title: Telomere length in leukocytes correlates with bone mineral density and is shorter in women with osteoporosis.
abstract: Telomere length decreases with age and is associated with osteoblast senescence. In 2,150 unselected women, leukocyte telomere length was significantly correlated with bone mineral density. Clinical osteoporosis was associated with shorter telomeres, suggesting that telomere length can be used as a marker of bone aging.
  
  
  BACKGROUND
  The length of telomeres in proliferative cells diminishes with age. Telomere shortening and telomerase activity have been linked to in vitro osteoblast senescence and to increased secretion of pro-inflammatory cytokines. We explored whether bone mineral density correlates with telomere length in leukocytes.
  
  
  METHODS
  The relationship between leukocyte telomere length, bone mineral density (BMD) and osteoporosis (as defined by the World Health Organization) was examined in a cohort of 2,150 women from a population-based twin cohort aged 18-79.
  
  
  RESULTS
  After adjusting for age, body mass index, menopausal status, smoking, hormone replacement therapy status, telomere length was positively correlated with BMD of the spine (p < 0.005), forearm (p < 0.013), but not the femoral neck (p < 0.06). Longer telomeres were associated with reduced the risk of clinical OP at two or more sites (odds ratio = 0.594 95% CI 0.42-0.84 p < 0.003) and in women over the age of 50, clinical osteoporosis was associated with 117 bp shorter telomere length (p < 0.02) equivalent to 5.2 years of telomeric aging.
  
  
  CONCLUSIONS
  Shortened leukocyte telomere length is independently associated with a decrease in BMD and the presence of osteoporosis in women. Our data provide evidence that leukocyte telomere length could be a marker of biological aging of bone.
authors.affiliation: Twin Research & Genetic Epidemiology Unit, King's College London, St Thomas' Hospital Campus, London, SE1 7EH, UK. ana.valdes@kcl.ac.uk
authors.forename: A M
authors.initials: AM
authors.lastname: Valdes
authors.forename: J B
authors.initials: JB
authors.lastname: Richards
authors.forename: J P
authors.initials: JP
authors.lastname: Gardner
authors.forename: R
authors.initials: R
authors.lastname: Swaminathan
authors.forename: M
authors.initials: M
authors.lastname: Kimura
authors.forename: L
authors.initials: L
authors.lastname: Xiaobin
authors.forename: A
authors.initials: A
authors.lastname: Aviv
authors.forename: T D
authors.initials: TD
authors.lastname: Spector
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D015519:Bone Density / Q000235:genetics*; D016922:Cellular Senescence / Q000235:genetics; D005260:Female; D005819:Genetic Markers; D006801:Humans; D007962:Leukocytes / Q000502:physiology / Q000648:ultrastructure*; D008875:Middle Aged; D010024:Osteoporosis / Q000235:genetics* / Q000473:pathology; D016615:Telomere / Q000235:genetics / Q000473:pathology*
chemical_list: D005819:Genetic Markers