Biochemical markers of maternal bone turnover are elevated in pre-eclampsia

Abstract

Objectives To investigate the hypothesis that bone turnover is reduced in pre-eclampsia compared with normal pregnancy. Design A prospective cross-sectional study. Setting Obstetric unit at the Chelsea and Westminster Hospital, London. Methods Third trimester maternal plasma levels of the cross-linked carboxyl-terminal telo-peptide of type I collagen (ICTP), (a marker of bone resorption) and the carboxyl terminal pro-peptide of type I pro-collagen (PICP), (a marker of bone formation) were compared in 25 women with pre-eclampsia and in 24 normal pregnant controls. The subjects were matched for maternal age, booking body mass index and gestational age. PICP and ICTP levels were measured by radio-immunoassay. Results ICTP and PICP levels were significantly increased in women with pre-eclampsia compared with the normal pregnant controls ( P = 0.0001 and P = 0.004, for ICTP and PICP respectively, Wilcoxon signed ranked test). There was no significant correlation between either of the markers and booking body mass index, blood pressure, serum uric acid levels or platelet count. Conclusions These data suggest that bone turnover is increased in established pre-eclampsia compared with normal pregnancy. Further studies are required to investigate whether this precedes the onset of the disease.