Study on the incidence of laryngopharyngeal reflux in healthy volunteers during a 90-day head-down tilt bed rest experiment
Objective To study the influence of long term simulated weightlessness on occurrence of laryngopharyngeal reflux(LPR)in healthy volunteers by detection of pepsin in saliva.Methods During a 90-day head-down tilt bed rest(HDTBR)experiment,11 volunteers(4 from the control group and 7 from the countermeasure group)were recruited in the study in the following seven sessions:before bed rest session(Pre),during bed rest sessions for 3 days(BR3),31 days(BR31),61 days(BR61),85 days(BR85)and post bed rest sessions for 7 days(R7)and 25 days(R25).During each testing session,saliva samples were collected for two consecutive days both in the morning and at night before sleeping.Then pepsin in the saliva was measured by enzyme-linked immunosorbent assay.Scale of otorhinolaryngological symptoms for the duration of"Pre-,During-and Post-"were retrospectively performed.Results Among 288 saliva samples of 11 volunteers,17 saliva samples of 8 volunteers were positive for pepsin.The incidence of LPR was 9.1%(1/11)in the Pre session,and it increased to 36.4%in the BR31 session which was higher than the following consequential sessions(0%in BR31,27.3%in BR61 and 27.3%in BR85).Intriguingly,it rose again to 45.5%in R7 session and decreased to 9.1%until in R25 session.There was no significant difference between the control group and the countermeasure group.Total scores for the scale of otorhinolaryngological symptoms showed that a slight elevation tendency emerged during HDTBR session,compared with the pre-HDTBR session.It recovered during the post bed rest sessions.Conclusion The laryngopharyngeal reflux was found in the Pre,During and Post HDTBR experiment.The incidence was significantly increased both in the BR3 and R7 sessions,which indicates that the change of the posture with the stimulation of gastrointestinal dynamic conditions,despite the changes from vertical to horizontal or from horizontal to vertical,might be the major impact factor contributing to the elevation tendency of the incidence of laryngopharyngeal reflux.
laryngopharyngeal refluxpepsinsalivasimulated weightlessnesshead-down bed rest
万方数据
维普
