Testosterone-Induced Changes in Markers of Bone Turnover in Adolescent Boys with Testicular Dysfunction

Abstract

The effects of testosterone (T) for pubertal induction on bone mineral density (BMD) and biochemical markers of bone turnover were evaluated in three boys with testicular dysfunction. Testosterone enanthate (50 mg) was administered every 4 weeks for 1 year intramuscularly in all subjects. BMD and markers of bone turnover including serum osteocalcin, bone-specific alkaline phosphatase (bALP), urinary deoxypyridinoline (Dpyr), and N-terminal telopeptide of type I collagen, were measured before and during T treatment. BMD steadily increased during treatment. All markers of bone turnover were increased at 6 months of treatment, although increases were statistically significant only in bALP and Dpyr. An initial increase in markers of bone turnover has not been described in adults, but the observed changes resemble spontaneous puberty. The effects of exogenous T administration on bone turnover appear to differ depending on age.