Respiratory symptoms and inflammatory responses to a Difflam^TM throat spray intervention in half-marathon runners: A randomised controlled trial

¹ Australian Institute of Sport, Australia
² University of Newcastle, Australia
³ Australian Institute of Sport,, Australia

^* To whom correspondence should be addressed. E-mail: amanda.cox{at}ausport.gov.au.

Accepted 6 May 2008

	Abstract

Objective: To investigate the effects of Difflam^TM Forte Anti-inflammatory Throat Spray on the incidence of upper respiratory symptoms (URS) and inflammatory responses following a half-marathon race. Design and Setting: Double-blind placebo-controlled randomised trial conducted in association with a half-marathon event.

Participants: Forty-five well-trained half-marathon runners

Interventions: Difflam^TM Forte Anti-inflammatory Throat Spray (n=25) or Placebo (n=20) throat sprays were self-administered three times daily for one week prior to and two weeks following the race.

Main outcome measures: Self-reported respiratory symptoms; plasma prostaglandin E2, myeloperoxidase, Interleukin (IL)-6, IL-8, IL-10 and IL-1 receptor antagonist (IL-1ra) concentrations; and salivary myeloperoxidase and IL-6 concentrations.

Results: All subjects completed the intervention without reporting any adverse events. The proportion of athletes reporting URS was not substantially different between Difflam (52%) and Placebo (56%) groups (p=0.82). However, symptom severity scores were ~30% lower during Difflam^TM Forte Anti-inflammatory Throat Spray treatment (7.4 ± 8.2 versus 9.9 ± 11.7 arbitrary units). Post-exercise responses in plasma inflammatory markers did not differ substantially between Difflam and Placebo groups. Post-race increases in salivary myeloperoxidase (~63%; trivial to moderate difference; p=0.13) and salivary IL-6 (~50%; trivial to moderate difference; p=0.25) were greater in the Difflam group.

Conclusions: Prophylactic use of the Difflam^TM Forte Anti-inflammatory Throat Spray reduced the severity, but not the frequency of upper respiratory symptoms among half-marathon runners. Post-race increases in systemic inflammatory markers were not altered by Difflam^TM Forte Anti-inflammatory Throat Spray use, but markers of local inflammation (salivary myeloperoxidase and IL-6) were augmented in the Difflam compared with the Placebo group.