title: Leukocyte Telomere Length in Young Adults Born Preterm: Support for Accelerated Biological Ageing.
abstract: BACKGROUND
  Subjects born preterm have an increased risk for age-associated diseases, such as cardiovascular disease in later life, but the underlying causes are largely unknown. Shorter leukocyte telomere length (LTL), a marker of biological age, is associated with increased risk of cardiovascular disease.
  
  
  OBJECTIVE
  To compare LTL between subjects born preterm and at term and to assess if LTL is associated with other putative cardiovascular risk factors at young adult age.
  
  
  METHODS
  We measured mean LTL in 470 young adults. LTL was measured using a quantitative PCR assay and expressed as T/S ratio. We analyzed the influence of gestational age on LTL and compared LTL between subjects born preterm (n = 186) and at term (n = 284). Additionally, we analyzed the correlation between LTL and potential risk factors of cardiovascular disease.
  
  
  RESULTS
  Gestational age was positively associated with LTL (r = 0.11, p = 0.02). Subjects born preterm had shorter LTL (mean (SD) T/S ratio = 3.12 (0.44)) than subjects born at term (mean (SD) T/S ratio = 3.25 (0.46)), p = 0.003). The difference remained significant after adjustment for gender and size at birth (p = 0.001). There was no association of LTL with any one of the putative risk factors analyzed.
  
  
  CONCLUSIONS
  Young adults born preterm have shorter LTL than young adults born at term. Although we found no correlation between LTL and risk for CVD at this young adult age, this biological ageing indicator may contribute to CVD and other adult onset diseases at a later age in those born preterm.
authors.affiliation: Department of Pediatrics, subdivision of Endocrinology, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Carolina C J
authors.initials: CC
authors.lastname: Smeets
authors.affiliation: Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom.|NIHR Leicester Cardiovascular Biomedical Research Unit, Glenfield Hospital, Leicester, United Kingdom.
authors.forename: Veryan
authors.initials: V
authors.lastname: Codd
authors.affiliation: Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom.|NIHR Leicester Cardiovascular Biomedical Research Unit, Glenfield Hospital, Leicester, United Kingdom.
authors.forename: Nilesh J
authors.initials: NJ
authors.lastname: Samani
authors.affiliation: Department of Pediatrics, subdivision of Endocrinology, Erasmus University Medical Center, Rotterdam, The Netherlands.|Dutch Growth Research Foundation, Rotterdam, The Netherlands.
authors.forename: Anita C S
authors.initials: AC
authors.lastname: Hokken-Koelega
mesh_terms: D000328:Adult; D000375:Aging / Q000235:genetics*; D002318:Cardiovascular Diseases / Q000235:genetics*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007962:Leukocytes / Q000166:cytology*; D008297:Male; D016615:Telomere / Q000235:genetics*; D055815:Young Adult