title: Gender differences in cardiac left ventricular mass and function: Clinical and experimental observations.
abstract: BACKGROUND
  The aim of this study was to evaluate gender-associated impact on left ventricular mass (LVM) and on left ventricular function (LVF) in humans and rats with aging.
  
  
  METHODS
  Myocyte area and collagen volume fraction (CVF) were studied in rats. LVM and LVF were evaluated in animals and humans by echocardiography and LVM index (LVMI) was obtained.
  
  
  RESULTS
  LVMI, myocyte area and CVF were similar in males and females of 1-month-old rats. LVMI in children was similar in both genders. In contrast, in 6-month-old rats (5 males and 5 females), LVMI (17.7 ± 0.7 mg/mm vs. 10.1 ± 0.2 mg/mm; p < 0.01), and myocyte area (4572.5 ± 72.6 μm² vs. 3293.85 ± 57.8 μm², p < 0.01) were higher in male animals without differences in CVF. Men (n = 25) exhibited greater LVMI than women (n = 25) (77.4 ± 3.2 g/m² vs. 63.3 ± 1.8 g/m², p < 0.01), whereas the LVF was higher in women (105.9 ± 2.9% vs. 95.3 ± 3.5%, p < 0.01).
  
  
  CONCLUSIONS
  There is a clear gender-associated impact on LVM with aging in humans and rats. Similar CVF and LVF associated to greater myocyte size and LVM in male rats suggest a process of physiological response. However, the increase in cardiac mass without an associated improved cardiac function in men in comparison to women could likely represent a potential disadvantage in the adaptive response during growth.
authors.affiliation: Centro de Investigaciones Cardiovasculares, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, CONICET, La Plata, Argentina. emescu@gmail.com.
authors.forename: Eduardo Manuel
authors.initials: EM
authors.lastname: Escudero
authors.forename: Alejandro
authors.initials: A
authors.lastname: Orlowski
authors.forename: Alejandro
authors.initials: A
authors.lastname: Díaz
authors.forename: Oscar Andrés
authors.initials: OA
authors.lastname: Pinilla
authors.forename: Irene Lucía
authors.initials: IL
authors.lastname: Ennis
authors.forename: Ernesto Alejandro
authors.initials: EA
authors.lastname: Aiello
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D002648:Child; D004195:Disease Models, Animal; D004452:Echocardiography; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012737:Sex Factors; D016277:Ventricular Function, Left / Q000502:physiology*; D055815:Young Adult