A longitudinal study of biochemical markers of bone turnover during normal pregnancy and pregnancies complicated by pre-eclampsia.
OBJECTIVE
To test the hypothesis that the increased bone turnover observed in established pre-eclampsia is present earlier in pregnancy prior to the diagnosis of pre-eclampsia.


METHODS
A prospective longitudinal study.


METHODS
Obstetric Unit at Chelsea and Westminster Hospital, London.


METHODS
Nine women who subsequently developed pre-eclampsia and 17 normal pregnant controls.


METHODS
Maternal plasma levels of the cross-linked carboxyl terminal telopeptide of the type I collagen (ICTP), a marker of bone resorption, and of the carboxy-terminal propeptide of type I collagen (PICP), a marker of bone formation, were measured longitudinally in nine women who developed pre-eclampsia and 17 women with normal pregnancy. Serial blood samples were obtained at 16, 20, 24, 28, 32 and 36 weeks of gestation and the levels of ICTP and PICP were measured by radio-immunoassay.


RESULTS
ICTP and PICP increased progressively in the normal pregnant and pre-eclampsia groups, but the rate of increase was significantly greater in the latter (P = 0.00002 and 0.0008, unpaired t test, for ICTP and PICP summary measures, respectively). In the pre-eclampsia group, positive correlation were observed between ICTP levels at 36 weeks of gestation and plasma uric acid (r = 0.9, P = 0.001) and degree of proteinuria (r = 0.78, P = 0.04). No correlation was observed between the two bone markers and other variables during normal pregnant group.


CONCLUSIONS
These data show that biochemical markers of bone turnover are greater in pregnancies complicated by pre-eclampsia compared with normal pregnancy but only when the disease is clinically evident.
Anim-Nyame
N
N
Department of Maternal-Fetal Medicine, Imperial College School of Medicine, Chelsea and Westminster Hospital, London, UK.
Sooranna
S R
SR
Jones
J
J
Alaghband-Zadeh
J
J
Steer
P J
PJ
Johnson
M R
MR
D000328:Adult; D015415:Biomarkers / Q000097:blood; D016723:Bone Remodeling / Q000502:physiology*; D003094:Collagen / Q000378:metabolism*; D024042:Collagen Type I; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D010446:Peptide Fragments / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism*; D011225:Pre-Eclampsia / Q000097:blood*; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D011347:Procollagen / Q000378:metabolism*; D011446:Prospective Studies; D011863:Radioimmunoassay / Q000379:methods
D015415:Biomarkers; D024042:Collagen Type I; D010446:Peptide Fragments; D010455:Peptides; D011347:Procollagen; C052929:collagen type I trimeric cross-linked peptide; C042813:procollagen type I carboxy terminal peptide; D003094:Collagen