Obesity and asthma: risk, control and treatment

Combined Exercise and Diet Induce Airway Hyperreactivity While Reducing Liver Steatosis in Mice with Diet-Induced Obesity

BACKGROUND

Obesity is a multi-organ system disease, which is associated with, e.g., a higher prevalence of non-alcoholic fatty liver disease (NAFLD) and asthma. Little is known regarding the effect of obesity-related parameters (including liver integrity) and the respiratory phenotype after a combination of physical activity and diet.

METHODS

Thirty-two C57BL/6 mice were, after 27 weeks of a high fat diet (HFD), randomly assigned to two dietary interventions for three weeks: a HFD or a normal chow diet (NCD). In both dietary groups, half of the animals were subjected to a sub-maximal exercise protocol. Lung function, lung inflammation, liver histology, and metabolic profile were determined.

RESULTS

Mice with obesity did not show airway hyperreactivity after methacholine provocation. Sub-maximal exercise with diet (NCD/E) induced a significant reduction in forced expiratory volume in 0.1 s after methacholine provocation. NCD/E had significantly more neutrophils and inflammation (IFN-γ, TNF-α, IL-4, and IL-17F) in bronchoalveolar lavage compared to non-exercising mice on a HFD (HFD/NE). However, more epithelial injury (serum surfactant protein D and IL-33) was seen in HFD/NE. Additionally, hepatic steatosis and fibrosis were reduced by combined diet and sub-maximal exercise.

CONCLUSIONS

Combining sub-maximal exercise with diet induced airway hyperreactivity and pulmonary inflammation, while body weight, hepatic steatosis, and fibrosis improved.

The absence of thioredoxin-interacting protein in alveolar cells exacerbates asthma during obesity

Obesity is associated with an increased incidence of asthma. However, the mechanisms underlying this association are not fully understood. In this study, we investigated the role of thioredoxin-interacting protein (TXNIP) in obesity-induced asthma. Asthma was induced by intranasal injection of a protease from Aspergillus oryzae in normal diet (ND)- or high fat diet (HFD)-fed mice to investigate the symptoms. We measured TXNIP expression in the lungs of patients with asthma and in ND or HFD asthmatic mice. To explore the role of TXNIP in asthma pathogenesis, we induced asthma in the same manner in alveolar type 2 cell-specific TXNIP deficient (TXNIPCre) mice. In addition, the expression levels of pro-inflammatory cytokines were compared based on TXNIP gene expression in A549 cells stimulated with recombinant human tumor necrosis factor alpha. Compared to ND-fed mice, HFD-fed mice had elevated levels of free fatty acids and adipokines, resulting in high reactive oxygen species levels and more severe asthma symptoms. TXNIP expression was increased in both, asthmatic patients and HFD asthmatic mice. However, in experiments using TXNIPCre mice, despite being TXNIP deficient, TXNIPCre mice exhibited exacerbated asthma symptoms. Consistent with this, in vitro studies showed highest expression levels of pro-inflammatory cytokines in TXNIP-silenced cells. Overall, our findings suggest that increased TXNIP levels in obesity-induced asthma is compensatory to protect against inflammatory responses.

Management of comorbidities in difficult and severe asthma

Difficult-to-treat and severe asthma are challenging clinical entities. In the face of suboptimal asthma control, the temptation for clinicians is to reflexively escalate asthma-directed therapy, including increasing exposure to corticosteroids and commencement of costly but potent biologic therapies. However, asthma control is objectively and subjectively assessed based on measurable parameters (such as exacerbations or variability in pulmonary physiology), symptoms and patient histories. Crucially, these features can be confounded by common untreated comorbidities, affecting clinicians' assessment of asthma treatment efficacy.

From Beneath the Skin to the Airway Wall: Understanding the Pathological Role of Adipose Tissue in Comorbid Asthma-Obesity

This article provides a contemporary report on the role of adipose tissue in respiratory dysfunction. Adipose tissue is distributed throughout the body, accumulating beneath the skin (subcutaneous), around organs (visceral), and importantly in the context of respiratory disease, has recently been shown to accumulate within the airway wall: "airway-associated adipose tissue." Excessive adipose tissue deposition compromises respiratory function and increases the severity of diseases such as asthma. The mechanisms of respiratory impairment are inflammatory, structural, and mechanical in nature, vary depending on the anatomical site of deposition and adipose tissue subtype, and likely contribute to different phenotypes of comorbid asthma-obesity. An understanding of adipose tissue-driven pathophysiology provides an opportunity for diagnostic advancement and patient-specific treatment. As an exemplar, the potential impact of airway-associated adipose tissue is highlighted, and how this may change the management of a patient with asthma who is also obese. © 2023 American Physiological Society. Compr Physiol 13:4321-4353, 2023.

Rural-Urban Differences in Physical Fitness and Overweight Prevalence of Children and Adolescents from Central South China

PURPOSE

This present study aims to determine the rural-urban differences in physical fitness and overweight prevalence among children and adolescents from Central South China.

METHODS

All the original parameters of physical fitness indicators for 216,718 participants aged from 7 to 15 years old were obtained from the website of the Chinese National Student Physical Fitness Database and were analyzed by SPSS.

RESULTS

(1) Children and adolescents from rural areas were observed to have a more adverse physical fitness ratio, and the urban-rural differences were identified in each physical fitness indicator. (2) Rural areas had a higher overweight prevalence (p < 0.01). When compared to urban cities, overweight students from rural towns measured a significantly poorer cardiorespiratory and muscular fitness in primary school (p < 0.05), while the result in middle school was showed the opposite. (3) Rural-urban residence and sex were the moderately correlated factors for muscular fitness among overweight students.

CONCLUSIONS

Urban children and adolescents in central south China had an overall healthier profile than their rural peers, particularly in overweight groups. The government and related functional departments should take the factors of rural-urban residence and sex of students into consideration when building a state strategy and interventions to promote physical activity and health.

Prevalence and associations between metabolically unhealthy obesity and asthma exacerbations and emergency department usage

BACKGROUND

Th1 cell polarization and monocyte cell activation influence FEV1/FVC and are affected by body mass index (BMI), insulin resistance, and serum lipoproteins. No study has assessed the impact of metabolic syndrome components on asthma symptom control.

OBJECTIVE

We aimed to determine the prevalence of patients with metabolically unhealthy obesity (MUO) and asthma. Our secondary objective was to compare the strength of associations between asthma outcomes in obese patients measured by BMI, waist circumference, and MUO.

METHODS

A cross-sectional analysis of the combined 2011-2016 cycles of NHANES was performed among persons with asthma. MUO was defined as a BMI ≥ 30kg/m 2 and one of the following: increased waist circumference, insulin resistance, low physical activity, hyperlipidemia, or hypertension. Multiple logistic regression models were computed to assess asthma exacerbations and emergency department usage for asthma in patients with metabolically healthy compared to unhealthy obesity.

RESULTS

Among respondents with MUO, 50.09% (n=543; N=17011880) had asthma compared to 7.91% in those with metabolically healthy obesity (n=77; N=2685858). Persons with MUO were significantly more likely to report the use of an emergency department for their asthma symptoms within the past 12 months (OR 3.53; 95%CI 1.54-8.09). Persons with elevated waist circumference were more likely to report asthma exacerbations (OR 1.58; 95%CI 1.09-2.26). No significant difference existed in reported asthma exacerbations or emergency department usage in patients measured by BMI.

CONCLUSION

Metabolically unhealthy obesity is associated with increased emergency department usage for asthma and is better at predicting exacerbations and emergency department usage than BMI alone.

Personalized Treatment of Asthma: The Importance of Sex and Gender Differences

An individual's sex (nominally male or female, based on biological attributes) and gender (a complex term referring to socially constructed roles, behaviors, and expressions of identity) influence the clinical course of asthma in several ways. The physiologic development of the lungs and effects of sex hormones may explain why more boys than girls have asthma, and after puberty, more women than men have asthma. Female sex hormones have an impact throughout the life span and are associated with poor asthma control. Gender may influence exposure to asthma triggers, and sex and gender can influence the prevalence of comorbidities and interactions with health care professionals. Despite widely reported sex- and gender-based differences in asthma and asthma management, these issues frequently are not considered by health care professionals. There is also inconsistency regarding the use of "sex" and "gender" in scientific discourse; research is needed to define sex- and gender-based differences better and how they might interact to influence asthma outcomes. This review outlines the impact an individual's sex and gender can have on the pathogenesis, clinical course, diagnosis, treatment, and management of asthma.

Glucagon-like peptide-1 receptor agonist inhibits aeroallergen-induced activation of ILC2 and neutrophilic airway inflammation in obese mice

BACKGROUND

Obesity is a risk factor for the development of asthma. However, pharmacologic therapeutic strategies that specifically target obese asthmatics have not been identified. We hypothesize that glucagon-like peptide-1 receptor agonist (GLP-1RA) treatment inhibits aeroallergen-induced early innate airway inflammation in a mouse model of asthma in the setting of obesity.

METHODS

SWR (lean) and TALLYHO (obese) mice were challenged intranasally with Alternaria alternata extract (Alt-Ext) or PBS for 4 consecutive days concurrent with GLP-1RA or vehicle treatment.

RESULTS

TALLYHO mice had greater Alt-Ext-induced airway neutrophilia and lung protein expression of IL-5, IL-13, CCL11, CXCL1, and CXCL5, in addition to ICAM-1 expression on lung epithelial cells compared with SWR mice, and all endpoints were reduced by GLP-1RA treatment. Alt-Ext significantly increased BALF IL-33 in both TALLYHO and SWR mice compared to PBS challenge, but there was no difference in the BALF IL-33 levels between these two strains. However, TALLYHO, but not SWR, mice had significantly higher airway TSLP in BALF following Alt-Ext challenge compared to PBS, and BALF TSLP was significantly greater in TALLYHO mice compared to SWR mice following airway Alt-Ext challenge. GLP-1RA treatment significantly decreased the Alt-Ext-induced TSLP and IL-33 release in TALLYHO mice. While TSLP or ST2 inhibition with a neutralizing antibody decreased airway eosinophils, they did not reduce airway neutrophils in TALLYHO mice.

CONCLUSIONS

These results suggest that GLP-1RA treatment may be a novel pharmacologic therapeutic strategy for obese persons with asthma by inhibiting aeroallergen-induced neutrophilia, a feature not seen with either TSLP or ST2 inhibition.

KRN7000 Reduces Airway Inflammation via Natural Killer T Cells in Obese Asthmatic Mice

Although natural killer T cells (NKT cells) are altered in obese asthmatic mice, their function remains completely unclear. To further explore the potential mechanism of NKT cells in airway inflammation of obesity-associated asthma, we examined the effects of α-galactosylceramide (KRN7000) on airway inflammation in obese asthmatic mice. Male C57BL/6J mice were divided into five groups: (1) control; (2) asthma; (3) A + KRN, asthma with KRN7000; (4) obese asthma; and (5) OA + KRN, obese asthma with KRN7000. Cytometric bead array (CBA) was used to detect interleukin-4 (IL-4), IL-10, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) in the serum. Flow cytometry was used to detect NKT cells and CD69⁺ NKT cells. Airway inflammation was observed in pathological sections, and calmodulin (CaM) expression was observed by immunohistochemistry in lung tissues. Airway inflammation in the obese asthma group was more severe than that of the asthma group. Airway inflammation of the OA + KRN group was reduced more than that of the A + KRN group. CD69+ NKT cells were only significantly reduced in the OA + KRN group. The levels of serum IFN-γ and TNF-α increased more in the OA + KRN group than in the A + KRN group. CaM is widely expressed in the cytoplasm of the lung tissues and was sharply decreased in the OA + KRN group. KRN7000 can significantly reduce airway inflammation in obesity-associated asthma by regulating NKT cell cytokine secretion and intracellular calcium. These results may contribute to the development of novel therapeutic approaches.

Clinical profile of chronic bronchial asthma patients in Poland: results of the PROKSAL study

Introduction

Asthma is a complex condition characterized by the presence of chronic inflammation in the lower respiratory tract resulting in many disturbing symptoms. The study of the clinical profile of the population with asthma allows us to understand a trend of a specific disease taking into account several indicators and its clinical characteristics.

Aim

Evaluation of the clinical profile of patients with chronic bronchial asthma in Poland.

Material and methods

The study included 10400 adult patients, of both sexes, diagnosed with chronic bronchial asthma who started therapy based on inhaled glucocorticosteroids accompanied by salmeterol, and 52 allergists. The examination was performed in a doctor's surgery. Standardized questionnaire interviews were used in order to carry out the procedure.

Results

The age of the patients ranged from 18 up to 97 years. Most of them suffer from overweight and obesity. 45.3% of the patients smoked cigarettes or declared to be passive smokers. Current asthma control was poor: over 56% of the patients suffered from diurnal symptoms more often than twice a week, almost 55% from nocturnal symptoms, in 72% of the patients' physical activity was limited, whereas 57% required immediate treatment. Most commonly used drugs were inhaled glucocorticosteroids and short acting β2-mimetics. After treatment change, fewer patients suffered from asthma symptoms.

Conclusions

Adjusting the therapy according to the current guidelines and to the patient's needs helps to improve asthma control.

Managing Asthma and Obesity Related Symptoms (MATADORS): An mHealth Intervention to Facilitate Symptom Self-Management among Youth

Youth with multi-morbidity (one or more chronic diseases) are at increased risk of further morbidity and early mortality as they enter their adult years. Recent increases in both asthma and obesity among youth have led to high health care utilization, increased health related complications, and expanded risks of subsequent cardiovascular disease burden. Common symptoms seen with asthma and obesity include fatigue, pain, depression, and anxiety. These symptoms can result in decreased physical activity, social isolation, and poor quality of life, which also may contribute to increased morbidity and mortality over time. Youth ages 10–17 are in a transitionary period where their overall health and disease management shifts from one of parental oversight to one where the youth gradually experience increased autonomy over their health and care management. Managing Asthma and Obesity Related Symptoms (MATADORS), is a mHealth technology-enhanced nurse-guided intervention that incorporates a novel mobile health application and motivational enhancement principles within a behavioral activation framework. Providing high-risk youth with strategies to enhance symptom self-management may result in decreased symptom prevalence, improved quality of life, and long-term reduction of cardiovascular morbidity and mortality as they move into adulthood. Moreover, developing low-cost, scalable tools with end-user input may facilitate promote early intervention and improved access to care, and reduce overall disease burden and healthcare costs.

Defining a role for exercise training in the management of asthma

The prevalence of asthma remains high worldwide, with increasing awareness of the morbidity and mortality from asthma in low-income countries. In the UK, despite the development of biological treatments, many patients remain suboptimally controlled, and mortality rates have been static for decades. Therefore, new approaches are needed to treat asthma that are scalable at minimal cost. Exercise immunology is an expanding field, and there is growing evidence that exercise can modulate inflammatory and immune processes in asthma. Whilst exercise is encouraged in current treatment guidelines, there are no specific recommendations as to the intensity, frequency or duration of exercise exposure. Despite national and international guidance to increase exercise, patients with asthma are less likely to engage in physical activity. This review explores the disease modifying benefit of exercise in asthma. We also review the domains in which exercise exerts positive clinical effects in asthma, including the effects of exercise on symptom scores, quality of life, psychosocial health, and in the obese asthma phenotype. Finally, we review the barriers to exercise in asthma, given the benefits it confers. A better understanding of the mechanisms through which exercise exerts its positive effects in asthma may provide more accurate prescription of exercise training programmes as part of broader asthma management, with the potential of identification of new drug targets.

[Asthma and obesity: relationship and therapeutic implications in patients with asthma at the Department of Pneumology in Monastir, Tunisia]

Introduction

L’obésité et l’asthme sont deux maladies chroniques touchant des millions d’individus à travers le monde. La présence d’un lien de causalité est suggérée. L'objectif de notre travail est d'étudier le profil de l’asthmatique obèse et de déterminer la relation entre les différents paramètres de sévérité de l’asthme avec les grades de l’obésité.

Méthodes

Il s'agit d'une étude rétrospective, monocentrique, analytique menée au Service de Pneumologie et d’Allergologie au CHU Fattouma Bourguiba de Monastir portant sur 450 asthmatiques, ayant un indice de masse corporelle (IMC) ≥ 30 kg/m² avec un recul d’au moins 6 mois.

Résultats

L’âge moyen au moment du diagnostic était de 45±12.8 ans. L’IMC moyen était de 34,8±4,2 kg/m². L’asthme était bien contrôlé chez 55,3% des patients. Des critères de sévérité étaient notés dans 37.4% des cas. Selon GINA 2016, 24,2% sont traités par le palier 4. Deux phénotypes de l’asthme associé à l’obésité étaient notés. Le premier phénotype (52,4%) était caractérisé par un asthme à début précoce, associé à une fréquence plus élevée d’allergie, et des manifestations d'atopie. Le deuxième (47,6 %) était caractérisé par un asthme à début tardif, fréquemment associé au sexe féminin et un taux plus élevé de comorbidités et d’hospitalisations. Les obèses de grade II et III avaient un déficit ventilatoire important (CVF: p = 0,002 et VEMS: p = 0,007).

Conclusion

L’obésité est l’un des facteurs clefs impliqués dans le mauvais contrôle de l’asthme. Sa prise en charge, qui n'est pas encore codifiée, doit être multidisciplinaire.

Adults With Asthma Experience No Increase in Asthma-related Exacerbations When Digital Communication Technology Tools Are Employed to Offset Provider Workload: A Pragmatic Randomized Trial

BACKGROUND

Challenges to health care efficiency are increasingly addressed with the help of digital communication technology tools (DCTs).

OBJECTIVE

The objective of this study was to test whether DCT, compared with Usual Care, can reduce health care clinician burden without increasing asthma-related exacerbations among patients with asthma in a large integrated health care system.

RESEARCH DESIGN

The (Breathewell) program was a pragmatic, randomized trial at (Kaiser Permanente Colorado), where asthma nurses screen patients for poor symptom control when beta2-agonist refill requests came within 60 days of previous fill or in the absence of a controller medication fill within 4 months (beta2-agonist overfill). A total of 14,978 adults with asthma were randomized to Usual Care or 1 of 2 DCT intervention groups (Text/Phone call or Email).

SUBJECTS

Participants included adults 18 and older with an asthma diagnosis at the time of randomization and no history of chronic obstructive pulmonary disease.

MEASURES

Primary outcome measures included asthma-related health care resource utilization (eg, asthma nurse contacts), medication use, and exacerbations.

RESULTS

A total of 1933 patients had 4337 events which met beta2-agonist overfill criteria. Of the 2874 events in the intervention arm, 1188 (41%) were resolved by DCT contact and did not require additional clinician contact. Asthma medication use and exacerbations over 12 months did not differ among the 3 groups.

CONCLUSIONS

DCT tools can successfully contact adult asthma patients to screen for symptoms and facilitate intervention. The absence of differences in medication fills and health care utilization indicates that the strategic replacement of nursing interventions by digital outreach did not reduce treatment adherence or compromise health care outcomes.