Is low birth weight an antecedent of CKD in later life? A systematic review of observational studies.
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.
White
Sarah L
SL
The George Institute, Faculty of Medicine, University of Sydney, Sydney, Australia. swhite@george.org.au
Perkovic
Vlado
V
Cass
Alan
A
Chang
Choon Lan
CL
Poulter
Neil R
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Spector
Tim
T
Haysom
Leigh
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Craig
Jonathan C
JC
Salmi
Isa Al
IA
Chadban
Steven J
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Huxley
Rachel R
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