title: Is low birth weight an antecedent of CKD in later life? A systematic review of observational studies.
abstract: BACKGROUND
  There has been considerable interest in the hypothesis that low birth weight may be a marker of impaired nephrogenesis and that this is causally related to chronic kidney disease (CKD).
  
  
  METHODS
  Systematic review and meta-analysis of observational studies.
  
  
  METHODS
  Studies of the relationship between birth weight and CKD published before February 1, 2008, were identified by using electronic searches.
  
  
  METHODS
  All studies that had collected data for birth weight and kidney function at greater than 12 months of age were eligible for inclusion, except for studies of extremely low-birth-weight infants, very premature infants, or toxic exposure in utero. STUDY FACTOR: Birth weight.
  
  
  RESULTS
  CKD defined as albuminuria, low estimated glomerular filtration rate (<60 mL/min/1.73 m(2) or < 10th centile for age/sex), or end-stage renal disease.
  
  
  RESULTS
  We analyzed 31 relevant cohort or case-control studies with data for 49,376 individuals and data for 2,183,317 individuals from a single record-linkage study. Overall, 16 studies reported a significant association between low birth weight and risk of CKD and 16 observed a null result. The combination of weighted estimates from the 18 studies for which risk estimates were available (n = 46,249 plus 2,183,317 from the record linkage study) gave an overall odds ratio (OR) of 1.73 (95% confidence interval [CI], 1.44 to 2.08). Combined ORs were consistent in magnitude and direction for risks of albuminuria (OR, 1.81; 95% CI, 1.19 to 2.77), end-stage renal disease (OR, 1.58; 95% CI, 1.33 to 1.88), or low estimated glomerular filtration rate (OR, 1.79; 95% CI, 1.31 to 2.45).
  
  
  CONCLUSIONS
  A reliance on published estimates and estimates provided on request rather than individual patient data and the possibility of reporting bias.
  
  
  CONCLUSIONS
  Existing data indicate that low birth weight is associated with subsequent risk of CKD, although there is scope for additional well-designed population-based studies with accurate assessment of birth weight and kidney function and consideration of important confounders, including maternal and socioeconomic factors.
authors.affiliation: The George Institute, Faculty of Medicine, University of Sydney, Sydney, Australia. swhite@george.org.au
authors.forename: Sarah L
authors.initials: SL
authors.lastname: White
authors.forename: Vlado
authors.initials: V
authors.lastname: Perkovic
authors.forename: Alan
authors.initials: A
authors.lastname: Cass
authors.forename: Choon Lan
authors.initials: CL
authors.lastname: Chang
authors.forename: Neil R
authors.initials: NR
authors.lastname: Poulter
authors.forename: Tim
authors.initials: T
authors.lastname: Spector
authors.forename: Leigh
authors.initials: L
authors.lastname: Haysom
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Craig
authors.forename: Isa Al
authors.initials: IA
authors.lastname: Salmi
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Chadban
authors.forename: Rachel R
authors.initials: RR
authors.lastname: Huxley