Variables influencing manometric parameters of deglutitive and non-deglutitive upper esophageal sphincter: A study of 89 asymptomatic participants.

Background High-resolution manometry overcomes limitations imposed by axial and radial asymmetry as well as swallow and respiration-induced movement of the upper esophageal sphincter (UES), allowing for its reliable use in evaluation of dysphagic and reflux patients. The aim of this study was to determine normative values and their variability across position, sex, age, height, weight, BMI, and volume for clinically relevant deglutitive and non-deglutitive UES parameters. Methods We studied 89 asymptomatic volunteers age 19-90 years, (45 female) during 3-10 repetitions of dry, 5 and 10 ml water swallows at 30-s intervals using high-resolution manometry. Key results Upper esophageal sphincter high-pressure zone was longer in men than women and in supine than upright position. UES basal contractile integral and mean basal pressure were higher in supine compared to upright; higher in men than women, inversely correlated with age, correlated positively with height and with weight in the supine position only. UES relaxation duration was longer in upright than in supine position but not affected by age, sex, height, weight, or BMI. It was longer with 5 and 10 ml compared with dry swallows. UES minimum/nadir relaxation and mean relaxation pressures were lower in upright than supine position, increased with increase in age and were higher in men than women. Conclusions and inferences Position, sex, age, height, weight, and volume affect some deglutitive and non-deglutitve UES manometric parameters. BMI does not affect the studied manometric parameters. These effects should be taken into consideration in clinical evaluation of UES.