Identifying the Characteristics of Responders and Nonresponders in a Behavioral Intervention to Increase Physical Activity Among Patients With Moderate to Severe Asthma: Protocol for a Prospective Pragmatic Study.

BACKGROUND: Previous research has suggested that most adults improve their asthma control after a short-term behavioral intervention program to increase physical activity in daily life (PADL). However, the characteristics of individuals who respond and do not respond to this intervention and the medium-term response remain unknown. OBJECTIVE: This study aims to (1) identify the characteristics of adult responders and nonresponders with asthma to a behavioral intervention to increase physical activity and (2) evaluate the functional and clinical benefits in the medium term. METHODS: This prospective pragmatic study will include adults with moderate to severe asthma who enroll in a behavioral intervention. All individuals will receive an educational program and an 8-week intervention to increase PADL (1 time/wk; up to 90 min/session). The educational program will be conducted in a class setting through group discussions and video presentations. Behavioral interventions will be based on the transtheoretical model using counseling, incentives, and individual feedback aiming to increase participation in physical activity. Motivational interviewing and guidelines for overcoming barriers will be used to stimulate individuals to reach their goals. Pre- and postintervention assessments will include the following: PADL (triaxial accelerometry), body composition (octopolar bioimpedance), barriers to PADL (questionnaire), clinical asthma control (Asthma Control Questionnaire), quality of life (Asthma Quality of Life Questionnaire), anxiety and depression levels (Hospital Anxiety and Depression Scale), and exacerbations. "Responders" to the intervention will be defined as those who demonstrate an increase in the number of daily steps (≥2500). RESULTS: In December 2021, the clinical trial registration was approved. Recruitment and data collection for the trial is ongoing, and the results of this study are likely to be published in late 2024. CONCLUSIONS: The intervention will likely promote different effects according to the clinical characteristics of the individuals, including asthma control, age, anxiety and depression levels, obesity, and several comorbidities. Identifying individuals who respond or do not respond to behavioral interventions to increase PADL will help clinicians prescribe specific interventions to adults with asthma. TRIAL REGISTRATION: ClinicalTrials.gov NCT05159076; https://clinicaltrials.gov/ct2/show/NCT05159076. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/49032.

Physical training in adults with asthma: An integrative approach on strategies, mechanisms, and benefits.

Asthma is a chronic airway disease characterized by airflow limitation and respiratory symptoms associated with chronic airway and systemic inflammation, bronchial hyperreactivity (BHR), and exercise-induced bronchoconstriction (EIB). Asthma is a heterogeneous disease classified according to distinct airway and systemic inflammation. Patients commonly present with several comorbidities, including anxiety, depression, poor sleep quality, and reduced physical activity levels. Individuals with moderate to severe asthma often have more symptoms and difficulty achieving adequate clinical control, which is associated with poor quality of life, despite proper pharmacological treatment. Physical training has been proposed as an adjunctive therapy for asthma. Initially, it was suggested that the effect of physical training might be attributed to the improved oxidative capacity and reduced production of exercise metabolites. However, in the last decade, there has been evidence that aerobic physical training promotes anti-inflammatory effects in asthma patients. Physical training improves BHR and EIB, asthma symptoms, clinical control, anxiety, and depression levels, sleep quality, lung function, exercise capacity, and dyspnea perception. Furthermore, physical training reduces medication consumption. The most commonly used exercise strategies are moderate aerobic and breathing exercises; however, other techniques, such as high-intensity interval training, have shown promising effects. In the present study, we reviewed the strategies and beneficial effects of exercise on clinical and pathophysiological asthma outcomes.

Quantification of 6-nitrodopamine in Krebs-Henseleit's solution by LC-MS/MS for the assessment of its basal release from Chelonoidis carbonaria aortae in vitro.

In this study, the development and validation of a method for quantification of 6-nitrodopamine in Krebs-Henseleit's solution by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) with positive ion electrospray ionization is described. Aortic rings taken from tortoise were either denuded or left with endothelium intact (15 mm, N = 6) and were incubated for 30 min in 5 mL Krebs-Henseleit's solution in an organ bath. Solid phase extraction (SPE) was performed for aliquots of 1 mL of the supernatant. The separation of 6-nitrodopamine was obtained on a 150 mm × 3 mm Shim-pack GIST-HP C18 column, using 75% of mobile phase A consisted of deionized water with 0.1% formic acid (v/v) and 25% of mobile phase B consisted of acetonitrile/deionized water (50/50, v/v) + 0.1% formic acid at a flow rate of 350 µL/min in an isocratic mode. The method was linear over the concentration range of 0.1-20 ng/mL. The method was sensitive, precise and accurate for the assessment of the basal release of 6-nitrodopamine from Chelonoidis carbonaria aortae in vitro. The mean ± SEM concentrations of 6-nitrodopamine released from endothelium-intact and endothelium-denuded aortae were 0.44 ± 0.06 ng/mL and 0.18 ± 0.05 ng/mL, respectively. These results indicate that tortoise's aortae display a basal endothelium-derived 6-nitrodopamine release.

The basal release of endothelium-derived catecholamines regulates the contractions of Chelonoidis carbonaria aorta caused by electrical-field stimulation.

The contractions of Chelonoidis carbonaria aortic rings induced by electrical field stimulation (EFS) are not inhibited by blockade of the voltage-gated sodium channels by tetrodotoxin but almost abolished by the α1/α2-adrenoceptor antagonist phentolamine. The objective of this study was to identify the mediator(s) responsible for the EFS-induced contractions of Chelonoidis carbonaria aortic rings. Each ring was suspended between two wire hooks and mounted in isolated 10 ml organ chambers filled with oxygenated and heated Krebs-Henseleit's solution. Dopamine, noradrenaline and adrenaline concentrations were analysed by liquid chromatography coupled to tandem mass spectrometry. The contractions caused by dopamine and EFS were done in absence and presence of the nitric oxide (NO) synthesis inhibitor L-NAME, the NO-sensitive guanylyl cyclase inhibitor ODQ, the D1-like receptor antagonist SCH-23390, the D2-like receptor antagonists risperidone, quetiapine, haloperidol, and the tyrosine hydroxylase inhibitors salsolinol and 3-iodo-L-tyrosine. Basal concentrations of dopamine, noradrenaline and adrenaline were detected in Krebs-Henseleit solution containing the aortic rings. The catecholamine concentrations were significantly reduced in endothelium-denuded aortic rings. L-NAME and ODQ significantly potentiated the dopamine-induced contractions. The D2-like receptor antagonists inhibited the EFS-induced contractions of the aortic rings treated with L-NAME, whereas SCH 23390 had no effect. Similar results were observed in the contractions induced by dopamine in L-NAME treated aortic rings. These results indicate that catecholamines released by endothelium regulate the EFS-induced contractions. This may constitute a suitable mechanism by which reptilia modulate specific organ blood flow distribution.This paper has an associated First Person interview with the first author of the article.