Raw Bioelectrical Impedance Analysis Variables Are Independent Predictors of Early All-Cause Mortality in Patients With COPD

Dynapenia and Sarcopenia as Risk Factors for Mortality in Interstitial Lung Disease

BACKGROUND AND OBJECTIVE

Fibrotic interstitial lung disease (ILD) is associated with high morbidity and mortality. Patients often exhibit impaired nutritional status and alterations in body composition, such as dynapenia and sarcopenia, which correlate with poor pulmonary function, reduced exercise tolerance and diminished quality of life. However, the impact of dynapenia and sarcopenia on prognosis has not been examined extensively in ILD patients. We assessed the impact of dynapenia and sarcopenia as risk factors for mortality and their prevalence in ILD.

METHODS

Prospective cohort study. ILD was classified into idiopathic pulmonary fibrosis (IPF), connective tissue disease-related ILD (CTD-ILD) and chronic hypersensitivity pneumonitis (CHP). Patients over 18 years old with a confirmed diagnosis of ILD were included, while those with diagnoses of cancer, human immunodeficiency virus and neurological disease were excluded. Dynapenia and sarcopenia were determined according to EWGSOP2 criteria.

RESULTS

Ninety-eight ILD patients were included; 33.66% had IPF, 47.96% had CTD-ILD, and 18.37% had CHP. The mean age was 63.89 ± 12.02 years; 37.76% were male. The risk factors associated with mortality included dynapenia (HR: 2.04, 95% CI: 1.10-3.77, p = 0.022), sarcopenia (HR: 1.88, 95% CI; 1.00-3.33, p = 0.049) and exercise tolerance (HR: 0.99, 95% CI; 0.99-0.99, p = 0.023), adjusted for confounding variables. The prevalence of dynapenia was 45% in ILD; 51% in IPF, 35% in CTD-ILD and 61% in CHP. The prevalence of sarcopenia was 29%; both IPF (39%) and CHP (50%) had a higher prevalence of sarcopenia than CTD-ILD (14%).

CONCLUSION

Sarcopenia and dynapenia are independent risk factors for mortality in ILD.

Segmental phase angle can predict incidence of severe exacerbation in male patients with COPD

OBJECTIVE

To investigate whether segmental phase angle (PhA) is a useful predictor of severe chronic obstructive pulmonary disease (COPD) exacerbation.

RESEARCH METHODS AND PROCEDURES

This prospective cohort study enrolled consecutive patients with COPD with a follow-up period of 3 years. The primary outcome was incidence of severe exacerbation. PhA was measured for the whole body and segmental body sites (trunk and upper and lower limbs). We used receiver operating characteristic (ROC) curves to determine the cut-off values and area under the curve (AUC) for predicting exacerbation based on PhA. We applied Cox proportional hazard regression analyses to estimate the independent prognostic effect of PhA on the incidence of severe exacerbation.

RESULTS

We analyzed 108 male participants (mean age 75.1±7.9 years) and the median follow-up period was 1082 [643-1103] days, with an annual severe exacerbation incidence rate of 0.23 per person-year. ROC analysis revealed that the AUC for Whole-body and segmental PhA were as follows: Whole-body: AUC = 0.69 (95% confidence interval [CI] = 0.59-0.79); right arm: AUC = 0.65 (95% CI = 0.53-0.77); left arm: AUC = 0.68 (95% CI = 0.56-0.79); right leg: AUC = 0.73 (95% CI = 0.64-0.82); left leg: AUC = 0.71 (95% CI = 0.62-0.81); trunk: AUC = 0.58 (95% CI = 0.46-0.69). Cox proportional hazard analysis demonstrated that PhA of the right leg (hazard ratio [HR]=3.50, 95% CI=1.33-9.20), left leg (HR=3.26, 95% CI=1.18-9.04), and left arm (HR=2.61, 95% CI=1.17-6.80) were independently and significantly associated with incidence of severe exacerbation. Whole and trunk PhA were not significantly associated with the incidence of severe exacerbation.

CONCLUSIONS

Segmental PhA may serve as a valuable predictive indicator of severe exacerbation in male patients with COPD. Notably, both leg PhA were strongly associated with the occurrence of severe exacerbations.

REGISTRY NUMBER

UMIN000044824.

Association between phase angle and all-cause mortality in adults aged 18-49 years: NHANES 1999-2004

Phase angle (PhA) is an indicator of nutritional status. The association between PhA and all-cause mortality has been confirmed in older adults, but no relevant studies have been conducted in adults aged 18-49 years. This study aimed to investigate the relationship between PhA and all-cause mortality in adults aged 18-49 years. Our study included 6338 adults aged 18-49 from the National Health and Nutrition Examination Survey (1999-2004). Kaplan-Meier (KM) curve, multiple Cox regression and stratified analyses were performed. These adults were divided into two groups based on the median PhA value (the low PhA group: PhA < 6.96°; the high PhA group: PhA ≥ 6.96°). During a median follow-up of 214 months, 307 all-cause deaths were recorded. The all-cause mortality rate was 5.07% in the low PhA group and 3.98% in the high PhA group. After full adjustment, a higher PhA value was significantly associated with reduced risk of all-cause mortality (HR = 0.73,95CI%:0.59-0.91, P = 0.005). Similarly, compared with those in the low PhA group, individuals in the high PhA group had a lower risk of all-cause mortality (HR = 0.67, 95% CI 0.46-0.98, P = 0.041). There was an interaction between smoking status and PhA (P for interaction = 0.029), with a statistically significant negative association between PhA and all-cause mortality in the non-smokers (HR:0.62, 95%CI:0.53-0.88, P = 0.003). In conclusion, there was a significant negative association between PhA and all-cause mortality in adults aged 18-49 years. The negative association was stronger in non-smokers.

The impact of body mass index on mortality in COPD: an updated dose-response meta-analysis

BACKGROUND AND OBJECTIVE

The obesity paradox is a well-established clinical conundrum in COPD patients. This study aimed to provide an updated analysis of the relationship between body mass index (BMI) and mortality in this population.

METHODS

A systematic search was conducted through Embase, PubMed, and Web of Science. International BMI cut-offs were employed to define underweight, overweight and obesity. The primary outcome was all-cause mortality, and the secondary outcome was respiratory and cardiovascular mortality.

RESULTS

120 studies encompassed a total of 1 053 272 patients. Underweight status was associated with an increased risk of mortality, while overweight and obesity were linked to a reduced risk of mortality. A nonlinear U-shaped relationship was observed between BMI and all-cause mortality, respiratory mortality and cardiovascular mortality. Notably, an inflection point was identified at BMI 28.75 kg·m-2 (relative risk 0.83, 95% CI 0.80-0.86), 30.25 kg·m-2 (relative risk 0.51, 95% CI 0.40-0.65) and 27.5 kg·m-2 (relative risk 0.76, 95% CI 0.64-0.91) for all-cause, respiratory and cardiovascular mortality, respectively, and beyond which the protective effect began to diminish.

CONCLUSION

This study augments the existing body of evidence by confirming a U-shaped relationship between BMI and mortality in COPD patients. It underscores the heightened influence of BMI on respiratory and cardiovascular mortality compared to all-cause mortality. The protective effect of BMI was lost when BMI values exceeded 35.25 kg·m-2, 35 kg·m-2 and 31 kg·m-2 for all-cause, respiratory and cardiovascular mortality, respectively.

Body composition, pulmonary function tests, exercise capacity, and quality of life in chronic obstructive pulmonary disease patients with obesity

PURPOSE OF THE STUDY

Larger proportions of chronic obstructive pulmonary disease (COPD) patients are currently overweight or with obesity than underweight, and the combination of COPD and obesity is increasing. The purpose of this study was to investigate differences in the body composition, pulmonary function tests, exercise capacity, and health-related quality of life among normal weight, overweight, and obese patients with COPD.

STUDY DESIGN

A total of 514 patients with COPD were included in the study. According to the World Health Organization criteria for body mass index, the patients were classified as normal weight, overweight, and obese. Evaluations included fat-free mass, fat-free mass index, phase angle, pulmonary function tests, and 6-minute walk test. Dyspnea was assessed using the modified Medical Research Council dyspnea scale, and the health-related quality of life was evaluated using COPD Assessment Test and St. George's Respiratory Questionnaire. Values were compared among the three groups.

RESULTS

There were 315 male and 199 female patients, with a mean age of 66.7 ± 8.4 years. Fat-free mass, fat-free mass index, and phase angle values were significantly higher in COPD patients with obesity than in other patients (P < .001, P < .001, P < .001). Forced expiratory volume in 1 s, forced expiratory volume in 1 s/forced vital capacity, and diffusing capacity of lung for carbon monoxide value in pulmonary function tests were significantly higher in COPD patients with obesity than in other patients (P = .046, P < .001, P < .001), while the forced vital capacity values were similar in all groups. Exercise capacity (6-min walk test distance), dyspnea symptoms (modified Medical Research Council scale), and health-related quality of life (COPD Assessment Test and St. George's Respiratory Questionnaire) did not differ significantly between groups.

CONCLUSIONS

According to our study, obesity has no negative effect on pulmonary function tests, dyspnea perception, exercise capacity, and health-related quality of life.

Phase angle as an indicator of physical activity in patients with stable chronic obstructive pulmonary disease

OBJECTIVES

Phase angle (PhA) reflects cell membrane integrity and vitality and is an indicator of sarcopenia. PhA is associated with physical function in patients with stable chronic obstructive pulmonary disease (COPD). To our knowledge, the association between PhA and physical activity (PA) has not been investigated. Therefore, the aim of this study was to investigate whether PhA reflects PA in patients with COPD.

METHODS

This single-center, cross-sectional, observational study included 103 patients with stable COPD (87 men; mean age, 74.7 ± 8.1 y; mean forced expiratory volume in 1s %predicted value, 58.9 ± 20.4%). PhA was measured by bioelectrical impedance analysis. Patients were stratified into low (n = 54) and high (n = 49) PhA groups based on median values (4.3° ± 0.6° and 5.4° ± 0.5°, respectively). PA was calculated as the average daily duration of high-intensity light PA (HLPA; 2.0-2.9 metabolic equivalents [METs] of PA) and moderate- to vigorous-intensity PA (MVPA; >3 METs). Correlation and multivariate analyses using multiple regression analysis were performed to confirm the association between PhA and PA.

RESULTS

The high-PhA group demonstrated greater HLPA (104.4 [16.5-332.5] versus 131.3 [61.1-328.7] min, P = 0.005) and MVPA (19.5 [4.7-96.0] versus 46.6 [8.9-139.3] min, P < 0.001) than the low-PhA group. PhA was positively correlated with HLPA (r = 0.32, P < 0.001) and MVPA (r = 0.49, P < 0.001). MVPA (β = 0.178, P = 0.029) and HLPA (β = 0.158, P = 0.026) were associated with PhA independent of age, sex, body mass index, respiratory function, muscle strength, skeletal muscle mass index, and 6-min walking distance.

CONCLUSION

In patients with COPD, PhA may reflect PA as well as muscle function.

Analysis of body composition with bioelectrical impedance analysis in patients with severe COPD and pulmonary emphysema

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) often suffer from cachexia and malnutrition. Less is known about body composition and nutritional behaviour in patients with advanced COPD and pulmonary emphysema.

METHODS

We performed a single-center prospective analysis of patients with COPD GOLD III/IV. Metabolic parameters, dietary and exercise behavior, lung function, exercise capacity and body composition by bioelectrical impedance analysis (BIA) were analyzed. Patients with severe emphysema (emphysema index [EI] >20%) were compared to patients with mild emphysema (EI ≤ 20%).

RESULTS

A total of 121 patients (45.5% female, mean age 64.8 ± 8.1 years, mean FEV1 31.0 ± 8.6%, mean RV 234.7 ± 50.6%) were analyzed, of whom 14.1% were underweight. Only 5% of the patients substituted protein and only about 1/3 performed regular exercise training. BIA showed an unfavourable body composition: body fat ↑, ECM/BCM-index ↑, phase angle ↓ (5.0 ± 0.9°), cell percentage ↓, FFMI (fat-free mass index) ↓. The 94 patients with severe emphysema (mean EI 36.6 ± 8.5%) had lower body-mass-index (22.8 ± 4.3 vs. 31.1 ± 5.8 kg/m2, p < 0.001), FFMI, body weight and body fat, but did not differ significantly in the quality of body composition (e.g. phase angle). Their lipid and glucose metabolism were even better than in mild emphysema patients.

CONCLUSION

The finding of significantly lower BMI but similar body composition and better metabolic status in severe emphysema patients needs further investigation. However, it should not distract from the necessity to implement dietary and exercise recommendations for advanced COPD patients.

Association of phase angle with sarcopenia and muscle function in patients with COPD: a case-control study

BACKGROUND AND AIMS

The predictive value of phase angle for sarcopenia diagnosis has been discussed for years. The present investigation was conducted to determine the association between phase angle and sarcopenia in patients with COPD.

METHODS

In this case-control study, 222 smoker men were divided into healthy and COPD groups. COPD was diagnosed by a pulmonologist through spirometry. Anthropometric indices, phase angle, muscle function, sarcopenia, and dietary intake were assessed.

RESULTS

A significant inverse association was observed between phase angle and sarcopenia after adjustment for age and energy intake (OR: 0.31, 95% CI 0.18-0.52) and after adjustment for BMI (OR: 0.31, 95% CI 0.18-0.52). A significant decrease was detected in anthropometric indices and indicators of sarcopenia and muscle function in COPD cases compared to the healthy controls.

CONCLUSIONS

Although further studies are suggested, phase angle might be considered an indicator of sarcopenia and muscle function in COPD patients.

Association between muscular atrophy and mortality risk in patients with COPD: a systematic review

BACKGROUND

Muscular atrophy often can be seen at the end of stage in many chronic diseases. It will also negatively influence patients' outcomes. Different studies showed that the association between muscular atrophy and mortality in patients with chronic obstructive pulmonary disease (COPD) was unclear. This study will continue to assess the influence of muscular atrophy on mortality in patients with COPD.

OBJECTIVES

To systematically evaluate the association between muscular atrophy and death in patients with COPD.

DESIGN

Systematic review.

METHODS AND DATA SOURCES

A systematic review and meta-analysis was conducted. Databases including PubMed, Web of Science, Embase, the Cochrane Library, the China Biomedical Literature Service System, China Biomedical Literature Service System (CINAHL), China National Knowledge Infrastructure, the Wanfang database, and the WeiPu (VIP) were systematically searched for cohort studies on muscular atrophy and COPD from inception to July 1st, 2023. Two reviewers independently review, assess, and extract data from the included studies. Meta-analysis was performed using RevMan 5.4 software.

RESULTS

Thirteen cohort studies were ultimately included, involving 10,528 patients with COPD. There were seven cohort studies included in the meta-analysis, including 3,458 COPD patients. The meta-analysis showed that patients with COPD combined with muscular atrophy had a higher mortality risk (HR = 2.20, 95%CI (1.74, 2.79), p < 0.00001). At the same time, patients with COPD who had muscular atrophy may had longer hospital stays.

CONCLUSION

Muscular atrophy is associated with the mortality and disease prognosis of patients with COPD. The conclusion needs to be supported and validated by more high-quality studies given the limitation of the number of articles included in this study.

TRIAL REGISTRATION

This systematic review protocol was prospectively registered with PROSPERO (No. CRD42024589435).

Dynapenia and Sarcopenia in Post-COVID-19 Syndrome Hospitalized Patients Are Associated with Severe Reduction in Pulmonary Function

BACKGROUND

After hospital discharge, post-COVID-19 syndrome has been observed to be associated with impaired diffusing capacity, respiratory muscle strength, and lung imaging abnormalities, in addition to loss of muscle mass/strength, sarcopenia, and obesity impact exercise tolerance, pulmonary functions, and overall prognosis. However, the relationship between lung function and the coexistence of obesity with low muscle strength and sarcopenia in post-COVID-19 patients remains poorly investigated. Therefore, our aim was to evaluate the association between lung function and the coexistence of obesity with dynapenia and sarcopenia in post-COVID-19 syndrome patients.

METHODS

This cross-sectional study included subjects who were hospitalized due to moderate to severe COVID-19, as confirmed by PCR testing. Subjects who could not be contacted, declined to participate, or died before the follow-up visit were excluded.

RESULTS

A total of 711 subjects were evaluated; the mean age was 53.64 ± 13.57 years, 12.4% had normal weight, 12.6% were dynapenic without obesity, 8.3% had sarcopenia, 41.6% had obesity, 21.2% had dynapenic obesity, and 3.8% had sarcopenic obesity. In terms of pulmonary function, the dynapenic subjects showed decreases of -3.45% in FEV1, -12.61 cmH2O in MIP, and -12.85 cmH2O in MEP. On the other hand, the sarcopenic subjects showed decreases of -6.14 cmH2O in MIP and -11.64 cmH2O in MEP. The dynapenic obesity group displayed a reduction of -12.13% in PEF.

CONCLUSIONS

In post-COVID-19 syndrome, dynapenia and sarcopenia-both with and without obesity-have been associated with lower lung function.

Differences in nutritional status of patients with chronic obstructive pulmonary disease between Mediterranean and non-Mediterranean regions in Croatia

The nutritional status of patients with chronic obstructive pulmonary disease (COPD) is a significant factor that influences the prognosis of the disease. This observational study aimed to analyze the nutritional status of COPD patients and assess the associations between nutritional status, disease severity, and exercise capacity in four different regions of Croatia. In this multicenter study, 534 COPD patients were recruited and evaluated concerning fat-free mass (FFM), FFM index (FFMI), skeletal muscle mass index (SMMI), phase angle (PhA), pulmonary function tests, and the 6-minute walk test (6MWT). There were 325 (60.9%) male and 209 (39.1%) female patients with a mean age of 66.7±8.4 years. Most patients (73.2%) exhibited a moderate to severely abnormal obstructive pattern and had a reduced 6MWT distance (396.5±110.8 m). Among the participants, 32.8% were overweight and 22.3% were obese, and they had satisfactory values for nutritional status variables (FFM, FFMI, SMMI, PhA). There were no statistical differences between the centers in terms of nutritional status variables. There was a significantly positive correlation of forced expiratory volume in one second with body mass index (BMI) (r=0.148, p=0.001), PhA (r=0.256, p=0.00), FFM (r=0.365, p=0.00), and SMMI (r=0.238, p=0.00). However, there was no significant correlation of the 6MWT with BMI (r=-0.049, p=0.254), FFM (r=0.065, p=0.133), and SMMI (r=-0.007, p=0.867). The data analysis demonstrated that our patients were not underweight and that there was no significant difference between the centers in terms of BMI, FFM, FFMI, SMMI, and PhA. This lack of significant difference was observed even though one of the regions studied was Mediterranean.

Phase angle and COVID-19: A systematic review with meta-analysis

Phase angle (PhA) has been identified as a poor prognostic factor in patients with COVID-19. This study aimed to achieve a systematic review, where we discussed the potential role of PhA value as a prognostic marker of adverse clinical outcomes such as mortality and complication in hospitalized with SARS-CoV2 infection and established the strength of recommendations for use. A systematic literature review with meta-analysis was done in the main electronic databases from 2020 to January 2023. The selected articles had to investigate adverse consequences of the COVID-19 population and raw bioimpedance parameters such as PhA and published in peer-reviewed journals. GRADE tools regarded the quality of the methodology. The review protocol was registered in PROSPERO. Only eight studies, 483 studies, were eligible for the analysis. In general, differences in PhA were seen between the comparative study groups. Patients with a low PhA experienced poor outcomes. A low PhA was associated with a significantly increased mortality risk [RR: 2.44; 95% CI (1.20-4.99), p = 0.01; I2 = 79% (p = 0.0008)] and higher complications risk [OR: 3.47, 95% CI (1.16 - 10.37), p = 0.03; I2 = 82% (p = 0.004)] in COVID-19 patients. Our analysis showed four evidence-based recommendations on the prognostic value of PhA with two strong recommendations, one of moderate and another of low-moderate quality, for predicting mortality and complications, respectively. We recommend using PhA as a prognostic marker for mortality and complications in this population. Although the results are promising, future studies must identify the PhA cut-off to guide therapeutic decisions more precisely.Registration code in PROSPERO: CRD42023391044.

Impact of Body Composition and Sarcopenia on Mortality in Chronic Obstructive Pulmonary Disease Patients

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) have alterations in body composition, such as low cell integrity, body cell mass, and disturbances in water distribution evidenced by higher impedance ratio (IR), low phase angle (PhA), as well as low strength, low muscle mass, and sarcopenia. Body composition alterations are associated with adverse outcomes. However, according to the European Working Group on Sarcopenia in Older People 2 (EWGSOP2), the impact of these alterations on mortality in COPD patients is not well-established. Our aims were to evaluate whether low strength, low muscle mass, and sarcopenia impacted mortality in COPD patients.

METHODS

A prospective cohort study performance was conducted with COPD patients. Patients with cancer, and asthma were excluded. Body composition was assessed by bioelectrical impedance analysis. Low strength and muscle mass, and sarcopenia were defined according to EWGSOP2.

RESULTS

240 patients were evaluated, of whom 32% had sarcopenia. The mean age was 72.32 ± 8.24 years. The factors associated with lower risk of mortality were handgrip strength (HR:0.91, CI 95%; 0.85 to 0.96, p = 0.002), PhA (HR:0.59, CI 95%; 0.37 to 0.94, p = 0.026) and exercise tolerance (HR:0.99, CI 95%; 0.992 to 0.999, p = 0.021), while PhA below the 50th percentile (HR:3.47, CI 95%; 1.45 to 8.29, p = 0.005), low muscle strength (HR:3.49, CI 95%; 1.41 to 8.64, p = 0.007) and sarcopenia (HR:2.10, CI 95%; 1.02 to 4.33, p = 0.022) were associated with a higher risk of mortality.

CONCLUSION

Low PhA, low muscle strength, and sarcopenia are independently associated with poor prognosis in COPD patients.

Phase angle in assessment and monitoring treatment of individuals with respiratory disease

Phase angle (PhA) represents a raw variable measured with bioelectrical impedance analysis (BIA) that is used to assess malnutrition in many diseases, including respiratory diseases, mainly chronic obstructive pulmonary disease (COPD). COPD patients with reduced PhA are older, more hypoxic and hypercapnic; patients with more severe COPD have reduced cell mass, evident skeletal muscle depletion, and worsening gas exchange. Malnourished patients with stable COPD in long-term oxygen therapy (LTOT) have more intense dyspnea at rest, greater weight loss over the past 12 months, and more exacerbations per year. Multiple regression analysis highlighted the significance of PhA° in the estimation of muscle strength: hand grip strength (HGS) and in that of respiratory muscles: maximal inspiratory pressure / max. expiratory pressure ratio (MIP/MEP). Furthermore, the relationship between PhA° and all-cause mortality in COPD patients was confirmed with the Cox regression model, Kaplan-Meier test, and log-rank tests. The role of malnutrition in idiopathic pulmonary fibrosis (IPF) is confirmed by the PhA° measurements which, regardless of body weight, is associated with the reduction in muscle mass of these patients, reduces their strength and exercise capacity, and greatly influences the prognosis. In conclusion PhA is a novel biomarker of morbidity and mortality in patients with severe respiratory diseases.

Phase angle and standardized phase angle from bioelectrical impedance measurements as a prognostic factor for mortality at 90 days in patients with COVID-19: A longitudinal cohort study

BACKGROUND & AIMS

Severe acute COVID-19 has taken on pandemic proportions with growing interest in identification of prognostic factors for mortality. Standardized bioelectrical impedance (BI) phase angle (SPhA), which is PhA adjusted by age and sex, has been related to mortality in patients with several diseases but never investigated in COVID-19. Inflammation, a consequence of COVID-19 infection, affects fluid status (hydration) and can be identified with PhA. The aim of this study was to determine the predictive role of PhA on 90 days survival of adults with COVID-19.

METHODS

We studied 127 consecutive patients diagnosed with COVID-19. BI measurements determined with a 50 kHz phase-sensitive BI device, body composition parameters and laboratory markers were evaluated as predictors of mortality.

RESULTS

Non-surviving COVID-19 patients had significantly lower PhA and SPhA values (p < 0.001) and increased hydration (p < 0.001) compared to surviving patients. Patients in the lowest SPhA quartile had increased (p < 0.001) mortality and hospital stay, hyperhydration (p < 0.001), increased inflammation biomarkers [CRP (p < 0.001)], decreased nutritional parameters: body mass cell index [BCMI (p < 0.001) albumin (p < 0.001)], and reduced other biomarkers [D-dimer (p = 0.002)]. Multivariate analysis (Cox regression) revealed that PhA and hydration status, adjusted for age, sex, BMI, diabetes, hypertension, dyslipidaemia or heart disease, were associated (p < 0.001) with increased mortality. The hazard ratio was 2.48 (95% CI, 1.60-3.84, p < 0.001) for PhA and 1.12 (95% CI, 1.04-1.20, p = 0.003) for hydration percentage. PhA <3.95° was the cut-off for predicting mortality in acute COVID-19 with 93.8% sensitivity and 66.7% specificity. PhA offers greater sensitivity as a predictive prognostic test at admission, compared to the established analytical parameters of poor prognosis (CRP, lymphocytes, prealbumin).

CONCLUSIONS

Low PhA (<3.95°), independent of age, sex, BMI, and comorbidities, is a significant predictor of mortality risk in COVID-19. These findings suggest that the evaluation of body composition with single-frequency phase-sensitive BI measurements should be included in the routine clinical assessment of COVID-19 patients at hospital admission to identify patients at increased mortality risk.

Brazilian Reference Percentiles for Bioimpedance Phase Angle of Healthy Individuals

Objectives

The present study was designed to estimate phase angle percentile curves for a broad age range of healthy individuals.

Methods

This is a cross-sectional study of healthy Brazilian individuals aged five to 80. InBodyS10 was used to assess phase angle. Reference curves were stratified by sex and estimated using Generalized additive models for location, scale, and shape as a continuous function of age. The phase angle determinants analyzed were physical activity, age, BMI, and SES variables.

Results

Data were analyzed from 2,146 individuals, 1,189 (55.2%) of whom were female. In both sexes, the phase angles showed a similar pattern (an increasing trend from childhood to the teenage phase, followed by stabilization during adult ages and a decrease in old adults). In female, the relationship between phase angle and age were associated with BMI and family income. In the male, the relationship between phase angle and age were associated with skin color and family income.

Conclusions

To the best of our knowledge, it is the first attempt to apply the GAMLSS technique to estimate phase angle percentiles in a healthy population covering most of the life cycle. We also showed that there are different phase angle determinants according to sex.

Body composition and risk factors associated with sarcopenia in post-COVID patients after moderate or severe COVID-19 infections

Background

Post-COVID-19 syndrome is characterized by diverse symptoms and abnormalities that persist beyond 12 weeks from the onset of acute COVID-19. Severity disease has been associated with more musculoskeletal alterations such as muscle weakness, dyspnea, and distance walking. The aim was to evaluate the impact of invasive mechanical ventilation (IMV) on body composition and investigate risk factors associated with sarcopenia in post-COVID-19 patients three months after moderate or severe COVID-19 infections.

Methods

Cross-sectional study. 530 patients with PCR-confirmed diagnoses of moderate to severe COVID-19, > 18 years old, oxygen saturation ≤ 93%, PaO₂/FiO₂ ratio < 300, who required hospitalization and were discharged were included. We excluded those who died before the follow-up visit, declined to participate, or could not be contacted.

Results

The mean age was 53.79 ± 12.90 years. IMV subjects had lower phase angle and handgrip strength and higher impedance index, frequency of low muscle mass, and low muscle strength than those without IMV. The risk factors of sarcopenia were > 60 years of age, diabetes, obesity, IMV, and prolonged hospital stay. The multivariate model showed that age > 60 years (OR: 4.91, 95% CI: 2.26–10.63), obesity (OR: 3.73, 95% CI: 1.21–11.54), and interaction between prolonged length of hospital stay and IMV (OR: 2.92; 95% CI: 1.21–7.02) were related to a higher risk of sarcopenia.

Conclusion

Obesity and the interaction between prolonged length of hospital stay and IMV are associated with a higher risk of sarcopenia at 3 months after severe or moderate COVID-19 infection.

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.

Association between body composition, sarcopenia and pulmonary function in chronic obstructive pulmonary disease

Background

Chronic Obstructive Pulmonary Disease (COPD) is characterized by progressive and irreversible airflow limitation. Different factors that modify pulmonary function include age, sex, muscular strength, and a history of exposure to toxic agents. However, the impact of body composition compartments and sarcopenia on pulmonary function is not well-established. This study aimed to evaluate how body composition compartments and sarcopenia affect pulmonary function in COPD patients.

Methods

In a cross-sectional study, patients with a confirmed diagnosis of COPD, > 40 years old, and forced expiratory volume in the first second /forced vital capacity ratio (FEV₁/FVC) < 0.70 post-bronchodilator were included. Patients with cancer, HIV, and asthma were excluded. Body composition was measured with bioelectrical impedance. Sarcopenia was defined according to EWGSOP2, and pulmonary function was assessed by spirometry.

Results

185 patients were studied. The mean age was 72.20 ± 8.39 years; 55.14% were men. A linear regression adjusted model showed associations between body mass index, fat-free mass, skeletal muscle mass index, appendicular skeletal muscle mass index, and phase angle (PhA), and sarcopenia with FEV₁ (%). As regards FVC (%), PhA and exercise tolerance had positive associations.

Conclusion

Body composition, especially PhA, SMMI, ASMMI, and sarcopenia, has a significant impact on pulmonary function. Early detection of disturbances of these indexes enables the early application of such therapeutic strategies in COPD patients.

Performance of bioelectrical impedance analysis compared to dual X-ray absorptiometry (DXA) in Veterans with COPD

We examined the performance of a commercially-available handheld bioimpedance (BIA) device relative to dual X-ray absorptiometry (DXA) to assess body composition differences among Veterans with chronic obstructive pulmonary disease (COPD). Body composition was measured using DXA and BIA (Omron HBF-306C) at a single time point. Correlations between BIA- and DXA-assessed percent fat, fat mass, and fat-free mass were analyzed using Spearman (ρ) and Lin Concordance Correlation Coefficients (ρ_c). Mean differences in fat mass were visualized using Bland–Altman plots. Subgroup analyses by obesity status (BMI < 30 versus ≥ 30) were performed. Among 50 participants (96% male; mean age: 69.5 ± 6.0 years), BIA-assessed fat mass was strongly correlated (ρ = 0.94) and demonstrate excellent concordance (ρ_c = 0.95, [95%CI: 0.93–0.98]) with DXA, with a mean difference of 2.7 ± 3.2 kg between BIA and DXA. Although Spearman correlations between BIA- and DXA-assessed percent fat and fat-free mass were strong (ρ = 0.8 and 0.91, respectively), concordance values were only moderate (ρ_c = 0.67 and 0.74, respectively). Significantly stronger correlations were observed for obese relative to non-obese subjects for total percent fat (ρ_obese = 0.85 versus ρ_non-obese = 0.5) and fat mass (ρ_obese = 0.96 versus ρ_non-obese = 0.84). A handheld BIA device demonstrated high concordance with DXA for fat mass and moderate concordance for total percent fat and fat-free mass.

ClinicalTrials.gov: NCT02099799.

The impact of hydration status and fluid distribution on pulmonary function in COPD patients

Chronic Obstructive Pulmonary Disease (COPD) patients have alterations in body composition. Bioelectrical impedance analysis (BIA) evaluates body composition, hydration status, and fluid distribution. Subjects with fluid disturbances have been found to have lower FEV1, respiratory muscle strength, and poor prognosis. We aimed to evaluate the effect of hydration status and fluid distribution on pulmonary function in COPD patients. A cross-sectional study, 180 patients with a confirmed diagnosis of COPD were included. Patients with asthma, advanced renal or liver disease, acute HF, exacerbation of COPD, or pacemakers were excluded. Hydration status variables (TBW, ECW, ICW) and disturbance of fluid distribution [impedance ratio (IR) > 0.84 and phase angle (PhA)] were evaluated by BIA. Pulmonary function was assessed by spirometry. The mean population age was 71.55 ± 8.94 years; 55% were men. Subjects were divided into two groups according to the IR ≥ 0.84 or < 0.84. The group with higher IR ≥ 0.84 had lower FEV1, FVC, FEV1/FVC, DLCO and, PhA compared to those with IR < 0.84. After adjusting for confounding variables TBW, ECW, IR ≥ 0.84, PhA, and resistance/height increase were associated with decreased FEV1. In the same way, with IR ≥ 0.84, edema index ≥ 0.48, trunk and abdominal IR were negatively associated with FVC, and PhA had a positive association with FVC. Fluid distribution, especially IR and PhA, could be a useful parameter for predicting pulmonary function in COPD patients.

Body Composition and Bioelectrical-Impedance-Analysis-Derived Raw Variables in Pole Dancers

Few data are available on the body composition of pole dancers. Bioelectrical impedance analysis (BIA) is a method that is used to estimate fat-free mass (FFM) and fat mass (FM), while raw BIA variables, such as the impedance ratio (IR) and phase angle (PhA), are markers of body cell mass and the ratio between extracellular and total body water. The aim of this study was to evaluate the body composition of pole dancers compared to controls, in particular, those raw BIA variables that are considered as markers of muscle composition. Forty female pole dancers and 59 controls participated in the study. BIA was performed on the whole body and upper and lower limbs, separately, at 5, 50, 100 and 250 kHz. The FFM, FFM index, FM and body fat percentage (BF%) were predicted. The bioelectrical impedance indexes IR and PhA were also considered. Pole dancers exhibited higher FFMI and BI indexes and lower BF%. PhA was greater and IRs were smaller in pole dancers than in controls for the whole body and upper limbs. Considering the training level, FFM, whole-body IR and PhA were higher in the professionals than non-professionals. Raw BIA variables significantly differed between the pole dancers and controls, suggesting a higher BCM; furthermore, practicing pole dancing was associated with a greater FFM and lower FM.

Longitudinal association between muscle loss and mortality in ever-smokers

BACKGROUND

Body composition measures, specifically low weight or reduced muscle mass, are associated with mortality in chronic obstructive pulmonary disease (COPD), but the effect of longitudinal body composition changes is undefined.

RESEARCH QUESTION

Is the longitudinal loss of fat-free mass (FFM) associated with increased mortality including in those with initially normal or elevated body composition metrics?

STUDY DESIGN AND METHODS

Participants with complete data for at least one visit in the COPDGene (n=9,268) and ECLIPSE studies (1,760) were included and followed for 12 and 8 years, respectively. Pectoralis muscle area (PMA) was derived from thoracic CT scans and used as a proxy for FFM. A longitudinal mixed sub-model for PMA and a Cox proportional hazards sub-model for survival were fitted on a joint distribution using a shared random intercept parameter and Markov chain Monte Carlo parameter estimation.

RESULTS

Both cohorts demonstrated a left shifted distribution of baseline FFM, not reflected in BMI, and an increase in all-cause mortality risk associated with longitudinal loss of PMA. For each one cm2 PMA loss, mortality increased 3.1% (95% CI 2.4, 3.7, p<0.001) in COPDGene, and 2.4% (95% CI 0.9, 4.0, p<0.001) in ECLIPSE. Increased mortality risk was independent of enrollment values for BMI and disease severity (BODE index quartiles) and was significant even in participants with initially greater than average PMA.

INTERPRETATION

Longitudinal loss of PMA is associated with increased all-cause mortality, regardless of BMI or initial muscle mass. Consideration of novel screening tests and further research into mechanisms contributing to muscle decline may improve risk stratification and identify novel therapeutic targets in ever-smokers.

Relationship between body composition, exercise capacity and health-related quality of life in idiopathic pulmonary fibrosis

INTRODUCTION

Bioelectrical impedance analysis (BIA) can be used to estimate Fat-Free Mass Index (FFMI). However, the use of directly measured BIA variables, such as phase angle (PhA), has gained attention. The frequency of low FFMI and PhA and its associations with exercise capacity and health-related quality of life (HRQL) in patients with idiopathic pulmonary fibrosis (IPF) have been scarcely studied.

OBJECTIVES

To investigate the frequency of low FFMI and PhA and their associations with exercise capacity and HRQL in patients with IPF.

METHODS

Patients underwent assessment of lung function, body composition, exercise capacity by the 6 min walk distance (6MWD), and HRQL by the Medical Outcomes Study Short-Form 36-item Questionnaire (SF-36). Patients were classified as presenting normal or low PhA or FFMI, accordingly to the 10th percentiles of age-sex-body mass index (BMI)-specific reference values.

RESULTS

98 patients (84 males, age: 68±8 years, forced vital capacity: 64%±18%predicted) were included. 24 patients presented low PhA. They were characterised by worse lung function, exercise capacity and HRQL compared with patients with normal PhA. 10 patients presented low FFMI, but despite differences in body composition, no differences were found between these patients and patients with normal FFMI. In a single regression analysis, age, lung function and body composition variables (except FFMI) were related to 6MWD and SF-36 Physical Summary Score (R²=0.06-0.36, p<0.05). None of the variables were related to SF-36 Mental Summary Score.

CONCLUSION

One-fourth of the patients with IPF with normal to obese BMI present abnormally low PhA. Patients classified as low PhA presented worse lung function, exercise capacity and HRQL.

Reduced calf circumference is an independent predictor of worse quality of life, severity of disease, frequent exacerbation, and death in patients with chronic obstructive pulmonary disease admitted to a pulmonary rehabilitation program: A historic cohort study

BACKGROUND

Muscle wasting is associated with worse outcomes in chronic obstructive pulmonary disease (COPD) patients. We assessed the association of calf circumference (CC) measurements with clinical outcomes in COPD patients referred to an outpatient pulmonary rehabilitation program (PRP).

METHODS

In this single-center, retrospective study, we analyzed demographic and clinical data ( spirometry tests, comorbidities, COPD exacerbations, dyspnea scoring, exercise capacity, quality-of-life scores, BMI, CC measurements, and all-cause deaths [for 2 years]) from COPD patients PRP medical records. Patients were grouped according to CC into reduced CC (male, ≤34 cm; female, ≤33 cm) or adequate CC groups.

RESULTS

We evaluated 144 patients (aged 64.6 ± 8.5 years; mostly males; forced expiratory volume in 1 s, 40.3% ± 15.8%, predicted). Eighteen patients (12.5%) died during the 2 years of follow-up. Logistic regression showed that patients with reduced CC were more likely to present worse outcomes compared with COPD patients with adequate CC: more advanced disease severity (odds ratio [OR] = 5.09; 95% CI, 2.00-12.96), COPD frequent exacerbators (OR = 2.34; 95% CI, 1.11-4.91), worse total quality-of-life score (OR = 2.70, 95% CI, 1.22-6.00), and higher mortality (OR = 3.69; 95% CI, 1.06-12.87).

CONCLUSION

Reduced CC in COPD patients under initial assessment for PRP admission was associated with disease severity, frequent exacerbation, poor health status, and higher mortality in 2 years of follow-up. Considering its clinical applicability, CC measurement should be introduced in the nutrition assessment of COPD patients admitted to the PRP.

Bioelectrical spectroscopy impedance phase angle is not associated with nutritional status in a stable cohort of paediatric inflammatory bowel disease patients

BACKGROUND & AIMS

Nutritional assessment in paediatric inflammatory bowel disease (IBD) is key to supporting growth whilst minimising adiposity. Bedside assessment using bioelectrical impedance spectroscopy (BIS) has previous identified patients with declining cellular and nutritional health. We aimed to assess BIS measures in stable paediatric IBD patient.

METHODS

Stable IBD patients were recruited at routine hospital visits. All patients underwent BIS, anthropometry and disease activity assessment. Multivariable regression and receiver operator curve (ROC) analyses were undertaken to assess the utility of BIS phase angle 50 KHz (PA-50) and 200/5 KHz impedance ratio (IR) in nutritional assessment.

RESULTS

There were 140 study visits from 97 patients, mean age 14.49 years, 62.9% Crohn's disease. Mean BMI Z-score (BMIZ) was 0.31 (range -2.97 to 3.99), 33% of patients were overweight (BMIZ>1) and 13.8% of patients were underweight (BMIZ < -1). Crohn's disease patients had a lower mean BMIZ score 0.14, compared to ulcerative colitis, 0.68, p = 0.007. There was no relationship between PA-50 and BMIZ or disease activity. IR was not related to disease activity but was negatively related to BMIZ in a multivariable regression, accounting for age, sex and disease subtype (beta -0.331, p = 0.001). ROC analyses did not identify a clinically useful cut off for either PA-50 or IR to identify patients with active disease, biologic use or BMIZ>1 or < -1.

CONCLUSION

BIS appears to have limited added value in nutritional assessment of stable paediatric IBD patients. Nearly 1/3 patients were overweight and personalised approach to supplementation is vital to avoid overnutrition.

Relationship between Phase Angle and Objective and Subjective Indicators of Nutritional Status in Cancer Patients: A Systematic Review

To investigate the relationship between phase angle (PA) and objective and subjective indicators of nutritional status in cancer patients, as well as to identify cutoff points for PA, to detect malnutrition in these patients. The study was a systematic review, carried out following the guidelines of the Preferred Reporting Items for Systematic Reviews and meta-analyses (PRISMA). Literature search was performed for two authors, in indexed databases, including the National Library of Medicine, Bethesda, MD (PubMed), Latin American and Caribbean Literature in Health Sciences (LILACS), and Scopus (Elsevier). We used the checklist from the Joanna Briggs Institute for assessing the risk of bias. The review was registered with the Systematic Review Registration (PROSPERO), number CRD42020134324. In total, nine papers were eligible. PA was correlated with several objective and subjective indicators of nutritional status in most cases. Cutoff point values for the PA, capable of detecting malnutrition, varied from 4.73° to 6°, despite the modest diagnostic accuracy. We assume that PA may be considered an indicator of nutritional status, when complementing additional data and assisting health practitioners in evaluating individuals with malignant neoplasms. However, a single cutoff point with fair and concomitant sensitivity and specificity was not identified.

Low Muscle Mass Is a Predictor of Malnutrition and Prolonged Hospital Stay in Patients With Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Longitudinal Study

BACKGROUND

Malnutrition in chronic obstructive pulmonary disease (COPD) patients is more prevalent during times of exacerbation. Fat-free mass index (FFMI), calf circumference (CC), and adductor muscle pollicis thickness (AMPT) can be used to identify reduced muscle mass and have been found to be good predictors of clinical outcomes in other conditions, but they have not been investigated in COPD. Therefore, this study evaluated low muscle mass as predictor of malnutrition, prolonged length of stay (LOS), and in-hospital death in COPD patients.

METHODS

This prospective cohort study was carried out in hospitalized patients with COPD exacerbation. Malnutrition diagnosis was performed by Subjective Global Assessment, and muscle mass was assessed by FFMI, calculated using fat-free mass from bioelectrical impedance, CC, and AMPT. Clinical outcomes (LOS and in-hospital death) were collected from records.

RESULTS

One hundred seventy-six patients were included (68.2 ± 10.4 years old, 56.2% women); 74.2% were classified as Global Initiative of Chronic Obstructive Lung Disease 2 or 3 and 58.2% as malnourished. The median LOS was 11 (7-19) days, and the incidence of death was 9.1%. Low FFMI and CC predicted malnutrition (low CC: odds ratio [OR], 4.6; 95% CI, 2.2-9.7 and low FFMI: OR, 8.8; 95% CI, 3.7-20.8) and were associated with prolonged LOS (low CC: OR, 2.3; 95% CI, 1.1-4.6 and low FFMI: OR, 2.5; 95% CI, 1.3-4.8).

CONCLUSION

Simple, inexpensive, and noninvasive parameters of muscle mass-FFMI and CC-are good predictors of malnutrition and prolonged LOS in COPD patients experiencing exacerbation.