Growth hormone therapy in Silver Russell Syndrome: 5 years experience of the Australian and New Zealand Growth database (OZGROW)

Abstract

Data were analysed on 33 children (22 males) with Silver Russell syndrome treated with growth hormone for periods up to 5 years. Baseline data (medians) at commencement of growth hormone (GH) therapy were age 6.7 years, bone age delay 1.7 years, height standard deviation score (SDS)-3.2, weight SDS -3.1, and growth velocity 5.7 cm/ year. All were prepubertal. Median birth weight SDS for gestational age was -3.2. GH was commenced at 14 IU/m2 per week and subsequently adjusted according to response. Growth velocity and growth velocity SDS for chronological age (CA) improved over baseline and gains in height SDS for CA were 1.0, 1.5 and 1.8 SD over 3, 4 and 5 years respectively (P < 0.001). No significant increase in height SDS for bone age was observed. Increased GH doses were required after the 1st year to maintain growth rates. Mean bone age advancement was 3.1 years after 3 years of treatment, and 6.0 years after 5 years treatment. Younger age was a predictor of the growth response over the 1st year. Predictors of response after 3 years were catch up growth, low weight SDS at birth and low height SDS for CA. Age at onset of puberty was normal, but height at onset of puberty was lower than normal means. We have demonstrated significant improvement in growth in Silver Russell syndrome after 3 years of GH therapy, however data on estimated mature height and final height are insufficient to conclude final outcomes. Further follow up is required to assess the long-term benefit.