Establishing an optimal diagnostic criterion for respiratory sarcopenia using peak expiratory flow rate.

BACKGROUND: The skeletal muscle changes as aging progresses, causing sarcopenia in the older adult population, which affects the respiratory muscles' mass, strength, and function. The optimal cut-off point of peak expiratory flow rate (PEFR) for respiratory sarcopenia (RS) diagnosis in accordance with sarcopenia identification is needed. AIM: To establish an optimal cut-off point of PEFR for RS diagnosis in community-dwelling Asian older women. METHODS: Sarcopenia diagnostic indicators were evaluated according to the Asian Working Group for Sarcopenia 2019 (AWGS) criteria. The respiratory parameters composed of respiratory muscle strength and respiratory function were evaluated by assessing maximal inspiratory pressure (MIP), percent predicted forced vital capacity (Pred FVC), and PEFR. RESULTS: A total of 325 community-dwelling older women were included in this study. PEFR was negatively associated with RS (OR: 0.440; 95% CI: 0.344-0.564). The area under the curve (AUC) of PEFR was 0.772 (p < 0.001). The optimal cut-off point of PEFR for RS diagnosis was 3.4 l/s (sensitivity, 63.8%; specificity, 77.3%). Significant differences were found between the robust, possible sarcopenia, sarcopenia, and RS groups in terms of both sarcopenia diagnostic indicators and respiratory parameters (p < 0.05). CONCLUSIONS: The cut-off point of PEFR can be used as a reasonable standard for RS diagnosis. This study finding can serve as a cornerstone for developing concrete criteria of RS in older women, supporting clinical judgment, which is crucial for providing appropriate treatment through accurate diagnosis.

Physiotherapy interventions on chest wall mobility in obstructive lung diseases: A systematic review.

PURPOSE: The aim of this systematic review was to investigate the effectiveness of physiotherapy interventions on chest mobility in obstructive lung diseases. METHODS: Searches were performed in PEDro, Pubmed and Cochrane Central Register of Controlled Trials databases without language restrictions between 2010 and 25th December 2020. Randomized controlled trials (RCTs) investigating physiotherapy interventions on chest wall mobility were included. Two independent reviewers screened studies, extracted data, and assessed methodological quality of included studies. The assessment of risk of bias was conducted using the PEDro scale for RCTs. The articles were excluded if they have less than 5 out of 10 score. RESULTS: Five studies included had good to excellent quality. A total of 139 patients were included in all RCTs. Intervention duration ranged from a single session to 12 weeks and the intervention schedules varied, consisting of 1-24 sessions, lasting 5-45 min per sessions. Three studies used respiratory muscle stretching and releasing techniques, one study combined respiratory muscle stretching with aerobic training, and one study planned diaphragmatic breathing. Four studies assessed chest wall mobility with optoelectronic plethysmography, whereas one study used measuring tape. CONCLUSIONS: The result of this first systematic review that investigates the effects of physiotherapy interventions on chest wall mobility in obstructive lung diseases suggests that more and better quality RCTs with objective measurement tools are required.

A comprehensive physical functional assessment of survivors of critical care unit stay due to COVID-19.

OBJECTIVE: To examine the physical function and respiratory muscle strength of patients - who recovered from critical COVID-19 - after intensive care unit discharge to the ward on Days one (D1) and seven (D7), and to investigate variables associated with functional impairment. METHODS: This was a prospective cohort study of adult patients with COVID-19 who needed invasive mechanical ventilation, non-invasive ventilation or high-flow nasal cannula and were discharged from the intensive care unit to the ward. Participants were submitted to Medical Research Council sum-score, handgrip strength, maximal inspiratory pressure, maximal expiratory pressure, and short physical performance battery tests. Participants were grouped into two groups according to their need for invasive ventilation: the Invasive Mechanical Ventilation Group (IMV Group) and the Non-Invasive Mechanical Ventilation Group (Non-IMV Group). RESULTS: Patients in the IMV Group (n = 31) were younger and had higher Sequential Organ Failure Assessment scores than those in the Non-IMV Group (n = 33). The short physical performance battery scores (range 0 - 12) on D1 and D7 were 6.1 ± 4.3 and 7.3 ± 3.8, respectively for the Non-Invasive Mechanical Ventilation Group, and 1.3 ± 2.5 and 2.6 ± 3.7, respectively for the IMV Group. The prevalence of intensive care unit-acquired weakness on D7 was 13% for the Non-IMV Group and 72% for the IMV Group. The maximal inspiratory pressure, maximal expiratory pressure, and handgrip strength increased on D7 in both groups, but the maximal expiratory pressure and handgrip strength were still weak. Only maximal inspiratory pressure was recovered (i.e., > 80% of the predicted value) in the Non-IMV Group. Female sex, and the need and duration of invasive mechanical were independently and negatively associated with the short physical performance battery score and handgrip strength. CONCLUSION: Patients who recovered from critical COVID-19 and who received invasive mechanical ventilation presented greater disability than those who were not invasively ventilated. However, they both showed marginal functional improvement during early recovery, regardless of the need for invasive mechanical ventilation. This might highlight the severity of disability caused by SARS-CoV-2.

Association of IGF-1 and IGF-2 genotypes with respiratory muscle strength in individuals with COPD: A cross-sectional study.

Introduction: Chronic obstructive pulmonary disease is a systemic disease characterized not only by respiratory symptoms but also by physical deconditioning and muscle weakness. One prominent manifestation of this disease is the decline in respiratory muscle strength. Previous studies have linked the genotypes of insulin-like growth factor 1 and 2 (IGF-1 and IGF-2) to muscle weakness in other populations without this disease. However, there is a notable knowledge gap regarding the biological mechanisms underlying respiratory muscle weakness, particularly the role of IGF-1 and IGF-2 genotypes in this pulmonary disease. Therefore, this study aimed to investigate, for the first time, the association between IGF-1 and IGF-2 genotypes with respiratory muscle strength in individuals with chronic obstructive pulmonary disease. In addition, we analyzed the relationship between oxidative stress, chronic inflammation, and vitamin D with respiratory muscle strength. Methods: A cross sectional study with 61 individuals with chronic obstructive pulmonary disease. Polymerase chain reaction of gene polymorphisms IGF-1 (rs35767) and IGF-2 (rs3213221) was analyzed. Other variables, related to oxidative stress, inflammation and Vitamin D were dosed from peripheral blood. Maximal inspiratory and expiratory pressure were measured. Results: The genetic polymorphisms were associated with respiratory muscle strength ( 3.0 and 3.5; = 0.57). Specific genotypes of IGF-1 and IGF-2 presented lower maximal inspiratory and expiratory pressure (<0.05 for all). Oxidative stress, inflammatory biomarkers, and vitamin D were not associated with respiratory muscle strength. Conclusion: The polymorphisms of IGF-1 and IGF-2 displayed stronger correlations with respiratory muscle strength compared to blood biomarkers in patients with chronic obstructive pulmonary disease. Specific genotypes of IGF-1 and IGF-2 were associated with reduced respiratory muscle strength in this population.

Introducción: La enfermedad pulmonar obstructiva crónica es una enfermedad sistémica caracterizada no solo por síntomas respiratorios, sino también por el deterioro físico y la debilidad muscular. Una manifestación destacada de esta enfermedad es el declive en la fuerza de los músculos respiratorios. Estudios previos han vinculado los genotipos de factor de crecimiento insulínico 1 y 2 (IGF-1 e IGF-2) con la debilidad muscular en poblaciones sin esta enfermedad. Sin embargo, existe un vacío de conocimiento con respecto a los mecanismos biológicos subyacentes a la debilidad de los músculos respiratorios, en particular el papel de los genotipos IGF-1 e IGF-2 en esta enfermedad pulmonar. Por lo tanto, este estudio tuvo como objetivo investigar, por primera vez, la asociación de los genotipos IGF-1 e IGF-2 con la fuerza de los músculos respiratorios en individuos con enfermedad pulmonar obstructiva crónica. Además, analizamos la relación entre el estrés oxidativo, la inflamación crónica y la vitamina D con la fuerza de los músculos respiratorios. Métodos: Un estudio transversal con 61 individuos con enfermedad pulmonar obstructiva crónica. Se analizó la reacción en cadena de la polimerasa de los polimorfismos genéticos IGF-1 (rs35767) e IGF-2 (rs3213221). Otras variables relacionadas con el estrés oxidativo, la inflamación y la vitamina D se dosificaron a partir de muestras de sangre periférica. Se midieron las presiones inspiratorias y espiratorias máximas. Resultados: Los polimorfismos genéticos están asociados con la fuerza de los músculos respiratorios (F: 3.0 y 3.5; R2= 0.57). Genotipos específicos de IGF-1 e IGF-2 presentaron bajos valores en las presiones inspiratorias y espiratorias (p<0.05 en todos los casos). El estrés oxidativo, los biomarcadores inflamatorios y la vitamina D no se asociaron con la fuerza de los músculos respiratorios. Conclusión: Los polimorfismos de IGF-1 e IGF-2 mostraron correlaciones más sólidas con la fuerza de los músculos respiratorios en pacientes con enfermedad pulmonar obstructiva crónica en comparación con los biomarcadores sanguíneos. Genotipos específicos de IGF-1 e IGF-2 se asociaron con una disminución de la fuerza de los músculos respiratorios en esta población.

Comparative analysis of health-related fitness in patients with acute versus chronic Chagas disease. / Análisis comparativo del estado físico relacionado con la salud en pacientes con enfermedad aguda versus crónica de Chagas

INTRODUCTION: Although Chagas disease causes high levels of morbidity, the muscle function and tolerance to physical activity in Chagas disease patients are still not completely understood. OBJECTIVE: To compare health-related fitness of patient groups with acute Chagas disease versus chronic Chagas disease. MATERIALS AND METHODS: We conducted a cross-sectional study involving 18 patients. The data were obtained from patient´s records, and functional capacity was measured with the sixminute walk test, the peripheral muscle strength with handgrip strength, and respiratory muscle strength using the maximum inspiratory pressure and the maximum expiratory pressure. RESULTS: The 18 patients were divided in two groups: acute Chagas disease (n=9) and chronic Chagas disease (n=9). The distance walked in the six-minute walk test was lower than the predicted distance walked in both groups (p < 0.0001). The maximum expiratory pressure was lower than the predicted one (p = 0.005), and statistically significant for chronic Chagas disease patients (p = 0.02). Heart rate increased faster in the chronic Chagas disease group within the first two minutes of the six-minute walk test (p = 0.04). The sixminute walk test in the acute Chagas disease group presented a strong correlation with peripheral muscle strength (p = 0.012) and maximum inspiratory pressure (p = 0.0142), while in the chronic Chagas disease group, only peripheral muscle strength and maximum inspiratory pressure were correlated (p = 0.0259). CONCLUSION: The results suggest lowered functional capacity and reduced respiratory and peripheral muscle strength in patients with Chagas disease, although no differences were observed between groups. The early increase in heart rate during exercise in the chronic Chagas disease group implies a greater myocardial overload.

Introducción. Aunque la enfermedad de Chagas causa gran morbilidad, la función muscular y la tolerancia a la actividad física de estos pacientes aún no se comprenden por completo. Objetivos. Comparar el estado físico relacionado con la salud de pacientes con enfermedad de Chagas aguda versus crónica de Chagas. Materiales y métodos. Se hizo un estudio transversal que incluyó 18 pacientes. La información se obtuvo de los registros de los pacientes. La capacidad funcional se evaluó con la prueba de la caminata de seis minutos, se determinó la fuerza de prensión manual para evaluar los músculos periféricos y se estableció la fuerza de los músculos respiratorios mediante presión inspiratoria máxima y la presión espiratoria máxima. Resultados. Se evaluaron 18 pacientes, nueve con enfermedad de Chagas aguda y nueve con enfermedad de Chagas crónica. La distancia recorrida en la prueba de caminata de seis minutos fue menor que la distancia recorrida predicha en ambos grupos (p < 0,0001). La presión espiratoria máxima fue más baja de lo previsto (forma aguda: p = 0,005; forma crónica: p = 0,02). La frecuencia cardíaca aumentó más rápido en el grupo con enfermedad de Chagas crónica dentro de los primeros dos minutos de la caminata (p = 0,04). La distancia recorrida en el grupo con la forma aguda se correlacionó con la fuerza de prensión manual (p = 0,01) y la presión inspiratoria máxima (p = 0,01). En el grupo con la enfermedad crónica, solo hubo correlación entre la fuerza de presión manual y la presión inspiratoria máxima (p = 0,02). Conclusiones. Los resultados sugirieren disminución de la capacidad funcional y de la fuerza muscular respiratoria y periférica, aunque sin diferencias entre ambos grupos. El aumento de la frecuencia cardiaca en el grupo con enfermedad de Chagas crónica sugiere una mayor sobrecarga miocárdica.

Inspiratory muscle endurance is similarly reduced in the early and late stages of chronic Chagas heart disease.

OBJECTIVE: Inspiratory muscle strength (IMS) appears to be reduced in subjects with chronic Chagas heart disease (CHD), especially in the presence of heart failure (HF). However, only one study about IMS and inspiratory muscle endurance (IME) in those with CHD without heart failure is available. This study aimed to compare IMS and IME in subjects with CHD in the presence and absence of HF. METHODS: This is a cross-sectional study in which 30 CHD adult patients were divided into CHD-CC group (initial phase of CHD, without HF; n = 15) and CHD-HF group (advanced phase of CHD, with HF; n = 15). We assessed IMS by maximum inspiratory pressure (MIP) and IME by incremental (Pthmax) and constant load (TLim) tests. Reduced IMS and IME were considered by predicted MIP values <70% and Pthmax/MIP <75%, respectively. RESULTS: Inspiratory muscle weakness (IMW) was more frequent in CHD-HF than in CHD-CC (46.7% vs. 13.3%; p = 0.05), and both groups had high frequencies of reduced IME (93.3% CHD-CC vs. 100.0% CHD-HF; p = 0.95). Age-adjusted logistic regression analysis using HF as a dependent variable showed that HF was associated with an increased chance of IMW compared with the CHD-CC group (OR = 7.47; p = 0.03; 95% CI 1.20-46.19). CONCLUSION: This study suggests that, in patients with CHD, HF is associated with IMW, and that reduction of IME is already present in the initial phase, similar to the advanced phase with HF.

Respiratory Muscle Strength Is Related to Handgrip Performance in Community-Dwelling Persons Aged 80+ from the BUTTERFLY Study.

INTRODUCTION: This study aimed to evaluate the association of respiratory muscle strength with sarcopenia and its indicators in the oldest old. METHODS: Maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), and sarcopenia-related factors (handgrip strength and appendicular lean mass) were evaluated in a cohort of n = 286 (45.5% female) non-frail, community-dwelling persons aged 83.6 ± 3.0 years (age range 80-97 years). RESULTS: The sample presented a sarcopenia prevalence of 32.2%. Sarcopenic subjects showed comparable MIP and MEP as non-sarcopenic ones (female: MIP 43.9 ± 18.9 vs. 50.3 ± 19.5, p = 0.053; MEP 63.0 ± 23.0 vs. 69.2 ± 19.1, p = 0.067; male: MIP, 65.1 ± 24.4 vs. 64.4 ± 23.9, p = 0.433; MEP 87.7 ± 33.3 vs. 93.8 ± 30.9, p = 0.124). Statistically significant but very low associations were found between grip strength and MIP (r = 0.193 for male, p < 0.05 and r = 0.257 for female participants, p < 0.01) and MEP (r = 0.200 for male, p < 0.01 and r = 0.191 for female participants, p < 0.05). Lean mass was significantly correlated to MIP and MEP in female (r = 0.253, p < 0.01 and r = 0.343, p < 0.01, respectively), whereas this association was not found in male participants. Grip strength was the only statistically significant predictor of MEP (r2 = 0.212, p < 0.001), while MIP was independently predicted by age, male sex, and grip strength (r2 = 0.177, p < 0.001). CONCLUSIONS: Peripheral muscle strength is a statistically significant, albeit weak predictor for respiratory muscle strength in well-functioning, community-dwelling persons aged 80+. When confronted to a low grip strength, one should be aware of concomitant respiratory muscle weakness, as this is a known risk factor for atelectasis and pneumonia. Given the relatively low association with handgrip strength, respiratory muscle strength testing might be indicated.

Respiratory function and respiratory muscle strength in adolescent idiopathic scoliosis.

PURPOSE: It was aimed to analyze the relationship of the respiratory functions, respiratory muscle strength, magnitude of the curvature, angle of trunk rotation (ATR) and brace-wearing duration in patients with adolescent idiopathic scoliosis (AIS). METHODS: Sixty patients with AIS (43 females), with maximum Cobb angles between 20° and 66° were included in the study. ATR values were measured with a scoliometer. Respiratory function parameters (forced vital capacity [FVC], forced expiratory volume in one second [FEV1], FEV1/FVC ratio, peak expiratory flow [PEF]) and respiratory muscle strengths (maximum inspiratory pressure [MIP] and maximum expiratory pressure [MEP]) were measured by combined spirometry. RESULTS: There was a negative significant correlation between maximum Cobb angle and ATR with respiratory function parameters except for PEF and FEV1/FVC (r = -0.258-0.441; p = <0.001-0.047). There was a moderate negative correlation between ATR with MIP (cmH2O) (r = -0.377; p = 0.003) and MEP (cmH2O) (r = -0.362; p = 0.005). On the other hand, no correlation was found between brace-wearing duration with respiratory functions, maximum Cobb angle and brace-wearing duration with respiratory muscle results. CONCLUSION: The results of this study showed that, respiratory functions were normal or mildly affected, and respiratory muscle strengths were weak in AIS. Increased Cobb angle and ATR negatively affected respiratory function; increased ATR was associated with decreased inspiratory and expiratory muscle strength. It is extremely important to carefully evaluate the respiratory system and to know the variables that affect respiratory functions and respiratory muscle strength in achieving optimum recovery in the holistic treatment of individuals with scoliosis.

Respiratory Muscle Contraction Characteristics and Potential Mechanisms in Severely Burned Rats.

Postburn hypermetabolism remains an important clinical problem. During this phase, there is a significant loss of diaphragmatic proteins. Better understanding of respiratory muscle dynamics and potential mechanisms affecting respiratory muscle function is necessary for the development of effective therapeutic approaches. Male Wistar rats were subjected to 50% TBSA burns and sham injuries, and respiratory muscle function was assessed with 0, 1, 4, 7, and 14 days postinjury, including pulmonary function, blood gas analysis, transdiaphragmatic pressure, diaphragm ultrasonography, isolated diaphragm contractility, fatigue index, protein oxidative stress content, and ATP levels. Burned rats had significantly reduced inspiratory time, expiratory time, and tidal volume and significantly increased respiratory rate and minute ventilation. At the same time, the isolated diaphragm contractility, specific force during fatigue, and fatigue index were significantly decreased in the burned rats. Pdi, Pdimax, diaphragm thickness, diaphragm thickening fraction, and diaphragm excursion also decreased significantly postburn, whereas the Pdi/Pdimax ratio increased significantly. Finally, the content of protein carbonyls and lactic acid of burned rats was increased, and ATP levels of burned rats were decreased. The present study demonstrates the dynamic changes in diaphragm contractile properties postburn from both in vivo and in vitro perspectives, while cursorily exploring the possibility that protein oxidative stress and reduced ATP production may be the cause of diaphragm dysfunction. This understanding contributes to the development of methods to mitigate the extent of diaphragmatic function loss after severe burns.

Compensatory responses to increased mechanical abnormalities in COPD during sleep.

PURPOSE: To assess whether night-time increases in mechanical loading negatively impact respiratory muscle function in COPD and whether compensatory increases in inspiratory neural drive (IND) are adequate to stabilize ventilatory output and arterial oxygen saturation, especially during sleep when wakefulness drive is withdrawn. METHODS: 21 patients with moderate-to-severe COPD and 20 age-/sex-matched healthy controls (CTRL) participated in a prospective, cross-sectional, one-night study to assess the impact of COPD on serial awake, supine inspiratory capacity (IC) measurements and continuous dynamic respiratory muscle function (esophageal manometry) and IND (diaphragm electromyography, EMGdi) in supine sleep. RESULTS: Supine inspiratory effort and EMGdi were consistently twice as high in COPD versus CTRL (p < 0.05). Despite overnight increases in awake total airways resistance and dynamic lung hyperinflation in COPD (p < 0.05; not in CTRL), elevated awake EMGdi and respiratory effort were unaltered in COPD overnight. At sleep onset (non-rapid eye movement sleep, N2), EMGdi was decreased versus wakefulness in COPD (- 43 ± 36%; p < 0.05) while unaffected in CTRL (p = 0.11); however, respiratory effort and arterial oxygen saturation (SpO2) were unchanged. Similarly, in rapid eye movement (stage R), sleep EMGdi was decreased (- 38 ± 32%, p < 0.05) versus wakefulness in COPD, with preserved respiratory effort and minor (2%) reduction in SpO2. CONCLUSIONS: Despite progressive mechanical loading overnight and marked decreases in wakefulness drive, inspiratory effort and SpO2 were well maintained during sleep in COPD. Preserved high inspiratory effort during sleep, despite reduced EMGdi, suggests continued (or increased) efferent activation of extra-diaphragmatic muscles, even in stage R sleep. CLINICAL TRIAL INFORMATION: The COPD data reported herein were secondary data (Placebo arm only) obtained through the following Clinical Trial: "Effect of Aclidinium/Formoterol on Nighttime Lung Function and Morning Symptoms in Chronic Obstructive Pulmonary Disease" ( https://clinicaltrials.gov/ct2/show/NCT02429765 ; NCT02429765).

Respiratory Characteristics in Patients With Major Burn Injury and Smoke Inhalation.

This study aimed to evaluate pulmonary function measurements and respiratory muscle parameters in patients with major burn injury and smoke inhalation. The inclusion criteria included patients who were diagnosed with a smoke inhalation burn or a major burn of more than 20% of total body surface area (TBSA). All subjects underwent a pulmonary function test, respiratory muscle strength test, peak cough flow and fluoroscopic diaphragmatic movement measurement, and 6-minute walk test before starting pulmonary rehabilitation. Evaluations were conducted on the 88th day after the injury, the average time of admission to the Department of the Rehabilitation Medicine for burn rehabilitation after the completion of the acute treatment. The average degree of burns of the total 67 patients was 34.6% TBSA. All parameters in the patient group were significantly lower than the healthy controls, and a mild restrictive pattern of impairment with a reduction in diffusing capacity and more reduced expiratory muscle, than inspiratory muscle strength were observed. Peak cough flow, respiratory muscle strength, and forced vital capacity in the patient group with inhalation burn were significantly lower than in those without inhalation burn. The conditions of the majority of patients with major burn and inhalation injury were consistent with restrictive impairment and significant reduction in diffusion capacity. The patients had expiratory muscle weakness, decreased diaphragmatic movement, and exercise capacity impairment.

Reduced pulmonary functions and respiratory muscle strength in Type 2 diabetes mellitus and its association with glycemic control.

OBJECTIVE: Diabetes mellitus is one of the main devastating causes of mortality and morbidity due to its detrimental complications. We aimed to evaluate the pulmonary functions and respiratory muscle strength in relationship with glycemic control and gender in type 2 Diabetes Mellitus (T2DM). MATERIALS AND METHODS: This cross-sectional study was performed at King Saud University and King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia from June 2107 to June 2019. We evaluated pulmonary functions, respiratory muscle strength, body composition and glycemic control in T2DM (n=110) and control group (n=119). Gender differences were also evaluated in T2DM. RESULTS: Subjects with T2DM have significantly decreased forced vital capacity (FVC) (3.6±0.7 vs 3.3±0.9, p = 0.012), forced expiratory volume in first second (FEV1) (3.3±2.2 vs 2.7±0.6, p = 0.019), peak expiratory flow (PEF) (127.4±210.9 vs. 49.2±133.6, p = 0.003), FEF25-75 (3.6±1.3 vs. 3.1±1.1, p-value = 0.025), and maximum inspiratory pressure (MIP) (99.3±26.9 vs. 87.4±19.3, p=0.001). However, no significant difference between control and diabetes was found in maximum expiratory pressure (MEP) (132.5±34.9 vs 126.2±30.0, p = 0.202). Significant reduction in FVC (male=3.7±0.8 vs female = 3.0±0.7 p = 0.000), FEV1 (3.3±1.9 vs 2.6±0.5 p = 0.000), FEF25-75 (3.6 ± 1.3 vs 2.9 ± 1.0 with p-value = 0.000), MIP (96.9±23.1 vs 87.5±27.1 with p = 0.017), and MEP (134.0±32.2 vs. 120.1±33.5 with p = .011) were observed in females compared to males in T2DM subjects. CONCLUSIONS: Decline in the pulmonary function and inspiratory muscle strength are associated with poor glycemic control in T2DM. Moreover, there are significant differences between male and female in lung parameters and inspiratory as well as expiratory muscles strength. The exact pathophysiological mechanism to explain this association requires further investigations.

Feasibility and Efficacy of Inspiratory Muscle Training in Patients with Head and Neck Cancer receiving Concurrent Chemoradiotherapy.

OBJECTIVES: Patients with head and neck cancer (HNC) undergoing concurrent chemoradiotherapy (CCRT) often experience pulmonary symptoms. This study evaluated if a 7-week inspiratory muscle training (IMT) program during CCRT is feasible, adherent, and safe in patients with HNC. This study also evaluated the effect of IMT on diaphragm thickness, mobility, and cardiorespiratory parameters in patients with HNC receiving CCRT. METHODS: Ten participants with advanced stage HNC receiving CCRT were recruited for the study. Feasibility, adherence, and safety of the intervention were the primary outcomes. Changes in diaphragm thickness and mobility, maximal inspiratory pressure, maximal expiratory pressure, forced vital capacity, forced expiratory volume in first second and functional capacity using 6-MWT were measured at baseline and post 7 weeks of CCRT. IMT was performed at one session per day for 5 days a week for 7 weeks. Eight sets of two minutes of inspiratory manoeuvres with one minute rest period between them with intensity of 40% MIP were given. RESULTS: Ten participants  were included in this study out of the 13 patients screened, indicating the feasibility to be 76.9%. Participants completed a total of 260 training sessions out of the 350 planned sessions denoting the adherence level as 74%. Diaphragm thickness and MEP remained significantly unchanged while significant decline was seen in diaphragm mobility, MIP,FVC, FEV1 and 6-MWD at the end of 7 weeks. No adverse events were reported following the intervention. CONCLUSION: Inspiratory muscle training did not show significant effect on the diaphragm thickness, mobility, and cardiorespiratory parameters; however, it was feasible, adherent, and safe in patients with HNC receiving CCRT.

Handgrip strength cutoff value predicting successful extubation in mechanically ventilated patients.

BACKGROUND: Handgrip strength (HGS) is an alternative tool to evaluate respiratory muscle function. HGS cutoff value indicating extubation success or failure has not been investigated. This study aimed to determine HGS cutoff value to predict successful extubation. METHODS: A prospective study was conducted. Patients requiring intubated mechanical ventilation with intubation ≥ 48 hours in medical wards were recruited. HGS test was performed at 10 minutes before and 30 minutes after spontaneous breathing trial (SBT). Rapid shallow breathing index (RSBI) was measured at 10 minutes before SBT. RESULTS: Ninety-three patients (58% men) were included. Mean age was 71.6 ± 15.2 years. Weaning failure rate was 6.5%. The area under the ROC curve of 0.84 for the best HGS cutoff value at 10 minutes before SBT was 12.7 kg, with 75.9% sensitivity and 83.3% specificity (P = 0.005). The best HSG cutoff value at 30 minutes after SBT was 14.9 kg, with the area under the ROC curve of 0.82, with 58.6% sensitivity and 83.3% specificity (P = 0.009). The best RSBI cutoff value was 43.5 breaths/min/L, with the area under the ROC curve of 0.46, 33.3% sensitivity and 66.6% specificity (P = 0.737). CONCLUSIONS: HGS may be a predictive tool to guide extubation with better sensitivity and specificity than RSBI. A prospective study is needed to verify HGS test as adjunctive to RSBI in ventilator weaning protocol.

Functionally relevant threshold of inspiratory muscle strength in patients with chronic obstructive pulmonary disease.

OBJECTIVES: We aimed to identify the inspiratory muscle strength thresholds below which exercise capacity is compromised in men with chronic obstructive pulmonary disease (COPD). METHODS: We measured the maximum static inspiratory mouth pressure (PImax) and the percentage of predicted values (%PImax) in 113 patients with COPD. Six-minute walk distance (6-MWD) was measured as an indicator of functional exercise capacity, and a 6-MWD of <350 m was defined as functional exercise intolerance. Thresholds were determined as values with high specificity (>0.90) and maximal sensitivity. Statistical significance was set at P < 0.01. RESULTS: The data of 96 patients (74 ± 6 years old; forced expiratory volume in 1-s [FEV1], 56.5 ± 26.2% predicted) were analyzed; three women and 14 participants with missing data were excluded. Multivariate logistic regression models identified significant associations of PImax (odds ratio at 99% confidence interval [CI]: 0.95 [0.92-0.98]) and %PImax (odds ratio at 99% CI: 0.97 [0.95-0.99]) with 6-MWD, after adjustments for height and FEV1. C-statistics showed that the area under the curves (99% CI) of PImax and %PImax were comparable (0.87 [0.77-0.96] and 0.83 [0.72-0.94]). The thresholds of PImax and %PImax were 45.1 cmH2O and 66%; PImax and %PImax also had moderate positive likelihood ratios of 4.44 and 5.00. CONCLUSIONS: Thresholds of inspiratory muscle strength in men with COPD could help clinicians evaluate whether their patient's inspiratory muscle strength is inadequate to achieve a 6-MWD of ≥350 m, and identify patients who should be targeted for inspiratory muscle training.

Sarcomeric deficits underlie MYBPC1-associated myopathy with myogenic tremor.

Myosin binding protein-C slow (sMyBP-C) comprises a subfamily of cytoskeletal proteins encoded by MYBPC1 that is expressed in skeletal muscles where it contributes to myosin thick filament stabilization and actomyosin cross-bridge regulation. Recently, our group described the causal association of dominant missense pathogenic variants in MYBPC1 with an early-onset myopathy characterized by generalized muscle weakness, hypotonia, dysmorphia, skeletal deformities, and myogenic tremor, occurring in the absence of neuropathy. To mechanistically interrogate the etiologies of this MYBPC1-associated myopathy in vivo, we generated a knock-in mouse model carrying the E248K pathogenic variant. Using a battery of phenotypic, behavioral, and physiological measurements spanning neonatal to young adult life, we found that heterozygous E248K mice faithfully recapitulated the onset and progression of generalized myopathy, tremor occurrence, and skeletal deformities seen in human carriers. Moreover, using a combination of biochemical, ultrastructural, and contractile assessments at the level of the tissue, cell, and myofilaments, we show that the loss-of-function phenotype observed in mutant muscles is primarily driven by disordered and misaligned sarcomeres containing fragmented and out-of-register internal membranes that result in reduced force production and tremor initiation. Collectively, our findings provide mechanistic insights underscoring the E248K-disease pathogenesis and offer a relevant preclinical model for therapeutic discovery.

Alterações posturais associadas a distúrbios respiratórios e sua correlação com as desordens temporomandibulares: uma revisão de literatura / Postural changes associated with respiratory disorders and their correlation with temporomandibular disorders: a literature review

Objetivo: a presente revisão almeja fornecer à prática clínico-odontológica e ao meio científico uma compreensão atualizada acerca da correlação entre as alterações posturais geradas pela presença de distúrbios respiratórios e as desordens temporomandibulares (DTMs). Revisão de literatura: foi realizada uma busca entre o período de 2005 a 2021 nas seguintes bases de dados: Medline (via PubMed), Portal de Periódicos Capes e Scopus, utilizando-se dos termos "temporomandibular joint; temporomandibular disorders; posture control; postural control; breathing". Como resultado, foram encontrados 4.384 documentos, que foram analisados por títulos, resumos, texto completo e critérios de elegibilidade, até se chegar ao total de 5 estudos a serem incluídos nesta revisão. Considerações finais: os principais fatores observados foram a associação das DTMs com condições como padrão de respiração do tipo bucal, postura anterior da cabeça, hiperatividade de músculos acessórios da respiração, rotação posterior da mandíbula e apneia obstrutiva do sono. Os estudos ressaltaram a necessidade da abordagem completa desses pacientes, visto que os papéis dos distúrbios respiratórios e das alterações posturais podem representar desafios no diagnóstico e no tratamento das DTMs.(AU)

Objective: this review aims to provide to the clinical dental practice and the scientific community an updated understanding of the correlation between postural changes generated by the presence of respiratory disorders and temporomandibular joint disorders (TMD). Literature review: a search was carried out covering the period from 2005 to 2021 in the following databases: Medline (via PubMed), Portal de Periódicos Capes and Scopus using the terms temporomandibular joint; temporomandibular disorders; posture control; postural control; breathing. As a result, 4,384 documents were obtained and shortlisted by title, abstracts, full text and eligibility criteria, resulting in the five studies included in this review. Final considerations: the main factors observed were the association of TMD with conditions as mouth breathing, anterior head posture, hyperactivity of accessory breathing muscles, posterior rotation of the jaw and obstructive sleep apnea. The studies underscored the need for a complete approach to these patients, given that the role of respiratory disorders and postural changes may represent a challenge in the diagnosis and treatment of TMD.(AU)

Evolution of inspiratory muscle function in children during mechanical ventilation.

BACKGROUND: There is no universally accepted method to assess the pressure-generating capacity of inspiratory muscles in children on mechanical ventilation (MV), and no study describing its evolution over time in this population. METHODS: In this prospective observational study, we have assessed the function of the inspiratory muscles in children on various modes of MV. During brief airway occlusion maneuvers, we simultaneously recorded airway pressure depression at the endotracheal tube (ΔPaw, force generation) and electrical activity of the diaphragm (EAdi, central respiratory drive) over five consecutive inspiratory efforts. The neuro-mechanical efficiency ratio (NME, ΔPaw/EAdimax) was also computed. The evolution over time of these indices in a group of children in the pediatric intensive care unit (PICU) was primarily described. As a secondary objective, we compared these values to those measured in a group of children in the operating room (OR). RESULTS: In the PICU group, although median NMEoccl decreased over time during MV (regression coefficient - 0.016, p = 0.03), maximum ΔPawmax remained unchanged (regression coefficient 0.109, p = 0.50). Median NMEoccl at the first measurement in the PICU group (after 21 h of MV) was significantly lower than at the only measurement in the OR group (1.8 cmH2O/µV, Q1-Q3 1.3-2.4 vs. 3.7 cmH2O/µV, Q1-Q3 3.5-4.2; p = 0.015). Maximum ΔPawmax in the PICU group was, however, not significantly different from the OR group (35.1 cmH2O, Q1-Q3 21-58 vs. 31.3 cmH2O, Q1-Q3 28.5-35.5; p = 0.982). CONCLUSIONS: The function of inspiratory muscles can be monitored at the bedside of children on MV using brief airway occlusions. Inspiratory muscle efficiency was significantly lower in critically ill children than in children undergoing elective surgery, and it decreased over time during MV in critically ill children. This suggests that both critical illness and MV may have an impact on inspiratory muscle efficiency.

Effects of supervised exercise program and home exercise program in patients with systemic sclerosis: A randomized controlled trial.

AIM: To compare the effects of supervised exercise and home exercise program in patients with systemic sclerosis (SSc). METHODS: Thirty-seven SSc patients were included. Patients with SSc were allocated into 2 groups as supervised and home exercise. Breathing, aerobic and resistance exercises were performed with a physiotherapist for 12 weeks in the supervised exercise group. Breathing, posture and aerobic exercises were given to the home exercise group as a home program for 12 weeks. All patients were assessed at baseline and 12 weeks later in terms of functional capacity, pulmonary functions, respiratory-peripheral muscle strength, dyspnea severity, health-related quality of life (HRQoL) and fatigue level. RESULTS: Significant improvements were observed in the functional capacity, measured by 6 minute walking test in the supervised exercise group (before = 376.21 ± 65.50, after = 518.78 ± 75.84 m) and home exercise group (before = 384.44 ± 68.14, after = 432.7 ± 70.8 m; (P < .05). Respiratory-peripheral muscle strength (with the exception of inspiratory muscle strength and upper limb strength in the home exercise group) and HRQoL were significantly increased and fatigue level was significantly decreased in the supervised exercise and home exercise groups (P < .05). However, pulmonary functions and dyspnea severity were significantly improved only in the supervised exercise group (P < .05). The supervised exercise program was found superior to the home exercise program for change in all parameters (P < .05). CONCLUSION: This study suggests that exercise interventions should be applied in addition to the medical treatments of patients with SSc as supervised and home exercise programs play an important role in the functionality and health status of these patients.