronic Obstructive Pulmonary Disease; FEV 1, Forced Expiratory Volume per second; BMI, Body Mass Index; %LBM, percentage Lean Body Mass; LBMI, lean body mass index; ASMI, appendicular skeletal muscle index; FFM, fat-free mass; FFMI, fat-free mass index; FM, Fat Mass; FMI, fat mass index, BMD, bone mineral density. *n15; ** n17; significantly different (P<0.05) compared to under/normal weight group (Mann-Whitney-U test); significantly different (P<0.01) compared to under/normal weight group (Mann-Whitney-U test) 6/14/2011 Project #

18 Weight, BMI, FFMI, FM, FMI and FM/FFM ratio of the whole body were significantly higher in overweight/obese COPD patients compared to under/normal weight COPD patients. %LBM was significantly lower in overweight/obese COPD patients compared to under/normal weight COPD patients. Abdominal FFMI, FM, FMI and FM/FFM ratio were significantly higher in overweight/obese COPD patients compared to under/normal weight COPD patients. Furthermore appendicular FM, FMI and FM/FFM ratio but not FFM were significantly higher in overweight/obese COPD patients compared to under/normal weight COPD patients. 4.1 Body composition in under/normal weight and overweight/obese patients Fat-free mass The correlation between BMI and whole body FFMI was significant (P<0.01) as well as the correlation between BMI and FFMI appendicular (P=0.03, Figure 2). Overweight/obese COPD patients had a significantly higher FFMI (P=0.04) compared to under/normal weight COPD patients (Figure 3). In COPD patients with severe COPD (FEV 1 <50%), the difference in FFMI was even higher (P<0.01) between overweight/obese COPD patients compared to under/normal weight patients. FFMI (kg/m2) BMI vs. FFMI 24 r=0.58 p=< BMI (kg/m2) BMI vs. FFMI appendicular 10 r=0.50 p= BMI (kg/m2) Figure 2. Correlation between BMI and FFMI (left) and BMI and FFMI appendicular (right). From the 18 COPD patients 7 under/normal weight COPD patients (3M,4F) and 8 overweight/obese COPD patients (5M,3F) were characterized with severe COPD (FEV 1 <50%). As shown in Figure 3 overweight/obese COPD patients had a significantly higher FFMI (P=0.04) compared to under/normal weight COPD patients. In addition, the difference appeared to be even more pronounced when only COPD patients with severe COPD (FEV 1 <50%) were considered. FFMI appendicular (kg/m2) 6/14/2011 Project #

19 22 FFMI in COPD patients 24 p= FFMI in patients with severe COPD p=<0.01 FFMI (kg/m2) FFMI (kg/m2) <25 >28 12 <25 >28 BMI (kg/m2) BMI (kg/m2) Figure 3. Difference between FFMI in under/normal weight COPD patients and overweight/obese COPD patients (left) and difference between FFMI in under/normal weight COPD patients with severe COPD (FEV 1 <50%) and overweight/obese COPD patients with severe COPD (FEV 1 <50%) (right) Appendicular skeletal muscle mass Abdominal FFMI in overweight/obese COPD patients was significantly higher compared to under/normal weight COPD patients (P=0.04). No significant differences were found for ASMI (P=0.10) between overweight/obese COPD patients and under/normal weight COPD patients (Table 6) If only patients with severe COPD were considered (FEV 1 <50%), the ASMI tended to be higher (P=0.05) in overweight/obese patients as compared to under/normal weight patients (Figure 4). FFMI (kg/m2) FFMI abdominal in COPD patients p=0.04 ASMI (kg/m2) ASMI (kg/m2) in patients with severe COPD 10 p= <25 >28 BMI (kg/m2) 0 <25 >28 BMI (kg/m2) Figure 4. Difference in ASMI between overweight/obese COPD patients and under/normal weight patients with severe COPD Fat mass Whole body FM, abdominal FM and abdominal FM/FFM ratio in overweight/obese COPD patients were significantly higher (P<0.01) compared to under/normal weight COPD patients (Table 6). However, no significant difference was found in abdominal FM/whole body FM ratio (P=0.18) between overweight/obese COPD patients and under/normal weight COPD patients. 6/14/2011 Project #

20 4.1.4 Bone mineral density Neither a significant difference was found for BMD (P=1.00) in the total group overweight/obese COPD patients compared to under/normal weight COPD patients (Table6), nor when only patients with severe COPD were considered (P=0.49). 4.2 Dietary intake in under/normal weight and overweight/obese patients No significant differences were found in energy, protein and fat intake (P=0.20, 1.00, 0.89 respectively) between overweight/obese COPD patients and under/normal weight COPD patients (Table 6). Difference in macronutrient intake between overweight/obese COPD patients and under/normal weight COPD patients is shown in Figure 5. Figure 5. Dietary intake in under/normal weight COPD patients (left) and overweight/obese patients (right). 4.3 Muscle/lung function in under/normal weight and overweight/obese patients Muscle function Significant correlation between FFMI vs. handgrip strength (P=<0.01) was found in the under/normal weight COPD group (Figure 6). The relationship between FFMI vs. maximal inspiratory pressure (MIP) (P=0.01) and maximal expiratory pressure (P=0.03) as measure of respiratory muscle strength was significant as well. No muscle function data were available in the overweight/obese group. Handgrip strength (N) FFMI vs. handgrip strength 500 r=0.91 p=< FFMI (kg/m2) Handgrip strength (N) FFMI appendicular vs. handgrip strength r=0.95 p=< FFMI appendicular (kg/m2) 6/14/2011 Project #

21 MIP (%) FFMI vs. maximal inspiratory pressure 150 r=0.74 p= MEP (%) FFMI vs. maximal expiratory pressure 250 r=0.68 p= FFMI (kg/m2) Figure 6. Relationship between FFMI and skeletal and respiratory muscle strength FFMI (kg/m2) Correlation between FFMI appendicular vs. handgrip strength (P<0.01, Figure 6) was significant in under/normal weight patients. No significant correlation was found in FFMI appendicular vs. MIP in under/normal weight COPD patients. No muscle function data were available in the overweight/obese group Lung function No significant difference (P=0.50) was found for predicted FEV 1 in the group overweight/obese COPD patients compared to under/normal weight COPD patients (Table 6). Furthermore, for the entire COPD group there was no correlation found between FEV 1 and FFMI whole body, FFMI abdominal, FFMI appendicular (Figure 7) and %LBM (Figure 8) 60 FEV1 vs. FFMI whole body r=0.11 p= FEV1 vs. FFMI abdominal r=-0.02 p=0.94 FEV1 (%) FEV1 (%) FFMI whole body (kg/m2) FFMI abdominal (kg/m2) 60 FEV1 vs. FFMI appendicular r=0.30 p=0.20 FEV1 (%) FFMI appendicular (kg/m2) Figure 7. Relationship between predicted FEV 1 and FFMI whole body (left top), relationship between FEV 1 and FFMI abdominal (right top) and relationship between FEV 1 and FFMI appendicular (left bottom) in COPD patients 6/14/2011 Project #

22 FEV1 vs. %LBM FEV1 (%) * ** FEV1 men FEV1 women * %LBM <22% cut off point muscle wasting women ** %LBM <31% cut off point muscle wasting men %LBM (%) Figure 8. Relationship between predicted FEV 1 and %LBM in COPD patients and patients with %LBM below cut-off point Janssen et al. [59] 4.4 Muscle wasting in under/normal weight and overweight/obese COPD patients. The criteria available to determine muscle wasting were applied to our study group and results are shown in Table 7. Muscle wasting was determined in the total group of 18 COPD patients. Table 7. Muscle wasting in COPD according to different criteria Formula Cut off point for muscle wasting Under/normal weight COPD patients BMI<25 kg/m 2 (n=8) Overweight/obese COPD patients BMI>28 kg/m 2 (n=10) n % n % Vestbo et al. [21] FFMI <17.1 kg/m 2 men, <14.6 women kg/m 2 Schols et al. [43] FFMI <16 kg/m 2 men, <15 kg/m 2 women Schutz et al. FFMI <25 th percentile [71] (Europe) NHANES III survey [73] FFM <25 th percentile (USA) Kyle et al [72] FFM <25 th percentile * (Europe) Baumgartner et al [61] ASMI <7.26 kg/m men, <5.45 kg/m 2 women Janssen et al [59] %LBM <31% men, ** <22% women Janssen et al [60] LBMI <10.76 kg/m 2 men, <6.76 kg/m 2 women ** *n=8; **n=7; FFMI, fat-free mass index; FFM, fat-free mass; ASMI, appendicular skeletal muscle index; %LBM, percentage lean body mass; LBMI, lean body mass index. As shown in Table 7 all COPD patients with muscle wasting defined by different cut-off points based on FFMI were under/normal weight. Side note: FFM is not adjusted for height. 6/14/2011 Project #

23 4.5 Body composition in COPD compared to healthy controls/reference group For aim 5, 11 COPD patients with a BMI kg/m 2 were compared to a healthy group matched for BMI and gender. General characteristics of the COPD patients are shown in table 8. FEV 1 was significantly higher in healthy subjects compared to COPD patients. Table 8. General characteristics of the COPD with BMI kg/m 2 and matched healthy subjects COPD patients Healthy subjects n 11 (8M, 3F) 9 (6M, 3F) Age (y) 66 ± ± 11 FEV 1 (%) 44.6 ± ± 21.6 Height (m) 1.73 ± ± 0.09 Weight (kg) 78.6 ± ± 13.6 BMI (kg/m 2 ) 26.2 ± ± 3.5 %LBM (%)* 36.1 ± ± 5.0 LBMI (kg/m 2 )* 9.0 ± ± 1.5 Whole body FFM (kg) 52.5 ± ± 12.2 FFMI (kg/m 2 ) 17.4 ± ± 2.8 FM (kg) 24.7 ± ± 6.2 FMI (kg/m 2 ) 8.3 ± ± 2.6 FM/FFM ratio 0.5 ± ± 0.2 Abdominal FFM (kg) 26.4 ± ± 5.6 FFMI (kg/m2) 8.8 ± ± 1.3 FM (kg) 13.6 ± ± 3.7 FMI (kg/m2) 4.5 ± ± 1.3 FM/FFM ratio 0.5 ± ± 0.1 Appendicular FFM (kg) 21.8 ± ± 6.5 FFMI (kg/m2) 7.2 ± ± 1.6 FM (kg) 10.0 ± ± 4.0 FMI (kg/m2) 3.4 ± ± 1.6 FM/FFM ratio 0.5 ± ± 0.3 Appendicular/abdominal ratio FFM 0.8 ± ± 0.1 FM 0.8 ± ± 0.3 BMD (g/cm 2 ) 1.2 ± ± 0.1 Results are expressed as mean ± SD. COPD, chronic obstructive pulmonary disease; FEV 1, forced expiratory volume per second; BMI, body mass index; %LBM, percentage lean body mass; LBMI, lean body mass index; ASMI, appendicular skeletal muscle index; FFM, fat-free mass; FFMI, fat-free mass index; FM, fat mass; FMI, fat mass index; BMD, bone mineral density. *n=18; significantly different (P <0.05) compared COPD patients (Mann-Whitney-U test); significantly different (P <0.01) compared to COPD patients (Mann-Whitney-U test) Fat-free mass No significant differences were found for FFMI (P=0.88) when COPD patients were compared to the healthy control groups (Table 8) and to the healthy reference group (P=0.94) Lean body mass No significant differences were found in %LBM (P=0.73) between COPD patients compared to healthy controls (Table 8). Also no significant differences were found in %LBM of COPD patients compared to the healthy reference group (P=0.61) Fat mass No significant differences were found in fat mass, abdominal fat mass and abdominal FM/FFM ratio (P=0.76, P=0.91 and P=0.91 respectively) between COPD patients compared to healthy controls (Table 8). 6/14/2011 Project #