title: Assessment of bone mineral density and markers of bone turnover in children under long-term oral anticoagulant therapy.
abstract: Oral anticoagulants antagonize vitamin K action and potentially impair the carboxylation of osteocalcin, a protein essential for normal bone matrix formation. In the present study, bone mineral density (BMD) and bone turnover markers were evaluated in 23 children under long-term oral anticoagulant therapy. BMD of the lumbar spine was assessed (Dual Energy x-ray Absorptiometry) and reported as z score. Osteoblast [bone alkaline phosphatase, osteocalcin (Gla-Oc), amino-terminal procollagen 1 extension peptide] and osteoclast (urinary calcium and deoxypyridinoline, serum cross-linked C telopeptide) activity markers were measured. Vitamin D {[25(OH) D], parathormone, calcium, phosphorus, magnesium} and vitamin K status [factors II, VII, IX, X, protein C, protein S, undercarboxylated osteocalcin (Glu-Oc)] were determined. The above parameters were also evaluated in 25 healthy controls. Patients presented with higher levels in Glu-Oc, parathormone, and bone resorption markers, lower levels in bone formation markers and 25(OH) D, whereas 52% of them showed signs of osteopenia (-1>BMD z score>-2.5). Statistical analysis demonstrated that anticoagulant therapy was an independent predictor of alterations in Glu-Oc, Gla-Oc, bone alkaline phosphatase, amino-terminal procollagen 1 extension peptide, and serum cross-linked C telopeptide levels. It seems that long-term use of coumarin derivatives may cause osteopenia in children with the risk of developing osteoporosis later in life.
authors.affiliation: Haemophilia Centre-Haemostasis Unit, Aghia Sophia Children's Hospital, Thivon and Levadias, Greece. m-avgeri@ath.forthnet.gr
authors.forename: Maria
authors.initials: M
authors.lastname: Avgeri
authors.forename: Anna
authors.initials: A
authors.lastname: Papadopoulou
authors.forename: Helen
authors.initials: H
authors.lastname: Platokouki
authors.forename: Kostas
authors.initials: K
authors.lastname: Douros
authors.forename: Spyridon
authors.initials: S
authors.lastname: Rammos
authors.forename: Polyxeni
authors.initials: P
authors.lastname: Nicolaidou
authors.forename: Sophia
authors.initials: S
authors.lastname: Aronis
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects*; D015415:Biomarkers / Q000032:analysis; D015519:Bone Density / Q000187:drug effects*; D016723:Bone Remodeling / Q000187:drug effects*; D001842:Bone and Bones / Q000187:drug effects*; D002648:Child; D002675:Child, Preschool; D005260:Female; D018729:Fontan Procedure; D006349:Heart Valve Diseases / Q000188:drug therapy; D006801:Humans; D008297:Male; D013927:Thrombosis / Q000517:prevention & control; D013995:Time
chemical_list: D000925:Anticoagulants; D015415:Biomarkers