title: No association between body size at birth and leucocyte telomere length in adult life--evidence from three cohort studies.
abstract: BACKGROUND
  Shorter leucocyte telomere length (LTL) is a promising marker of biological ageing. It is predicted by cumulative adverse conditions throughout life course, but few studies have data from the prenatal period when most developmental processes and cell replication take place. We studied whether body size at birth and underlying factors including severely preterm birth predict LTL in adult life.
  
  
  METHODS
  We used data from following three cohorts: (i) 1894 subjects (age: 56-69 years) from the Helsinki Birth Cohort Study (HBCS), representing normal variation in fetal growth; (ii) the Helsinki Study of Very Low Birth Weight Adults encompassing 164 subjects born preterm at very low birthweight (<1500 g; representing extreme pre- and neonatal conditions) and 170 term-born controls (18-27 years) and (iii) 248 twins (23-31 years) from the FinnTwin16 cohort, allowing comparisons between twin pairs. Relative telomere length was measured from leucocytes by real-time quantitative polymerase chain reaction.
  
  
  RESULTS
  Shorter LTL was associated with higher age in HBCS and among men in the Helsinki Study of Very Low Birth Weight Adults and with lower childhood socio-economic status in HBCS and FinnTwin16. LTL was not associated with weight, length or gestational age at birth in any cohort. LTL was similar in very-low-birthweight and control subjects.
  
  
  CONCLUSIONS
  LTL is unlikely to be a useful marker of a mechanism linking body size at birth with individual differences in ageing in the general population.
authors.affiliation: National Institute for Health and Welfare, Helsinki, Finland. eero.kajantie@helsinki.fi
authors.forename: Eero
authors.initials: E
authors.lastname: Kajantie
authors.forename: Kirsi H
authors.initials: KH
authors.lastname: Pietiläinen
authors.forename: Karoliina
authors.initials: K
authors.lastname: Wehkalampi
authors.forename: Laura
authors.initials: L
authors.lastname: Kananen
authors.forename: Katri
authors.initials: K
authors.lastname: Räikkönen
authors.forename: Aila
authors.initials: A
authors.lastname: Rissanen
authors.forename: Petteri
authors.initials: P
authors.lastname: Hovi
authors.forename: Jaakko
authors.initials: J
authors.lastname: Kaprio
authors.forename: Sture
authors.initials: S
authors.lastname: Andersson
authors.forename: Johan G
authors.initials: JG
authors.lastname: Eriksson
authors.forename: Iiris
authors.initials: I
authors.lastname: Hovatta
mesh_terms: D000368:Aged; D000375:Aging / Q000378:metabolism*; D001724:Birth Weight / Q000502:physiology*; D001837:Body Weights and Measures; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007962:Leukocytes / Q000166:cytology*; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D012959:Socioeconomic Factors; D016615:Telomere / Q000378:metabolism*