Body composition and resting energy expenditure in clinically stable, non-weight-losing patients with severe emphysema

STUDY OBJECTIVES: To characterize the metabolic status of weight-stable and clinically stable individuals with advanced emphysema. PATIENTS: Seventy-nine patients with severe emphysema (FEV(1), 29 +/- 13% of predicted [mean +/- SD]) evaluated for enrollment in the National Emphysema Treatment Trial and 20 age-matched healthy subjects were studied. SETTING: Pulmonary function laboratory of university-affiliated teaching hospital. INTERVENTIONS: Data collection. Measurements and results: We measured lung function, body composition, serum leptin levels, serum tumor necrosis factor receptors (sTNF-Rs), resting oxygen consumption (RVO(2)) normalized to weight in kilograms (RVO(2)/kg), and RVO(2) normalized to fat-free mass (FFM) [RVO(2)/FFM]. The patient group and healthy group had similar age, body mass index (BMI), and body composition. RVO(2)/kg, RVO(2)/FFM, and sTNF-R levels were higher in patients compared to healthy subjects. There were no differences in serum leptin levels between emphysematous and healthy subjects, and there was no correlation between leptin and sTNF-R and RVO(2)/kg. Furthermore, both groups had similar gender-related differences in FFM, percentage of body fat, and serum leptin levels. Patients with lower BMI showed the greatest differences from control subjects in RVO(2)/kg. CONCLUSION: In weight-stable subjects with advanced emphysema, RVO(2)/kg and RVO(2)/FFM were higher compared to healthy subjects, especially in those with BMI in the lower end of the normal range. RVO(2)/kg and RVO(2)/FFM did not correlate with leptin or sTNF-R levels. These data show that a higher metabolic rate is found in patients with emphysema who are clinically and weight stable. Thus, hypermetabolism is a feature of the disease and not sufficient to lead to weight loss.     

Influence of fat-free mass and functional status on resting energy expenditure in underweight elders

BACKGROUND: In underweight elders, resting energy expenditure (REE) and its relationship with fat-free mass (FFM) could be modified by sarcopenia, physical activity, and functional limitation. The aims of this study were to investigate REE and its relationship with quantity and metabolic activity of FFM and to evaluate the influence of functional status on REE in underweight elderly subjects. METHODS: Forty-eight underweight elders (BMI < 20) and 54 normal weight elderly subjects (BMI 20-30) as a control group were selected. Body composition was determined by dual energy x-ray absorptiometry (DEXA). REE was measured by indirect calorimetry. Ability in activities of daily living (ADLs) was assessed by the Katz index. RESULTS: Underweight elders had significantly lower FFM, FFM index (FFM/height(2)), and REE than healthy subjects. REE adjusted for FFM with analysis of covariance remained significantly lower in the underweight group (1287 +/- 85 vs 1715 +/- 139 kcal/day in men, and 1124 +/- 63 vs 1366 +/- 91 kcal/day in women). Katz index in the underweight group was inversely correlated with REE (r = -0.68; p <.001) even after removal of FFM, FM, and gender, by multiple regression analysis. In this model, FFM and Katz index together explained approximately 54% of REE variability. CONCLUSIONS: Underweight elderly subjects show a hypometabolism due to a reduction of both FFM quantity and its metabolic activity. Functional status in ADLs comes out as an important predictor of REE independently from FFM. The limited physical activity might be the underlying determinant of this hypometabolism, but further investigations are necessary to confirm this issue.     

慢性阻塞性肺疾病患者去脂体重与最高运动状态反应的相关性

目的 探讨去脂体重(FFM)与慢性阻塞性肺疾病(COPD)患者最高运动状态反应的相关性.方法 26例正常对照组和62例稳定期COPD患者进行负荷连续递增的运动心肺功能试验.其中稳定期COPD患者按照第1秒用力呼气容积占预计值百分比(FEV1%pred)分成轻度、中度和重度,在运动中检测受试者最高运动状态时氧耗量(peakVO2)、最高运动状态时运动负荷(peakLoad)、最高运动状态时氧脉搏(peakO2 pulse)、无氧阈(AT)等各项参数.运动前进行FFM测定和常规肺功能检查.结果 ①重度COPD患者FFM明显低于对照组,差异有统计学意义(P＜0.05);②重度COPD组的peakVO2、peakVO2%pred、peakLoad、peakLoad%pred、peakO2 pulse、peakO2 pulse%pred和AT均显著低于对照组,差异有统计学意义(P＜0.05);③FFM与peakVO2%pred、peakLoad%pred、AT和peakO2pulse%pred呈正相关(r=0.671,0.478.0.423,0.618,P值均＜0.05).结论 FFM与COPD 患者肌肉代谢和运动耐力相关.

Abstract：

Objective To explore the relationship between fat-free mass (FFM) and peak exercise performance in chronic obstructive pulmonary disease(COPD) patients. Methods 26 healthy subjects and 62 stable COPD patients performed incremental cardiopulmonary exercise testing with cycle ergometer. 62stable COPD patients were divided three groups(mild COPD,moderate COPD,severe COPD) according to FEV1%pred, peakVO2, peakLoad, peakO2 pulse, AT were measured during exercise. FFM and routine subjects, peakVO2 ,peakVO2 %pred,peakLoad,peakLoad%pred,peakO2 pulse,peakO2 pulse% pred and AT peakLoad%pred,AT and peakO2 pulse% pred ( r =0. 671,0. 478,0. 423,0. 618, P＜0. 05) in COPD patients.Conclusions FFM is significantly associated with muscle aerobic capacity and exercise tolerance in COPD patients.     

Resting energy expenditure in chronic hepatitis C

BACKGROUND/AIMS: Hypermetabolism is considered to be of clinical interest in liver disease and in several chronic viral infections. Whether resting energy expenditure (REE) increases during chronic hepatitis C is not known. Our aims were: (a) to determine the metabolic state of patients with chronic hepatitis C, and (b) to evaluate the effects of interferon therapy on REE. METHODS: Forty-seven patients and 20 controls were studied. Sixteen patients failed to respond to interferon and 12 patients stopped the treatment during the first 2 months for various reasons. The 19 responders all received 1 year of interferon. REE (indirect calorimetry) and fat-free mass (FFM, bioelectric impedance analysis) were evaluated before (day 0) and after 90, 180, and 360 days of interferon. The virus load was evaluated in patients before treatment. RESULTS: On day 0, REE expressed as a ratio of FFM (REE/FFM) was higher in patients than in controls (129.2 +/- 14.7 vs 117.9 +/- 9.6 kJ kg FFM(-1) 24 h(-1), p<0.01), and was positively correlated with the viral load (r=0.45, p=0.01). On day 90, REE/FFM had significantly decreased in responders but it did not decrease in non-responders (p<0.01). In responders, REE/FFM on days 180 and 360 was similar to that of the controls. CONCLUSIONS: Chronic hepatitis C induces hypermetabolism that is normalized by interferon therapy in responders. The underlying mechanisms of chronic hepatitis C-induced hypermetabolism and its clinical relevance remain to be determined.     

Comparison of the Sit-to-Stand Test with 6 min walk test in patients with chronic obstructive pulmonary disease

OBJECTIVE: To discuss the utility of Sit-to-Stand Test (STST) compared to the 6min walking test (6MWT) for the evaluation of functional status in patients with chronic obstructive pulmonary disease (COPD). MATERIAL-METHOD: SUBJECTS: Fifty-three patients with stable COPD (mean forced expiratory volume in 1s (FEV(1)) 46+/-9% predicted, mean age 71+/-12 year) and 15 healthy individuals (mean FEV(1) 101+/-13% predicted and mean age 63+/-8) were included. INTERVENTIONS: Functional performance was evaluated by STST and 6MWT. During the tests, severity of dyspnea (by Modified Borg Scale), heart rate, pulsed oxygen saturation (SpO(2), by Modified Borg Scale) (by pulse oxymeter), blood pressure were measured. The pulmonary function (by spirometry), quadriceps femoris muscle strength (by manual muscle test) and quality of life (by Nottingham Health Profile Survey) were evaluated. RESULTS: The STST and 6MWT results were lower in COPD group than the healthy group (P<0.05). During the 6MWT the rise in the heart rate, systolic blood pressure and the decrease in SpO(2) were statistically significant according to STST in COPD groups (P<0.05). The STST and 6MWT were strongly correlated with each other in both groups (P<0.05). Similarly, they were correlated with age, quality of life, peripheral muscle strength and dyspnea severity in COPD groups (P<0.05). CONCLUSION: Similar to 6MWT, STST is also able to determine the functional state correctly. Additionally, it produces less hemodynamical stress compared to the 6MWT. In conclusion, STST can be used as an alternative of the 6MWT in patients with COPD.     

Total body mass, fat mass, fat-free mass, and skeletal muscle in older people: cross-sectional differences in 60-year-old persons

OBJECTIVES: To evaluate body composition parameters, including fat-free mass (FFM), appendicular skeletal muscle mass (ASMM), relative skeletal muscle mass (RSM) index, body cell mass (BCM), BCM index, total body potassium (TBK), fat mass, percentage fat mass (FM), and their differences between age groups and to evaluate the frequency of sarcopenia in healthy older subjects DESIGN: Cross-sectional, nonrandomized study. SETTING: Outpatient clinic. PARTICIPANTS: Ninety-one healthy men and 100 healthy women age 60 and older. MEASUREMENTS: FFM, ASMM, FM, and percentage fat mass by whole-body dual-energy x-ray absorptiometry; TBK, BCM, and TBK/FFM ratio by whole body potassium-40 counter. RESULTS: All lean body mass parameters were significantly (P <.05) lower in subjects age 80 and older than in those age 70 to 79, except ASMM in women. Mean FFM was 4.2 kg (7.3%) lower in men age 80 and older than in those younger than 70 and 2.9 kg (6.8%) lower in women age 80 and older than in those younger than 70. The skeletal muscle mass, reflected by ASMM, decreased more than FFM. This suggests that nonskeletal muscle mass is proportionally preserved during aging. Forty-five percent of men and 30% of women were sarcopenic by definition of BCM index and 11.0% of men and women by definition of RSM index. CONCLUSIONS: Significant age-related differences exist in body composition of older men and women between age 60 and 95. The greater decrease in TBK and BCM than the decrease in FFM and skeletal muscle mass suggests changing composition of FFM with age. Lack of agreement between two independent sarcopenia indexes suggests that further refinement in the definition of a sarcopenia index is necessary.     

Resting energy expenditure and nutritional status in children with juvenile rheumatoid arthritis.

OBJECTIVE: Undernutrition is frequently encountered in children with juvenile rheumatoid arthritis (JRA). We assessed resting energy expenditure (REE) in relation to nutritional status and body composition in patients with JRA. METHODS: We selected 33 children (age 6 to 18 yrs) with JRA (13 oligoarticular, 10 polyarticular, 10 systemic JRA) and 17 controls matched for age and sex. Nutritional status was assessed for height, weight, and fat-free mass (FFM), and REE was measured with indirect calorimetry. RESULTS: Nutritional status in the patients with systemic JRA was diminished compared to the controls for height (140 vs. 159 cm; p<0.01) and FFM (28 vs. 38 kg; p = 0.03). Oligo and polyarticular patients with JRA had normal height and FFM. No significant differences existed in crude REE among the groups. However, after correcting REE for body weight and FFM, the patients with systemic JRA, compared to controls, had 18% higher REE per kg body weight (159 vs. 134 kJ/kg/day; p<0.01) and 21% higher REE per kg FFM (196 vs. 162 kJ/kg/day; p<0.01). Oligo and polyarticular JRA patients had 8% increased values for REE per kg body weight or FFM, but these differences were not statistically significant. CONCLUSION: Patients with systemic JRA show stunting, low FFM, and a significantly increased REE when nutritional status is taken into account. These data suggest that assessment of individual energy requirements should include correction for fat-free mass in the treatment of malnutrition in patients with systemic JRA.     

慢性阻塞性肺疾病患者静息能量与呼吸力学及气体交换关系的研究

目的　探究慢性阻塞性肺疾病 (COPD)患者静息能量消耗 (REE)与肺通气功能、呼吸驱动及呼吸肌功能间的关系。方法　用canopy法间接测定 2 6例COPD患者和 2 1例健康对照者的REE、氧耗量 ( VO2 )、二氧化碳产生量 ( VCO2 )及呼吸商 (RQ)。同时测静息肺通气功能、口腔阻断压(P0 1)、最大吸气压 (PIMAX)及最大呼气压 (PEMAX) ,并进行动脉血气分析。结果　 (1)COPD组患者REE实测值 [(15 77 6 9± 311 31)kcal/d]较健康对照组 [(1388 2 9± 194 89)kcal/d]高 (P <0 0 5 ) ;PIMAX[(44 5 3± 10 6 0 )mmHg]较健康对照组 [(71 4 3± 2 2 34)mmHg]低 (P <0 0 1) ,P0 1/PIMAX(0 0 6 8± 0 0 2 6 )较健康对照组 (0 0 39± 0 0 14 )高 (P <0 0 5 ) ;第 1秒钟用力呼气容积 (FEV1)占预计值的百分比 [(5 0 4 6± 2 1 35 ) % ]、动脉血氧分压 (PaO2 ) [(77 72± 8 84 )mmHg]、动脉血氧饱和度(SaO2 ) [(92 5 4± 2 5 5 ) % ]均较健康对照组低 (P <0 0 1) ;心率 [(83 4 6± 11 36 )次 /min]较健康对照组 [(6 9 71± 5 73)次 /min]高 (P <0 0 5 )。 (2 )相关分析显示 ,COPD组REE实测值与身高、体重、体重指数、P0 1/PIMAX及心率呈正相关 (r分别为 0 5 7、0 6 5、0 6 2、0 4 1、0 5 1) ,与FEV1占预计     

Short-term energy restriction reduces resting energy expenditure in patients with HIV lipodystrophy and hypermetabolism

We have previously shown that resting energy expenditure (REE) is increased in patients with HIV lipodystrophy. This hypermetabolism could be the result of an inadequate storage capacity for lipid fuel secondary to atrophy of the subcutaneous adipose tissue depot. Therefore, energy restriction may be able to alleviate this hypermetabolism. To test this hypothesis, we measured REE in HIV-infected patients with lipodystrophy and hypermetabolism and in HIV-infected and healthy controls. Measurements were taken during the overnight fasted state after 3 days on a eu-energetic diet and again after 3 days on a diet of similar composition but reduced in energy by 50%. After 3 days of eu-energetic feeding, REE was significantly higher in HIV-infected patients with lipodystrophy compared with healthy controls (139.5 +/- 1.3 vs 117.2 +/- 1.3 kJ/kg lean body mass, P < .001) and tended to be higher compared with HIV-infected subjects without lipodystrophy (139.5 +/- 13 vs 127.3 +/- 1.4 kJ/kg lean body mass, P = .06). Furthermore, energy restriction caused a significant decline in REE in patients with HIV lipodystrophy (P < .001). This dietary manipulation did not lead to a significant reduction in REE in either HIV-infected or healthy controls. This suggests that energy intake and REE may be uniquely coupled in patients with lipodystrophy as a means to dissipate energy that cannot be stored in a normal manner. A better understanding of this coupling would have important implications for weight regulation in general.     

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 ¹³C-bicarbonate and 1-¹³C-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.     

Effect of organ and tissue masses on resting energy expenditure in underweight, normal weight and obese adults

BACKGROUND: In normal-weight subjects, resting energy expenditure (REE) can be accurately calculated from organ and tissue masses applying constant organ-specific metabolic rates. This approach allows a precise correction for between-subjects variation in REE, explained by body composition. Since a decrease in organ metabolic rate with increasing organ mass has been deduced from interspecies comparison including human studies, the validity of the organ- and tissue-specific REE calculation remains to be proved over a wider range of fat-free mass (FFM). DESIGN: In a cross-sectional study on 57 healthy adults (35 females and 22 males, 19-43 y; 14 underweight, 25 intermediate weight and 18 obese), magnetic resonance imaging (MRI) and dual-energy X-ray absorptiometry (DXA) were used to assess the masses of brain, internal organs, skeletal muscle (MM), bone and adipose tissue. REE was measured by indirect calorimetry (REEm) and calculated from detailed organ size determination by MRI and DXA (REEc1), or in a simplified approach exclusively from DXA (REEc2). RESULTS: We found a high agreement between REEm and REEc1 over the whole range of FFM (28-86 kg). REE prediction errors were -17 +/- 505, -145 +/- 514 and -141 +/- 1058 kJ/day in intermediate weight, underweight and obese subjects, respectively (n.s.). Regressing REEm on FFM resulted in a significant positive intercept of 1.6 MJ/day that could be reduced to 0.5 MJ/day by adjusting FFM for the proportion of MM/organ mass. In a multiple regression analysis, MM and liver mass explained 81% of the variance in REEm. DXA-derived REE prediction showed a good agreement with measured values (mean values for REEm and REEc2 were 5.72 +/- 1.87 and 5.82 +/- 1.51 MJ/day; difference n.s.). CONCLUSION: Detailed analysis of metabolically active components of FFM allows REE prediction over a wide range of FFM. The data provide indirect evidence for a view that, for practical purposes within humans, the specific metabolic rate is constant with increasing organ mass. Nonlinearity of REE on FFM was partly explained by FFM composition. A simplified REE prediction algorithm from regional DXA measurements has to be validated in future studies.     

Striking similarities in systemic factors contributing to decreased exercise capacity in patients with severe chronic heart failure or COPD

AIMS: Chronic heart failure (CHF) and COPD are both characterized by muscular impairment. To assess whether the severity and functional consequences of muscular impairment are disease specific, we compared skeletal muscle function, body composition, and daily activity level relative to exercise capacity between these two disorders. METHODS: Twenty-five patients with CHF and 25 patients with COPD, and 36 healthy gender- and age-matched control subjects underwent measurement of fat-free mass (FFM) [by bioelectrical impedance analysis] as an index of muscle mass. Quadriceps and biceps functions were tested by isokinetic methods, and daily activity level was assessed by the Physical Activity Scale for Elderly (PASE) questionnaire. Peak oxygen consumption (O(2)peak) was measured by incremental cycle ergometry. RESULTS: PASE results were similar in patients with CHF and in patients with COPD, each group scoring lower than control subjects. FFM was also lower in patients than control subjects and correlated closely with quadriceps and biceps strength in all three subgroups, R values ranging from 0.63 to 0.78, with identical slopes. FFM also correlated significantly with O(2)peak (p < 0.05), but slopes were less steep in patients than in control subjects. The type and severity of muscle dysfunction were similar in each group of patients. There were no significant correlations between indexes of cardiopulmonary function and muscle function or exercise performance in patients with CHF or in patients with COPD. In both control subjects and patients, FFM was the most significant determinant of O(2)peak. CONCLUSION: Muscle dysfunction is not limited to the lower limbs, but generalized and comparable between patients with CHF and patients with COPD with similar exercise capacity. FFM is a strong predictor of peripheral muscle strength, to a lesser extent of O(2)peak, and not at all of peripheral muscle endurance.     

Nutritional status and dietary patterns in disabled people

BACKGROUND AND AIM: Obesity, cardiovascular diseases, diabetes and osteoporosis are the most frequent pathologies among people with a severe reduction of physical activity. The impairment in nutritional status, consequent to quantitative and qualitative inadequacy of diet, could be one of the first steps in the development of co-morbidities in disabled subjects. In order to evaluate this hypothesis we investigated the nutritional status and the food intake in patients with physical or mental disabilities. METHODS AND RESULTS: Thirty-seven disabled subjects (24 with exclusively physical inactivity and 13 with mental retardation and physical inactivity) mean age 33.5+/-9.2 years and 25 healthy subjects (mean age 31.0+/-9.3 years) were enrolled. Anthropometric measurements, indirect calorimetry, dual-energy X-ray absorptiometry, dietary intake and biochemical parameters were collected for each subject. Forty percent of disabled were overweight and 14% were obese. Fat free mass (FFM) and bone mineral content (BMC) was lower and fat mass (FM) was higher than able-bodied control. Absolute resting energy expenditure (REE) was lower in disabled subjects, but this difference disappeared when REE was normalized to FFM. Dietary intake resulted unbalanced (16%, 31%, 50% of total daily energy intake derived from protein, lipid and carbohydrate respectively) with a distribution of dietary fatty acid quite far from the recommended ratio [3.1(SFA):4.1(MUFA):1.0(PUFA)] and an excessive consumption of simple carbohydrates (mean intake 17.5+/-4.9%). Insufficient intake of fibre, iron, calcium, potassium and zinc was also found. Finally, alterations in the cholesterol profile were evident in more than one third of the disabled subjects, whereas fasting glucose intolerance was evident in one fourth. CONCLUSION: This study shows a consistent nutritional status impairment in disabled patients resulting in an reduction of FFM and BMC, in an over-representation of FM and in a number of biochemical risk factors for cardiovascular disease. The altered nutritional status is counterparted by a widespread inadequacy of dietary patterns. This nutritional and dietary impairment occurs both in subjects with mental and physical diseases.     

Energetic cost of protein turnover in healthy elderly humans

OBJECTIVE: Whole body protein turnover (PTO) and resting energy expenditure (REE) are both correlated to fat-free mass (FFM), in young and elderly subjects, and REE is positively correlated to PTO in young adults. Thus, the aim of this study was to compare the energetic cost of PTO in young (n=39, 23.4+/-3.1 y) and elderly (n=41, 67.5+/-3.6 y) healthy volunteers. MEASUREMENTS: REE (indirect calorimetry), PTO ((13)C-leucine isotopic dilution) and body composition (bioelectrical impedance analysis with age-specific equations) were measured in the postabsorptive state. RESULTS: Elderly subjects had a higher fatness (30.5+/-7.1 vs 18.2+/-5.5%, elderly vs young, P<0.001), a similar REE (0.97+/-0.13 vs 1.06+/-0.15 kcal min(-1)), and a lower PTO (1.28+/-0.22 vs 1.44+/-0.18 micromol kg(-1) min(-1), P<0.001). PTO, REE and FFM were significantly correlated and after adjustment for FFM, REE was positively correlated to PTO (r=0.61, P<0.001). The slope of this relationship was the same in both groups, while the adjusted mean REE was lower in elderly subjects (0.97+/-0.09 vs 1.05+/-0.07 kcal min(-1), P<0.01). CONCLUSION: In comparison with young subjects, the energetic cost associated with PTO in elderly subjects is not different, but the proportion of REE not associated with PTO is lower.     

Resting energy expenditure in lung and colon cancer

Elevated resting energy expenditure (REE) is a possible mechanism of cancer cachexia. We measured REE by whole-body direct calorimetry in patients with colon and non-small cell lung cancer and compared the results with REE in groups of healthy subjects and in patients with anorexia nervosa, with nonmalignant gastrointestinal (GI) disease, with miscellaneous reasons for weight loss, and with chronic lung disease. The mean REE of the cancer patients was not different from healthy subjects, those with GI disease, miscellaneous causes of cachexia, and chronic lung disease, and there was no significant difference in REE between those cancer patients with weight loss and controls with weight loss, except for the anorexia nervosa patients. The REE of the anorexia nervosa patients (female) was significantly lower than the REE of females with lung cancer. Weight loss correlated with REE in female lung cancer patients. Serial comparison of REE of ten cancer patients who lost 5% to 18% of their body weight during study showed no consistent change in REE. We conclude that patients with colon and non-small cell lung cancer, including those with weight loss, have REE similar to normal controls. Relative hypermetabolism may contribute to cancer cachexia, as may absolute hypermetabolism in some subsets of cancer patients.     

Reliability, validity, and responsiveness of a 2-min walk test to assess exercise capacity of COPD patients

PURPOSES: To investigate the reliability, validity, and responsiveness of a 2-min walk test (2MWT) in Chinese COPD patients with moderate-to-severe disease. METHODS: This study consisted of two parts. Forty-seven stable COPD patients with moderate-to-severe disease participated in the first part of study for the investigation of reliability and validity. The demographic and anthropomorphic data collected included age, gender, body weight, height, and body mass index. Each subject performed a pulmonary function test, a cardiopulmonary exercise test, three trials of a 2MWT, and two trials of 6-min-walk test (6MWT) in random order within a 5-day period. Fifteen of these subjects participated in the second part of study for the evaluation of the responsiveness of the 2MWT following pulmonary rehabilitation. The 2MWT and 6MWT were conducted before and after the program for comparison. RESULTS: Forty-five subjects (mean [+/- SD] age, 71.8 +/- 8.3 years; mean FEV1, 0.88 +/- 0.27 L) completed the first part of study, and 9 subjects (mean age, 74 +/- 8.7 years; mean FEV1, 0.94 +/- 0.28 L) completed the second part of study. The intraclass correlation coefficient of the repeated 2MWTs was high (R = 0.9994; p < 0.05), mean differences across trials ranged from 0.3 to 0.8 m (95% confidence interval, -3.1 to 4.6 m) demonstrated its high test-retest reliability. Significant correlations were found between the 2MWT and the 6MWT, the maximum oxygen uptake (V(O2)max) in milliliters per minute, and the V(O2)max in milliliters per kilogram per minute (r = 0.937, 0.454, and 0.555 respectively; p < 0.0125). Following rehabilitation, there were significant improvements in the mean 2MWT and 6MWT walking distance of 17.2 +/- 13.8 m and 60.6 +/- 35.5 m, respectively, with moderate effect sizes (0.61 and 0.53, respectively) and large standardized mean responses (1.25 and 1.70, respectively). High correlation was found between changes in the 2MWT and the 6MWT (r = 0.70; p < 0.05). CONCLUSION: The 2MWT was shown to be a reliable and valid test for the assessment of exercise capacity and responsive following rehabilitation in patients with moderate-to-severe COPD. It is practical, simple, and well-tolerated by patients with severe COPD symptoms.     

Energy expenditure and rib cage-abdominal motion in chronic obstructive pulmonary disease

The resting energy expenditure (REE) was measured by indirect calorimetry in 10 patients with chronic obstructive pulmonary disease (COPD) in stable clinical state and in 10 normal subjects. In order to avoid artefactually increased values, REE was obtained from prolonged measurements in steady state using a ventilated hood, without facial apparatus. The REE of COPD patients was significantly increased to 117% of predicted basal metabolic rate and to 125% of the control group values. Rib cage and abdominal movements were measured in COPD patients by inductance plethysmography and expressed with three indices: rib cage contribution to tidal volume (RC/VT), variability in compartmental contribution to tidal volume (SD RC/VT), and maximal compartmental amplitude/tidal volume ratio (MCA/VT). No correlation was found between REE and any of the indices of rib cage and abdominal motion. We conclude that the REE is increased in patients with COPD in stable clinical state, but is not related to the degree of abnormal rib cage-abdominal motion.     

Body composition and resting energy expenditure in humans: role of fat, fat-free mass and extracellular fluid

OBJECTIVE: The objective of this study was to determine whether there are independent effects of extracellular fluid volume (ECF) and fat mass (FM) on resting energy expenditure (REE) relative to fat-free mass (FFM) in adult men and women. METHODS: Multiple linear regression analysis was used to relate REE, as determined by indirect calorimetry, to FFM and FM (measured using dual energy X-ray absorptiometry) and ECF (measured using bromide space and/or the radiosulfate washout space) in 153 women and 100 men with varying amounts of body fat. RESULTS: REE correlated significantly with FFM and FM in women (r=0.65 and r=0.63, both P<0.001) and men (r=0.62 and r=0.48, both P<0.001, FFM and FM, respectively). In a multiple linear regression analysis FFM, FM and age significantly contributed to the ability to predict REE in both genders. The models that were derived were not significantly different between women and men. In women the contribution to REE from FM was easier to detect when FM was greater. Adjustment of FFM for ECF did not improve the relationship between FFM and REE. CONCLUSIONS: FFM, FM and age are significant, independent predictors of REE in both men and women. Adjustment of FFM for ECF does not improve the ability of FFM to predict REE, which suggests that ECF is a highly integrated component of FFM in healthy adults. Expressing REE relative to FFM alone will introduce errors when lean and obese populations are compared.     

The effect of gender and body composition method on the apparent decline in lean mass-adjusted resting metabolic rate with age

BACKGROUND: Declining resting energy expenditure (REE) is a hallmark of normal aging, but the cause of this decline remains controversial. Some, but not all, studies have shown that the decline in REE with age is eliminated after adjustment for fat-free mass (FFM). METHODS: We examined the effect of four body composition methods used to assess FFM (underwater weighing [UWW], bioimpedance analysis [BIA], tritium dilution, and total body potassium [TBK]) on the relationship between REE and age in 30 healthy men and 101 healthy women aged 18 to 87 years. RESULTS: The decline in REE with age was significant in women (-80.3 kJ/d/y, p < .004) but not in men (-46.9 kJ/d/y, p = .328). After adjustment for FFM, the decline in REE with age persisted when FFM was measured by BIA, UWW, or tritium dilution, but no decline was seen when TBK was used to adjust for FFM. In both women and men, fat mass was significantly associated with REE after adjusting for age and FFM. CONCLUSION: It is the decline in cell mass with age, detectable by TBK but not by other methods, rather than any metabolic alteration, that explains the decline in FFM-adjusted REE with age.     

Effects of whole-body exercise training on body composition and functional capacity in normal-weight patients with COPD

BACKGROUND: Skeletal muscle wasting is related to muscle dysfunction, exercise intolerance, and increased mortality risk in patients with COPD. STUDY OBJECTIVES: The aims of this study were to investigate the effects of whole-body exercise training on body composition in normal-weight patients with COPD, and to study the relationship between changes in body composition and functional capacity. SETTING AND PARTICIPANTS: Fifty patients with COPD (FEV(1), 39% of predicted [SD, 16]) admitted to the pulmonary rehabilitation center at Hornerheide, and 36 healthy age-matched control subjects (for baseline comparison) were included. INTERVENTIONS: Patients participated in a standardized inpatient exercise training program consisting of daily submaximal cycle ergometry, treadmill walking, weight training, and gymnastics during 8 weeks. MEASUREMENTS: Fat-free mass (FFM) was measured by bioelectrical impedance analysis. None of the patients met the criteria for nutritional supplementation (body mass index 相似文献