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Completed

NCT Number: NCT01903785

Salbutamol, Pharmacogenetics and Breathing Mechanics

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.

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Key information

Conditions

Bronchoconstriction Cycling Performance Inhaled Salbutamol

Age range

19 year–45 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

Environmental Physiology Laboratory, University of British Columbia

Vancouver, British Columbia, V6T 1Z1, Canada

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Salbutamol

Drug

60 minutes prior to the start of a 10km cycling time trial on a bike ergometer, subjects will inhale either 400ug of salbutamol 1600ug of salbutamol or 400ug of placebo in a randomly assigned manner in a single dose.

Other names: ventolin

Placebo

Drug

Primary outcomes

  1. The effect of inhaled salbutamol on mean power output during cycling performance in female and male athletes

    Time frame: 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.

    Athletes perform a two time trials, each on a separate day. The time trials are performed 60min after the inhalation of salbutamol or placebo.

  2. The effect of inhaled salbutamol on work of breathing (WOB) and expiratory flow limitation (EFL) in female and male athletes

    Time frame: 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.

    EFL and WOB will be assessed with the help of an esophageal balloon and mouth pressure.

Secondary outcomes

  1. The effect of inhaled salbutamol on minute ventilation in asthmatic and non-asthmatic trained, female and male cyclists

    Time frame: 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).

Sponsors and collaborators

Lead sponsor

University of British Columbia

Other

Collaborators

  • World Anti-Doping Agency

Registry information

Official study title

The Pharmacogenetic Effects of Inhaled Salbutamol on Breathing Mechanics and Cycling Performance

Important dates

Study start
2013
Primary completion
2014
Study completion
2016
First posted
Jul 19, 2013
Registry last updated
Nov 2, 2016

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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