Clinical trial NCT01903785: Salbutamol, Pharmacogenetics and Breathing Mechanics
Official title: The Pharmacogenetic Effects of Inhaled Salbutamol on Breathing Mechanics and Cycling Performance
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Bronchoconstriction
Inhaled Salbutamol
Cycling Performance
Keywords: exercise-induced bronchoconstriction (EIB)
inhaled salbutamol
performance enhancing
cycling
Lead sponsor: University of British Columbia
Sponsor class: OTHER
Collaborators: name: World Anti-Doping Agency
First posted: 2013-07-19
Enrollment: 94
Sex: ALL
Minimum age (years): 19
Maximum age (years): 45
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief summary: Athletes using asthma medications called β2-agonists win a disproportionately high number of medals at Olympic Games. Due to a large variety in the genes that affect how individuals respond to β2-agonists, the investigators will look at variations in the genetic response to these medications by dividing athletes into high-responders and low-responders. The investigators will then compare athletic performance after the inhalation of β2-agonists to placebo. Furthermore, the investigators will analyze the effect of β2-agonists on breathing mechanics. Due to differences in their anatomy females may decrease the energy needed for breathing during high-intensity exercise to a greater extent compared to male athletes after the inhalation of β2-agonists.


Eligibility criteria: Inclusion Criteria:

* trained, experienced cyclists
* maximal oxygen consumption of at least 50ml/kg/min or 4l/min for women; and 60ml/kg/min or 5l/min for men
* athletes with and without exercise-induced bronchoconstriction

Exclusion Criteria:

* any uncontrolled heart or lung condition
* maximal oxygen consumption of less than 50ml/kg/min or 4L/min for women; and less than 60ml/kg/min or 5L/min for men
* pregnancy
* smoking

Primary outcomes:
measure: The effect of inhaled salbutamol on mean power output during cycling performance in female and male athletes
timeFrame: Mean power output is assessed over the duration of a 10km time trial (start of time trial until completion of time trial) on a bike ergometer.
measure: The effect of inhaled salbutamol on work of breathing (WOB) and expiratory flow limitation (EFL) in female and male athletes
timeFrame: WOB and EFL will be assessed during an incremental exercise test. Exercise will start at 0 Watts and will then be increased every 2.5min by 30 Watts until maximal exertion.
Secondary outcomes:
measure: The effect of inhaled salbutamol on minute ventilation in asthmatic and non-asthmatic trained, female and male cyclists
timeFrame: Minute ventilation will be assessed during two 10km time trials (one time trial will be started 60min after the inhalation of salbutamol, the second time trial will be started 60min after the inhalation of placebo).
Other outcomes:
Locations:
city: Vancouver
country: Canada
facility: Environmental Physiology Laboratory, University of British Columbia
state: British Columbia
Study officials:
affiliation: University of British Columbia
name: Michael S Koehle, MD, PhD
role: PRINCIPAL_INVESTIGATOR
References: