Gender effects on esophageal motility.

It has been suggested that there are no gender effects on esophageal motility. However, in previous studies the subjects did not perform multiple swallows and the quantitative features of esophageal contractions were not evaluated. In order to investigate the gender effects on esophageal motility we studied 40 healthy normal volunteers, 20 men aged 37 +/- 15 years (mean +/- SD), and 20 women aged 38 +/- 14 years. We used the manometric method with an eight-lumen polyvinyl catheter and continuous perfusion. The upper and lower esophageal sphincter pressures were measured by the rapid pull-through method. With the catheter positioned with one lumen opening in the lower esophageal sphincter, and the others at 5, 10 and 15 cm above the sphincter, ten swallows of a 5-ml water bolus alternated with ten dry swallows were performed. Statistical analysis was done by the Student t-test and Mann-Whitney test. Gender differences (P < 0.05) were observed for wet swallows in the duration of contractions 5 cm above the lower esophageal sphincter (men: 3.7 +/- 0.2 s, women: 4.5 +/- 0.3 s, mean +/- SEM), and in the velocity of contractions from 15 to 10 cm above the lower esophageal sphincter (men: 4.7 +/- 0.3 cm/s, women: 3.5 +/- 0.2 cm/s). There was no difference (P > 0.05) in sphincter pressure, duration and percentage of complete lower esophageal sphincter relaxation, amplitude of contractions, or in the number of failed, multipeaked and synchronous contractions. We conclude that gender may cause some differences in esophageal motility which, though of no clinical significance, should be taken into consideration when interpreting esophageal motility tests.