title: Leukocyte telomere length dynamics in women and men: menopause vs age effects.
abstract: BACKGROUND
  A longer leukocyte telomere length (LTL) in women than men has been attributed to a slow rate of LTL attrition in women, perhaps due to high estrogen exposure during the premenopausal period.
  
  
  METHODS
  To test this premise we performed a longitudinal study (an average follow-up of 12 years) in a subset of the population-based Danish National Twin Registry. Participants consisted of 405 women, aged 37.5 (range 18.0-64.3) years, and 329 men, aged 38.8 (range 18.0-58.5) years, at baseline examination.
  
  
  RESULTS
  Women showed a longer LTL [kb ± standard error(SE)] than men (baseline: 7.01 ± 0.03 vs 6.87 ± 0.04; follow-up: 6.79 ± 0.03 vs 6.65 ± 0.03; both P = 0.005). Women displayed deceleration of LTL attrition (bp/years ± SE), as they transitioned from the premenopausal period (20.6 ± 1.0) through the perimenopausal period (16.5 ± 1.3) to the postmenopausal period (15.1 ± 1.7). Age was not associated with LTL attrition in women after statistical control for menopausal status. Men, in contrast, displayed a trend for age-dependent increase in the rate of LTL attrition, which differed significantly from the pattern in women (P for interaction = 0.01).
  
  
  CONCLUSIONS
  Results indicate that the premenopausal period is expressed in a higher rate of LTL attrition than the postmenopausal period. They further suggest that the sex gap in LTL stems from earlier ages-the period of growth and development. The higher rate of LTL attrition in premenopausal women, we propose, might relate to estrogen-mediated increased turnover of erythrocytes, menstrual bleeding or both.
authors.affiliation: Department of Public Health - Environmental Medicine, University of Southern Denmark, Odense, Denmark.
authors.forename: Christine
authors.initials: C
authors.lastname: Dalgård
authors.affiliation: Département de Médecine Gériatrique, CHU de Nancy, Nancy, France, INSERM, U1116, Vandoeuvre-les-Nancy F54000, Nancy, France, Université de Lorraine, Nancy, France.
authors.forename: Athanase
authors.initials: A
authors.lastname: Benetos
authors.affiliation: Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands.
authors.forename: Simon
authors.initials: S
authors.lastname: Verhulst
authors.affiliation: INSERM, U1116, Vandoeuvre-les-Nancy F54000, Nancy, France, Université de Lorraine, Nancy, France.
authors.forename: Carlos
authors.initials: C
authors.lastname: Labat
authors.affiliation: Hebrew University-Hadassah School of Public Health and Community Medicine, Jerusalem, Israel.
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Kark
authors.affiliation: Danish Twin Registry, University of Southern Denmark, Odense, Denmark, Department of Clinical Genetics, Department of Clinical Biochemistry and Pharmacology, Odense University Hospital, Odense, Denmark.
authors.forename: Kaare
authors.initials: K
authors.lastname: Christensen
authors.affiliation: Center of Human Development and Aging, Rutgers, State University of New Jersey, Newark, NJ, USA and.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kimura
authors.affiliation: Institute of Regional Health Services Research, University of Southern Denmark, and Odense Patient Data Explorative Network (OPEN), Odense University Hospital, Odense, Denmark.
authors.forename: Kirsten Ohm
authors.initials: KO
authors.lastname: Kyvik
authors.affiliation: Center of Human Development and Aging, Rutgers, State University of New Jersey, Newark, NJ, USA and avivab@njms.rutgers.edu.
authors.forename: Abraham
authors.initials: A
authors.lastname: Aviv
mesh_terms: D000293:Adolescent; D000328:Adult; D000375:Aging / Q000235:genetics*; D001699:Biometry; D003718:Denmark; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007962:Leukocytes / Q000378:metabolism*; D008137:Longitudinal Studies; D008297:Male; D008593:Menopause / Q000235:genetics*; D008875:Middle Aged; D017698:Postmenopause; D012727:Sex Characteristics; D016615:Telomere / Q000235:genetics*; D014427:Twins / Q000235:genetics*; D055815:Young Adult
keywords: Telomeres; men; menopause; women