Impact of obesity on pulmonary function: current understanding and knowledge gaps

Functional Sitting Balance and Anthropometric Measures Are Related to Inspiratory Muscle Performance in People with Spinal Cord Injury

Background

Respiratory complications are a leading cause of mortality post spinal cord injury (SCI). Along with breathing, respiratory muscles have a role in maintaining seated balance. Postinjury breathing influences respiratory muscle function. Preliminary evidence indicates a relation between respiratory muscle function and seated balance in people with chronic SCI dwelling in the community, but the relationship between balance and body habitus has not been explored.

Objectives

To explore the relationships among inspiratory muscle function, functional seated balance (FSB), and body habitus in people with SCI.

Methods

A convenience sample of inpatients with SCI (C5-T12) aged 18 to 60 years who were using a wheelchair was recruited from November 2022 to March 2023. Those with additional neurological disorders or respiratory support were excluded. Respiratory muscle function measures included maximal inspiratory pressure (MIP), sustained MIP (SMIP), and Fatigue Index Test (FIT). FSB was scored using the Function in Sitting Test (FIST). Body habitus was assessed using the axillary: umbilical (A:U) ratio. Spearman correlations explored the relationships.

Results

Thirty-eight of 42 screened participants were eligible and participated (male, 32). Levels of injury ranged from C5 to T12. The mean (SD) age and duration of injury of the sample was 25.61 (6.68) years and 31.03 (28.69) months, respectively. SMIP and FIT correlated significantly with FSB (r s= .441, p = .01, and r s= .434, p = .006, respectively). A significant correlation between SMIP and A:U ratio (r s= -.330, p = .043) was observed.

Conclusion

We observed a significant correlation between inspiratory pressure parameters and both functional seated balance and body habitus, adding to evidence on postural role of respiratory muscles.

Dynamic hyperinflation on exercise and its relationship with lung mechanics at rest in adults with central obesity

This study aimed to evaluate the presence of dynamic hyperinflation (DH) during the Glittre-ADL test (TGlittre) coupled to the dynamic ventilation measurements in people with central obesity (pwCO) and to correlate it with lung mechanics at rest. Sixty-four pwCO underwent TGlittre and the following resting lung function tests: spirometry and impulse oscillometry system (IOS). On TGlittre, 22 participants presented DH at the end of the test (DH group), while 42 did not present DH (NDH group). Body mass index (BMI), waist circumference (WC), and hip circumference (HC) were higher in the DH group than in the NDH group. IOS abnormalities were more common in the DH group compared to the NDH group. TGlittre time significantly correlated with BMI, WC, waist-to-hip ratio (WHR), and neck circumference (NC). Delta inspiratory capacity correlated significantly with WC, HC, NC, and resonance frequency measured by IOS. Thus, pwCO perform worse on TGlittre, and DH is frequent in those with higher anthropometric indices and worse lung mechanics.

Impact of Transplant Body Mass Index and Post-Transplant Weight Changes on the Development of Chronic Lung Allograft Dysfunction Phenotypes

INTRODUCTION

Chronic lung allograft dysfunction (CLAD) is a lung transplant complication for which four phenotypes are recognized: Bronchiolitis obliterans syndrome (BOS), Restrictive allograft syndrome (RAS), mixed and undefined phenotypes. Weight gain is common after transplant and may negatively impact lung function. Study objectives were to describe post-transplant weight trajectories of patients who developed (or did not) CLAD phenotypes and examine the associations between BMI at transplant, post-transplant changes in weight and BMI, and the risk of developing these phenotypes.

METHODS

Adults who underwent a bilateral lung transplant between 2000 and 2020 at our institution were categorized as having (or not) one of the four CLAD phenotypes based on the proposed classification system. Demographic, anthropometric, and clinical data were retrospectively collected from medical records and analyzed.

RESULTS

Study population included 579 recipients (412 [71.1%] CLAD-free, 81 [14.0%] BOS, 20 [3.5%] RAS, 59 [10.2%] mixed, and 7 [1.2%] undefined phenotype). Weight gains of greater amplitude were seen in recipients with restrictive phenotypes than CLAD-free and BOS patients within the first five years post-transplant. While the BMI category at transplant was not statistically associated with the risk of developing CLAD phenotypes, an increase in weight (Hazard ratio [HR]: 1.04, 95% CI [1.01-1.08]; P = .008) and BMI (HR: 1.13, 95% CI [1.03-1.23]; P = .008) over the post-transplant period was associated with a greater risk of RAS.

CONCLUSION

Post-LTx gain in weight and BMI modestly increased the risk of RAS, adding to the list of unfavorable outcomes associated with weight gain following transplant.

The Role of Obstructive Sleep Apnea in Hypercapnic Respiratory Failure Identified in Critical Care, Inpatient, and Outpatient Settings

An emerging body of literature describes the prevalence and consequences of hypercapnic respiratory failure. While device qualifications, documentation practices, and previously performed clinical studies often encourage conceptualizing patients as having a single "cause" of hypercapnia, many patients encountered in practice have several contributing conditions. Physiologic and epidemiologic data suggest that sleep-disordered breathing-particularly obstructive sleep apnea (OSA)-often contributes to the development of hypercapnia. In this review, the authors summarize the frequency of contributing conditions to hypercapnic respiratory failure among patients identified in critical care, emergency, and inpatient settings with an aim toward understanding the contribution of OSA to the development of hypercapnia.

Perioperative Dexmedetomidine Infusion Improves Perioperative Care of Bariatric-Metabolic Surgery: A Single Center Experience with Meta-Analysis

PURPOSE

This study aims to determine the effects of perioperative dexmedetomidine infusion (PDI) on Asian patients undergoing bariatric-metabolic surgery (BMS), focusing on the need for pain medications and management of postoperative nausea and vomiting (PONV), and to investigate the association with these variables, including patients' characteristics and BMS data.

MATERIALS AND METHODS

A retrospective review of prospectively collected data was conducted in an Asian weight management center from August 2016 to October 2021. A total of 147 native patients with severe obesity were enrolled. All patients were informed of the full support of perioperative pain medications for BMS. The pain numeric rating scale scores, events of PONV, needs for pain medications, and the associated patients' characteristics were analyzed. A p-value of < 0.05 was considered statistically significant. Furthermore, to verify the effects of perioperative usage of dexmedetomidine for BMS, a systematic review with meta-analysis of currently available randomized control trials was performed.

RESULTS

Among the 147 enrolled patients, 107 underwent laparoscopic sleeve gastrectomy and 40 underwent laparoscopic Roux-en-Y gastric bypass. PDI has been used as an adjunct multimodal analgesia for BMS in our institution since June 2017 (group D; n = 114). In comparison with those not administered with perioperative dexmedetomidine (group C; n = 33), lower pain numeric rating scale scores (2.52 ± 2.46 vs. 4.27 ± 2.95, p = 0.007) in the postanesthesia care unit, fewer PONV (32.46% vs. 51.52%; p = 0.046), and infrequent needs of additional pain medications (19.47% vs. 45.45%; p = 0.003) were observed in group D. Multivariable analysis demonstrated that type II diabetes mellitus was correlated with the decreased need of pain medications other than PDI (p = 0.035). Moreover, dexmedetomidine seemed to have a better analgesic effect for patients with longer surgical time based on our meta-analysis.

CONCLUSION

Based on our limited experience, PDI could be a practical solution to alleviate pain and PONV in Asian patients undergoing BMS. Moreover, it might reduce the need for rescue painkillers with better postoperative pain management for patients with type II diabetes mellitus or longer surgical time.

Association of Diaphragm Thickness and Respiratory Muscle Strength With Indices of Sarcopenia

OBJECTIVE

To evaluate the relationship between respiratory muscle strength, diaphragm thickness (DT), and indices of sarcopenia.

METHODS

This study included 45 healthy elderly volunteers (21 male and 24 female) aged 65 years or older. Sarcopenia indices, including hand grip strength (HGS) and body mass index-adjusted appendicular skeletal muscle (ASM/BMI), were measured using a hand grip dynamometer and bioimpedance analysis, respectively. Calf circumference (CC) and gait speed were also measured. Maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) were obtained using a spirometer, as a measure of respiratory muscle strength. DT was evaluated through ultrasonography. The association between indices of sarcopenia, respiratory muscle strength, and DT was evaluated using Spearman's rank correlation test, and univariate and multiple regression analysis.

RESULTS

ASM/BMI (r=0.609, p<0.01), CC (r=0.499, p<0.01), HGS (r=0.759, p<0.01), and gait speed (r=0.319, p<0.05) were significantly correlated with DT. In the univariate linear regression analysis, MIP was significantly associated with age (p=0.003), DT (p<0.001), HGS (p=0.002), CC (p=0.013), and gait speed (p=0.026). MEP was significantly associated with sex (p=0.001), BMI (p=0.033), ASM/BMI (p=0.003), DT (p<0.001), HGS (p<0.001), CC (p=0.001) and gait speed (p=0.004). In the multiple linear regression analysis, age (p=0.001), DT (p<0.001), and ASM/BMI (p=0.008) showed significant association with MIP. DT (p<0.001) and gait speed (p=0.050) were associated with MEP.

CONCLUSION

Our findings suggest that respiratory muscle strength is associated with DT and indices of sarcopenia. Further prospective studies with larger sample sizes are needed to confirm these findings.

Implications of obesity and adiposopathy on respiratory infections; focus on emerging challenges

Obesity is characterized by excessive adipose tissue accumulation, which impacts physiological, metabolic, and immune functions. Several respiratory infections, including bacterial pneumonia, influenza, and coronavirus disease 2019, appear to be linked to unfavorable results in individuals with obesity. These may be attributed to the direct mechanical/physiological effects of excess body fat on the lungs’ function. Notably, adipose tissue dysfunction is associated with a low-grade chronic inflammatory status and hyperleptinemia, among other characteristics. These have all been linked to immune system dysfunction and weakened immune responses to these infections. A better understanding and clinical awareness of these risk factors are necessary for better disease outcomes.

The effects of breast reduction on pulmonary functions: A systematic review

Breast reduction is one of the most commonly requested and performed plastic surgery procedures, and its psychological, esthetic, and analgesic benefits are well known. Several studies dealing with the effects of reduction mammoplasty on the physiology of respiration have been published in the past decades. This systematic review aims to assess whether bilateral breast reduction is associated with measurable improvement in lung function in women with macromastia. This review was performed in accordance with the PRISMA guidelines. PubMed, SCOPUS, and Web of Science databases were queried in search of clinical studies that investigated lung function in women undergoing breast reduction for macromastia and reported any type of parameter or outcome measure relevant to pulmonary function. The search yielded 394 articles of which 15 articles met our specific inclusion criteria. The primary outcome measures of the studies and their respective results were tabulated, contrasted, and compared. The 15 studies included in this review cover the period from 1974 to 2018. According to most included studies, reduction mammaplasty produces a change of objective respiratory parameters, such as spirometric tests or arterial blood gas (ABG) measurements; nevertheless, the clinical and functional relevance of the observed changes is debatable.

Determinants of Longitudinal Change of Lung Function in Different Gender in a Large Taiwanese Population Follow-Up Study Categories: Original Investigation

Chronic lung disease is associated with tremendous social and economic burden worldwide. The aim of this study was to investigate the sex-specific risk factors for changes in lung function in a large longitudinal study. We included 9059 participants from the Taiwan Biobank. None of the participants had a history of smoking, asthma, emphysema or bronchitis. Lung function was assessed using spirometry measurements of forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1). Change in the FEV1/FVC (ΔFEV1/FVC) was calculated as a follow-up FEV1/FVC minus baseline FEV1/FVC. Linear regression analysis was used to identify associations between variables and ΔFEV1/FVC in the male and female participants. After multivariable adjustments, the male participants (vs. females; p = 0.021) were significantly associated with a low ΔFEV1/FVC. In addition, the male participants with low aspartate aminotransferase (AST) (p = 0.003), high alanine aminotransferase (ALT) (p = 0.006) and a low estimated glomerular filtration rate (eGFR) (p = 0.003) were significantly associated with a low ΔFEV1/FVC. For the female participants, low systolic blood pressure (p = 0.005), low diastolic blood pressure (p = 0.031), low AST (p < 0.001), high ALT (p < 0.001) and a low eGFR (p = 0.001) were significantly associated with a low ΔFEV1/FVC. In this large follow-up study, we found that the male participants had a faster decrease in the FEV1/FVC than the female participants. In addition, liver and renal functions were correlated with changes in lung function in both the male and female participants. Our findings provide useful information on sex-specific changes in lung function.

Influencing Factors of Daytime Sleepiness in Patients with Obstructive Sleep Apnea Hypopnea Syndrome and Its Correlation with Pulse Oxygen Decline Rate

Objective

To explore the influencing factors of daytime sleepiness in patients with obstructive sleep apnea hypopnea syndrome (OSAHS) and the correlation between daytime sleepiness and pulse oxygen decline rate in patients with severe OSAHS.

Methods

From January 2018 to April 2021, 246 consecutive patients with OSAHS diagnosed by polysomnography (PSG) in our hospital were selected. All patients were grouped according to the minimum nocturnal oxygen saturation and apnea hypopnea index (AHI). There were 33 cases in the no sleep hypoxia group, 34 cases in the mild hypoxia group, 119 cases in the moderate hypoxia group, and 60 cases in the severe hypoxia group. There were 30 cases in the simple snoring group, 55 cases in the mild OSAHS group, 48 cases in the moderate OSAHS group, and 113 cases in the severe OSAHS group. The Epworth Sleepiness Scale (ESS) scores of each group were compared. All patients were grouped according to ESS score. Those with score ≥9 were included in the lethargy group (n = 118), and those with score ≤10 were included in the no lethargy group (n = 128). Univariate and multivariate logistic regression analyses were used to explore the influencing factors of daytime sleepiness in OSAHS patients. Pearson correlation analysis showed the correlation between ESS score and pulse oxygen decline rate in patients with severe OSAHS.

Results

The ESS score of the severe hypoxia group > the moderate hypoxia group > the mild hypoxia group > the no sleep hypoxia group. There was significant difference among the groups (F = 19.700, P < 0.0001). There were significant differences between the severe hypoxia group and other groups and between the moderate hypoxia group and the no sleep hypoxia group and the mild hypoxia group (P < 0.05). The ESS score of the severe OSAHS group > the moderate OSAHS group > the mild OSAHS group > the simple snoring group. There was significant difference among the groups (F = 19.000, P < 0.0001). There were significant differences between the severe OSAHS group and other groups and between the moderate OSAHS group and the simple snoring group (P < 0.05). Univariate analysis showed that BMI, neck circumference, snoring degree, total apnea hypopnea time, AHI, micro arousal index (MAI), oxygen saturation (CT90%), lowest oxygen saturation (LSaO2), and mean oxygen saturation (MSaO2) were the influencing factors of daytime sleepiness in OSAHS patients (P < 0.05). Multiple logistic regression analysis showed that AHI and CT90% were independent risk factors for daytime sleepiness in OSAHS patients (P < 0.05). Pearson correlation analysis showed that there was a positive correlation between ESS score and pulse oxygen decline rate in patients with severe OSAHS (r = 0.765, P < 0.0001).

Conclusion

OSAHS patients may be accompanied by daytime sleepiness in varying degrees, which may be independently related to AHI and CT90%. The degree of daytime sleepiness in patients with severe OSAHS may be closely related to the decline rate of pulse oxygen, which should be paid great attention in clinic.