title: Genetic and constitutional influences on bone turnover markers: a study of male twin pairs.
abstract: Biochemical markers of bone turnover originating from type I procollagen synthesis or type I collagen breakdown were examined in men using a classic twin study design based on monozygotic (MZ) and dizygotic (DZ) twins. The aim was to estimate the influence of heredity (genes and shared family childhood elements) and constitutional factors in determining procollagen type I amino-terminal propeptide (PINP), type I collagen carboxy-terminal telopeptide (ICTP), and urinary amino-terminal type I collagen telopeptide (NTx) marker levels in a sample of in 98 MZ and 108 DZ male twin pairs. We are not aware of any prior studies conducted in men that address the influence of genetic factors on bone turnover marker variability. The findings support a dominant role for heredity in the variation of bone resorption marker levels in men, with additive genetic effects explaining two-thirds of the variance in the bone resorption markers NTx and ICTP. Genetic factors may contribute less for PINP, a marker of bone formation. The genetic loci influencing PINP or NTx and body weight/disc axial area, although related in part, appeared to be largely independent, indicating that genetic effects on bone turnover are unlikely to be to a large degree a result of genetic regulation of individual body weight.
authors.affiliation: Faculty of Rehabilitation Medicine, University of Alberta, 3-50 Corbett Hall, Edmonton, Alberta T6G 2G4, Canada. oana@ualberta.ca
authors.forename: O S
authors.initials: OS
authors.lastname: Donescu
authors.forename: M C
authors.initials: MC
authors.lastname: Battié
authors.forename: J
authors.initials: J
authors.lastname: Kaprio
authors.forename: E
authors.initials: E
authors.lastname: Levalahti
authors.forename: J
authors.initials: J
authors.lastname: Risteli
authors.forename: D
authors.initials: D
authors.lastname: Eyre
authors.forename: T
authors.initials: T
authors.lastname: Videman
mesh_terms: D015415:Biomarkers / Q000032:analysis; D001824:Body Constitution / Q000502:physiology*; D001842:Bone and Bones / Q000378:metabolism*; D024042:Collagen Type I / Q000652:urine; D005387:Finland; D006801:Humans; D008297:Male; D010012:Osteogenesis / Q000235:genetics* / Q000502:physiology; D010446:Peptide Fragments / Q000097:blood*; D010455:Peptides / Q000652:urine; D011347:Procollagen / Q000097:blood*; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic
chemical_list: D015415:Biomarkers; D024042:Collagen Type I; D010446:Peptide Fragments; D010455:Peptides; D011347:Procollagen; C052929:collagen type I trimeric cross-linked peptide; C047202:procollagen Type I N-terminal peptide; C042813:procollagen type I carboxy terminal peptide