Is low birth weight an antecedent of CKD in later life? A systematic review of observational studies

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. The authors 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 chronic kidney didease (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: 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.