Critical view on diagnosing muscle wasting by single-frequency bio-electrical impedance in COPD

Malnutrition Screening Tools Are Not Sensitive Enough to Identify Older Hospital Patients with Malnutrition

This study evaluates the concurrent validity of five malnutrition screening tools to identify older hospitalized patients against the Global Leadership Initiative on Malnutrition (GLIM) diagnostic criteria as limited evidence is available. The screening tools Short Nutritional Assessment Questionnaire (SNAQ), Malnutrition Universal Screening Tool (MUST), Malnutrition Screening Tool (MST), Mini Nutritional Assessment-Short Form (MNA-SF), and the Patient-Generated Subjective Global Assessment-Short Form (PG-SGA-SF) with cut-offs for both malnutrition (conservative) and moderate malnutrition or risk of malnutrition (liberal) were used. The concurrent validity was determined by the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and the level of agreement by Cohen's kappa. In total, 356 patients were included in the analyses (median age 70 y (IQR 63-77); 54% male). The prevalence of malnutrition according to the GLIM criteria without prior screening was 42%. The conservative cut-offs showed a low-to-moderate sensitivity (32-68%) and moderate-to-high specificity (61-98%). The PPV and NPV ranged from 59 to 94% and 67-86%, respectively. The Cohen's kappa showed poor agreement (k = 0.21-0.59). The liberal cut-offs displayed a moderate-to-high sensitivity (66-89%) and a low-to-high specificity (46-95%). The agreement was fair to good (k = 0.33-0.75). The currently used screening tools vary in their capacity to identify hospitalized older patients with malnutrition. The screening process in the GLIM framework requires further consideration.

Multimodal prehabilitation in patients with non-small cell lung cancer undergoing anatomical resection: protocol of a non-randomised feasibility study

BACKGROUND

The preoperative period can be used to enhance a patient's functional capacity with multimodal prehabilitation and consequently improve and fasten postoperative recovery. Especially, non-small cell lung cancer (NSCLC) surgical patients may benefit from this intervention, since the affected and resected organ is an essential part of the cardiorespiratory fitness. Drafting a prehabilitation programme is challenging, since many disciplines are involved, and time between diagnosis of NSCLC and surgery is limited. We designed a multimodal prehabilitation programme prior to NSCLC surgery and aimed to conduct a study to assess feasibility and indicative evidence of efficacy of this programme. Publication of this protocol may help other healthcare facilities to implement such a programme.

METHODS

The multimodal prehabilitation programme consists of an exercise programme, nutritional support, psychological support, smoking cessation, patient empowerment and respiratory optimisation. In two Dutch teaching hospitals, 40 adult patients with proven or suspected NSCLC will be included. In a non-randomised fashion, 20 patients follow the multimodal prehabilitation programme, and 20 will be assessed in the control group, according to patient preference. Assessments will take place at four time points: baseline, the week before surgery, 6 weeks postoperatively and 3 months postoperatively. Feasibility and indicative evidence of efficacy of the prehabilitation programme will be assessed as primary outcomes.

DISCUSSION

Since the time between diagnosis of NSCLC and surgery is limited, it is a challenge to implement a prehabilitation programme. This study will assess whether this is feasible, and evidence of efficacy can be found. The non-randomised fashion of the study might result in a selection and confounding bias. However, the control group may help putting the results of the prehabilitation group in perspective. By publishing this protocol, we aim to facilitate others to evaluate and implement a multimodal prehabilitation programme for surgical NSCLC patients.

TRIAL REGISTRATION

The current study is registered as NL8080 in the Netherlands Trial Register on the 10th of October 2019, https://www.trialregister.nl/trial/8080 . Secondary identifiers: CCMO (Central Committee on Research Involving Human Subjects) number NL70578.015.19, reference number of the Medical Ethical Review Committee of Máxima MC W19.045.

Use of different reference values for handgrip strength in individuals with COPD: analysis of agreement, discriminative capacity, and main clinical implications

Objective: To identify reference values for handgrip strength through a literature search and compare the agreement of reference values from Brazil with others for handgrip strength in a sample of COPD patients in Brazil, as well as to determine which set of reference values is more discriminative regarding differences in clinical characteristics between individuals with low handgrip strength and normal handgrip strength. Methods: To identify reference values for handgrip strength, a literature search was performed; a retrospective cross-sectional analysis of baseline-only data from two unrelated studies was then performed. Individuals were evaluated for handgrip strength, peripheral muscle strength, respiratory muscle strength, pulmonary function, body composition, exercise capacity, dyspnea, and functional status. Results: Of the 45 studies that were initially selected, 9 met the criteria for inclusion in the analysis, which included 99 COPD patients in Brazil (52% of whom were male with GOLD stage II-IV COPD). The prevalence of low handgrip strength varied across studies (from 9% to 55%), the set of reference values for handgrip strength in a sample of individuals in Brazil having classified 9% of the study sample as having low handgrip strength. The level of agreement between the reference values for a sample of individuals in Brazil and the other sets of reference values varied from weak to excellent. The reference values for a sample of individuals in Brazil showed the highest number of significantly different characteristics between individuals with low and normal handgrip strength. Conclusions: The level of agreement between national and international sets of reference values for handgrip strength varied from weak to excellent in COPD patients in Brazil. Reference values for handgrip strength with higher discriminative capacity are not necessarily those that identify more individuals as having low handgrip strength.

Poor Nutritional Status and Dynapenia Are Highly Prevalent in Post-Acute COVID-19

Poor nutritional status is common (estimated prevalence 5–69%) in acute coronavirus disease-2019 (COVID-19), and has been associated with hospitalization, the need for intensive care, and mortality. Body composition (BC) and muscle function have also been related in such patients to poor disease outcomes.

As the evidence in the literature is limited, a cross-sectional study was carried out to determine the frequency of malnutrition in a cohort of post-acute COVID-19 patients referred to a rehabilitation center after hospital discharge. BC and muscle strength were assessed and the differences between bedridden and not bedridden patients were specifically evaluated.

The study sample was composed of 144 post-acute COVID-19 patients (mean age 64.8 years; males = 95), 37% of whom were bedridden (males = 60%). Nutritional status was evaluated with Mini-Nutritional Assessment (MNA) and Controlling Nutritional status (CONUT). Fat-free mass (FFM) and skeletal muscle mass (SM) were estimated using bioelectrical impedance analysis (BIA). Raw BIA variables (phase angle = PhA and impedance ratios = IRs) were also determined and handgrip strength (HGS) was measured. Dynapenia was identified according to the 2019 EWGSOP criteria.

According to MNA, 18% (n. 26) of patients were malnourished and 62% (n. 89) were at risk of malnutrition. As for CONUT, 21% (n. 31) of cases had moderate–severe malnutrition and 58% (n. 83) had light malnutrition. Abnormalities of raw BIA variables (low PhA and high IRs) and low HGS were more common in bedridden patients, in those who were malnourished, or had low FFM or SM. Dynapenic patients were 65% men and 47% women.

In conclusion, malnutrition, BC alterations, and low HGS occur in post-acute COVID-19 patients and are more common in bedridden patients. Further studies are needed to identify reliable algorithms for assessing nutritional status in post-acute COVID-19 patients undergoing rehabilitation.

Isolated Resistance Training Programs to Improve Peripheral Muscle Function in Outpatients with Chronic Obstructive Pulmonary Diseases: A Systematic Review

This systematic review aims to establish which isolated resistance training (RT) programs have been used in outpatients with chronic obstructive pulmonary disease (COPD) and their impact on all aspects of peripheral skeletal muscle function. Electronic databases were systematically searched up to June 2021. The eligibility criteria were: (1) randomized controlled trials investigating the effects of supervised and isolated RT programs in outpatients with COPD and (2) RT programs lasting 8-12 weeks, (3) including at least one outcome measure related to trainable muscle characteristics. Initially, 6576 studies were identified, whereas 15 trials met the inclusion criteria. All the included trials reported that isolated RT improved both upper and lower limbs' maximal strength. Muscle endurance and power also increased after RT but received less attention in the analysis. Furthermore, few studies assessed the effect of RT on muscle mass and cross-sectional area, reporting only limited improvement. Isolated RT programs carried out 2-3 days a week for 8-12 weeks improved skeletal muscle function in individuals with COPD. The RT program should be specifically focused to the trainable muscle characteristic to be improved. For this reason, we further encourage the introduction of a detailed assessment of muscle function and structure during the pulmonary rehabilitation practice.

Body composition parameters and functional status test in predicting future acute exacerbation risk among hospitalized patients with chronic obstructive pulmonary disease

BACKGROUND & AIMS

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. Nutritional and functional status derangement is a commonly seen in COPD patients, and this is associated with a higher disease severity and mortality. To assess body composition analysis - measured by segmental multi-frequency bioelectrical impedance analysis (BIA)- and functional status and investigate their relationship with the COPD acute exacerbation risk.

METHODS

Eighty COPD patients admitted to hospital for COPD acute exacerbation were prospectively followed-up for one year after discharge, focusing on a new incidence of COPD acute exacerbation. Following discharge, participants' body composition was assessed with the use of segmental multi-frequency BIA, whereas physical function by performing 5-repetitions and 30 s sit-to-stand (STS) tests. Unadjusted and multivariate logistic regression analyses were performed to evaluate the ability of the various measures to predict incidence of future COPD acute exacerbation in one-year period.

RESULTS

Seventy-six out of 80 participants completed the study and were analyzed. Fifty-one [24 male (47.1%)] out of 76 participants (67.1%), mean aged of 69.3 ± 8.9 years, developed at least one new COPD acute exacerbation during the one year follow-up. The probability of COPD acute exacerbation in one year was significantly related to BMI (OR = 0.75, 95% CI; 0.61-0.91, p = 0.004) and Fat Free Mass (OR = 0.88, 95% CI; 0.79-0.97, p = 0.012) after adjustment for sex, age and smoking index (pack × years). Both 5-repetitions and 30 s STS tests had a good predictive ability for the incidence of COPD acute exacerbation in one year (AUC = 0.80, 95% CI; 0.65-0.95, p = 0.009 and AUC = 0.83, 95% CI; 0.70-0.96, p = 0.004, respectively).

CONCLUSION

In an observational study among patients admitted with COPD acute exacerbation, body composition analysis parameters and functional status are related to acute exacerbation risk incidence.

Dynapenia is highly prevalent in older patients with advanced idiopathic pulmonary fibrosis

Body composition and muscle strength are emerging aspects in idiopathic pulmonary fibrosis (IPF) clinical assessment. We aimed to study the relationships of handgrip strength (HGS) with anthropometric variables, body composition, and disease staging, and to evaluate the prevalence of dynapenia in 102 clinically stable IPF patients (70 M; mean age: 69.4 years). Fat-free mass (FFM), skeletal muscle (SM) were estimated with bioimpedance analysis. HGS was measured with a digital handle dynamometer for both dominant and non-dominant body sides. Dynapenia was identified according to six recognized criteria sets. Mean body mass index (BMI) was 28.2 ± 4.7 kg/m², with a prevalence of overweight (BMI > 25 and < 30 kg/m²) and obesity (BMI ≥ 30 kg/m²) of 35% and 37%, respectively. FFM and SM were greater in males, whereas percentage body fat was higher in women. HGS was higher and declined with age slightly more rapidly in men, showing a stronger correlation with FFM and SM. Dynapenia prevalence ranged from 20.6 to 56.9%, depending on the criteria used, and was more frequent in older patients and advanced disease. Dynapenia is highly prevalent in IPF. HGS is a promising proxy marker of muscle function to be used in clinical evaluation and follow-up programs.

Effect of malnutrition and body composition on the quality of life of COPD patients

BACKGROUND

Pathological alterations in nutritional status may develop in Chronic Obstructive Pulmonary Disease (COPD) patients through production of inflammatory cytokines and inadequate diet.

OBJECTIVE

The aim of our study was to determine the correlation between nutritional status and quality of life of COPD patients.

METHODS

We evaluated the nutritional status of COPD patients of Hungarian National Koranyi Institute for Pulmonology using the Malnutrition Universal Screening Tool (MUST) and bioelectrical impedance analysis (BIA) between January 1 and June 1, 2019. Lung function, physical fitness, and respiratory muscle strength were included in the assessment.

RESULTS

Fifty patients (mean age was 66.3 ± 9.6 years) participated in our study. Mean body mass index (BMI) was 26.2 ± 6.1 kg/m2 and mean fat-free mass index (FFMI) was 16.8 ± 2.4 kg/m2. Overweight patients had better lung function values (FEV1ref%: 46.3 ± 15.2) than normal (FEV1ref%: 45.1 ± 20.9) and underweight patients (FEV1ref%: 43.8 ± 16.0). The Modified Medical Research Council Dyspnea Scale (mMRC) was significantly associated with various parameters; strongest correlation was found with FFMI (r = -0.537, P < 0.001), skeletal muscle mass index (SMMI) (r = -0.530, P < 0.001), and 6-minute walking distance (6MWD) (r = -0.481, P < 0.001).

CONCLUSIONS

Our results indicate that malnourished COPD patients may have reduced lung function and lower quality of life compared to normal weight patients. Thus, our findings suggest that nutritional therapy be included in the treatment of COPD patients combined with nutritional risk screening and BIA during the follow-up.

Towards Personalized Management of Sarcopenia in COPD

The awareness of the presence and consequences of sarcopenia has significantly increased over the past decade. Sarcopenia is defined as gradual loss of muscle mass and strength and ultimately loss of physical performance associated with aging and chronic disease. The prevalence of sarcopenia is higher in chronic obstructive pulmonary disease (COPD) compared to age-matched controls. Current literature suggests that next to physical inactivity, COPD-specific alterations in physiological processes contribute to accelerated development of sarcopenia. Sarcopenia in COPD can be assessed according to current guidelines, but during physical performance testing, ventilatory limitation should be considered. Treatment of muscle impairment can halt or even reverse sarcopenia, despite respiratory impairment. Exercise training and protein supplementation are currently at the basis of sarcopenia treatment. Furthermore, effective current and new interventions targeting the pulmonary system (eg, smoking cessation, bronchodilators and lung volume reduction surgery) may also facilitate muscle maintenance. Better understanding of disease-specific pathophysiological mechanisms involved in the accelerated development of sarcopenia in COPD will provide new leads to refine nutritional, exercise and physical activity interventions and develop pharmacological co-interventions.

Are there differences in muscular activation to maintain balance between individuals with chronic obstructive pulmonary disease and controls?

BACKGROUND

The mechanisms underlying impaired balance in chronic obstructive pulmonary disease (COPD) are poorly understood, which makes it difficult to choose the best therapeutic approaches. Therefore, this study aimed to investigate patterns of muscular activation to maintain balance and its determinants in this population.

METHODS

Thirty-three subjects with COPD and 33 controls were assessed by a force platform in four tasks: standing with eyes opened (FHEO) and closed (FHEC); standing on unstable surface (SUS) and one-legged stance (OLS). Electromyographic activity of lower limb, trunk and neck muscles was concomitantly recorded. To asses functional balance, Brief-balance evaluation systems and timed up & go (TUG) tests were applied. Lung function, exercise capacity and muscle force were also assessed.

RESULTS

Subjects with COPD presented worse balance and higher scalene activation than controls in OLS (mean difference 23.0 [95%CI 1.7-44.3] _%Δ μV_RMS; P = 0.034), besides presenting also higher activation of gluteus medius during FHEC task (mean difference 1.5 [95%CI 0.2-2.8] _%Δ μV_RMS; P = 0.023) and taking longer to complete the TUG (mean difference 0.6 [95%CI 0.1-1.2] seconds; P = 0.042). Exercise capacity and peripheral muscle force were determinants of functional balance (r² = 0.505), whereas age (OR = 1.24; 95%CI 1.02-1.52) and total lung capacity (OR = 2.42; 95%CI 1.05-5.56) were determinants of static balance.

CONCLUSION

Individuals with COPD have worse static and functional balance in comparison with controls, besides presenting higher activation of scalene and gluteus medius during static balance tasks. Exercise capacity and peripheral muscle force emerged as determinants of functional balance, whereas age and lung hyperinflation contributed to poor static balance.

Tossing and turning: association of sleep quantity-quality with physical activity in COPD

The association between characteristics of sleep and physical activity in daily life (PADL) has not yet been investigated in depth in subjects with COPD. This study evaluated whether time spent per day in physical activity (PA) and sedentary behaviour are associated with sleep quantity and quality in this population. Sleep and PADL were objectively assessed by an activity monitor for 7 days and analysed on a minute-by-minute basis. Subjects also underwent spirometry and 6-min walking test (6MWT). Fifty-five subjects with moderate-to-severe COPD (28 male, 67±8 years) were studied. Subjects with total time in bed (TIB) per night ≥9 h had higher wake-after-sleep onset than TIB 7-9 h and TIB ≤7 h (195 (147-218) versus 117 (75-167) and 106 (84-156) min) and more fragmented sleep than TIB ≤7 h (8.2 (6.7-14.3) versus 6.3 (5.6-6.9) sleeping bouts; p<0.05 for all). Subjects with TIB ≥9 h also spent more time per day in sedentary behaviour and less time per day in PA of light and moderate-to-vigorous intensity than those with TIB 7-9 h and ≤7 h. In multiple linear regression, TIB ≥9 h was the only significant predictor of physical inactivity (β=-3.3 (-5.1, -1.6), p≤0.0001), accounting for 20% of its variation. Sleep fragmentation was frequent and more pronounced in physically inactive than active patients (7.5 (6.3-9.6) versus 6.4 (5.5-7.3) sleeping bouts; p=0.027). In summary, subjects with COPD with TIB ≥9 h·night-1 have more fragmented sleep, are more sedentary and less physically active than those with <9 h·night-1, independently of the awake time. Sleep quality is frequently poor and even worse in patients classified as physically inactive.

The associations of body mass index, bioimpedance spectroscopy-based calf intracellular resistance, single-frequency bioimpedance analysis and physical performance of older people

BACKGROUND

Bioimpedance skeletal muscle indices (SMI) are used as a surrogate for skeletal muscle mass, but their associations with physical functioning and obesity need further evaluation.

AIMS

To compare the associations of body mass index (BMI), bioimpedance spectroscopy-based calf intracellular resistance (Cri-SMI), and single-frequency bioimpedance analysis (SF-SMI) indices with physical performance and the functioning of community-dwelling older people at risk of or already suffering from sarcopenia.

METHODS

Pre-intervention measurements of the screened subjects and the participants of the Porvoo sarcopenia trial (N = 428) were taken. Cri-SMI, whole-body SF-SMI, and BMI were related to hand-grip strength, walking speed, short physical performance battery (SPPB), and the physical component of the RAND-36.

RESULTS

Among the older people (aged 75-96), Cri-SMI correlated inversely with age (men r = - 0.113, p < 0.001; women r = - 0.287, p < 0.001), but positively with SPPB (r = 0.241, p < 0.001) and the physical component of the RAND-36 (r = 0.114, p = 0.024), whereas BMI was inversely associated with SPPB (r = - 0.133, p < 0.001) and RAND-36 (r = - 0.286, p < 0.001). After controlling for age, gender, and comorbidity, one unit of Cri-SMI (cm²/Ω) was associated with a 3.3-fold probability of good physical performance (SPPB ≥ 9 points, OR = 3.28, p < 0.001) and one unit of BMI (kg/m²) decreased the respective probability 4% (OR= 0.96, p = 0.065). Physical inactivity partly explained the negative association of BMI. When Cri-SMI and BMI were controlled for, a 1% difference in Cri-SMI was associated with a 0.7% (p < 0.001) higher probability of good performance, the respective figure being - 2.2% (p = 0.004) for BMI. The associations of SF-SMI with physical functioning indices were insignificant.

CONCLUSIONS

Independent of each other, Cri-SMI was positively and BMI was inversely associated with the physical performance and functioning of community-dwelling older people who were at risk of or already suffering from sarcopenia. We found no association between SF-SMI and physical functioning.

Coexistence of malnutrition, frailty, physical frailty and disability in patients with COPD starting a pulmonary rehabilitation program

BACKGROUND & AIMS

Malnutrition, frailty, physical frailty, and disability are common conditions in patients with chronic obstructive pulmonary disease (COPD). Insight in the coexistence and relations between these conditions may provide information on the nature of the relationship between malnutrition and frailty. Such information may help to identify required interventions to improve the patient's health status. We therefore aimed to explore whether malnutrition, frailty, physical frailty, and disability coexist in patients with COPD at the start of pulmonary rehabilitation.

METHODS

For this cross-sectional study, from March 2015 to May 2017, patients with COPD were assessed at the start of a pulmonary rehabilitation program. Nutritional status was assessed with the Scored Patient-Generated Subjective Global Assessment (PG-SGA) based Pt-Global app. Frailty was assessed by the Evaluative Frailty Index for Physical activity (EFIP), physical frailty by Fried's criteria, and disability by the Dutch version of World Health Organization Disability Assessment Schedule 2.0 (WHODAS). These variables were dichotomized to determine coexistence of malnutrition, frailty, physical frailty, and disability. Associations between PG-SGA score and respectively EFIP score, Fried's criteria, and WHODAS score were analyzed by Pearson's correlation coefficient. Two tailed P-values were used, and significance was set at P < 0.05.

RESULTS

Of the 57 participants included (age 61.2 ± 8.7 years), malnutrition and frailty coexisted in 40%. Malnutrition and physical frailty coexisted in 18%, and malnutrition and disability in 21%. EFIP score and PG-SGA score were significantly correlated (r = 0.43, P = 0.001), as well as Fried's criteria and PG-SGA score (r = 0.37, P = 0.005).

CONCLUSIONS

In this population, malnutrition substantially (40%) coexists with frailty. Although the prevalence of each of the four conditions is quite high, the coexistence of all four conditions is limited (11%). The results of our study indicate that nutritional interventions should be delivered by health care professionals across multiple disciplines.

Sarcopenia in COPD: a systematic review and meta-analysis

COPD is associated with a progressive loss of muscle mass and function. However, there is an unmet need to define and standardise methods to estimate the prevalence of sarcopenia in COPD patients.

We performed a systematic review and meta-analysis of the prevalence of this extrapulmonary manifestation in COPD patients. We searched Embase, Medline (Ovid), CINAHL (EBSCO), Web of Science, Scopus and Google Scholar for studies published up to January 17, 2019, assessing sarcopenia in COPD patients based on low muscle mass and decreased muscle function. Interventional studies, in vitro experiments, protocols or reviews and meta-analyses were excluded. We estimated heterogeneity (I²) and assessed significance (Q) using a Chi-squared test for estimates obtained from random-effects models.

4465 articles were initially identified. After removing the duplicates and applying the selection criteria, we reviewed 62 full-text articles. Finally, 10 articles (n=2565 COPD patients) were included in this systematic review and meta-analyses. Overall, the prevalence of sarcopenia in patients with COPD was 21.6% (95% CI 14.6–30.9%, I²=94%), ranging from 8% in population-based to 21% in clinic-based studies, and 63% in COPD patients residing in nursing homes.

Sarcopenia is frequently observed in COPD patients, with varying prevalence across population settings. Sarcopenia in COPD should be assessed using standardised tests and cut-off points from sarcopenia consensus criteria for clinical practice and international comparisons.

We confirmed a high prevalence of sarcopenia in COPD patients, with varying prevalence across population settings. We recommend adhering to the sarcopenia consensus criteria to systematically evaluate the muscle health of COPD patients.http://bit.ly/2KA6weh

The added value of ultrasound muscle measurements in patients with COPD: An exploratory study

BACKGROUND AND AIMS

Malnutrition and sarcopenia are common nutrition (-related) disorders in patients with COPD and are associated with negative health outcomes and mortality. This study aims to correlate ultrasound measured rectus femoris size with fat-free mass and muscle function in patients with COPD.

METHODS

Patients with COPD, at the start of a pulmonary rehabilitation program, were asked to participate in this study. Rectus femoris (RF) size (thickness in cm, cross-sectional area [CSA] in cm²) was determined by ultrasound. Fat-free mass index (FFMI in kg/m²) was estimated with bioelectrical impedance analyses, using a disease-specific equation. Handgrip strength (HGS) was measured in kilograms and the five times sit to stand test (in seconds, higher scores indicating decreased strength) was performed to assess leg muscle power. The Incremental Shuttle Walk Test (ISWT, in m) was used to assess maximal exercise capacity.

RESULTS

In total, 44 patients with COPD (mean age 59.8 ± 8.6 years, 43% male, median FEV1%pred 37 [IQR = 23-52]) were included. Greater RF-CSA and thickness were associated with higher FFMI (r = 0.57, p < 0.001; r = 0.53, p = 0.003, respectively) and HGS (CSA r = 0.58, p < 0.001, thickness r = 0.48, p = 0.009). No significant correlations between RF-thickness, CSA, and leg muscle power were found (r = -0.33, p = 0.091; r = -0.35, p = 0.073, respectively). Furthermore, no correlation between RF size and maximal exercise capacity was observed (thickness r = 0.21, p = 0.297, CSA r = 0.22, p = 0.274).

CONCLUSIONS

This exploratory study shows that in patients with COPD, rectus femoris size is moderately correlated with FFMI and HGS. Future studies should focus on the role of ultrasound in evaluating nutritional status.

Ultrasound assessment of rectus femoris muscle in rehabilitation patients with chronic obstructive pulmonary disease screened for sarcopenia: correlation of muscle size with quadriceps strength and fat-free mass

PURPOSE

To determine the relationship of the size of the rectus femoris muscle, assessed by ultrasonography, with parameters of muscle strength and body composition that are commonly used in the case-finding of sarcopenia in rehabilitation patients with chronic obstructive pulmonary disease (COPD).

METHODS

Cross-sectional pilot study of 18 men with severe COPD and 17 healthy controls.

MAIN OUTCOME VARIABLES

cross-sectional area, thickness, and width of the non-dominant rectus femoris muscle obtained by ultrasound, muscle strength determined by voluntary maximum isometric contraction of the quadriceps muscle, and fat-free mass assessed by bioimpedance analysis.

RESULTS

Ultrasounds detected differences in the size of the rectus femoris muscle: cross-sectional area was 4.3 (SD 1.05) cm² in patients, compared to 5.6 (SD 1.25) cm² in controls; patients also presented lower quadriceps strength, and fat-free mass index. Cross-sectional area of the rectus femoris muscle showed a moderate correlation with quadriceps strength (R = 0.497, p = 0.036) and fat-free mass (R = 0.584, p = 0.011). In a multivariate linear model adjusted for age, body mass index, fat-free mass and muscle size, muscle strength was 7.44 kg lower (p value = 0.014) in patients, compared to controls.

CONCLUSIONS

A causal relationship was observed between the cross-sectional area of the rectus femoris muscle, assessed with ultrasonography, and maximum isometric strength of knee extension in COPD rehabilitation patients. Reduced cross-sectional area was also associated with loss of fat-free mass. Muscle ultrasound and bioimpedance analysis provide complementary and relevant information that could be useful in the case-finding of sarcopenia in COPD patients.

Validation of a bioelectrical impedance analysis system for body composition assessment in patients with COPD

OBJECTIVE

To investigate the validity of an eight-contact electrode bioelectrical impedance analysis (BIA) system within a household scale for assessing whole body composition in COPD patients.

METHODS

Seventeen patients with COPD (mean age = 67 ± 8 years; mean FEV1 = 38.6 ± 16.1% of predicted; and mean body mass index = 24.7 ± 5.4 kg/m2) underwent dual-energy X-ray absorptiometry (DEXA) and an eight-contact electrode BIA system for body composition assessment.

RESULTS

There was a strong inter-method correlation for fat mass (r = 0.95), fat-free mass (r = 0.93), and lean mass (r = 0.93), but the correlation was moderate for bone mineral content (r = 0.73; p < 0.01 for all). In the agreement analysis, the values between DEXA and the BIA system differed by only 0.15 kg (-6.39 to 6.70 kg), 0.26 kg (-5.96 to 6.49 kg), -0.13 kg (-0.76 to 0.50 kg), and -0.55 kg (-6.71 to 5.61 kg) for fat-free mass, lean mass, bone mineral content, and fat mass, respectively.

CONCLUSIONS

The eight-contact electrode BIA system showed to be a valid tool in the assessment of whole body composition in our sample of patients with COPD.

Chest computed tomography-derived low fat-free mass index and mortality in COPD

Low fat-free mass index (FFMI) is an independent risk factor for mortality in chronic obstructive pulmonary disease (COPD) not typically measured during routine care. In the present study, we aimed to derive fat-free mass from the pectoralis muscle area (FFM_PMA) and assess whether low FFMI_PMA is associated with all-cause mortality in COPD cases. We used data from two independent COPD cohorts, ECLIPSE and COPDGene.Two equal sized groups of COPD cases (n=759) from the ECLIPSE study were used to derive and validate an equation to calculate the FFM_PMA measured using bioelectrical impedance from PMA. We then applied the equation in COPD cases (n=3121) from the COPDGene cohort, and assessed survival. Low FFMI_PMA was defined, using the Schols classification (FFMI <16 in men, FFMI <15 in women) and the fifth percentile normative values of FFMI from the UK Biobank.The final regression model included PMA, weight, sex and height, and had an adjusted R² of 0.92 with fat-free mass (FFM) as the outcome. In the test group, the correlation between FFM_PMA and FFM remained high (Pearson correlation=0.97). In COPDGene, COPD cases with a low FFMI_PMA had an increased risk of death (HR 1.6, p<0.001).We demonstrated COPD cases with a low FFMI_PMA have an increased risk of death.

Fat-free mass depletion in patients with COPD in Brazil: development of a new cutoff point and its relation with mortality and extrapulmonary manifestations

BACKGROUND/OBJECTIVES

None of the cutoff points for fat-free mass index (FFMI) were tested for the Brazilian population, and it is unknown whether the available ones are able to discriminate extrapulmonary disease manifestations. This cross-sectional study aims to develop and validate a cutoff point for FFM depletion based on Brazilian patients with chronic obstructive pulmonary disease (COPD) and to verify its association and of previously published cutoffs with extrapulmonary manifestations.

SUBJECTS/METHODS

A new cutoff point was obtained from the best FFMI value for discrimination of preserved exercise capacity in a sample of patients (n=57). The discriminative capacity was assessed in another sample (n=96). The new cutoff point and other previously published ones were tested to discriminate low exercise capacity, physical inactivity, sedentary lifestyle and low quality of life. A receiver operation characteristics curve with area under the curve (AUC) value was plotted and each cutoff points' discriminative capacity was calculated. Cox regression and Kaplan-Meier method assessed the association between the cutoff points and mortality.

RESULTS

The new cutoff points for FFMI were 14.65 kg/m² for women (AUC=0.744; sensitivity (Se)=0.88; specificity (Sp)=0.60) and 20.35 kg/m² for men (AUC=0.565; Se=0.36; Sp=0.81). The new cutoffs were the best to discriminate poor exercise capacity assessed by walked distance in % predicted and quality of life. Only the new cutoff point was associated with mortality (HR=2.123; 95% CI: 1.03-4.33, P=0.039, log rank P=0.035).

CONCLUSIONS

Only the new cutoff point was associated with all-cause mortality, and it had the highest discriminating capacity for exercise capacity and quality of life in Brazilian patients with COPD.

The role of DXA in sarcopenia

Sarcopenia is a condition characterized by progressive and generalized reduction in skeletal muscle mass and muscle strength, associated with an increased risk of adverse outcomes (disability, hospitalization, death). The growing attention in the last years, aiming to establish a consensus definition and treatment, reflects the interest of the scientific community toward this complex condition, which has many implications in clinical practice and public health. Dual-energy X-ray absorptiometry (DXA) is the gold-standard technique in the analysis of body composition at molecular level, providing assessment and quantification of fat mass, lean mass and bone mineral content, both in a single body region of interest and at whole-body level. In particular, through the assessment of non-bone lean mass parameters, such as appendicular lean mass adjusted for BMI or height (ALM/BMI and ALM/ht², respectively), it is possible to discriminate subjects with "physiological" loss of muscle mass from those with "pathological" impoverishment of this compartment, referring to specific cutoff values validated in the literature, but keeping in mind the lack of standardization of DXA measures. In addition, it is useful in treatment planning, estimating resting energy expenditure, and in follow-up, because it allows quantifying with high reproducibility the modifications in BC, distinguishing when the change is biological (deterioration due to a progression of the disease or improvement due to treatment). Due to DXA favorability in terms of accuracy, simplicity, availability, low cost and low radiation exposure, its role in sarcopenia diagnosis is becoming increasingly important, emerging as reference assessment technique in muscle mass evaluation.

Clinical management of chronic obstructive pulmonary disease patients with muscle dysfunction

Muscle dysfunction is frequently observed in chronic obstructive pulmonary disease (COPD) patients, contributing to their exercise limitation and a worsening prognosis. The main factor leading to limb muscle dysfunction is deconditioning, whereas respiratory muscle dysfunction is mostly the result of pulmonary hyperinflation. However, both limb and respiratory muscles are also influenced by other negative factors, including smoking, systemic inflammation, nutritional abnormalities, exacerbations and some drugs. Limb muscle weakness is generally diagnosed through voluntary isometric maneuvers such as handgrip or quadriceps muscle contraction (dynamometry); while respiratory muscle loss of strength is usually recognized through a decrease in maximal static pressures measured at the mouth. Both types of measurements have validated reference values. Respiratory muscle strength can also be evaluated determining esophageal, gastric and transdiaphragmatic maximal pressures although there is a lack of widely accepted reference equations. Non-volitional maneuvers, obtained through electrical or magnetic stimulation, can be employed in patients unable to cooperate. Muscle endurance can also be assessed, generally using repeated submaximal maneuvers until exhaustion, but no validated reference values are available yet. The treatment of muscle dysfunction is multidimensional and includes improvement in lifestyle habits (smoking abstinence, healthy diet and a good level of physical activity, preferably outside), nutritional measures (diet supplements and occasionally, anabolic drugs), and different modalities of general and muscle training.

Evaluation of body composition in COPD patients using multifrequency bioelectrical impedance analysis

Background

Multifrequency bioelectrical impedance analysis (MF-BIA) is a technique that measures body impedance (Z) at different frequencies (5, 10, 50, 100, and 250 kHz). Body composition may be estimated using empirical equations, which include BIA variables or, alternatively, raw BIA data may provide direct information on water distribution and muscle quality.

Objectives

To compare raw MF-BIA data between COPD patients and controls and to study their relationship with respiratory and functional parameters in COPD patients.

Methods

MF-BIA was performed (Human Im-Touch analyzer) in 212 COPD patients and 115 age- and BMI-matched controls. Fat-free mass (FFM) and fat mass were estimated from BIA data, and low- to high-frequency (5 kHz/250 kHz) impedance ratio was calculated. Physical fitness, lung function and respiratory muscle strength were also assessed in COPD patients.

Results

After adjusting for age, weight, and body mass index, FFM and the 5/250 impedance ratio were lower in COPD patients (P<0.001) and were negatively affected by disease severity. In both male and female patients, the 5/250 impedance ratio was significantly correlated mainly with age (r=−0.316 and r=−0.346, respectively). Patients with a 5/250 impedance ratio below median value had lower handgrip strength (P<0.001), 6-minute walk distance (P<0.005), respiratory muscle strength (P<0.005), forced expiratory volume in 1 second (P<0.05) and vital capacity (P<0.005). Finally, the 5/250 impedance ratio was reduced (P<0.05) in patients with Global Initiative for Chronic Obstructive Lung Disease (GOLD) III and IV (compared to those with GOLD I and II) or a BODE index between 6 and 10 points (compared to those with BODE index between 1 and 5 points).

Conclusion

MF-BIA may be a useful tool for assessing body composition and nutritional status in COPD patients. In particular, the impedance ratio could give valuable information on cellular integrity and muscle quality.

Why and How Limb Muscle Mass and Function Should Be Measured in Patients with Chronic Obstructive Pulmonary Disease

Impaired limb muscle function is a common occurrence in patients with chronic obstructive pulmonary disease (COPD), and it negatively influences exercise tolerance, quality of life, and even survival. Assessment of limb muscle mass and function in COPD is highly encouraged; it should include the quadriceps muscle, but other lower and upper limb muscles may also be evaluated to provide valuable information. Quantification of muscle mass as well as assessment of muscle strength and endurance are suggested. Bioelectrical impedance and dual-energy X-ray absorption can be realistically used in the clinical environment to monitor body composition. Although sophisticated computerized dynamometers provide the most accurate assessment, simple exercise and testing equipment are valid alternatives and they should help in implementing limb muscle function assessment in clinical settings. Isometric measurements, using strain-gauges or hand-held dynamometers, should be favored for their simplicity, availability, and quality of information provided. This perspective provides a rationale for the evaluation of limb muscle mass and function in COPD in routine clinical practice. In addition, measurement techniques used to assess limb muscle mass, strength, endurance, and fatigue in various clinical settings are discussed.

Health Status and Morbidities in Resident Relatives of Patients With COPD

OBJECTIVES

Resident relatives of patients with chronic obstructive pulmonary disease (COPD) may play a major role in obtaining a healthy lifestyle for patients. Little is known about resident relatives. This study aimed to compare health status, morbidities, care dependency, and mobility between patients with COPD and their resident relatives.

DESIGN

Cross-sectional study.

PARTICIPANTS

Stable patients with moderate to very severe COPD (n = 194) and their resident relatives (n = 194) were visited in their home environment.

MEASUREMENTS

Post-bronchodilator spirometry was assessed and generic health status was measured using the EuroQol-5 Dimensions and the Assessment of Quality of Life with 8 dimensions. Care dependency was measured using the Care Dependency Scale. Mobility was measured using the Timed "Up and Go" test (TUG). Morbidities (COPD, hypertension, anxiety and depression, obesity, and muscle wasting) were determined using accepted disease cutoff points and/or receiving specific treatment.

RESULTS

Age (patients: 66.0 [8.7], resident relatives: 64.8 [9.7]) and gender (male patients: 53%, male resident relatives: 45%) were comparable. Patients had worse generic health status, higher level of care dependency, and worse mobility. 29% of the resident relatives had airflow limitation based on the Tiffeneau index and 19% based on the lower limit of normal, 33% were current smokers, and 92% had at least one chronic condition. Resident relatives more frequently had hypertension (46% versus 69%).

CONCLUSION

Resident relatives of patients with COPD are often current smokers and often have undiagnosed morbidities. Although their health status is better compared with patients, their disease management and health behavior should also be considered when advising patients in obtaining a healthier lifestyle and also when involving them as informal caregivers.

Disease Progression and Changes in Physical Activity in Patients with Chronic Obstructive Pulmonary Disease

RATIONALE

Little is known about the role of physical activity in the course of chronic obstructive pulmonary disease (COPD).

OBJECTIVES

To assess changes in physical activity in COPD in relation to severity stages and changes in other disease components, and to evaluate the longitudinal association between sustained physical inactivity and disease progression.

METHODS

In this prospective cohort study, we measured physical activity (multisensory armband), airflow obstruction (FEV1), health status (St. George's Respiratory Questionnaire), exercise capacity (6-min-walk distance [6MWD]), muscle mass (fat-free mass [FFM]), and systemic inflammation (fibrinogen and high-sensitivity C-reactive protein) over a 3-year period in 137 patients with COPD and 26 with chronic bronchitis (normal spirometry).

MEASUREMENTS AND MAIN RESULTS

Independent of baseline disease severity, steps per day, total daily energy expenditure, and (daily) physical activity level (PAL) decreased by 393, 76 kcal, and 0.04 per year, respectively. The decline in PAL was significantly associated with a decline in FEV1 and an increase in St. George's Respiratory Questionnaire total score. Changes in 6MWD, FFM, and inflammatory markers were not associated with changes in PAL. Independent of FEV1, sustained physical inactivity (i.e., PAL(T0andT1)  < 1.40) was related to a greater decline in 6MWD and FFM compared with that in patients with some level of activity (i.e., PAL(T0and/orT1) ≥ 1.40; difference, 17 m/yr and 0.87 kg/yr, respectively).

CONCLUSIONS

Over time, physical activity substantially decreases across all severity stages of COPD, and this decline is paralleled by a worsening of lung function and health status. Sustained physical inactivity is associated with a progression of exercise intolerance and muscle depletion.

Impact of cardiovascular comorbidities on COPD Assessment Test (CAT) and its responsiveness to pulmonary rehabilitation in patients with moderate to very severe COPD: protocol of the Chance study

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality. Patients with COPD are characterised by a reduced health status, which can be easily assessed by the COPD Assessment Test (CAT). Previous studies show that health status can be worsened by the presence of comorbidities. However, the impact of cardiovascular comorbidities on health status as assessed with CAT is not sufficiently investigated. Therefore, the current study has the following objectives: (1) to study the clinical, (patho)physiological and psychosocial determinants of the CAT, and impact of previously established and/or newly diagnosed cardiovascular comorbidities on health status in tertiary care patients with COPD; (2) to assess the effects of pulmonary rehabilitation on CAT scores in patients with COPD; (3) to develop reference values for the CAT in Dutch elderly patients without COPD; and (4) to validate the CAT in a broad sample of Dutch patients with COPD.

METHODS AND ANALYSIS

The COPD, Health status and Comorbidities (Chance) study is a monocentre study consisting of an observational cross-sectional part and a longitudinal part. Demographic and clinical characteristics will be assessed in primary care, secondary care and tertiary care patients with COPD, and in patients without COPD. To assess health status, the CAT, Clinical COPD Questionnaire (CCQ) and St George's Respiratory Questionnaire (SGRQ) will be used. The longitudinal part consists of a comprehensive pulmonary rehabilitation programme in 500 tertiary care patients. For the cross-sectional part of the study, 150 patients without COPD, 100 primary care patients and 100 secondary care patients will be assessed during a single home visit.

ETHICS AND DISSEMINATION

The Medical Ethical Committee of the Maastricht University Medical Centre+ (MUMC+), Maastricht, the Netherlands (METC 11-3-070), has approved this study. The study has been registered at the Dutch Trial Register (NTR 3416).

Bioelectrical impedance phase angle relates to function, disease severity and prognosis in stable chronic obstructive pulmonary disease

BACKGROUND & AIMS

Bioelectrical impedance analysis (BIA) provides a simple method to assess changes in body composition. Raw BIA variables such as phase angle provide direct information on cellular mass and integrity, without the assumptions inherent in estimating body compartments, e.g. fat-free mass (FFM). Phase angle is a strong functional and prognostic marker in many disease states, but data in COPD are lacking. Our aims were to describe the measurement of phase angle in patients with stable COPD and determine the construct and discriminate validity of phase angle by assessing its relationship with established markers of function, disease severity and prognosis.

METHODS

502 outpatients with stable COPD were studied. Phase angle and FFM by BIA, quadriceps strength (QMVC), 4-m gait speed (4MGS), 5 sit-to-stand time (5STS), incremental shuttle walk (ISW), and composite prognostic indices (ADO, iBODE) were measured. Patients were stratified into normal and low phase angle and FFM index.

RESULTS

Phase angle correlated positively with FFM and functional outcomes (r = 0.35-0.66, p < 0.001) and negatively with prognostic indices (r = -0.35 to -0.48, p < 0.001). In regression models, phase angle was independently associated with ISW, ADO and iBODE whereas FFM was removed. One hundred and seventy patients (33.9% [95% CI, 29.9-38.1]) had a low phase angle. Phenotypic characteristics included lower QMVC, ISW, and 4MGS, higher 5STS, ADO and iBODE scores, and more exacerbations and hospital days in past year. The proportion of patients to have died was significantly higher in patients with low phase angle compared to those with normal phase angle (8.2% versus 3.6%, p = 0.02).

CONCLUSION

Phase angle relates to markers of function, disease severity and prognosis in patients with COPD. As a directly measured variable, phase angle offers more useful information than fat-free mass indices.

An observational, longitudinal study on the home environment of people with chronic obstructive pulmonary disease: the research protocol of the Home Sweet Home study

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) represents an important public health challenge. Patients are confronted with limitations during activities of daily living (ADLs). Resident loved ones of patients with COPD may be uniquely positioned to witness these limitations. COPD may have an impact on not only the patients' life, but also on the lives of the resident loved ones. Furthermore, COPD exacerbation-related hospital admissions often occur in patients with COPD. However, whether and to what extent these admissions influence resident loved ones' burden and health status remains currently unknown. Therefore, the primary objectives of this study are to investigate the differences between patients with COPD and resident loved ones' perceptions of patients' health status and problematic ADLs and to study prospectively the effects of a COPD exacerbation on resident loved ones' perceptions of patients' health status and problematic ADLs.

METHODS AND ANALYSIS

An observational, longitudinal study will be performed in 192 patients with COPD and their 192 resident loved ones. Primary outcomes are daily functioning, ADL, disease-specific health status, generic health status and dyspnoea. These will be assessed during home visits at baseline and after 12 months. Additional home visits will be performed when a COPD exacerbation-related hospital admission occurs during the 12-month follow-up period.

ETHICS AND DISSEMINATION

This protocol was approved by the Medical Ethics Committee of the Catharina Hospital Eindhoven, the Netherlands (NL42721.060.12/M12-1280) and is registered in the Dutch Trial Register (NTR3941).

Growing healthy muscles to optimise metabolic health into adult life

The importance of skeletal muscle for metabolic health and obesity prevention is gradually gaining recognition. As a result, interventions are being developed to increase or maintain muscle mass and metabolic function in adult and elderly populations. These interventions include exercise, hormonal and nutritional therapies. Nonetheless, growing evidence suggests that maternal malnutrition and obesity during pregnancy and lactation impede skeletal muscle development and growth in the offspring, with long-term functional consequences lasting into adult life. Here we review the role of skeletal muscle in health and obesity, providing an insight into how this tissue develops and discuss evidence that maternal obesity affects its development, growth and function into adult life. Such evidence warrants the need to develop early life interventions to optimise skeletal muscle development and growth in the offspring and thereby maximise metabolic health into adult life.

An official American Thoracic Society/European Respiratory Society statement: update on limb muscle dysfunction in chronic obstructive pulmonary disease

BACKGROUND

Limb muscle dysfunction is prevalent in chronic obstructive pulmonary disease (COPD) and it has important clinical implications, such as reduced exercise tolerance, quality of life, and even survival. Since the previous American Thoracic Society/European Respiratory Society (ATS/ERS) statement on limb muscle dysfunction, important progress has been made on the characterization of this problem and on our understanding of its pathophysiology and clinical implications.

PURPOSE

The purpose of this document is to update the 1999 ATS/ERS statement on limb muscle dysfunction in COPD.

METHODS

An interdisciplinary committee of experts from the ATS and ERS Pulmonary Rehabilitation and Clinical Problems assemblies determined that the scope of this document should be limited to limb muscles. Committee members conducted focused reviews of the literature on several topics. A librarian also performed a literature search. An ATS methodologist provided advice to the committee, ensuring that the methodological approach was consistent with ATS standards.

RESULTS

We identified important advances in our understanding of the extent and nature of the structural alterations in limb muscles in patients with COPD. Since the last update, landmark studies were published on the mechanisms of development of limb muscle dysfunction in COPD and on the treatment of this condition. We now have a better understanding of the clinical implications of limb muscle dysfunction. Although exercise training is the most potent intervention to address this condition, other therapies, such as neuromuscular electrical stimulation, are emerging. Assessment of limb muscle function can identify patients who are at increased risk of poor clinical outcomes, such as exercise intolerance and premature mortality.

CONCLUSIONS

Limb muscle dysfunction is a key systemic consequence of COPD. However, there are still important gaps in our knowledge about the mechanisms of development of this problem. Strategies for early detection and specific treatments for this condition are also needed.

Disturbed intestinal integrity in patients with COPD: effects of activities of daily living

BACKGROUND

COPD is accepted to be a multicomponent disease with various comorbidities. To our knowledge, the contribution of the GI tract to the systemic manifestation of COPD has never been investigated. This metabolically active organ may experience recurring local oxygen deficits during daily life, leading to disturbed intestinal integrity in patients with COPD.

METHODS

Eighteen patients with moderate COPD (mean FEV₁, 55 ± 3% predicted) and 14 matched healthy control subjects were tested on two occasions: a baseline measurement at rest and, on another day, during the performance of activities of daily living (ADLs). To assess enterocyte damage, plasma intestinal fatty acid binding protein (IFABP) levels were determined, whereas urinary excretion of orally ingested sugar probes was measured using liquid chromatography and mass spectrometry to assess GI permeability.

RESULTS

Plasma IFABP concentrations were not different between patients with COPD and healthy control subjects at rest. In contrast, 0- to 3-h urinary lactulose to rhamnose and sucralose to erythritol ratios and 5- to 24-h urinary sucralose to erythritol ratios were significantly higher in patients with COPD compared with control subjects, indicating increased permeability of the small intestine and colon. Furthermore, the performance of ADLs led to significantly increased plasma IFABP concentrations in patients with COPD but not in control subjects. Similarly, the intestinal permeability difference between patients and control subjects was intensified.

CONCLUSIONS

Besides an altered intestinal permeability in patients with COPD when at rest, performing ADLs led to enterocyte damage in addition to intestinal hyperpermeability in patients with COPD but not in control subjects, indicating functional alteration in the GI tract. Hence, intestinal compromise should be considered as a new component of the multisystem disorder COPD.

TRIAL REGISTRY

ISRCTN Register; No.: ISRCTN33686980; URL: www.controlled-trials.com.

The Official Positions of the International Society for Clinical Densitometry: body composition analysis reporting

Dual-energy x-ray absorptiometry (DXA) measurements of body composition increasingly are used in the evaluation of clinical disorders, but there has been little guidance on how to effectively report these measures. Uniformity in reporting of body composition measures will aid in the diagnosis of clinical disorders such as obesity, sarcopenia, and lipodystrophy. At the 2013 International Society for Clinical Densitometry Position Development Conference on body composition, the reporting section recommended that all DXA body composition reports should contain parameters of body mass index, bone mineral density, BMC, total mass, total lean mass, total fat mass, and percent fat mass. The inclusion of additional measures of adiposity and lean mass are optional, including visceral adipose tissue, appendicular lean mass index, android/gynoid percent fat ratio, trunk to leg fat mass ratio, lean mass index, and fat mass index. Within the United States, we recommend the use of the National Health and Nutrition Examination Survey 1999-2004 body composition dataset as an age-, gender-, and race-specific reference and to calibrate BMC in 4-compartment models. Z-scores and percentiles of body composition measures may be useful for clinical interpretation if methods are used to adjust for non-normality. In particular, DXA body composition measures may be useful for risk-stratification of obese and sarcopenic patients, but there needs to be validation of thresholds to define obesity and sarcopenia. To summarize, these guidelines provide evidence-based standards for the reporting and clinical application of DXA-based measures of body composition.

Body composition by whole-body bioelectrical impedance and prediction of clinically relevant outcomes: overvalued or underused?

BACKGROUND/OBJECTIVES

Body composition calculated using whole-body bioelectrical impedance analysis (BIA), almost invariably with height (H) and often with weight (W), can help patient management and predict clinical outcomes. This study aimed to examine the merits of this approach compared with simple anthropometry (W+H).

SUBJECTS/METHODS

Use was made of original data and validation studies based on reference body composition methods: water dilution, densitometry, dual-energy X-ray absorptiometry, and more robust methods. Prediction of clinical outcomes, including mortality and length of hospital stay, was examined in six studies of chronic obstructive pulmonary disease and a study with multiple patient groups. Vector analysis, phase angle, multi-frequency BIA and segmental impedance were not considered.

RESULTS

In a broad range of study populations, from neonates to older people, in health and disease, body composition calculated using BIA with simple anthropometry frequently offered no advantage over W+H alone, but in some situations it was superior and in others inferior. In predicting clinically relevant outcomes, the fat-free mass index (FFMI), established using BIA, had comparable and sometimes greater power than body mass index (BMI), but none of the reviewed papers used FFMI calculated from W+H or BMI to predict clinical outcomes.

CONCLUSIONS

A variable and generally weak evidence base was found to suggest that BIA with anthropometry is better at predicting body composition than simple anthropometry alone. No evidence was found from the reviewed studies that FFMI calculated from BIA and anthropometry was better at predicting clinical outcomes than FFMI calculated by simple anthropometry alone.

Exposure to cigarette smoke induces overexpression of von Hippel-Lindau tumor suppressor in mouse skeletal muscle

Cigarette smoke (CS) is a well-established risk factor in the development of chronic obstructive pulmonary disease (COPD). In contrast, the extent to which CS exposure contributes to the development of the systemic manifestations of COPD, such as skeletal muscle dysfunction and wasting, remains largely unknown. Decreased skeletal muscle capillarization has been previously reported in early stages of COPD and might play an important role in the development of COPD-associated skeletal muscle abnormalities. To investigate the effects of chronic CS exposure on skeletal muscle capillarization and exercise tolerance, a mouse model of CS exposure was used. The 129/SvJ mice were exposed to CS for 6 mo, and the expression of putative elements of the hypoxia-angiogenic signaling cascade as well as muscle capillarization were studied. Additionally, functional tests assessing exercise tolerance/endurance were performed in mice. Compared with controls, skeletal muscles from CS-exposed mice exhibited significantly enhanced expression of von Hippel-Lindau tumor suppressor (VHL), ubiquitin-conjugating enzyme E2D1 (UBE2D1), and prolyl hydroxylase-2 (PHD2). In contrast, hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) expression was reduced. Furthermore, reduced muscle fiber cross-sectional area, decreased skeletal muscle capillarization, and reduced exercise tolerance were also observed in CS-exposed animals. Taken together, the current results provide evidence linking chronic CS exposure and induction of VHL expression in skeletal muscles leading toward impaired hypoxia-angiogenesis signal transduction, reduced muscle fiber cross-sectional area, and decreased exercise tolerance.

Physical activity monitoring in COPD: compliance and associations with clinical characteristics in a multicenter study

BACKGROUND

Little is known about COPD patients' compliance with physical activity monitoring and how activity relates to disease characteristics in a multi-center setting.

METHODS

In a prospective study at three Northern European sites physical activity and clinical disease characteristics were measured in 134 COPD patients (GOLD-stage II-IV; BODE index 0-9) and 46 controls. Wearing time, steps per day, and the physical activity level (PAL) were measured by a multisensory armband over a period of 6 consecutive days (in total, 144 h). A valid measurement period was defined as ≥22 h wearing time a day on at least 5 days.

RESULTS

The median wearing time was 142 h:17 min (99%), 141 h:1 min (98%), and 142 h:24 min (99%), respectively in the three centres. A valid measurement period was reached in 94%, 97%, and 94% of the patients and did not differ across sites (P = 0.53). The amount of physical activity did not differ across sites (mean steps per day, 4725 ± 3212, P = 0.58; mean PAL, 1.45 ± 0.20, P = 0.48). Multivariate linear regression analyses revealed significant associations of FEV1, 6-min walk distance, quadriceps strength, fibrinogen, health status, and dyspnoea with both steps per day and PAL. Previously unrecognized correlates of activity were grade of fatigue, degree of emphysema, and exacerbation rate.

CONCLUSIONS

The excellent compliance with wearing a physical activity monitor irrespective of study site and consistent associations with relevant disease characteristics support the use of activity monitoring as a valid outcome in multi-center studies.

Physical activity is the strongest predictor of all-cause mortality in patients with COPD: a prospective cohort study

BACKGROUND

Systemic effects of COPD are incompletely reflected by established prognostic assessments. We determined the prognostic value of objectively measured physical activity in comparison with established predictors of mortality and evaluated the prognostic value of noninvasive assessments of cardiovascular status, biomarkers of systemic inflammation, and adipokines.

METHODS

In a prospective cohort study of 170 outpatients with stable COPD (mean FEV(1), 56% predicted), we assessed lung function by spirometry and body plethysmography; physical activity level (PAL) by a multisensory armband; exercise capacity by 6-min walk distance test; cardiovascular status by echocardiography, vascular Doppler sonography (ankle-brachial index [ABI]), and N-terminal pro-B-type natriuretic peptide level; nutritional and muscular status by BMI and fat-free mass index; biomarkers by levels of high-sensitivity C-reactive protein, IL-6, fibrinogen, adiponectin, and leptin; and health status, dyspnea, and depressive symptoms by questionnaire. Established prognostic indices were calculated. The median follow-up was 48 months (range, 10-53 months).

RESULTS

All-cause mortality was 15.4%. After adjustments, each 0.14 increase in PAL was associated with a lower risk of death (hazard ratio [HR], 0.46; 95% CI, 0.33-0.64; P < .001). Compared with established predictors, PAL showed the best discriminative properties for 4-year survival (C statistic, 0.81) and was associated with the highest relative risk of death per standardized decrease. Novel predictors of mortality were adiponectin level (HR, 1.34; 95% CI, 1.06-1.71; P = .017), leptin level (HR, 0.81; 95% CI, 0.65-0.99; P = .042), right ventricular function (Tei-index) (HR, 1.26; 95% CI, 1.04-1.54; P = .020), and ABI < 1.00 (HR, 3.87; 95% CI, 1.44-10.40; P = .007). A stepwise Cox regression revealed that the best model of independent predictors was PAL, adiponectin level, and ABI. The composite of these factors further improved the discriminative properties (C statistic, 0.85).

CONCLUSIONS

We found that objectively measured physical activity is the strongest predictor of all-cause mortality in patients with COPD. In addition, adiponectin level and vascular status provide independent prognostic information in our cohort.

Quantitative CT: Associations between Emphysema, Airway Wall Thickness and Body Composition in COPD

The objective of the present study was to determine the association between CT phenotypes-emphysema by low attenuation area and bronchitis by airway wall thickness-and body composition parameters in a large cohort of subjects with and without COPD. In 452 COPD subjects and 459 subjects without COPD, CT scans were performed to determine emphysema (%LAA), airway wall thickness (AWT-Pi10), and lung mass. Muscle wasting based on FFMI was assessed by bioelectrical impedance. In both the men and women with COPD, FFMI was negatively associated with %LAA. FMI was positively associated with AWT-Pi10 in both subjects with and without COPD. Among the subjects with muscle wasting, the percentage emphysema was high, but the predictive value was moderate. In conclusion, the present study strengthens the hypothesis that the subgroup of COPD cases with muscle wasting have emphysema. Airway wall thickness is positively associated with fat mass index in both subjects with and without COPD.