Both pre-pubertal growth and magnitude of the pubertal growth spurt are the prerequisites of potential of growth hormone therapy to optimize final height. We analyzed impact of pre-pubertal and pubertal growth components on the total effect of growth hormone therapy in a cohort of 397 children (221 boys) registered in the Czech national database of growth hormone recipiensts REPAR. All were born small for gestational age, had persistent short stature in childhood (SGA-SS) and already achieved their near-final-height. We separately evaluated children according to parental heights (with both parants over -2 ht-SDS, one below -2 ht-SDS both below -2 ht-SDS) and according to their size at birth - low birth weight, low birth length, low both parameters.
Up to treatment completion, treatment led to a height gain of 1,59 ht-SDS; ot this, the pre-pubertal gain was 1,57 ht-SDS. Thus, ht-SDS remained unchanged within puberty, despite continuous growth hormone administration. The final ht-SDS, gain adjusted for age 18 years was 0,91 (all three parameters p<0.0001 if compared to pre-treatment). Children with both parents taller than -2 SD and children with exclusively low birth weight had significantly better treatment outcomes.
Analysis results of the REPAR database confirm efficacy of growth hormone therapy in SGS-SS children. The treatment success is based on pre-pubertal growth component. Therefore, a careful follow-up of children born SGA and a timely initiation of growth hormone therapy in early childhood are of crucial importance.