Treadmill test and six minute step test for evaluation of exercise-induced bronchospasm: are they interchangeable?

• Grant number: 17/16607-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2017
• End date: June 30, 2019
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Simone Dal Corso
• Grantee: Laryssa Souza Leitão
• Host Institution: Universidade Nove de Julho (UNINOVE). Campus Vergueiro. São Paulo , SP, Brazil

Abstract

The bronchoprovocation tests with exercises most used and cited in the literature are the tests with constant load in cycle ergometer and treadmill. The step test is a simple test, low cost and easy to apply. The objective of this study was to compare the six-minute step test (TD6) with incremental treadmill cardiopulmonary exercise test to evaluate exercise-induced bronchospasm (EIB) in patients diagnosed with asthma; Secondarily, to contrast the cardiorespiratory demand during exercise between both tests. It will be evaluated 53 patients with asthma from the Department of the Federal University of São Paulo (UNIFESP), aged between 7 and 18 years, of both genders and clinically stable. The exclusion criteria will be: severity score 5, according to Global Initiative for Asthma (GINA), presence of other chronic lung diseases, comorbidities and smoking. The protocol will consist of two visits, separated by at least 72 hours, and the order of the tests will be randomized. In both visits, the patients will perform the following sequence: pre-exercise spirometry, bronchoprovocation exercise test (according to randomization) together with analysis of expired gases and spirometry at times 5, 10, 15, 20 and 30 minutes after exercise. The hypothesis of our study is that the six-minute step test and the treadmill test will be equivalent in inducing the BIE because cardiopulmonary demands will be similar between these tests. If our hypothesis is confirmed, the TD6 can be used as a bronchial challenge test, with the advantage of being more accessible and inexpensive to be performed in the office or outpatient clinic. (AU)