title: Influence of age, gender, and menstrual cycle on the normal electrogastrogram.
abstract: OBJECTIVE
  Dyspeptic symptoms, which are more prevalent in females, are associated with gastric myoelectric and motor abnormalities. Age, gender, and menstrual cycle affect gastric emptying, but their effects on gastric myoelectric activity are not well characterized. The aim of this study was to determine the effects of age, gender, and menstrual cycle on gastric myoelectric activity.
  
  
  METHODS
  Healthy subjects (34 male, 49 female; ages 20-79 yr) underwent cutaneous electrogastrography with 60-min fasting and 60-min postprandial recordings. Premenopausal females were studied during days 1-3, 8-10, and 18-20 after onset of menses. Dominant slow wave frequency (DF), power of the DF, and percent time the DF was in a 2- to 4-cpm rhythm were determined for fasting and postprandial periods.
  
  
  RESULTS
  The DF, power of the DF, and percent time the DF was in a 2- to 4-cpm rhythm increased from the fasting to the postprandial period. The postprandial increase in the DF was less in females (5.3 +/- 1.2%) than in males (13.0 +/- 2.6%; p < 0.01). In premenopausal females, the DF increased from fasting to the postprandial period for days 1-3 (6.6 +/- 1.5%; p < 0.01) and 8-10 (6.6 +/- 2.3%; p < 0.01), but not during days 18-20 of the menstrual cycle (1.3 +/- 1.8%). The postprandial frequency increase in DF was less for male subjects > or = 60 yr (3.8 +/- 4.0%) than for males < 60 yr (14.6 +/- 2.8%; p < 0.05).
  
  
  CONCLUSIONS
  The DF of the electrogastrogram is affected by age, gender, and phase of the menstrual cycle. The influence of these factors should be recognized when interpreting electrogastrograms in symptomatic patients.
authors.affiliation: Department of Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA.
authors.forename: H P
authors.initials: HP
authors.lastname: Parkman
authors.forename: A D
authors.initials: AD
authors.lastname: Harris
authors.forename: M A
authors.initials: MA
authors.lastname: Miller
authors.forename: R S
authors.initials: RS
authors.lastname: Fisher
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D004568:Electrodiagnosis / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D005746:Gastric Emptying / Q000502:physiology; D006801:Humans; D008297:Male; D008597:Menstrual Cycle / Q000502:physiology*; D008875:Middle Aged; D017698:Postmenopause / Q000502:physiology; D017697:Premenopause / Q000502:physiology; D012016:Reference Values; D012727:Sex Characteristics; D013270:Stomach / Q000502:physiology*