ABSTRACT
OBJECTIVE: Constitutional delay of growth and puberty (CDGP) is a frequent variant of the normal leading to short stature and/or pubertal delay. To distinguish CDGP from hypogonadotropic hypogonadism (HH), we evaluated height, growth and weight pattern of CDGP and HH in the first 5 years of life. DESIGN AND PATIENTS: We studied retrospectively height and weight in the first 5 years (y) of life in 54 boys with CDGP and 8 boys with HH. RESULTS: In boys with CDGP, height-SDS decreased (change -0.94 (interquartile range [IQR] -1.69 to -0.05); P < 0.001) between birth and 2 years. BMI-SDS decreased (change -0.38 (IQR -1.21-0.16); P < 0.001) in the same time period. There were no significant changes in height-SDS or BMI-SDS between 2 years and 5 years, while height-SDS (change + 1.49 (IQR 1.02-1.95); P < 0.001) and BMI-SDS (change + 0.91 (IQR 0.12-1.69); P < 0.001) increased between pubertal and adult age. In boys with HH, height-SDS and BMI-SDS did not change significantly in the first 5 years of life. Height-SDS decreased (change -1.39 (IQR -1.96 to -0.67); P = 0.018) significantly between 5 years of life and puberty, while there were no significant changes in BMI-SDS in this time period. At pubertal age, BMI-SDS was significantly (P = 0.001) higher in boys with HH compared with boys with CDGP. CONCLUSION: Height deflection and weight deflection in CDGP occur already during the first two years of life in contrast to HH. This different pattern of growth and weight might be helpful to distinguish CDGP from HH.
Subject(s)
Body Height , Body Weight , Growth Disorders/diagnosis , Hypogonadism/diagnosis , Puberty, Delayed/diagnosis , Child, Preschool , Diagnosis, Differential , Growth Disorders/physiopathology , Humans , Hypogonadism/physiopathology , Infant , Infant, Newborn , Male , Puberty, Delayed/physiopathology , Retrospective StudiesABSTRACT
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.
