title: Birthweight and mortality in adulthood: a systematic review and meta-analysis.
abstract: BACKGROUND
  Small birth size may be associated with increased risk of cardiovascular diseases (CVD), whereas large birth size may predict increased risk of obesity and some cancers. The net effect of birth size on long-term mortality has only been assessed in individual studies, with conflicting results.
  
  
  METHODS
  The Meta-analyses of Observational Studies in Epidemiology (MOOSE) guidelines for conducting and reporting meta-analysis of observational studies were followed. We retrieved 22 studies that assessed the association between birthweight and adult mortality from all causes, CVD or cancer. The studies were systematically reviewed and those reporting hazard ratios (HRs) and 95% confidence intervals (95% CIs) per kilogram (kg) increase in birthweight were included in generic inverse variance meta-analyses.
  
  
  RESULTS
  For all-cause mortality, 36,834 deaths were included and the results showed a 6% lower risk (adjusted HR = 0.94, 95% CI: 0.92-0.97) per kg higher birthweight for men and women combined. For cardiovascular mortality, the corresponding inverse association was stronger (HR = 0.88, 95% CI: 0.85-0.91). For cancer mortality, HR per kg higher birthweight was 1.13 (95% CI: 1.07-1.19) for men and 1.04 (95% CI: 0.98-1.10) for women (P(interaction) = 0.03). Residual confounding could not be eliminated, but is unlikely to account for the main findings.
  
  
  CONCLUSIONS
  These results show an inverse but moderate association of birthweight with adult mortality from all-causes and a stronger inverse association with cardiovascular mortality. For men, higher birthweight was strongly associated with increased risk of cancer deaths. The findings suggest that birthweight can be a useful indicator of processes that influence long-term health.
authors.affiliation: Department of Public Health, Norwegian University of Science and Technology, Trondheim, Norway. kari.risnes@ntnu.no
authors.forename: Kari R
authors.initials: KR
authors.lastname: Risnes
authors.forename: Lars J
authors.initials: LJ
authors.lastname: Vatten
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Baker
authors.forename: Karen
authors.initials: K
authors.lastname: Jameson
authors.forename: Ulla
authors.initials: U
authors.lastname: Sovio
authors.forename: Eero
authors.initials: E
authors.lastname: Kajantie
authors.forename: Merete
authors.initials: M
authors.lastname: Osler
authors.forename: Ruth
authors.initials: R
authors.lastname: Morley
authors.forename: Markus
authors.initials: M
authors.lastname: Jokela
authors.forename: Rebecca C
authors.initials: RC
authors.lastname: Painter
authors.forename: Valter
authors.initials: V
authors.lastname: Sundh
authors.forename: Geir W
authors.initials: GW
authors.lastname: Jacobsen
authors.forename: Johan G
authors.initials: JG
authors.lastname: Eriksson
authors.forename: Thorkild I A
authors.initials: TI
authors.lastname: Sørensen
authors.forename: Michael B
authors.initials: MB
authors.lastname: Bracken
mesh_terms: D000328:Adult; D000367:Age Factors; D001724:Birth Weight; D002318:Cardiovascular Diseases / Q000401:mortality*; D002423:Cause of Death / Q000639:trends*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D008297:Male; D009026:Mortality / Q000639:trends*; D009369:Neoplasms / Q000401:mortality*; D009664:Norway; D018570:Risk Assessment; D012737:Sex Factors