Endocrine Abstracts

Aim - To assess the effect of transdermal testosterone (TT) on free testosterone concentrations in saliva and on short-term growth and bone turnover in boys with growth or pubertal delay.

Method - Prospective, randomized, cross-over study over 26 weeks with 4 weeks of Run-In, 8 weeks of Treatment I (8 hours/12 hours), 4 weeks of Wash-Out, 8 weeks of Treatment II (8 hours/12 hours) and 4 weeks of final Wash-Out.

Main Outcome Measures - Salivary Testosterone (SalT) profiles during the different study periods. Weekly change in Lower Leg Length (LLL) as measured by knemometry, i.e. LLL velocity (LLLV). Absolute and percentage change in Bone Alkaline Phosphatase levels (bALP). Deoxypyridinoline crosslinks (DPD) measured in urine.

Subjects - Eight boys who took part in the study had a median age of 13.5 years (range 12.4,14.9 yrs), height SDS -2.4 (minus1.44,-3.35), testicular volume of 3 ml(2,6) and bone age (BA) delay of 2 years (3,2).

Results - Median SalT during 8-hours and 12-hours treatment (179 pg/ml (r,7, 3579) and (150pg/ml (r,12,3472) (NS)) was significantly higher than during the Run-In and Wash-Outblocks (p<0.0001)(9 pg/ml (r,<7,122) and 13 pg/ml (r,<7,285) (NS)). LLLV in the treatment blocks (median 0.64 mm/wk, r, 0.1,1.08) was significantly higher than during the run-in and washout periods (median 0.48 mm/wk, r, -0.06, 0.92) (p<0.001). The main rise in bALP occurred during the first treatment block with a median %bALP of 44.2% (r,-4,87) and a smaller %bALP at the end of the second treatment block of 9.8% (r,-4,55). The increases in bALP were not significantly different between the 8 hours and 12 hours treatment periods and there was no significant decline during the Wash-Out periods.

Conclusion - Overnight transdermal testosterone application, as Virormone 5mg, may be a potentially, acceptable method of induction of puberty and stimulates short-term growth and bone turnover.