Prediction of First-Year Growth Velocity Response to Growth Hormone Therapy in Patients with Growth Hormone Deficiency.

INTRODUCTION

First-year growth response to biosynthetic growth hormone (GH) largely varies between populations. We aimed to predict first-year growth response to growth hormone replacement therapy (GHRT) in children with growth hormone deficiency (GHD).

METHODS

Growth response during the first year of GHRT was determined for both prepubertal and peripubertal children with congenital isolated GHD. The diagnosis of GHD was made using a standard work-up plan. Subjects with acquired causes of GHD were excluded. GHRT was started as per standard treatment guidelines. A predictive growth model based on these variables was derived from the analysis for the first-year growth response.

RESULTS

A total of 107 children with congenital GHD were studied (70 prepubertal; 37 peripubertal). The age at initiation of GHRT was 11.36 ± 3.83 years. In the prepubertal group, age at baseline and differences between mid-parental height (MPH; MPH-standard deviation score [SDS] and height-SDS) were significant predictors of first-year growth velocity response. The first-year height velocity was 11.12 ± 3.62 cm. Prediction formula for prepubertal group is as follows: first-year growth velocity = 10.24 + 1.27*(difference between MPH-SDS and height-SDS) -0.27* Age. In peripubertal children with GHD, gender, mother's height, and the difference between MPH-SDS and height-SDS were important predictors of first-year growth velocity. The first-year height velocity was 8.85 ± 2.84 cm. Prediction formula for the peripubertal group is as follows: 14.09 + 0.69*(difference between MPH-SDS and height-SDS) + 0.16*Mother height-2.51*gender.

CONCLUSION

This model is an accurate and practicable tool to predict first-year growth response in GHD children in the Indian subcontinent.