Growth curves for congenital adrenal hyperplasia from a national retrospective cohort.

Background: In congenital adrenal hyperplasia (CAH), adjusting hydrocortisone dose during childhood avoids reduced adult height. However, there are currently no CAH-specific charts to monitor growth during treatment. Our objective was to elaborate growth reference charts and bone maturation data for CAH patients. Methods: We conducted a retrospective observational cohort study, in 34 French CAH centers. Patients were 496 children born 1970-1991 with genetically proven 21-hydroxylase deficiency. Their growth and bone maturation data were collected until age 18 together with adult height, puberty onset, parental height, and treatment. The mean (SD) heights were modeled from birth to adulthood. The median +/- 1 SD and +/- 2 SDs model-generated curves were compared with the French references. A linear model for bone maturation and a logistic regression model for the probability of short adult height were built. Results: Growth charts were built by sex for salt wasting (SW) and simple virilizing (SV) children treated before 1 year of age. In girls and boys, growth was close to that of the general French population up to puberty onset. There was almost no pubertal spurt and the mean adult height was shorter than that of the general population in girls (-1.2 SD, 156.7 cm) and boys (-1.0 SD, 168.8 cm). Advanced bone age at 8 years had a strong impact on the risk of short adult height (OR: 4.5 per year advance). Conclusions: The 8-year bone age is a strong predictor of adult height. It will help monitoring the growth of CAH-affected children.