Analyse du poids de naissance chez les jumeaux

Birth Weight and Creatinine Clearance in Young Adult Twins: Influence of Genetic, Prenatal, and Maternal Factors.
J Am Soc Nephrol. 2005 Jun 8

Previous studies have shown that low birth weight (LBW) is a risk factor for renal impairment in adult life. The effects of LBW and renal function were studied by using twins, which allows distinguishing among fetoplacental, maternal, and genetic influences. Perinatal data were obtained at birth, and absolute creatinine clearance (not corrected for body surface area) was measured at a mean age of 25.6 yr in 653 individuals. Twins were considered both as individuals and as members of twin pairs. Statistical analyses were performed with and without adjusting for gestational age, zygosity, gender, age, body mass index, glucose level, BP, and smoking status. Creatinine clearance was 4 ml/min lower in twins with LBW (<2500 g) than in twins with a high birth weight (P < 0.04, adjusted). Intrapair birth weight difference correlated positively with the intrapair difference in creatinine clearance equally in monozygotic and dizygotic twins (r = 0.35, P < 0.0001; r = 0.43, P < 0.0001, respectively). This suggests that fetoplacental factors are related to renal function and that genetic factors are less important. There was no significant difference in creatinine clearance between twins who both had LBW as compared with twins who both had a high birth weight. This may suggest that maternal factors, which influence the relation between LBW and renal function, are less important. LBW is related to a lower creatinine clearance at adult age. This relationship is probably due to fetoplacental factors. Surprising, genetic and maternal factors seem less important.

Commentaire: la première étude à ma connaissance de ce type qui indique assez clairement même si les différences de clairance ne sont pas énormes que le poids de naissance influe la filtration glomérulaire à long terme. L'effet "maternel" et les facteurs génétiques n'interviennent à priori pas ici.