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.
Highlights
Klinefelter syndrome (KS) is a common chromosomal disorder with a prevalence of 120–153 per 100,000 live-born male births [1, 2]
Our results revealed that KS patients have an impaired bone mineral status that begins early in life
KS children and adolescents showed an impaired bone metabolism, with significantly reduced 25(OH)D levels and higher parathyroid hormone (PTH) levels compared with controls
Summary
Klinefelter syndrome (KS) is a common chromosomal disorder with a prevalence of 120–153 per 100,000 live-born male births [1, 2]. KS is commonly characterized by the presence of one extra X chromosome in a male phenotype resulting in a 47, XXY karyotype [2, 3]. The clinical phenotype includes increased stature, gynecomastia, small testes, and infertility [4], and the most frequently associated medical disorders can be categorized as follows: (1) motor, cognitive, and behavioural dysfunction; (2) tumours; (3) vascular disease; and (4) endocrine/metabolic and autoimmune diseases [5]. In KS metabolic bone disorders have been reported [7, 8] and low testosterone
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