The Newcastle team looked at the long-term follow-up of a cohort of 15 boys with Duchenne muscular dystrophy on corticosteroids who were treated with increasing doses of testosterone for two years:
- the average age of participants at the end of the study was 18.7 years and the average duration of corticosteroid treatment was 11.2 years;
- testosterone levels increased during treatment and remained similar when treatment was stopped and three years later;
- inhibin B levels increased significantly with testosterone; they remained stable and below reference values three years after treatment was stopped; similarly, testicular volume increased with testosterone, but remained significantly below adult values;
- bone density was significantly reduced three years after testosterone was stopped, and bone age was 15 years for a chronological age of 18.7 years.
The authors propose to investigate further whether the effects of exogenous testosterone on muscle strength constitute a beneficial effect in their own right or a temporary suspension of muscle decline.