title: An evaluation of the impact of gender and age on QT dispersion in healthy subjects.
abstract: OBJECTIVE
  To determine if gender, age, and gender per age category, have an impact on QT and QTc dispersion in healthy volunteers.
  
  
  METHODS
  This study was undertaken in 150 patients (50 per age group, 75 males, 75 females). The age groups included young (20-40 years), middle-aged (41-69 years) and elderly (> 70 years) subjects. The QT intervals on a 12 lead ECG were determined and Bazett's formula was used to derive the QTc intervals. The QT and QTc dispersion were determined by subtracting the shortest QTc interval from the longest on each 12-lead recording.
  
  
  RESULTS
  Males had higher QT dispersion than females (50 +/- 22 vs 42 +/- 18 ms, P = 0.017) but QTc dispersion was not significantly changed. No significant differences were seen among the different age categories for QT or QTc dispersion. In elderly subjects, males had higher QT and QTc dispersion than females (54 +/- 23 vs 42 +/-15 ms, P = 0.039 and 63 +/- 23.7 vs 48 +/- 21 ms, P = 0.032, respectively).
  
  
  CONCLUSIONS
  When evaluating the effect of gender in different age categories, elderly males have significantly greater QT and QTc dispersion than elderly female subjects. No other gender differences were noted for QT or QTc dispersion in the other two age categories. When evaluating a population of healthy volunteers, regardless of age, gender has an impact on QT dispersion but no significant interaction with QTc dispersion. Evaluating age without dividing the data by gender yields no significant differences in QT or QTc dispersion.
authors.affiliation: Drug Information, Hartford, CT, USA.
authors.forename: H
authors.initials: H
authors.lastname: Tran
authors.forename: C M
authors.initials: CM
authors.lastname: White
authors.forename: M S
authors.initials: MS
authors.lastname: Chow
authors.forename: J
authors.initials: J
authors.lastname: Kluger
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000502:physiology*; D016757:Death, Sudden, Cardiac / Q000453:epidemiology / Q000209:etiology; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006329:Heart Conduction System / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008133:Long QT Syndrome / Q000453:epidemiology / Q000209:etiology; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012727:Sex Characteristics; D017678:Sex Distribution; D016037:Single-Blind Method; D016171:Torsades de Pointes / Q000453:epidemiology / Q000209:etiology; D014693:Ventricular Fibrillation / Q000453:epidemiology / Q000209:etiology