A New Model of Adult Height Prediction Validated in Boys with Constitutional Delay of Growth and Puberty.

BACKGROUND

For children with retarded bone ages such as in constitutional delay of growth and puberty (CDGP) there are no specific methods to predict adult height based on bone age. Widely used methods such as Bayley-Pinneau (BP) tend to overestimate adult height in CDGP.

OBJECTIVE

We aimed to develop a specific adult height prediction model for teenage boys with retarded bone ages >1 year.

METHODS

Based on the adult heights of 68 males (median age 22.5 years) a new height prediction model was calculated based on 105 height measurements and bone age determinations at a median age of 14.0 years. The new model was adapted for the degree of bone age retardation and validated in an independent cohort of 32 boys with CDGP.

RESULTS

The BP method overestimated adult height (median +1.2 cm; p = 0.282), especially in boys with a bone age retardation ≥2 years (median +1.6 cm; p = 0.027). In the validation study, there was no significant difference between adult height and predicted adult height based on the new model (p = 0.196), while the BP model led to a significant overestimation of predicted adult height (median +4.1 cm; p = 0.009).

CONCLUSIONS

The new model to predict adult height in boys with CDGP provides novel indices for height predictions in bone ages >13 years and is adapted to different degrees of bone age retardation. The new prediction model has a good predictive capability and overcomes some of the shortcomings of the BP model.