title: Bone Mineral Status in Children and Adolescents with Klinefelter Syndrome.
abstract: Objective. Klinefelter syndrome (KS) has long-term consequences on bone health. However, studies regarding bone status and metabolism during childhood and adolescence are very rare. Patients. This cross-sectional study involved 40 (mean age: 13.7 ± 3.8 years) KS children and adolescents and 80 age-matched healthy subjects. For both patient and control groups, we evaluated serum levels of ionised and total calcium, phosphate, total testosterone, luteinising hormone, follicle stimulating hormone, parathyroid hormone (PTH), 25-hydroxyvitamin D (25(OH)D), 1,25-dihydroxyvitamin D, osteocalcin, bone alkaline phosphatase, and urinary deoxypyridinoline concentrations. We also calculated the z-scores of the phalangeal amplitude-dependent speed of sound (AD-SoS) and the bone transmission time (BTT). Results. KS children and adolescents showed significantly reduced AD-SoS (p < 0.005) and BTT (p < 0.0005) z-scores compared to the controls. However, KS patients presented significantly higher PTH (p < 0.0001) and significantly lower 25(OH)D (p < 0.0001), osteocalcin (p < 0.05), and bone alkaline phosphatase levels (p < 0.005). Interestingly, these metabolic bone disorders were already present in the prepubertal subjects. Conclusions. KS children and adolescents exhibited impaired bone mineral status and metabolism with higher PTH levels and a significant reduction of 25-OH-D and bone formation markers. Interestingly, this impairment was already evident in prepubertal KS patients. Follow-ups should be scheduled with KS patients to investigate and ameliorate bone mineral status and metabolism until the prepubertal ages.
authors.affiliation: Department of Health Sciences, University of Florence, Anna Meyer Children's University Hospital, 50139 Florence, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Stagi
authors.affiliation: Department of Health Sciences, University of Florence, Careggi Hospital, 50134 Florence, Italy.
authors.forename: Mariarosaria
authors.initials: M
authors.lastname: Di Tommaso
authors.affiliation: Department of Health Sciences, University of Florence, Anna Meyer Children's University Hospital, 50139 Florence, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Manoni
authors.affiliation: Department of Health Sciences, University of Florence, Anna Meyer Children's University Hospital, 50139 Florence, Italy.
authors.forename: Perla
authors.initials: P
authors.lastname: Scalini
authors.affiliation: Department of Paediatrics, University of Chieti, 66100 Chieti, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Chiarelli
authors.affiliation: Department of Paediatrics, University of L'Aquila, 67100 L'Aquila, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Verrotti
authors.affiliation: Genetics and Molecular Medicine Unit, Anna Meyer Children's University Hospital, 50139 Florence, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Lapi
authors.affiliation: Genetics and Molecular Medicine Unit, Anna Meyer Children's University Hospital, 50139 Florence, Italy.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Giglio
authors.affiliation: Genetics and Molecular Medicine Unit, Anna Meyer Children's University Hospital, 50139 Florence, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Dosa
authors.affiliation: Department of Health Sciences, University of Florence, Anna Meyer Children's University Hospital, 50139 Florence, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: de Martino