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.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology