title: Effects of gender and age on esophageal biomechanical properties and sensation.
abstract: OBJECTIVE
  The effects of gender and age on human esophageal function is poorly defined. Our aim was to investigate the sensory perception and the biomechanical properties of the esophagus both at the smooth muscle and the striated muscle segments in age- and gender-matched healthy subjects. Eleven older individuals (five men and six women, aged 55-82 yr) and 11 younger healthy individuals (five male and six female, aged 22-45 yr) participated in this study.
  
  
  METHODS
  Graded balloon distentions were performed at the striated muscle and the smooth muscle segments of the esophagus in a random order using impedance planimetry. Impedance planimetry facilitated simultaneous assessments of the biomechanical properties and sensory perception.
  
  
  RESULTS
  We found that both at the striated and smooth muscle segments, the cross-sectional area, circumferential wall tension-strain relationship and the sensory thresholds were similar between men and women. In contrast, at both of these segments, the cross-sectional area was larger (p < 0.05), the circumferential wall tension-strain association had shifted significantly (p < 0.05) to the left (i.e., the wall was stiffer), and the median thresholds for discomfort and pain were higher (p < 0.05) in older subjects. The biomechanical properties and thresholds for sensory perception also varied between the two esophageal segments.
  
  
  CONCLUSIONS
  Aging was associated with a larger lumen and a stiffer but less sensitive esophageal wall. Thus, aging but not gender may influence esophageal function.
authors.affiliation: Department of Internal Medicine, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242, USA.
authors.forename: Satish S C
authors.initials: SS
authors.lastname: Rao
authors.forename: Ranjit S
authors.initials: RS
authors.lastname: Mudipalli
authors.forename: Victor R
authors.initials: VR
authors.lastname: Mujica
authors.forename: Rig S
authors.initials: RS
authors.lastname: Patel
authors.forename: Bridget
authors.initials: B
authors.lastname: Zimmerman
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D001696:Biomechanical Phenomena; D001837:Body Weights and Measures; D004947:Esophagus / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000502:physiology; D012684:Sensory Thresholds / Q000502:physiology; D012737:Sex Factors