ESPE Abstracts (2016) 86 P-P1-107

Bone Mineral Status in Children and Adolescents with Klinefelter Syndrome

Stefano Stagia, Perla Scalinia, Mariarosaria Di Tommasob, Francesco Chiarellic, Cristina Manonia, Maria Parpagnolia, Alberto Verrottid, Elisabetta Lapie, Sabrina Giglioe, Laura Dosae & Maurizio de Martinoa

aHealth Science Department, Anna Meyer Children’s University Hospital, University of Florence, Florence, Italy; bDepartment of Health Sciences, Careggi Hospital, University of Florence, Florence, Italy; cDepartment of Paediatrics, University of Chieti, Chieti, Italy; dDepartment of Paediatrics, University of L’Aquila, L’Aquila, Italy; eGenetics and Molecular Medicine Unit, Anna Meyer Children’s University Hospital, Florence, Italy

Background: Klinefelter syndrome (KS) has long-term consequences on bone health. However, studies regarding bone status and metabolism in childhood and adolescence are very rare.

Objective and hypotheses: The purpose of our study was to evaluate bone status and metabolism in a cohort of KS children and adolescents.

Method: This cross-sectional study involves 40 (mean age 13.7±3.8 years) KS children and adolescents and 80 age-matched healthy subjects. In patients and controls, 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 phalangeal amplitude-dependent speed of sound (AD-SoS) and the bone transmission time (BTT) z-scores.

Results: KS children and adolescents showed a significantly reduced AD-SoS (P<0.005) and BTT (P<0.0005) z-scores than the controls. However, KS patients presented a significantly higher PTH (P<0.0001) and a 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 present already in prepubertal subjects. AD-SoS and BTT z-scores correlated negatively with PTH (P<0.005) and with age (P<0.0001) and positively with 25(OH)D levels (P<0.005). PTH correlated significantly with calcium (P<0.005), age (P<0.0001), LH (P<0.0001), FSH (P<0.0001), total testosterone (P<0.0001), vitamin D (P=0.04), and osteocalcin (P=0.002).

Conclusion: KS children and adolescents exhibit an impaired bone mineral status and metabolism with a frequent increase of PTH levels and a significant reduction of 25-OH-D and bone formation markers. Interestingly, this impairment is already evident in prepuberal KS patients, even if we showed a deterioration with LH and FSH increase and the reduction of testosterone.