Associations of Sex Steroids With Changes in Calcaneal Quantitative Ultrasound Measurements: A Longitudinal Study in Chinese Male Adolescents.

This 2-year longitudinal study aimed to detect the associations of sex steroids, sex hormone-binding globulin with bone parameters and the changes thereof in Chinese male adolescents. A total of 642 male students aged 12-16 years from a secondary school in Jiangmen, China, were included. Total testosterone (T), total oestradiol (E2), and sex hormone-binding globulin were measured by chemiluminescence immunoassay. The bioavailable T (BioT) and E2 (BioE2) were calculated. The speed of sound, broadband ultrasound attenuation, and stiffness index of the right heel were measured by Sahara Clinical Bone Sonometer at both baseline and 2-year follow-up. The confounding effects of age, height, weight, pubertal stage, physical activity, energy-adjusted dietary calcium intake, and dietary vitamin D intake were adjusted. The baseline value of each bone parameter was also adjusted in the longitudinal analysis. Results showed that total T and BioT were positively associated with bone parameters and changes in them (β = 0.076-0.115, p < 0.05). A threshold effect of BioT on broadband ultrasound attenuation, stiffness index and their changes were also observed. Positive associations between BioT and bone mass gain were observed only in individuals with BioT levels <240.0 ng/dl (β = 0.088-0.131, p < 0.05). Moreover, total E2 or BioE2 were found to be inversely associated with speed of sound and its change (β = -0.109 to -0.077, p < 0.05). This study supported that in Chinese male adolescents, serum T was a positive predictor for bone formation with a threshold effect, and E2 could have influence on the changes in bone architecture during puberty. These findings may improve the understanding of the effects of sex steroids on the acceleration of bone formation in male adolescents and provide useful information for the prediction model establishment of peak bone mass.