The prevalence and determinants of nutritional changes in chronic obstructive pulmonary disease

Computed Tomography Registration-Derived Regional Ventilation Indices Compared to Global Lung Function Parameters in Patients With COPD

CT registration-derived indices provide data on regional lung functional changes in COPD. However, because unlike spirometry which involves dynamic maximal breathing maneuvers, CT-based functional parameters are assessed between two static breath-holds, it is not clear how regional and global lung function parameters relate to each other. We assessed the relationship between CT-density change (dHU), specific volume change (dsV), and regional lung tissue deformation (J) with global spirometric and plethysmographic parameters, gas exchange, exercise capacity, dyspnoea, and disease stage in a prospective cohort study in 102 COPD patients. There were positive correlations of dHU, dsV, and J with spirometric variables, DLCO and gas exchange, 6-min walking distance, and negative correlations with plethysmographic lung volumes and indices of trapping and lung distension as well as GOLD stage. Stepwise regression identified FEV1/FVC (standardized β = 0.429, p < 0.0001), RV/TLC (β = −0.37, p < 0.0001), and BMI (β = 0.27, p=<0.001) as the strongest predictors of CT intensity-based metrics dHU, with similar findings for dsV, while FEV1/FVC (β = 0.32, p=<0.001) and RV/TLC (β = −0.48, p=<0.0001) were identified as those for J. These data suggest that regional lung function is related to two major pathophysiological processes involved in global lung function deterioration in COPD: chronic airflow obstruction and gas trapping, with an additional contribution of nutritional status, which in turn determines respiratory muscle strength. Our data confirm previous findings in the literature, suggesting the potential of CT image-based regional lung function metrics as the biomarkers of disease severity and provide mechanistic insight into the interpretation of regional lung function indices in patients with COPD.

Can muscle protein metabolism be specifically targeted by nutritional support and exercise training in chronic obstructive pulmonary disease?

Chronic obstructive pulmonary disease (COPD) associates with several extra-pulmonary effects. Muscle dysfunction and wasting is one of the most prominent extra-pulmonary effects and contributes to exercise limitation and health related quality of life (HRQoL), morbidity as well as mortality. The loss of muscle mass is characterised by an impaired balance between protein synthesis (anabolism) and protein breakdown (catabolism) which relates to nutritional disturbances, muscle disuse and the presence of a systemic inflammation, among other factors. Current approaches to reverse skeletal muscle dysfunction and wasting attain only modest improvements. The development of new therapeutic strategies aiming at improving skeletal muscle dysfunction and wasting are needed. This requires a better understanding of the underlying molecular pathways responsible for these abnormalities. In this review we update recent research on protein metabolism, nutritional depletion as well as physical (in)activity in relation to muscle wasting and dysfunction in patients with COPD. We also discuss the role of nutritional supplementation and exercise training as strategies to re-establish the disrupted balance of protein metabolism in the muscle of patients with COPD. Future areas of research and clinical practice directions are also addressed.

Ageing and the border between health and disease

Ageing is associated with a progressive degeneration of the tissues, which has a negative impact on the structure and function of vital organs and is among the most important known risk factors for most chronic diseases. Since the proportion of the world's population aged >60 years will double in the next four decades, this will be accompanied by an increased incidence of chronic age-related diseases that will place a huge burden on healthcare resources. There is increasing evidence that many chronic inflammatory diseases represent an acceleration of the ageing process. Chronic pulmonary diseases represents an important component of the increasingly prevalent multiple chronic debilitating diseases, which are a major cause of morbidity and mortality, particularly in the elderly. The lungs age and it has been suggested that chronic obstructive pulmonary disease (COPD) is a condition of accelerated lung ageing and that ageing may provide a mechanistic link between COPD and many of its extrapulmonary effects and comorbidities. In this article we will describe the physiological changes and mechanisms of ageing, with particular focus on the pulmonary effects of ageing and how these may be relevant to the development of COPD and its major extrapulmonary manifestations.

Body composition in patients with stable chronic obstructive pulmonary disease: comparison with malnutrition in healthy smokers

OBJECTIVE

Although malnutrition (body mass index (BMI)<18.5kg/ m(2)) has been associated with impaired health status in patients with chronic obstructive pulmonary disease (COPD), the effects of body composition (body fat and protein percentage) in patients with COPD have not been clearly demonstrated.

MATERIALS AND METHODS

A total of 180 stable patients with COPD at the stages of moderate, severe, very severe, and 50 healthy subjects were included in this prospective study. All subjects underwent a clinical evaluation, spirometry tests, anthropometric measurements and blood analysis.

RESULTS

Frequency of underweight was higher in COPD (11.7%) patients than the control group (8%). The frequency of underweight increased as the severity of COPD worsens. There was body decomposition (protein or fat depletion) in not only all underweight patients but also some normal/overweight COPD patients, as well as in the healthy subjects. Deterioration in FEV1 (L), and FEV1/FVC was more evident in underweight patients with protein and fat depletion compared to normal/overweight patients (p=0.004, and p=0.005). Inspiratory and expiratory respiratory muscle power was lower in under-weight patients with depletion than in normal/overweight patients (p=0.02, and p=0.01). DLCO and DLCO/VA were significantly lower in underweight patients than in normal/overweight patients (p=0.003, and p=0.004), they were also lower in normal/overweight patients with depletion than in normal/overweight patients with no depletion (p=0.01, and p=0.07). Normal/overweight patients with protein depletion had the most frequent number of exacerbations than others (p=0.04).

CONCLUSION

These results show that the body decomposition is important in patients with COPD. Assessment of body composition should be a part of nutritional assessment besides BMI in patients with COPD.

Predictors' factors of nutritional status of male chronic obstructive pulmonary disease patients

Chronic obstructive pulmonary disease (COPD) is a systemic disease that leads to weight loss and muscle dysfunction resulting in an increase in mortality. This study aimed to determine the prevalence rate of malnutrition and nutritional status and also factors associated with nutritional status. A total of 149 subjects were involved in the cross-sectional study. The study was conducted at two medical centers in Kuala Lumpur, Malaysia. The results of the study showed that malnutrition was more prevalent (52.4%) in the subjects with severe stages of COPD as compared to mild and moderate COPD stages (26.2%) (P < 0.05). Fat-free mass depletion as assessed using fat-free mass index (FFMI) affected 41.9% of the subjects. Plasma vitamin A, peak expiratory flow (PEF), and handgrip were the predictors for body mass index (BMI) (R(2) = 0.190, P < 0.001). Plasma vitamin A and force expiratory volume in one second (FEV(1)) were the predictors of FFMI (R(2) = 0.082, P = 0.007). BMI was the predictor of respiratory factors, that is, FEV(1)% predicted (R(2) = 0.052, P = 0.011). It can be concluded that there is a need to identify malnourished COPD patients for an appropriate nutrition intervention.

Resting energy expenditure and protein turnover are increased in patients with severe chronic obstructive pulmonary disease

The mechanisms leading to weight loss in patients with chronic obstructive pulmonary disease (COPD) are poorly understood. Changes in protein metabolism and systemic inflammation may contribute to increased resting energy expenditure (REE) in COPD, leading to an energy imbalance and loss of fat and fat-free mass. The objective of this study was to determine first whether REE was increased in patients with COPD and, second, whether this was associated with increased protein turnover and/or systemic inflammation. Resting energy expenditure was determined using indirect calorimetry in 14 stable outpatients with severe COPD (7 with low and 7 with preserved body mass indices) and 7 healthy controls. Endogenous leucine flux, leucine oxidation, and nonoxidative disposal, indices of whole-body protein breakdown, catabolism, and synthesis, were measured using intravenous infusions of (13)C-bicarbonate and 1-(13)C-leucine. Total body water, from which fat-free mass and fat mass were calculated, was determined using an intravenous bolus of deuterated water. Plasma markers of systemic inflammation were also measured. As a group, subjects with COPD had increased REE adjusted for fat-free mass (P < .001) and faster rates of endogenous leucine flux (P = .006) and nonoxidative leucine disposal (P = .002) compared with controls. There was a significant correlation between REE and both endogenous leucine flux (P = .02) and nonoxidative leucine disposal (P = .008). Plasma concentrations of the inflammatory markers C-reactive protein and interleukin-6 were not different between COPD subjects and controls. Increased rates of protein turnover are associated with increased REE and loss of fat-free mass in COPD.

Structural and functional changes of peripheral muscles in chronic obstructive pulmonary disease patients

PURPOSE OF REVIEW

The purpose of this review is to identify new advances in our understanding of skeletal muscle dysfunction in patients with chronic obstructive pulmonary disease (COPD).

RECENT FINDINGS

Recent studies have confirmed the relevance of muscle dysfunction as an independent prognosis factor in COPD. Animal studies have shed light on the molecular mechanisms governing skeletal muscle hypertrophy/atrophy. Recent evidence in patients with COPD highlighted the contribution of protein breakdown and mitochondrial dysfunction as pathogenic mechanisms leading to muscle dysfunction in these patients.

SUMMARY

COPD is a debilitating disease impacting negatively on health status and the functional capacity of patients. COPD goes beyond the lungs and incurs significant systemic effects among which muscle dysfunction/wasting is one of the most important. Muscle dysfunction is a prominent contributor to exercise limitation, healthcare utilization and an independent predictor of morbidity and mortality. Gaining more insight into the molecular mechanisms leading to muscle dysfunction/wasting is key for the development of new and tailored therapeutic strategies to tackle skeletal muscle dysfunction/wasting in COPD patients.

COPD as a lung disease with systemic consequences--clinical impact, mechanisms, and potential for early intervention

The natural course of chronic obstructive pulmonary disease (COPD) is complicated by the development of systemic consequences and co-morbidities. These may be major features in the clinical presentation of COPD, prompting increasing interest. Systemic consequences may be defined as non-pulmonary manifestations of COPD with an immediate cause-and-effect relationship, whereas co-morbidities are diseases associated with COPD. The major systemic consequences/co-morbidities now recognized are: deconditioning, exercise intolerance, skeletal muscle dysfunction, osteoporosis, metabolic impact, anxiety and depression, cardiovascular disease, and mortality. The mechanisms by which these develop are unclear. Probably many factors are involved. Two appear of paramount importance: systemic inflammation, which presents in some patients with stable disease and virtually all patients during exacerbations, and inactivity, which may be a key link to most COPD-related co-morbidities. Further studies are required to determine the role of inflammatory cells/mediators involved in systemic inflammatory processes in causing co-morbidities; the link between activity and co-morbidities; and how COPD therapy may affect activity. Both key mechanisms appear to be influenced significantly by COPD exacerbations. Importantly, although the prevalence of systemic consequences increases with increasing severity of airflow obstruction, both systemic consequences and co-morbidities are already present in the Global Initiative for Chronic Obstructive Lung Disease Stage II. This supports the concept of early intervention in chronic obstructive pulmonary disease. Although at present early intervention studies in COPD are lacking, circumstantial evidence suggests that current treatments may influence events leading to the systemic consequences and co-morbidities, and thus may affect the clinical manifestations of the disease.

[Malnutrition in children with chronic bronchitis]

OBJECTIVE

To study nutritional status in children with chronic bronchitis (CB) in relation with lung function.

METHODS

In this cohort of study, 46 patients aged 6.0 to 17.5 years (mean: 11.9 years) with chronic bronchitis were recruited. None had cystic fibrosis. Body weight, height, skinfold thicknesses, percentage of ideal body weight-for-height (percentage of IBW), body mass index (BMI), BMI Z-score, fat mass and fat-free mass were used to evaluate nutritional status. Arterial blood gases, vital capacity (VC), forced expiratory volume in one s (FEV1), functional residual capacity (FRC) and maximum inspiratory (Pi(max)) and expiratory (Pe(max)) pressures at the mouth were used to evaluate respiratory function.

RESULTS

Thirteen children (28%) had malnutrition defined as percentage of IBW lower than 90%, with a predominant fat mass depletion. VC (65+/-13% versus 79+/-15%; p=0.006) and FEV1 (59+/-16% versus 69+/-14%; p=0.03) were significantly lower in children with malnutrition than in children without malnutrition, but no significant differences were observed with regard to the FEV1/VC ratio and blood gases. Pi(max) (56+/-11% versus 88+/-37%, p=0,02) and Pe(max) (46+/-12% versus 58+/-19%, p=0,3) were also lower in children with malnutrition as compared to than without malnutrition.

CONCLUSION

Malnutrition can be observed in children with CB and is associated with significant lower lung function parameters. This could be explained by decrease in respiratory muscle strength.

Chronic obstructive pulmonary disease and body mass index in five Latin America cities: the PLATINO study

BACKGROUND

The body mass index (BMI) is a prognostic factor for chronic obstructive pulmonary disease (COPD). Despite its importance, little information is available regarding BMI alteration in COPD from a population-based study. We examined characteristics by BMI categories in the total and COPD populations in five Latin-American cities, and explored the factors influencing BMI in COPD.

METHODS

COPD was defined as a postbronchodilator forced expiratory volume in the first second/forced vital capacity (FEV(1)/FVC) <0.70. BMI was categorized as underweight (< 20 kg/m(2)), normal weight (20-24.9 kg/m(2)), overweight (25.0-29.9 kg/m(2)), and obese (> or = 30.0 kg/m(2)).

RESULTS

Interviews were completed in 5571 subjects from 6711 eligible individuals, and spirometry was performed in 5314 subjects. There were 759 subjects with COPD and 4555 without COPD. Compared with the non-COPD group, there was a higher proportion of COPD subjects in the underweight and normal weight categories, and a lower proportion in the obese category. Over one-half COPD subjects had BMI over 25 kg/m(2). No differences in BMI strata among countries were found in COPD subjects. Factors associated with lower BMI in males with COPD were aging, current smoking, and global initiative for chronic obstructive lung disease (GOLD) stages III-IV, whereas wheeze and residing in Santiago and Montevideo were associated with higher BMI. In females with COPD, current smoking, lower education, and GOLD stages II-IV were associated with lower BMI, while dyspnea and wheeze were associated with higher BMI.

CONCLUSIONS

BMI alterations are common in COPD with no significant differences among countries. Current smoking, age, GOLD stages, education level, residing in Santiago and Montevideo, dyspnea and wheeze were independently associated with BMI in COPD.

Optimizing oral nutritional drink supplementation in patients with chronic obstructive pulmonary disease

Nutritional support is indicated in some patients with chronic obstructive pulmonary disease to restore nutritional status and improve functional capacity. However, the efficacy of nutritional supplements is sometimes disappointing, partly owing to a compensatory drop in habitual food intake. We retrospectively studied the effect of nutritional drink supplements, differing in portion size and energy content, on weight gain and body composition. Thirty-nine patients with stable chronic obstructive pulmonary disease, participating in an 8-week pulmonary rehabilitation programme and eligible for nutritional support, were studied. Group A (n19) received three portions of 125 ml (2380 kJ), whereas group B (n20) received three portions of 200 ml (3350 kJ) daily. The macronutrient composition of the regimens was similar (20 % protein, 60 % carbohydrates and 20 % fat). Lung function, body weight, body composition (by bio-electrical impedance analysis), habitual dietary intake (by dietary history) and resting energy expenditure (by ventilated hood) were determined. Weight gain was compared with expected weight as predicted by a computer simulation model. Although patients in both groups significantly increased in weight, this increase was higher in group A (A, 3·3 (sd 1·9) kg; B, 2·0 (sd 1·2) kg;P=0·019), while receiving less energy. The observed weight gain in group A was similar to that expected, but in group B it was lower than expected (P<0·001). In both groups, fat-free mass and fat mass were gained in a ratio of 2:1, fat-free mass increasing primarily during the first 4 weeks. This study illustrates that there might be an optimum for the portion size of nutritional drink supplements in chronic obstructive pulmonary disease and that more is not always better.

Prevalence of nutritional depletion in a large out-patient population of patients with COPD

OBJECTIVE

The present study focuses on the prevalence of nutritional depletion in relation to functional performance, airflow limitation, experienced dyspnoea and health status in a large multi-center out-patient population with chronic obstructive pulmonary disease (COPD).

METHODS

In 39 out-patient centers in The Netherlands, 389 patients with moderate to severe COPD (217 men) were recruited. The study evaluated on the baseline characteristics of the COSMIC study. Measurements included body composition by bioelectrical impedance analysis, dyspnoea by MRC-score, peripheral muscle function by isometric handgrip strength and disease-specific health status by St. George Respiratory Questionnaire.

RESULTS

The prevalence of nutritional depletion (defined as body mass index (BMI)<or=21 kg/m2 and/or fat-free mass index (FFMI)<or=15 (females) or <or=16 (males) kg/m2) was high (27%). Prevalence of normal BMI and low FFMI was 15%, and of low BMI and low FFMI 11%. The prevalence of low BMI as well as low FFMI was significantly higher in female than in male COPD patients, 18% and 40% vs. 10% and 20%, respectively (both P<0.01). No differences in FEV1%predicted, dyspnoea score and health status were observed between depleted and non-depleted COPD patients. Multiple linear regression analysis in the total group showed that handgrip strength correlated with FFMI after correction for sex distribution and age, but not FEV1%predicted.

CONCLUSIONS

The prevalence of nutritional depletion was high in a large out-patient COPD population in The Netherlands, especially in female COPD patients. Depletion of FFM was associated with impaired peripheral muscle strength, independent of disease severity.

BMI and oral glucocorticoids as predictors of prognosis in COPD patients on long-term oxygen therapy

AIMS

The objectives of the study were to determine whether body mass index (BMI), and oral corticosteroid use predict survival and hospitalization in hypoxaemic chronic obstructive pulmonary disease (COPD) patients.

METHODS

The study was a prospective cohort study with analysis of a nationwide database (Danish Oxygen Register). We studied survival and hospitalization in 221 hypoxaemic COPD patients who were on long-term oxygen therapy (LTOT).

RESULTS

Low BMI was strongly associated with high mortality (P < 0.001). Maintenance treatment with steroids was only associated with higher mortality in overweight patients (BMI > or = 25 kg/m2), RR = 3.8 (1.4-10.5), P = 0.011. Whereas BMI had no influence on risk of any hospitalization in patients using oral steroids, high BMI was independently associated with reduced risk of any hospitalization in patients without oral steroids [the RR of any hospitalization for each 1 kg/m2 increase in BMI was 0.94 (CI: 0.90-0.99), P = 0.009]. Overall, the use of oral steroids was associated with increased risk of any hospitalization, RR = 1.7 (1.2-2.4), P = 0.002. This increase was especially pronounced in the group with BMI above 25 kg/m2, where steroid treatment increased the risk of any hospitalization with RR = 3.6 (1.5-8.7), P = 0.005.

CONCLUSIONS

In hypoxaemic patients on LTOT, low BMI is an independent risk factor of death and any hospitalization. Maintenance treatment with oral corticosteroids is associated with increased mortality and hospitalization in COPD patients with high BMI. Our findings suggest that loss of body weight should be avoided, and that oral corticosteroids should be used cautiously in patients on LTOT--especially those with high BMI. Further research on the role of changes in body composition as a prognostic factor is needed.

Physiological effects of meals in difficult-to-wean tracheostomised patients with chronic obstructive pulmonary disease

OBJECTIVES

To evaluate effects of meals in difficult-to-wean tracheostomised patients with chronic obstructive pulmonary diseases during spontaneous breathing or Inspiratory Pressure Support.

DESIGN

Prospective, crossover, randomised, and physiological study.

SETTING

Weaning centre.

PATIENTS

Sixteen COPD undergoing either decreasing levels of pressure support or increasing periods of spontaneous breathing.

MEASUREMENTS

Each patient underwent monitoring during a 30-min procedure, during and after meals either under pressure support or spontaneous breathing on two consecutive days. Inductance plethysmography was used to monitor respiratory rate and tidal volume. Tidal volume by a flow transducer, arterial oxygen saturation, pulse rate, end-tidal CO2(,) and dyspnoea by a visual analogue scale were also assessed.

RESULTS

ANOVA analysis showed a significant increase under spontaneous breathing for respiratory rate (P<0.001) and for end tidal CO(2) (P<0.03) induced by the meals. Inspiratory pressure support was associated to significantly greater tidal volume (P<0.001), lower respiratory rate (P<0.032), lower respiratory rate/tidal volume (P<0.001), and lower pulse rate (P<0.047) than spontaneous breathing. Under spontaneous breathing but not under pressure support a statistically worsening in meal-induced dispnoea (P<0.001) was found.

CONCLUSIONS

In tracheostomised difficult-to-wean COPD patients: 1) under unassisted breathing, meals may induce an increase in respiratory rate, end-tidal CO(2), and dyspnoea; 2) inspiratory pressure support ventilation prevents dyspnoea from worsening during meals.

Optimization of lung function before pulmonary resection: pulmonologists' perspectives

Many risk factors for morbidity and mortality with lung resection have been identified. Factors such as age, gender, and cancer stage cannot be altered, but lung function can be optimized by treating COPD or asthma with bronchodilators, corticosteroids, or antibiotics (when indicated) and by inspiratory muscle training. Although smoking cessation 2 months in advance of surgery may not be feasible, cessation nevertheless should be encouraged because it may decrease postoperative inflammation and in the long-term may decrease the risk of recurrence. In addition, morbidity and mortality can be minimized by careful patient selection using lung scanning or CT to determine predicted postoperative functions (FEV1% and DLco%) and some form of exercise testing, such as cardiopulmonary exercise testing or simple stair climbing. When the risk of surgery is high, any benefit from possible cure must be weighed against the risk of long-term disability or death. Although much data are available to guide clinicians in these decisions, there still is no one test that provides the answer in individual cases. The art and science of medicine must merge at this point.

[Prevalence of malnutrition in outpatients with stable chronic obstructive pulmonary disease]

OBJECTIVE

To determine the prevalence of malnutrition in outpatients with stable chronic obstructive pulmonary disease (COPD) followed at a respiratory clinic.

MATERIAL AND METHOD

In this prospective study, we assessed the nutritional status of consecutive outpatients with stable COPD by investigating various anthropometric parameters. Patients were malnourished (low body weight) if their body mass index was within the bottom quartile of a reference population. Muscle mass was determined from the midarm muscle area and if this mass was at or within the bottom quartile, muscle wasting was present. Albumin and transferrin plasma concentrations were used as a measure of visceral protein stores. Fat stores were assessed from body fat and if this value was at or within the bottom quartile, calorific malnutrition was present. All patients underwent arterial blood gas sampling at rest and spirometry.

RESULTS

A total of 178 patients--one woman (0.6%) and 177 men (99.4%)--were enrolled in the study, with a mean (SD) age of 69 (9) years. We found low body weight in 19.1% of the patients, muscle wasting in 47.2%, visceral protein depletion in 17.4%, and fat depletion in 19.1%. Of the patients with normal weight, 62.9% showed muscle wasting. The proportion of patients with a body mass index or midarm muscle area at or within the bottom quartile increased significantly with increased bronchial obstruction (P<.001 and P=.015, respectively), though 35.7% of the patients showed muscle wasting even when COPD was mild.

CONCLUSIONS

Many patients with stable COPD suffer malnutrition. Nutritional state is worse with more severe COPD. Depletion involves both fat stores and muscle and visceral protein stores, but the greatest effect is seen in muscle wasting. A significant number of patients with normal weight also suffer muscle wasting. Although changes in body composition were common in our patients, low body weight was less prevalent than has been reported for populations in countries that are socially and economically similar to Spain.

Growth hormone resistance in chronic heart failure and its therapeutic implications

BACKGROUND

In recent years the administration of recombinant human growth hormone (GH) has received great attention. This review compares the potential of this therapeutic intervention in heart failure with that in other diseases where wasting is commonly seen. The pathophysiologic importance of GH and insulin-like growth factor (IGF)-I in these conditions will be discussed.

METHODS AND RESULTS

Abnormalities of the GH-IGF-I axis play an important role in the development of cachexia in chronic illnesses. GH resistance is a major determinant of the wasting process, acting through several different mechanisms: increased catabolism, impaired anabolism, and enhanced apoptosis in peripheral tissues. GH therapy has been evaluated in chronic heart failure (CHF); acquired GH resistance may explain the general lack of therapeutic success in the majority of studies. The assessment of plasma levels of GH, IGF-I, and, in particular, GH binding protein may help to guide dosing of GH for CHF patients.

CONCLUSIONS

GH resistance might be overcome by use of intermittent or higher doses of GH, or alternatively by combining GH with IGF-I. Randomized studies of GH therapy in catabolic states, with targeted dosing and longer duration of treatment are required to fully assess the safety and efficacy of this treatment approach.

Reversal of COPD-associated weight loss using the anabolic agent oxandrolone

STUDY OBJECTIVE

Weight loss is a common complication of COPD, associated with negative outcomes. Weight restoration has been associated with improved outcomes. The effects of oxandrolone, an adjunct to help restore weight, were evaluated in patients with COPD.

DESIGN

Prospective, open-label, 4-month clinical trial.

SETTING

Twenty-five community-based pulmonary practices throughout the United States.

PATIENTS

A primary pulmonary diagnosis of moderate-to-severe COPD as defined by FEV1 < 50% of predicted and FEV1/FVC ratio < 0.7, along with significant involuntary weight loss (weight < or = 90% ideal body weight).

INTERVENTIONS

Oral oxandrolone, 10 mg bid.

MEASUREMENTS AND RESULTS

Body weight, body composition (bioelectric impedance analysis), spirometry, and 6-min walking distance were measured. Data for 82 patients at 2 months and 55 patients at 4 months are presented. At month 2, 88% of patients had gained a mean +/- SD of 6.0 +/- 4.36 lb (p < 0.05) and 12% had lost a mean of 1.7 +/- 2.15 lb (not statistically significant [NS]). At month 4, 84% had gained a mean of 6.0 +/- 5.83 lb (p < 0.05) and 16% had lost a mean of 1.8 +/- 1.74 lb (NS). Month 4 bioelectric impedance analysis showed the weight to be primarily lean tissue, with a mean increase in body cell mass of 3 +/- 2.6 lb (p < 0.05), and a mean increase in fat of 1.2 +/- 4.6 lb (NS).

CONCLUSIONS

Oxandrolone is an effective adjunct to facilitate weight restoration in patients with COPD-associated weight loss. Weight gain is primarily lean body mass. Oxandrolone was relatively well tolerated and, therefore, should be a consideration in the comprehensive management of patients with COPD and weight loss.

Effect of prolonged undernutrition on rat diaphragm mitochondrial respiration

Previous studies have shown that undernutrition induces an impairment of the respiratory muscle function in patients with chronic lung disease. To explain this, we hypothesized that undernutrition could decrease oxidative metabolism in the diaphragm. We therefore examined the effect of prolonged undernutrition on diaphragm mitochondrial oxygen uptake with pyruvate and palmitate as substrates in adult rats. Ten rats served as controls (CTL). Ten nutritionally deprived rats (ND) received 40% of their estimated daily nutrition. Five weeks of undernutrition induced a 33% decrease in state 3 respiration with pyruvate plus malate as substrate (993 +/- 171 versus 1488 +/- 167 nmol atomic O/mg/min, P < 0.01) and a 39% decrease with palmitate plus malate (516 +/- 89 versus 850 +/- 165 nmol atomic O/mg/min, P < 0.05). With succinate plus rotenone, there was no significant difference in the respiratory rate between groups. In the ND group, we found a significant decrease in citrate synthase activity (P < 0.01), and also in reduced nicotinamine adenine dinucleotide (NADH) dehydrogenase activity (P < 0.05), which cannot alone induce such a state 3 respiratory decrease. This showed that undernutrition in rat diaphragm does not induce an alteration in protein complexes I, II, III, and IV, or the F complex containing the mitochondrial ATPase of the electron transport chain. In conclusion, the main result of this study was that prolonged undernutrition induced a decrease in mitochondrial respiration secondary to a significant reduction in NADH generation by the Krebs cycle, which may affect respiratory muscle function with implications for patient care.

The impact of nutritional depletion in chronic obstructive pulmonary disease

Nutritional depletion is prevalent in patients with advanced chronic obstructive pulmonary disease (COPD). These nutritional abnormalities are pronounced in patients with the "emphysematous" form of COPD on chronic corticosteroid therapy. The pathophysiologic mechanisms for the involuntary weight loss appear to be multifactorial. Clinical research has revealed that nutritional depletion in advanced COPD is associated with an increased morbidity and mortality. This review will address the implications of nutritional depletion in addition to potential therapeutic options.

Enteral feeding in stable chronic obstructive pulmonary disease patients

OBJECTIVE

The study aimed to compare the effectiveness of a defined formula diet with a blenderized diet on nutritional and respiratory function parameters and to determine the bacteriological load of the two formulations.

METHODOLOGY

Seventeen patients, aged 50-75 years, admitted to the University of the Philippines-Philippine General Hospital for chronic bronchitis and/or emphysema, were studied. They were divided into two groups according to dietary regimens. Each group of patients received either the standardized commercial formula or the blenderized formula for 2 weeks. Evaluation of dietary intake, anthropometric measurements, laboratory examinations and lung function were assessed. Subjective evaluation (patient's and physician's assessment) was also sought. Microbiological examinations were performed on the prepared enteral formulas.

RESULTS

There was a slight increase in weight and in pulmonary function in both groups but these results did not differ significantly. Possible formula contamination was confirmed. Furthermore, in the overall assessment, the physician and patients rated both formulas as comparable.

Extrapulmonary effects of chronic obstructive pulmonary disease

Although airflow obstruction is the most obvious and most studied manifestation of chronic obstructive pulmonary disease (COPD), it should not be overlooked that COPD, particularly in its later stages, is associated with many extrapulmonary features that contribute to the morbidity, reduced quality of life, and, possibly, mortality of this disease. We review here the literature on skeletal muscle dysfunction, osteoporosis, and weight loss in COPD, with particular attention to possible approaches to their management. Patients with COPD may also have other extrapulmonary effects such as hormonal abnormalities that could probably be corrected, but less is known about them. COPD, therefore, should be regarded as a systemic disorder. Its systemic manifestations should not be overlooked in the overall care of the patient, because there are important ways in which they can be addressed.

Influence of body weight on the severity of dyspnea in chronic obstructive pulmonary disease

A substantial number of patients with COPD are underweight (UW); they comprise the clinical subtype of "dyspneic" or emphysematous. To determine whether these patients are more dyspneic than normal weight (NW) patients with COPD, we quantitated the severity of dyspnea, using a modified Medical Research Council (MRC) dyspnea scale, in 33 UW and 57 NW patients and compared their pulmonary function tests (PFTs), arterial blood gases (ABGs), and respiratory muscle strength as estimated by maximum static inspiratory (PI(max)) and expiratory (PE(max)) mouth pressures (all as means +/- SEM). Body mass index was 18.7 +/- 1.2 and 24.5 +/- 1.8 kg/m(2) in UW and NW patients, respectively (p < 0.0001). The MRC dyspnea scale was 3. 1 +/- 0.9 in UW and 2.5 +/- 1.2 in NW groups (p = 0.035). All PFT and ABG parameters were similar in the two groups except for DCO (36 +/- 11% in UW and 57 +/- 17% in NW, p < 0.001) and PI(max) (55 +/- 18 mm Hg in UW and 66 +/- 19 mm Hg in NW, p = 0.020). In a stepwise multiple regression model, %DCO and %MVV combined were the best predictors of dyspnea severity (R(2) = 0.30, p = 0.001). We conclude that UW patients with COPD are more dyspneic than NW patients. Although the origin of dyspnea in COPD is multifactorial, changes in DCO and respiratory muscle strength may contribute to its intensity.

Delayed type of hypersensitivity and late allergic reactions in patients with stable COPD

BACKGROUND

Malnutrition, a common feature among patients with COPD, has adverse effects on the immune system. Delayed type of hypersensitivity (DTH) tests have been used to evaluate the nutritional and immune status of patients and to predict outcome in various conditions. DTH is known to be and late allergic reaction (LAR) has been suggested to be dependent on T-lymphocyte function.

STUDY OBJECTIVES

To compare DTH and LAR tests in COPD patients and healthy controls, to investigate whether skin tests have any value in estimating nutritional status and outcome in COPD patients, and to see whether there is any relationship between DTH and LAR.

METHODS

Twenty-five patients with stable COPD and 20 healthy controls were tested for DTH and LAR. The patients were investigated with spirometry and anthropometric measurements and were followed for 1 year.

RESULTS

Both the LAR and DTH reactions were diminished in the patient group (p < 0.001) compared with controls. The skin tests did not correlate with anthropometric parameters. DTH correlated to lung function, which was expressed as FEV(1) (percent predicted) (r = 0.56; p < 0.01), and LAR correlated to the number of exacerbations (at 3 months, r = - 0.61; p < 0.01). No correlation was found between LAR and DTH reactions.

CONCLUSIONS

We conclude that patients with COPD in stable condition have diminished DTHs and LARs. Our results indicate that the magnitude of the LAR may be a prognostic marker in patients with COPD.

The impact of nutritional status on the outcome of lung volume reduction surgery: a prospective study

OBJECTIVES

To study the incidence and clinical significance of nutritional deficiencies in patients with emphysema undergoing lung volume reduction surgery (LVRS).

DESIGN

Prospective observational study.

SETTING

University-based teaching hospital.

PATIENTS

Fifty-one consecutive patients with end-stage emphysema undergoing video-assisted thoracoscopic surgery for LVRS.

INTERVENTIONS

All patients had their body mass index (BMI) and serum nutritional indexes (albumin, transferrin, total protein, cholesterol) measured preoperatively and postoperatively. Various clinical parameters were also compared between two groups.

RESULTS

The BMI was normal in 24 patients (47%), and 27 patients (53%) had a below normal BMI. A preoperative analysis of the serum nutritional indexes revealed no clinically significant differences between the two groups, but postoperative levels were significantly lower in the low BMI group. Anthropometric measurements supported the designation of nutritional status by BMI. Clinically, 26% of the patients in the low BMI group required prolonged ventilatory support (> 24 h), compared to only 4% of the patients with a normal BMI. The hospital length of stay (LOS) also differed, averaging 15.9 days in the low BMI group, compared to an average of 11.8 days in the normal BMI group.

CONCLUSION

Approximately 50% of patients undergoing LVRS for emphysema have a deficient nutritional status identifiable by BMI, but not by standard nutritional indexes. This impaired nutritional status is associated with increased morbidity following LVRS. We suggest that BMI is an accurate determinant of nutritional status in this patient population, and we speculate that preoperative repletion of nutritional deficiencies may decrease hospital morbidity, hospital LOS, and overall costs in the malnourished population undergoing LVRS.

Body composition analysis by dual energy X-ray absorptiometry and exercise performance in underweight patients with COPD

STUDY OBJECTIVES

The aim of this study was to examine the effect of body composition on maximal exercise performance in patients with COPD.

METHODS

The study was carried out on 27 patients with COPD and was confirmed by pulmonary function testing. Body composition was measured by dual energy x-ray absorptiometry (DXA). Exercise performance was conducted on a cycle ergometer and was measured as maximal work rate (WRmax) and maximal oxygen uptake (VO2max). Bone mineral content (BMC), lean mass (LEAN), and fat mass (FAT) were assessed by DXA and were expressed as a percentage of ideal body weight, BMC, LEAN, and FAT.

RESULTS

LEAN% correlated significantly with VO2max (r = 0.66, p = 0.0002) and WRmax (r = 0.70, p < 0.0001). No significant correlation was found between FAT% and exercise performance. By stepwise regression analysis, variables significantly contributing to WRmax and VO2max were LEAN% and the maximal voluntary ventilation. Total variance explained in these models was 81% for WRmax aid 82% for VO2max.

CONCLUSION

Lean mass was an important determinant of maximal exercise performance in patients with COPD.

Disease management of COPD with pulmonary rehabilitation

Pulmonary rehabilitation is a set of tools and disciplines that attends to the multiple needs of the COPD patient. It extends beyond standard care by addressing the disabling features of chronic and progressive lung disease. It centers on self-management, exercise, functional training, psychosocial skills, and contributes to the optimization of medical management. Exercise enables other components by building strength, endurance, confidence, and reducing dyspnea. Patients who have undergone rehabilitation often enjoy a reduced need for health-care utilization. On the downside, rehabilitation is a one-time intervention, the benefits of which dissolve over time. The patient's physician is rarely a participant in the program; thus, the physician is at a disadvantage in being able to support a long-term response. Rehabilitation is available to a small percentage of a large patient population who could benefit. Optimal disease management would entail redesigning standard medical care to integrate rehabilitative elements into a system of patient self-management and regular exercise. It should emphasize physician involvement in self-management, which is essential in developing and maintaining an effective exacerbation protocol. Pulmonary rehabilitation should take its place in the mainstream of disease management through its integrative and reconciliative role in the multidisciplinary continuum of services, as defined by the National Institutes of Health, Pulmonary Rehabilitation Research, Workshop of 1994.

Nutritional support of the hospitalized patient

Comprehensive care of patients in hospitals includes assessment of nutritional status and provision of appropriate support. This approach is facilitated by knowledge of the essential differences in metabolism between starved and stressed states. Nutritional assessment and care of patients in a hospital are based on answers to the following questions: Who gets it? When do they get it? How much do they get? What route is used to administer it? What kind do they get? What are common complications of enteral and parenteral support? What nutritional aspects are pertinent to common diseases?

Fat metabolism and its response to infusion of insulin and glucose in patients with advanced chronic obstructive pulmonary disease

In order to investigate fat metabolism and the regulation of lipolysis and blood fuel metabolites by insulin, nine patients with chronic obstructive pulmonary disease (COPD) with chronic hypoxaemia and seven healthy control subjects of similar age were investigated by determination of the turnover rate of free fatty acids (TOR), using 1-14C-oleic acid as a tracer, and arterial concentrations of FFA, glycerol and 3-hydroxybutyrate. The measurements were performed in the basal state and during insulin and glucose infusion, aiming at euglycaemia at insulin levels of 50 and 100 mU l-1. The subjects' ages were 64 +/- 2.7 and 66 +/- 1.1 (mean +/- SEM) years in the COPD and control groups, respectively. TOR was 0.73 +/- 0.06 and 0.52 +/- 0.02 mmol min-1 (P < 0.05) in the basal state, 0.33 +/- 0.04 and 0.30 +/- 0.02 at an insulin level of 50 mU l-1 and 0.32 +/- 0.08 and 0.24 +/- 0.02 at an insulin level of 100 mU l-1, in the COPD and control groups, respectively. Arterial FFA concentration was 0.98 +/- 0.08 and 0.75 +/- 0.06 mmol l-1 (P < 0.05) in the basal state in the COPD and control groups, respectively. During the clamp, the decrease in FFA mirrored that in TOR. The results show that the state of lipolysis is increased in severe COPD patients with chronic hypoxaemia. Furthermore, the results suggest a reduced effect of insulin in lipolysis.

[Artificial nutrition in patients with chronic respiratory insufficiency undergoing surgery]

Denutrition is a common finding in patients with chronic respiratory failure (CRF). Preoperative denutrition increases the risk of nosocomial pneumonia and difficulties in weaning from mechanical ventilation. A preoperative nutritional support may have beneficial effects on respiratory muscles performance. However, prospective studies need to be carried out in patients with CRF to substantiate this hypothesis. Postoperative nutritional support is indicated if weaning from the ventilator is expected to require more than several days, in order to preserve the diaphragmatic function. Lipid-enriched nutrition may have a beneficial effect, when energy supply is high, as the resulting decrease in CO2 production may facilitate the weaning from the ventilator. A beneficial effect of branched-chain amino acid-enriched solutions has not been demonstrated in patients with CRF.

Biochemical assessment of nutritional status in patients with chronic obstructive pulmonary disease and acute respiratory failure on admission to an intensive care unit

Although chronic obstructive pulmonary disease (COPD) is associated with weight loss and malnutrition, there is a paucity of relevant data on COPD patients with acute respiratory failure (ARF). We studied 30 consecutive patients on the day of admission to our intensive care unit for ARF. In addition to a clinical work-up, the following biochemical parameters were determined: markers of nutritional status (albumin - ALB, transferrin - TRF, transthyretin - TTR, retinol binding protein - RBP, fibronectin), inflammation (C-reactive protein - CRP, alpha(1) glycoprotein acid - alpha(1)GPA) and catabolism (plasma phenylalanine - PHE, urinary 3-methylhistidine - 3-MH). Values were expressed as mean +/- SD and compared to those of 10 healthy subjects matched for age. COPD-ARF patients had a poor protein status (ALB = 30 +/- 5 vs 42 +/- 3 g.l(-1); TTR = 118 +/- 75 vs 251 +/- 43 mg.l(-1); RBP = 23 +/- 12 vs 46 +/- 8 mg.l(-1); p < 0.001), were hypercatabolic (3-MH Cr = 31 +/- 12 vs 22 +/- 7 mumol.mmol Cr (-1); PHE = 62 +/- 27 vs 46 +/- 10 mumol.l(-1); p < 0.001) and inflamed (CRP = 68 +/- 50 vs 12 +/- 5 mg.l(-1); alpha(1)GPA = 1.2 +/- 0.4 vs 0.5 +/- 0.1 g.l(-1); p < 0.001). Severity of the disease correlated with short half-life proteins and protein catabolism markers but not with inflammation markers. Considering ALB, TTR, RBP, the 3- MH Cr ratio and PHE values, the 30 COPD patients fell into 3 groups: chronic malnutrition (n = 7), acute malnutrition (n = 2), and acute + chronic malnutrition (n = 18). 3 patients had normal nutritional status. We conclude that an assessment of nutritional status at admission to intensive care units could contribute towards a rapid formulation of specific nutritional therapy.

The effects of high-fat and high-carbohydrate diet loads on gas exchange and ventilation in COPD patients and normal subjects

Reducing the CO2 production (VCO2) is a plausible means to lower the ventilatory demand in the treatment of patients with COPD. The purpose of this study was to examine the effects of high-fat and high-carbohydrate (high-CHO) diet loads on gas exchange and ventilation in the COPD patients and normal subjects. The percentage of changes in the averaged values of VCO2, O2 consumption (VO2), respiratory quotient (RQ), minute ventilation (VE), and end-tidal CO2 (ETCO2) measured by a mass spectrometer for 5 min every 30 min after the diet were compared between diets and between study subjects. Compared with the high-fat diet, the high-CHO diet can lead to significantly higher levels of VCO2, VO2, RQ, and VE in the COPD patients 30 to 60 min after the diet, and the differences can last for about 1.5 h. The comparison between COPD patients and normal control subjects also showed that the high-CHO diet load can result in significantly higher levels of VCO2, VO2, and VE, and significantly lower level of ETCO2 in the COPD patients, whereas the high-fat diet cannot. In addition, enhanced thermic effect of food within 150 min (TEF150) occurred in the COPD patients as compared with that of normal controls, and the increase in TEF150 occurred only with the high-CHO diet. This study suggested that a high-fat diet is more beneficial to the COPD patient than a high-CHO diet, and that the gas exchange and energy utilization of the COPD patients following a high-CHO diet might be different from that of normal control subjects.

Nutritional status of patients with chronic obstructive pulmonary disease and acute respiratory failure

The prevalence and features of malnutrition in COPD patients have been studied extensively in stable conditions but are poorly defined in the presence of acute respiratory failure (ARF). Nutritional status was prospectively assessed, on hospital admission, in 50 consecutive COPD patients presenting with ARF, 27 of them requiring mechanical ventilation (MV). Malnutrition, defined on a multiparameter nutritional index, was observed in 60 percent (30/50) of all patients, and in 39 percent (13/33) of those whose body weight was equal to or above 90 percent ideal body weight (IBW). Malnutrition was more frequent in those patients who required MV than in those who did not (74 percent vs 43 percent, p < 0.05). Subcutaneous fat stores were decreased (triceps skinfold thickness [TSF] < 80 percent pred) in 68 percent of patients, and markedly depleted (TSF < 60 percent pred) in 52 percent of them. The indices of lean body mass, ie, mid-arm muscle circumference (MAMC) and creatinine height index (CHI) were decreased in, respectively, 42 percent and 71 percent of patients, but MAMC was severely depressed (< 60 percent pred) in only 6 percent of them. A severe decrease of prealbumin (< 100 mg/L), retinol-binding-protein (< 20 mg/L), and albumin (< 20 g/L) serum concentrations was observed in, respectively, 22 percent, 28 percent, and 4 percent of patients. These results suggest that an assessment of nutritional status using a multiparameter approach should be systematically performed in COPD patients with ARF, especially in those requiring MV, as malnutrition may have deleterious effects on weaning off MV.

Energy balance in stable malnourished patients with chronic obstructive pulmonary disease

We have measured caloric intake, energy expenditure, and the thermogenic effect of food in ten patients with stable COPD who had a history of involuntary weight loss over several years and were malnourished (< 85 percent ideal body weight). Each patient completed a 7-day food record. Indirect calorimetry was performed in the resting postabsorptive state. After placement of a nasoenteric tube, patients were randomly assigned to be refed or sham-fed (mean +/- SD, 16 +/- 3 days), following which, metabolic measurements were repeated. Indirect calorimetry was also performed before and after a large meal in each patient. Home caloric intake was 135 +/- 23 percent of resting energy expenditure. Resting energy expenditure was 94 +/- 16 percent of that predicted by the Harris-Benedict equation and did not change significantly during inpatient refeeding. Refeeding resulted in weight gain (2.4 +/- 1.9 kg, p < 0.02). A large meal caused substantial increases in energy expenditure (24 +/- 18 percent), carbon dioxide production (39 +/- 18 percent), and oxygen consumption (23 +/- 16 percent). We conclude that stable malnourished COPD patients consume adequate calories to meet average energy requirements and are not hypermetabolic. Inpatient refeeding by nocturnal nasoenteric infusion is well tolerated and results in weight gain, but the thermogenic effect of a large meal poses a considerable metabolic and ventilatory load that could precipitate acute respiratory failure.

Physiologic effects of oral supplemental feeding in malnourished patients with chronic obstructive pulmonary disease. A randomized control study

The association between severe nutritional depletion and chronic obstructive pulmonary disease (COPD) has long been recognized. A potential therapeutic benefit to nutritional support was previously suggested by us in a pilot investigation. Subsequent studies have reported conflicting results regarding the role of nutritional therapy in this clinical population. We report a randomized controlled study of nutritional therapy in underweight patients with COPD that combines an initial inpatient investigation (controlled nutritional support) with a prolonged outpatient follow-up interval. Provision of adequate calorie and protein support, adjusted to metabolic requirements, resulted in weight gain (intervention = +2.4 kg versus control -0.5 kg), improved handgrip strength (intervention = +5.5 kg-force versus control -6.0 kg-force), expiratory muscle strength (intervention = +14.9 cm H2O versus control -9.2 cm H2O), and walking distance (intervention = +429 feet versus control -1.0 foot). Inspiratory muscle strength was also improved (intervention = +11.4 cm H2O versus control +4.8 cm H2O) although this did not quite reach statistical significance. We conclude that provision of adequate nutrient supply under controlled conditions results in significant clinical improvements in the COPD patient population. However, the intervention is costly, time-intensive, and of limited therapeutic magnitude. More detailed work of alternative outpatient strategies combined with additional rehabilitative measures is indicated to delineate the full therapeutic potential of nutritional support for this clinical population.

Muscle protein degradation in severely malnourished patients with chronic obstructive pulmonary disease subject to short-term total parenteral nutrition

Patients with chronic obstructive pulmonary disease (COPD) often lose weight and muscle mass with progression of the disease. Muscle protein degradation in patients with COPD has never been examined before and during hypercaloric feeding. Eight severely malnourished patients with COPD were examined at home consuming their usual intake, in the hospital after 3 days of a meat-free regular oral diet (period B), and during a hypercaloric (55 kcal/kg) high-lipid (55%) parenteral formula (total parenteral nutrition [TPN]). During period B, 8 well-nourished patients and 10 malnourished cancer patients were used as control groups. Measurements included plasma assays, leg blood flow, leg exchange (of 3-methylhistidine [3MeH], glucose, lactate, and oxygen) and urinary measures of 3MeH, creatinine, and nitrogen. During period B, net release of 3MeH across the leg in patients with COPD was similar to that in well-nourished control subjects and cachectic cancer patients. In COPD patients, there was only a transient decrease in leg exchange values of 3MeH with administration of TPN. COPD patients demonstrated a reduction (p less than .01) in urinary 3MeH excretion and an increase in nitrogen balance (p less than .01) with TPN compared with period B. The decrease in muscle protein degradation with administration of TPN accounts for about 50% of the increase in nitrogen retention in patients with COPD. These data suggest that in severely malnourished patients with COPD the weight loss is not dependent on increased rates of skeletal muscle protein degradation; nevertheless, degradation rates attenuate with a positive nitrogen balance during nutrition repletion.