Obesity-related reduced spirometry and altered breathing pattern are associated with mechanical disadvantage of the diaphragm

The aim of this study was to characterize the breathing patterns of individuals with obesity during routine activities such as sitting and standing, and to identify potential contributors to alterations in these patterns. Measurements performed in 20 male subjects with obesity (BMI, 31.8±1.5 kg/m2) and 20 controls (BMI, 23.5±1.4 kg/m2) included anthropometric parameters, breathing-patterns in sitting and standing positions, spirometry, maximal respiratory pressures, and diaphragm B-mode ultrasonography. Individuals with obesity exhibited lower tidal volume and increased respiratory rate to maintain a similar minute-ventilation (p<0.05). Subjects with obesity demonstrated impaired spirometry and respiratory muscle strength, with inspiratory functions being notably compromised (p<0.05). Individuals with obesity had a greater diaphragm thickness at end inspiration but lower thickening-fraction at end quiet and forced breathings and reduced diaphragmatic displacement and excursion during maximal breaths (p<0.05). BMI was negatively associated with all respiratory function markers (p<0.05). Individuals with obesity exhibit a higher respiratory rate but lower tidal volume, likely to accommodate decreased compliance and excess thoracic and abdominal fat, further hindering inspiratory function. Moreover, increased adiposity is associated with a thicker but weaker diaphragm, primarily due to the diaphragm's mechanical disadvantage rather than its intrinsic inability to generate force.

Evaluation of the therapeutic efficacy and tolerability of current drug treatments on the clinical outcomes of paediatric spinal muscular atrophy type 1: A systematic review

Spinal muscular atrophy (SMA) is a severe hereditary lower motor neuron disorder characterised by degeneration of alpha motor neurons in the spinal cord, resulting in progressive weakness and paralysis of proximal muscles. A systematic literature search was carried out by using PRISMA guidelines and searching through different databases that could provide findings of evidence on the health outcomes of the approved therapies for the management of paediatric SMA type 1 regarding efficacy with follow-up in terms of motor and respiratory functions and the tolerability and incidence of adverse drug reactions (ADRs) post-treatment from real-world publications. Half of the publications (50%) had a prospective observational design. Eight studies (66.7%) assessed nusinersen, and three studies (25%) assessed onasemnogene abeparvovec with a duration of follow-up ranging from 6 months to 3 years to evaluate the motor and respiratory functions using different assessment tools, hospitalisation rates, and the tolerability and incidence of ADRs post-treatment. The three currently approved treatments for SMA type 1 provided good support and health outcomes in terms of motor function, respiratory outcomes, reduction of hospitalisations, and improvement of survival. Nevertheless, uncertainties regarding continued improvement after long-term illness and the generalizability of results are still unknown.

Clinical determinants of sleep quality in patients with amyotrophic lateral sclerosis

OBJECTIVES

Poor sleep quality is more prevalent in patients with amyotrophic lateral sclerosis (ALS) than in healthy populations. The purpose of this study was to examine whether or not motor dysfunction at various distinct levels correlates with subjective sleep quality.

METHODS

Patients with ALS and controls were assessed using the Pittsburgh Sleep Quality Index (PSQI), ALS Functional Rating Scale Revised (ALSFRS-R), Beck Depression Inventory-II (BDI-II), and the Epworth Sleepiness Scale (ESS). The ALSFRS-R was used to obtain information on 12 different aspects of motor function in patients with ALS. We compared these data between the groups with poor and good sleep quality.

RESULTS

A total of 92 patients with ALS and 92 age- and sex-matched controls entered the study. The global PSQI score was significantly higher in patients with ALS than in healthy subjects (5.5 ± 4.2 vs. 4.0 ± 2.8) and 44% of the patients with ALS had poor sleep quality (PSQI score > 5). The sleep duration, sleep efficiency, and sleep disturbances components were significantly worse in patients with ALS. Sleep quality (PSQI) score correlated with ALSFRS-R score, BDI-II score, and ESS score. Of the 12 ALSFRS-R functions, swallowing significantly affected sleep quality. Orthopnea, speech, salivation, dyspnea, and walking had a medium effect. In addition, turning in bed, climbing stairs, and dressing and hygiene were found to have a small effect on sleep quality among patients with ALS.

CONCLUSIONS

Nearly half of our patients had poor sleep quality related to disease severity, depression, and daytime sleepiness. Bulbar muscle dysfunction may be associated with sleep disturbances in individuals with ALS, particularly when swallowing is impaired. In addition, patients suffering from axial or lower limb muscle disruptions are likely to have trouble sleeping.

Pulmonary functions and anthropometric parameters of young male and female adults participating in moderate aerobic exercise

Respiratory disorders may be one of the adverse effects of sedentary lifestyle. This study investigated respiratory functions (FEV1, FVC and PEFR) and anthropometric parameters (body weight and body mass index) of healthy young males and females participating in moderate aerobic exercise. Forty young healthy untrained non-athletes, twenty males and twenty females (age, 25 ± 5.6 years; body weight, 65 ± 4.0 kg; body height, 176.9 ± 2.5 cm) volunteered to participate in this study. The exercise regimen was of moderate intensity lasting for 20 min daily on a treadmill consistently at the speed of 13 km/h for 14 days. The weight and height of participants were measured using medical scale and wall-mounted stadiometer respectively. The forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and peak expiratory flow rate (PEFR) were assessed using digital spirometer. The results showed a significant (p < 0.05) decrease in body weight and body mass index of female participants after 14 days of exercise regimen. The FEV1, FVC and PEFR were significantly increased (p < 0.05) in both male and female subjects after exercise. The Pearson correlation showed a significant (p < 0.05) positive correlation between BMI with FEVI/FVC% in female participants. There was an increase in calories burnt from day 4 of the study in both male and female participants. It is concluded that moderate aerobic exercise improved respiratory functions (FEV1, FVC and PEFR) in both male and female subjects with greater improvement in females while reducing body weight and body mass index in females.

Multiomic characterisation of the long-term sequelae of SARS survivors: a clinical observational study

BACKGROUND

We aimed to characterise the long-term health outcomes of survivors of severe acute respiratory syndrome (SARS) and determine their recovery status and possible immunological basis.

METHODS

We performed a clinical observational study on 14 health workers who survived SARS coronavirus infection between Apr 20, 2003 and Jun 6, 2003 in Haihe Hospital (Tianjin, China). Eighteen years after discharge, SARS survivors were interviewed using questionnaires on symptoms and quality of life, and received physical examination, laboratory tests, pulmonary function tests, arterial blood gas analysis, and chest imaging. Plasma samples were collected for metabolomic, proteomic, and single-cell transcriptomic analyses. The health outcomes were compared 18 and 12 years after discharge. Control individuals were also health workers from the same hospital but did not infect with SARS coronavirus.

FINDINGS

Fatigue was the most common symptom in SARS survivors 18 years after discharge, with osteoporosis and necrosis of the femoral head being the main sequelae. The respiratory function and hip function scores of the SARS survivors were significantly lower than those of the controls. Physical and social functioning at 18 years was improved compared to that after 12 years but still worse than the controls. Emotional and mental health were fully recovered. Lung lesions on CT scans remained consistent at 18 years, especially in the right upper lobe and left lower lobe lesions. Plasma multiomics analysis indicated an abnormal metabolism of amino acids and lipids, promoted host defense immune responses to bacteria and external stimuli, B-cell activation, and enhanced cytotoxicity of CD8⁺ T cells but impaired antigen presentation capacity of CD4⁺ T cells.

INTERPRETATION

Although health outcomes continued to improve, our study suggested that SARS survivors still suffered from physical fatigue, osteoporosis, and necrosis of the femoral head 18 years after discharge, possibly related to plasma metabolic disorders and immunological alterations.

FUNDING

This study was funded by the Tianjin Haihe Hospital Science and Technology Fund (HHYY-202012) and Tianjin Key Medical Discipline (Specialty) Construction Project (TJYXZDXK-063B, TJYXZDXK-067C).

Within- and cross-tissue gene regulations were disrupted by PM2.5 nitrate exposure and associated with respiratory functions

BACKGROUND

Pathogenesis of complex diseases often involves multiple organs/tissue-types. To date, the PM_2.5 exposure's toxic effects and induced disease risks were not studied at multi-tissue level.

METHODS

C57BL/6 mice (n = 40) were exposed to PM_2.5 NO₃^- and clean air, respectively, and afterwards assessed respiratory functions and transcriptome in relevant tissues: blood and lung. We constructed within- and cross-tissue gene regulation networks and identified network modules associated with exposure and respiratory functions.

RESULTS

PM_2.5 NO₃^- exposure elevated naïve B cells proportion in blood (p = 0.0028). Among the 6000 highest expressed genes in blood, 18.8 % (1133 genes) were altered by exposure at p ≤ 0.05 level, among which 763 genes were also associated with respiratory function (enrichment folds = 7.63, p = 2.7E-189). The exposure disrupted blood genes were primarily in the immunoregulation pathways. Both within- and cross-tissue gene network modules were perturbed by exposure and associated with respiratory function. An immunodeficiency related cross-tissue module of 555 genes was affected by exposure (p = 0.0023) and strongly correlated with FEV_0.05/FVC (r = 0.61 and p = 3E-5).

CONCLUSIONS

This study aims to fill in a major knowledge gap and investigated the effect of PM_2.5 exposure simultaneously in multiple tissues. We provided novel evidence that PM_2.5 NO₃^- exposure profoundly perturbed within- and cross-tissue gene regulations, and highlighted their roles in the etiology of respiratory decline.

The relationships between isometric muscle strength and respiratory functions of the Turkish National Paralympic Goalball Team

Goalball is a unique sport for only blind and visually disabled people to prevent physical inactivity and its harmful consequences. Determining the profile of physical fitness parameters and their relationship is crucial for all sports discipline. The purpose of the study is to determine the characteristics and the relationship between isometric muscle strength and respiratory functions. A total of 14 (10 female, four male athletes) goalball athletes were included in the study. Upper-extremity, lower-extremity and trunk isometric muscle strength and pulmonary function tests measurements were performed to the athletes on two different days. The relationship between parameters was evaluated by Spearman correlation test. Strength and pulmonary function parameters were higher in male athletes (P<0.05). A medium/strong/very strong correlation was found between respiratory function and upper extremity isometric muscle strength (r=0.529–0.917, P<0.05). A moderate/strong correlation was found between lower extremity isometric muscle strength and respiratory function (r=0.534–0.867, P<0.05). A moderate correlation was found between trunk isometric muscle strength and respiratory function (r=0.538–0.640, P<0.05). It was seen that respiratory functions were associated with upper-lower extremity and trunk muscle strength. With this result, the idea arises that strength exercises can affect the improvement of respiratory function in individuals with disabilities, which is very important for both overall health and sports performance.

Evaluation of respiratory functions and quality of life in multiple sclerosis patients

The aim of this study was to evaluate respiratory muscle strength, respiratory functions and quality of life in multiple sclerosis (MS) patients and compare the results with the healthy volunteers. The study included a group of 24 patients diagnosed with MS (16 women, 8 men) with an EDSS score of ≤ 5, who were without clinical respiratory impairment. MS patients were compared with the healthy volunteer group (16 women, 8 men). Respiratory muscle strength and respiratory functions were evaluated with specific devices. Maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) parameters were measured for the muscle strength. Forced vital capacity (FVC), forced expiratory volume (FEV1), FEV1/FVC, peak expiratory flow, and forced expiratory flow (FEF_25-75) parameters were measured for the respiratory functions. Questionnaire SF-36 was applied to evaluate health-related quality of life. A total of 24 MS patients' respiratory function test results were compared with healthy volunteers and significant changes were found at MIP, MEP, and FEV1 parameters. Quality of life was compared between the groups and there was a significant difference in parameters related with physical performance and physical-health-related role limitations. There is an early involvement of the respiratory muscles in patients with MS, yet clinical symptoms appear in later stages. Respiratory functions should be evaluated at the earlier stage of the disease so that rehabilitation can be planned in order to reduce respiratory complications and improve the quality of life in patients.

Comparative study on respiratory function among rural women using biomass fuel and non-biomass fuel: evidence of a cross-sectional survey in Bangladesh

Respiratory diseases' mortality and morbidity have been a major public health burden primarily attributed to widespread exposure to indoor and outdoor pollutants in the environment. The study conducted among 510 Bangladeshi women residing in the northeastern zone of the Sylhet division from semi-urban and rural settings to compare the biomass fuel users (N = 255) with the non-biomass users (N = 255). It has been observed that all the symptoms had a higher prevalence among the women who were exposed to biomass fuel compared with those exposed to clean gas fuel. Women exposed to biomass group reported frequent cough and phlegm production episodes during a 3-month timeline before the survey period which was found statistically higher (p < 0.001) compared with that of the clean gas fuel group. Moreover, the use of biomass fuel has been associated with a significant decrease in forced expiratory volume in one second (FEV₁), forced vital capacity (FVC), and peak expiratory flow rate (PEFR). Appropriate strategies from stakeholders and government authorities in disseminating health hazards from biomass fuel along with supporting the community by providing alternative energy sources for cooking can largely impact people's lives.

Airway microbiome is associated with respiratory functions and responses to ambient particulate matter exposure

BACKGROUND

Ambient particulate matter (PM) exposure has been associated with respiratory function decline in epidemiological studies. We hypothesize that a possible underlying mechanism is the perturbation of airway microbiome by PM exposure.

METHODS

During October 2016-October 2017, on two human cohorts (n = 115 in total) in Shanghai China, we systematically collected three categories of data: (1) respiratory functions, (2) airway microbiome from sputum, and (3) PM2.5 (PM of ≤ 2.5 µm in diameter) level in ambient air. We investigated the impact of PM2.5 on airway microbiome as well as the link between airway microbiome and respiratory functions using linear mixed regression models.

RESULTS

The respiratory function of our primary interest includes forced vital capacity (FVC) and forced expiratory volume in 1st second (FEV1). FEV1/FVC, an important respiratory function trait and key diagnosis criterion of COPD, was significantly associated with airway bacteria load (p = 0.0038); and FEV1 was associated with airway microbiome profile (p = 0.013). Further, airway microbiome was significantly influenced by PM2.5 exposure (p = 4.48E-11).

CONCLUSIONS

To our knowledge, for the first time, we demonstrated the impact of PM2.5 on airway microbiome, and reported the link between airway microbiome and respiratory functions. The results expand our understanding on the scope of PM2.5 exposure's influence on human respiratory system, and point to novel etiological mechanism of PM2.5 exposure induced diseases.

[The effect of expiratory muscle strength training on the oral and respiratory functions of community-dwelling older people: An analysis using the swallowing, oral, phonatory, and respiratory muscle function indices]

PURPOSE

This study was performed to determine the effects of expiratory muscle strength training (EMST) on the oral and respiratory functions of community-dwelling older people.

METHODS

Older people using a visiting-rehabilitation center were divided into an intervention group of 31 subjects and a control group of 15 subjects. Those in the intervention group were assigned home training for 8 weeks, which included 5 sets of 5 breaths per day with a 75% load of the maximum expiratory pressure using an EMST device. The outcome indices included (1) oral functions, evaluated by the cumulative time spent swallowing three times and the maximum phonation time (MPT) and (2) respiratory functions, evaluated by the maximum expiratory pressure and maximum inspiratory pressure (MEP/MIP). An independent t-test and paired t-test were used to analyze the data.

RESULTS

The cumulative time spent swallowing three times was lower in the intervention group than in the control group. This difference remained significant even after adjusting for sex, age, and baseline values. The MPT was 2.1 seconds higher than baseline in the intervention group but 0.4 seconds lower than baseline in the control group. An average increase of 5.7 cmH₂O in the PEmax was observed in the intervention group compared with an average decrease of 4.6 cmH₂O in the control group, indicating a significant difference.

CONCLUSION

These results suggest that EMST improves the oral and respiratory functions of community elderly subjects. This may be explained by the fact that the pathway for swallowing is partially shared with that for phonation, which contributes to a shortened swallowing time by repeated suprahyoid muscle contractions.

Impact of short term forced oral breathing induced by nasal occlusion on respiratory function in mice

Inconsistent findings regarding the experimental nasal obstruction on respiratory functions in small animals have been reported. The purpose of this study was to investigate the impact of short term forced oral breathing on respiratory functions as well as the therapeutic implication of esophageal intubation in BALB/c mice. Thirty BALB/c mice were randomized equally to two groups: an experimental group and control group. Oral breathing was induced by applying petrolatum ointment in nostrils for occlusion both nasal cavities. Esophageal tube was inserted to enlarge the oropharyngeal airway in the experimental mice. Respiratory parameters were measured by barometric whole-body plethysmography (WBP) in the following condition: normal nasal breathing; nasal breathing loading in a soft bag; forced oral breathing loading in a soft bag; forced oral breathing loading in a soft bag after undergoing esophageal intubation. After applying petrolatum ointment of nostrils, all the mice switch to oral breathing with apparent discomfort (bradypnea). Nasal occlusion was associated with a decrease in the average respiratory rate (268±36 vs. 90±10 breaths/min; P<0.01) and an increase in Penh (0.67±0.14 vs. 19.23±2.12; P<0.01). After undergoing esophagus intubation, these mice switched to oral breathing with less discomfort. Compared with the control mice, respiratory rate (175±25 vs. 90±10) was higher; the Penh (8.84±1.05 vs. 18.09±2.03; P<0.01) was lower. Short term forced oral breathing induced by nasal occlusion caused respiratory insufficiency in mice. Stenotic oropharyngeal airway was supposed to be one of the most important factors. Enlarging oropharyngeal airway by esophagus intubation could improve the respiratory insufficiency under nasal occlusion.