Effect of oxandrolone and timing of pubertal induction on final height in Turner's syndrome: Randomised, double blind, placebo controlled trial

Objective: To examine the effect of oxandrolone and the timing of pubertal induction on final height in girls with Turner's syndrome receiving a standard dose of growth hormone. Design: Randomised, double blind, placebo controlled trial. Setting: 36 paediatric endocrinology departments in UK hospitals. Participants: Girls with Turner's syndrome aged 7-13 years at recruitment, receiving recombinant growth hormone therapy (10 mg/m2/week). Interventions: Participants were randomised to oxandrolone (0.05 mg/kg/day, maximum 2.5 mg/day) or placebo from 9 years of age. Those with evidence of ovarian failure at 12 years were further randomised to oral ethinylestradiol (year 1, 2 μg daily; year 2, 4 μg daily; year 3, 4 months each of 6, 8, and 10 μg daily) or placebo; participants who received placebo and those recruited after the age of 12.25 years started ethinylestradiol at age 14. Main outcome measure Final height. Results: 106 participants were recruited, of whom 14 withdrew and 82/92 reached final height. Both oxandrolone and late pubertal induction increased final height: by 4.6 (95% confidence interval 1.9 to 7.2) cm (P=0.001, n=82) for oxandrolone and 3.8 (0.0 to 7.5) cm (P=0.05, n=48) for late pubertal induction with ethinylestradiol. In the 48 children who were randomized twice, the effects on final height (compared with placebo and early induction of puberty) of oxandrolone alone, late induction alone, and oxandrolone plus late induction were similar, averaging 7.1 (3.4 to 10.8) cm (P