Longitudinal monitoring of bone accretion measured by quantitative multi-site ultrasound (QUS) of bones in patients with delayed puberty (a pilot study)

Objective: to compare the effect of anabolic agents on bone accretion in boys with constitutional delay of puberty (CGDP). Rationale: it has been suggested that an appropriate timing of puberty is necessary for normal bone mineral density (BMD) acquisition. Proper bone development during childhood is the key factor in achieving higher peak bone mass during middle age, which may not be achievable in CGDP children, and thereby osteoporosis may appear at an earlier age then expected. Patients and methods: 45 boys with CGDP aged 14-16 years were monitored longitudinally, every 3 months over 12 months with Sunlight Omnisense, a quantitative ultrasound device (Tel Aviv, Israel). The apparatus is a multi-site bone sonometer that obtains axial Speed of Sound (SOS). Based on a reference database obtained on n=1,085 (490 boys) 0-18 years, a normative curve was determined. Fifteen (14-16 years old) of the CGDP patients were treated with I.M. testovirone depot 100 mg monthly for 6 months, 15 (14-16 years old) were treated with oxandrolone 5 mg/m(2) daily for 6 months, and 15 (14-16 years old) were in an observation group. Results: whereas the quantitative ultrasound (QUS) Z-score had shown some increase over time in CGDP-treated patients, an increase was found in tibia Z-score from -0.5(-0.64, -0.36) to -0.4(-0.54, -0.26) and from -0.52(-0.67, -0.38) to -0.31(-0.44, -0.11) in the testosterone and oxandrolone-treated groups, respectively, [median (25%, 75%)]. An increase in radius Z-score from -0.52(-0.65, -0.25) to -0.4(-0.54, -0.15) and from -0.51(-0.61, -0.21) to -0.37(-0.47, -0.07) in the testosterone- and oxandrolone-treated groups respectively [median (25%,75%)]. Z-score SOS decreased in the observation group -0.5(-0.66, -0.3) to -0.69(-0.85, -0.54) and -0.5(-0.59, -0.41) to -0.81(-0.95, -0.55) in tibia (P = 0.032) and radius (P = 0.029), respectively. Despite the fact that QUS remained in the normative range in all patients, a clear deterioration was demonstrated in untreated CGDP patients. Conclusion: longitudinal follow-up of patients with CGDP may detect an early pattern of deterioration of bone mass.